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1
Miller, Woutrina Ann. "Cryptosporidium species in coastal California ecosystems /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Testo completo
2
Pikelnaya, Olga. "Reactive iodine species at North American coastal sites". Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1773833421&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Testo completo
3
Einsmann, Juliet Caroline Jr. "Nutrient Foraging in Ten Southeast Coastal Plain Plant Species". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36849.
Testo completoAbstract (sommario):
Plant root system response to nutrient heterogeneity was tested in ten plant species of varying life form and successional status. All plants tested are native to the South Carolina coastal plain. Morphological responses of the root system (scale, precision and discrimination) and overall plant response (sensitivity) to increasing nutrient heterogeneity were tested. Ten individuals of each species were placed into four treatments which had varying nutrient distribution but the same overall nutrient addition. Plants were harvested when roots reached pot edge. I observed high variation in scale (mass and extent of a root system), precision (the ability to proliferate roots in nutrient patches) and sensitivity (growth benefits gained as nutrient heterogeneity increases; measured as total biomass). No significant discrimination responses were observed, although greatest mean root density occurred at intermediate fertility levels for all species. I tested the hypothesis that scale and precision would be negatively correlated, and I did not observe this relationship in these plant species. However, in herbaceous species scale and precision were positively correlated. Sensitivity was not closely related to precision indicating that proliferating roots in fertile patches does not always yield growth benefits in heterogeneous soils. Further, some sensitive species had very low precision suggesting that other characteristics lead to positive growth response in heterogeneous environments. Plasticity of root uptake rates and demography of roots are proposed as two other mechanisms which may play important roles in plant sensitivity responses. Scale was negatively correlated to sensitivity for herbaceous plants suggesting that plants that monopolize the most soil space are not able to gain benefits from nutrient patches within the soil matrix. There was no trend observed to suggest that plant life form was correlated with precision or sensitivity. However, scale was greater in herbs than in woody plants, possibly because the two life forms develop at different times.Master of Science
4
Cuschieri, Katie Sarah. "Species diversity of aggregate-associated marine ammonia-oxidising bacteria". Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602054.
Testo completoAbstract (sommario):
Two broad communities can be distinguished in marine systems, those attached to amorphous aggregate material dispersed throughout the water column and those that are freely suspended in the water column (planktonic). It has been suggested that two distinct microbial populations are associated with each habitat due to phenotypic adaptation to the different conditions in aggregates and the surrounding water. The aim of this study was to investigate the diversity of aggregate-associated and planktonic marine ammonia oxidisers (AOBs - the organisms responsible for the rate limiting step in nitrification) in both natural environments and laboratory-reared systems and to determine whether aggregate material selected for particular groups of AOBs. Detection of AOBs relied heavily on the use of molecular analysis of extracted DNA. Thus, a preliminary study was performed to assess whether preferential lysis occurred when representatives of both genera within the B-subgroup AOBs {Nitrosospira multiformis and Nitrosomonas europaea) were exposed to lysis procedures commonly applied to marine samples. Minimal bias existed, with Nitrosomonas europaea proving to be less susceptible to lysis only when the lytic agents (sodium dodecyl sulphate and lysozyme) were absent or at concentrations 100-fold less than those applied in routine environmental extraction. Environmental populations of aggregate-associated and planktonic AOBs in the NW Mediterranean Sea were assessed in summer and winter at stations both within and beyond regions of fresh water inflow (the plume). Molecular analysis involved amplification, by the polymerase chain reaction, of 16S rRNA genes from extracted DNA using AOB-specific primers. Analysis of 16S rDNA sequences coupled with DGGE and specific probing revealed temporal and spatial effects in community structure of AOBs. In the summer, genus level selection of AOBs was observed with Nitrosospira dominating in the aggregate population and Nitrosomonas dominating in the planktonic phase. This was found in the surface waters of geographically distant sites within and outside the plume. Between-site differences were evident in the deeper waters with Nitrosospira-like sequences more abundant in plume diluted waters and Nitrosomonas like sequences more abundant outside this zone, while genus level selection between aggregate-associated and planktonic communities was not detected. In winter, a uniform pattern of AOB distribution emerged with an even distribution of two Nitrosospira sequences at each site on all aggregate and planktonic samples. The AOB community structure of sediment samples was not wholly resolved by application of direct molecular techniques and the culturable diversity was later examined by an enrichment-based approach. A laboratory-reared aggregate system was developed to assess the distribution and selection of inoculated pure and enrichment cultures of AOBs and to assess the effect of sampling technique on the observed community structure. Enclosed vessels containing North Sea water were rotated until aggregation of autochthonous particulate material formed discrete aggregates. No genus level selection of AOBs was observed in aggregate-associated and planktonic communities in North Sea water yet differences in the distribution of closely related sequences within cluster 1 Nitrosospira were observed between the two communities. Observed aggregate and planktonic community structure was affected by the method used to separate the two fractions. Active bacterial production was not necessary for aggregate formation if a pooled suspension of aggregates was sterilised and added to a medium of cell-free filtered sea water. Thus, the successful inoculation and retrieval of an N. multiformis culture within the cell free system suggested that it was appropriate for investigation of the colonisation dynamics of inoculated AOBs.
5
Thompson, Christine Mingione. "Species-specific patterns in bivalve larval supply to a coastal embayment". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62785.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2011.Cataloged from PDF version of thesis.
Includes bibliographical references.
Larval supply is an important process linking reproductive output to recruitment of benthic marine invertebrates. Few species-specific studies of bivalve larvae have been performed due to the lack of suitable methods for species identification. This thesis focused on applying a method to identify larvae from field samples from Waquoit Bay, MA using shell birefringence patterns. This method was then used to address variability in larval supply for three bivalve species on weekly, tidal, and hourly scales. Sampling weekly for six months during two years showed large variability in larval concentrations on this time scale. Abundances of most species were related to bay temperature, and species distributions among sampling sites were indicative of transport potential and population coherence. Greater growth of larvae in 2009 compared to 2007 was attributed to more wind-induced mixing and better food availability in 2009. Integrative samples over each tidal event for a 14-day period demonstrated that larvae were mostly constrained by water masses. During a period when there were sharp tidal signals in temperature and salinity, larval concentrations were higher in bay water compared to coastal waters on incoming tides. After a storm event, water mass properties were less distinct between tidal events and a semidiurnal signal in larval concentrations was no longer apparent. The timing of periods of high larval concentrations did not always coincide with periods of highest water mass flux reducing net export in some cases. On an hourly scale, the vertical distribution of larvae affected by water column stratification and strength of tidal flow. Strong currents and a fresh upper layer both prevented larvae from concentrating at the surface. There was little evidence of peaks in larval concentrations associated with a given tidal period. Species-specific data can provide new perspectives on larval transport. For the three species studied, Anomia simplex, Guekensia demissa, and Mercenaria mercenaria, different source areas, patterns for growth, and potential for export were observed. Applying species-specific identification methods to future studies of bivalve larval transport has the potential to relate larval abundance to settlement patterns, an important component of larval ecology and shellfish management.
by Christine Mingione Thompson.
Ph.D.
6
Knevel, Irma Cornelia. "The life history of selected coastal foredune species of South Africa". Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1003776.
Testo completoAbstract (sommario):
South African dune fields are severely threatened by human expansion and in the long run the stabilisation of many dunes will be necessary. The alien grass Ammophila arenaria is the most important drift sand stabiliser at present in South Africa. Although not invasive, the current impact of A. arenaria on the dune systems of South Africa is considerable, and thus the stabilising benefit of the grass seemed to may be outweighed by its negative consequences. It is therefore preferable to use indigenous sand stabilising species. In order to define guidelines for the application of indigenous plants for stabilisation, their autecology should be studied first to enhance the chance of successful stabilisation results. The main aim of the present thesis was to gather information on the life history processes of selected indigenous, sand stabilising foredune species. To investigate the growth of foredune pioneer species, the common pioneer Scaevola plumieri was followed over a three-year period to determine the growth season and leaf phenology. Soil-borne pathogens are known to influence the growth and vegetation dynamics of foredune species. To examine this effect on the South African foredunes the rhizosphere soil and the roots of several species were studied. To test the effect of the nematode fauna on succeeding plant species a transplantation experiment was carried out. The seed stage is the only life-cycle stage that can survive unfavourable conditions. Therefore, the seed ecology of several foredune species was studied extensively to determine the reproductive season, the seed production, the fate of seeds after shedding (germination, seawater dispersal), germination requirements and seed bank strategy. Seeds of the species Arctotheca populifolia, Ipomoea pes-caprae, Myrica cordifolia, and Scaevola plumieri were subjected to germination trials, field observations on seedling survival, and scarification and stratification experiments. This was done to obtain information about the germination requirements and to determine the reproductive season and growth season. The seed bank strategy of the foredune species, as well as the seed bank density, was determined by extensive sampling along the Cape coast. The species S. plumieri thrived under sand accretion situations, which makes it a good candidate for stabilisation purposes. The growth of S. plumieri was seasonal, with the highest leaf production during spring and summer. The stem position on the foredune had a strong effect on the overall performance of S. plumieri , with the stems situated on the landward face of the foredune showing higher leaf and seed production. Theiii nematode survey of soil and roots of several foredune species showed that all plant species featured a specific nematode fauna in the rhizosphere soil and the roots. The specific nematode fauna affected the growth of foreign plant species in the transplantation experiment, resulting in a lower root and/or shoot biomass production. Most of the foredune species produce seeds from spring to late summer. For S. plumieri the position of the stem on the dunes, as well as the predation of unripe seeds affected the number of seeds produced. The highest production was found for the landward faced stems. The S. plumieri seeds were able to float on seawater for at least three months without losing viability, as was observed for seeds of I. pes-caprae. The seeds of M. cordifolia, however, sank after a few days, but their viability was not affected. The rhizome fragments of A. arenaria and S. virginicus floated for 120 days, whereas the fragments of E. villosa sunk after one day. The viability of S. virginicus fragments was affected by the duration in seawater by an increase in sprouting time. The seeds of all species tested germinated readily under controlled conditions, except S. plumieri seeds which required a long lag-phase before germination. In the field the seeds of A. populifolia, I. pes-caprae and S. plumieri germinated, producing many seedlings. Only the seedlings of A. populifolia and S. plumieri survived. Of the species found in the foredunes 57% was represented in the soil seed bank. For most species, the seeds that were found in the seed bank showed viability of at least 40%. Many of the seeds found were older than one year, suggesting a short-term persistent seed bank. The present study is a start in filling the gap in information on dune pioneer and foredune species. The conclusion was that in general all species in the present study were easy to grow under controlled conditions, and thus could be used for stabilisation purposes. When the more rapidly growing pioneer species are planted in combination with succeeding foredune species, a functional and aesthetic ecosystem could be created.
7
Jackson, Juliette Elizabeth. "The influence of engineering design considerations on species recruitment and succession on coastal defence structures". Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/4781.
Testo completoAbstract (sommario):
Engineering design considerations of artificial coastal structures were tested to resemble as far as possible the nearest natural equivalent habitat, ecologically valuable rocky shores, as a potential management option. Coastal areas around the world attract urbanisation but these transitional areas between sea and land are inherently vulnerable to risk of flooding and erosion. Thus hard structures are often built in sensitive coastal environments to defend assets such as property and infrastructure (roads, railways, ports) against rising and stormy seas. The design, construction and maintenance of hard defences should wherever possible incorporate ecological considerations to enhance biodiversity, including maintaining or restoring natural habitats and wild species to ensure favourable conservation status. Artificial habitats are less topographically complex than natural rocky shores, at millimetre scales in terms of surface roughness, centimetre to meter scales for crevices and pools to tens, hundreds and occasionally thousands of meters for variation in tidal height and wave action gradients. The habitat value of design features of an existing seawall and breakwater, such as areas of different slope and orientation, and the presence of crevices and pools, that are analogous to habitat created by topographical features on a natural shore, were demonstrated by their ability to support distinct assemblages of species. X Furthermore, evidence is provided that a greater variation in the type of design features led to a higher species diversity occupying the structure, and included species that would otherwise not be present on the structure. The long term succession on artificial structures and the biodiversity reached on intertidal coastal defence structures is described to inform understanding of timescales over which successional processes operate. As a consequence of succession, artificial structures of large extent eventually resemble natural rocky shores of the same exposure. Increased surface heterogeneity of concrete armour units on Plymouth Breakwater by drilling holes was effective in adding habitat and increasing local species diversity. These can be added at the construction stage or post construction. In a real case study, added recessed pools, holes and surface texture during the construction of a tidal defence sea wall at Shaldon made heterogeneous surfaces to add habitat and influence species diversity, without compromising the engineering function or aesthetics of the structure. This study provides coastal engineers and decision makers with well researched practical design options to inform future construction and maintenance of coastal defence structures that will encourage specific outcomes to mitigate the negative environmental impact of artificial structures and contribute to conservation priorities.
8
Delfeld, Bradley. "Movin' on Up: Mycorrhizal Mutualisms and Assisted Migration of Coastal Plant Species". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2603.
Testo completoAbstract (sommario):
Coastal marshes are among the first ecosystems to be altered by climate change. With increasing sea-level rise, assisted migration may be necessary to establish founder populations in more favorable upslope habitats. Mycorrhizal mutualisms could play a key role in determining success of these moving populations. If the assemblages of fungal spores are well mixed across the coastal transition gradient, then landward-retreating plant species can form associations with the same fungal species in the new habitat. The objectives of this study were: (1) to identify potential mycorrhizal relationships by determining if assemblages of spores exhibit zonation mirroring that of coastal plant communities and (2) to test whether or not abundance and composition of mycorrhizae in roots of a dominant marsh species (Juncus roemerianus) differ with simulated assisted migration into upslope soils. Soil samples and seeds for trap plants were collected from the coastal coenocline at Grand Bay National Estuarine Research Reserve in coastal Mississippi, USA. A total of 1607 unique operational taxonomic units (OTUs) was found across the entire gradient and was classified into five genera: Rhizophagus, Glomus, Funneliformis, Diversispora and Scutellospora. The soil samples had an average of 196.25 OTUs per sample, while the root samples were less diverse with an average of 29.04 OTUs per sample. DNA analysis of soil samples show that Glomeromycete propagules exhibit zonation on the seaward-most end of the gradient (salt marsh), but AMF composition becomes increasingly mixed with increasing elevation in brackish marsh, fresh marsh and pine woodlands zones. Salt marsh showed isolation in its species composition, sharing only two OTUs with the other three zones. Only one OTU (Rhizophagus sp.) was present across all four vegetation zones. Species richness and abundance of mycorrhizal spores in the soil samples increased along the elevation gradient; they were highest in the pine woodlands (dry end) and lowest in the salt marsh (wet end). OTU richness and abundance significantly increased in the roots of J. roemerianus trap plants when transplanted to soils upslope of its naturally dominant zone (brackish marsh). These results indicate that, apart from the salt marsh, plant-mycorrhizae relationships can persist after upslope migration of coastal plant species. New, as well as old, fungal associations may aid in the survival of the host plant in the new habitat.
9
De, Wet Morne. "A systematic health assessment of two dolphin species by-caught in shark nets off the KwaZulu-Natal Coast, South Africa". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/36782.
Testo completoAbstract (sommario):
Coastal dolphin populations are indicators of environmental health and may be sensitive to
anthropogenic influences. An observed increase in lesions during routine necropsies of
dolphins prompted the first systematic health assessment of dolphins incidentally caught in
shark nets off the KwaZulu-Natal coast. A detailed standard dissecting and sampling
protocol for small cetaceans was developed for use in South Africa. Thirty five Indian Ocean
bottlenose dolphins (Tursiops aduncus) and five Indo-Pacific humpback dolphins (Sousa
chinensis), incidentally caught between 2010 and 2012, were subsequently evaluated by full
necropsy and sampling using this protocol.
All animals were considered to be in good nutritional condition, based on blubber thickness
measurements and muscle condition. A large proportion of dolphins had lesions with
parasitic aetiology, including pneumonia (34/40), bronchiolar epithelial mineralisation
(33/40), gastroenteritis (28/40), hepatitis (24/39); endometritis (11/26), capsular inflammation
of various abdominal and thoracic organs (30/40), and splenic capsular tags (18/40). Four
parasite species (Halocercus sp., Crassicauda sp., Brachycladiinae, and Xenobalanus
globicipitis) were recovered from six animals. Non-specific encephalomeningitis was found in
7/18 animals. Adrenal cortical hyperplasia (18/37,) possibly related to chronic stress, was
also found, as well as myocardial fibrosis (10/39). Pulmonary pneumoconiosis and lymph
node foreign material accumulation, possibly indicating exposure to polluted air, was seen in
three animals. Lesions suggestive of morbillivirus, Toxoplasma gondii, or Brucella spp.
tested negative on immunohistochemistry. The first confirmed cases of lobomycosis and
sarcocystosis in South Africa were found. Most lesions were mild, although their high and
apparently increasing prevalence may indicate a change in the host/parasite interface. This
may be attributed to anthropogenic factors, such as stress or environmental pollution,
suggesting degradation of the marine environment. This could also negatively impact human
populations associated with the marine environment.
The results indicate a need for continued health monitoring of coastal dolphin populations
and for further research into disease pathophysiology and anthropogenic factors affecting
these populations. This standard necropsy protocol will encourage a more complete health
investigation of incidentally caught and stranded cetaceans in the region and will assist in
expanding the current knowledge of diseases affecting dolphin populations in southern
Africa. Furthermore, we provide valuable information regarding the baseline of disease
affecting these populations, which may be used to determine and monitor temporal trends.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Production Animal Studies
unrestricted
10
Adams, Jessica L. "Age and Growth of Three Coastal Pelagic Tuna Species in the Florida Straits". NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/184.
Testo completoAbstract (sommario):
Understanding the life history of a species is essential for fully understanding its role within an ecosystem. However, many of the fish species of high ecological value have not been studied due to their less prominent roles in local recreational and commercial fisheries in comparison to other targeted species. This study describes the age and growth patterns of three small tuna species inhabiting South Florida waters: blackfin tuna Thunnus atlanticus, little tunny Euthynnus alletteratus, and skipjack tuna Katsuwonus pelamis. Tuna specimens were collected via donations obtained from various fishing tournaments and charter captains in the areas of the Florida Straits as well as hook-and-line by the Nova Southeastern University Oceanographic Center. Age was described via sagittal otolith deposition patterns. They were removed, dried, sectioned, and rings were counted as well as measured. Validation of the timing of ring deposits was done by marginal increment analysis. Growth parameters were determined by comparison of fish fork length to count measurements. This comparison via the Von Bertalanffy growth equation produced a growth rate for each species: blackfin, L∞ = 95.34 cm, K = 0.28, and t0 = -1.53; little tunny, L∞ = 77.93 cm, K = 0.69, and t0 = -0.69; and skipjack, L∞ = 112.76 cm, K = 0.24, and t0 = -1.70. The curves indicate an average size of an individual of a given species at a certain age. They also give an estimation of a maximum length (L∞) of each species, in addition to specific growth rate, which is indicated by the slope. Parameters of each resulting Von Bertalanffy equation were compared among species. Results were also compared with growth rates currently used in stock assessments by fisheries management organizations, such as the International Commission for the Conservation of Atlantic Tunas (ICCAT).
11
Rathbun, Leah C. "Growth of British Columbia coastal species in response to thinning and fertilization treatments". Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30235.
Testo completoAbstract (sommario):
The successional processes of the mixed-species Pacific coastal temperate rain forests of British Columbia (BC), Canada, are defined by gap dynamics, where small-scale disturbances, mainly due to windthrow, create openings in the canopy necessary for regeneration. Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) is the dominant, pioneer species in this area and western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn) are the late-successional, shade-tolerant species. Silvicultural systems such as variable retention systems have been applied to many of the secondary growth mixed-conifer forests. Variable retention in this area is designed to differ dramatically from stand to stand. This approach differs from the traditional even-aged management applied to forests of the Pacific Northwest coast. In this study, a model-based approach was used to investigate how multiple treatment interventions as a part of active management across a landscape affect mortality and growth within actively managed stands. There is a need for this information as current growth and yield models used in this area are limited by either the number of species which can co-exist in a stand (e.g., the model TASS of BC) or are limited by the need for data not commonly obtained in inventory databases (e.g., the models FVS and ORGANON of USA). Additionally, no growth and yield models have been developed to include variable retention systems, where a variety of thinning intensities and spatial patterns, timing of thinning and fertilization treatments, and number of treatments are used. Mortality, diameter increment, and height increment models were developed and the effects of thinning, fertilization and the combination of thinning and fertilization were examined for Douglas-fir, western redcedar, and western hemlock. For each species, shade-tolerance was found to impact the possible predictor variables included in model development. The use of a generalized logistic survival model resulted in accurate estimates for larger trees, but poor results for smaller trees. To model the effects of fertilization, additional fertilization effect variables were included in the models; conversely, thinning effects were modeled using the immediate change in state variables such as basal area of larger trees which occurred immediately following thinning.
12
Bliss, Kristin Mays. "Impact of nutrient heterogeneity on plant response and competition in Coastal plain species". Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/29755.
Testo completoAbstract (sommario):
Relationships between nutrient heterogeneity, root foraging behavior and short-term competitive interactions were investigated for six species native to southeastern USA. Monoculture, two- and six-species garden plots were established and fertilized to create spatially homogeneous or heterogeneous nutrient conditions. After 3.5 months, root proliferation in rich patches (precision) and aboveground biomass response to heterogeneity were assessed in monocultures, and competitive outcomes (aboveground biomass) were determined from mixed-species plots. In monoculture plots, two species were relatively precise foragers, but no species showed significant aboveground biomass response to nutrient treatment. Correlations between precision and aboveground biomass were weak (-0.40 < r < 0.17). In two-species plots, interspecific competition was influenced by soil heterogeneity in two of six cases tested (P < 0.05), and precision was the behavior most correlated with competitive success. In six-species plots, spatial pattern of nutrients had no influence on aboveground growth or competition. Results suggest that heterogeneity influences competition, but the influence is context-specific and generally small. Precision may be the foraging behavior that most influences interspecific interactions.Ph. D.
13
Sato, Aya. "Patterns of species assemblages and geographical distributions of coastal tiger beetles in Japan". 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147851.
Testo completo
14
Bissett, Wesley Thurlow Jr. "Ecosystem health at the Texas coastal bend: a spatial analysis of exposure and response". Texas A&M University, 2007. http://hdl.handle.net/1969.1/85889.
Testo completoAbstract (sommario):
This dissertation investigated locational risks to ecosystem health associated with
proximity to industrial complexes. The study was performed at the behest of ranchers
and citizens living and working down-prevailing wind from the Formosa Plastics, Inc.
and ALCOA facilities located in Calhoun County, Texas. Concerns expressed were for
potential genotoxicity resulting from exposure to complex chemical mixtures released by
the facilities. Exposure assessment of the marine environment was performed with
sediments and oysters from Lavaca Bay being analyzed. Numerous chemicals were
found to be present at concentrations considered likely to result in adverse responses in
exposed populations. Bayesian geostatistical analysis was performed to determine if the
concentrations were affected by a spatial process. Mercury and polycyclic aromatic
hydrocarbons were the most notable of the chemicals found to be present at elevated
concentrations and affected by a spatial process. Evaluation of maps generated from
spatial modeling revealed that proximity to ALCOA resulted in elevated risks for
exposure to harmful concentrations of pollutants. Genotoxicity was measured in two
sentinel species. Oysters (Crassostrea virginica) were utilized for evaluation of the
marine environment and cattle (Bos taurus and Bos taurus crossbred cattle) were chosen
for evaluation of the terrestrial environment. Chromosomal aberration analysis was
performed on oyster hematocytes. Analysis of the results failed to demonstrate the
presence of an important generalized spatial process but some specific locations close to
the ALCOA plant had elevations in this measure of genotoxicity. Stress as measured by
the lysosomal destabilization assay was also performed on oyster hematocytes. These results were found to be affected by a significant spatial process with the highest degree
of destabilization occurring in close proximity to ALCOA. Genotoxicity in cattle was
evaluated with the single cell gel electrophoresis assay and chromosomal aberration
analysis. Bayesian geostatistical analyis revealed the presence of important spatial
processes. DNA-protein cross-linkage was the most notable with a strong indication of
increased damage down-prevailing wind from the industrial complexes. Results
indicated that proximity to industrial facilities increased the risk for harmful exposures,
genotoxicity, and lysosomal destabilization.
15
Brittain, Ross. "Trophic status, habitat use and climate change impacts on avian species of coastal, Georgia". [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3380064.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--Indiana University, School of Public and Environmental Affairs, 2009.Title from PDF t.p. (viewed on Jul 19, 2010). Source: Dissertation Abstracts International, Volume: 70-12, Section: B, page: 7462. Adviser: Christopher Craft.
16
Fowler, John Daniel. "A survey and comparison of bird species inhabiting adjoining developed and undeveloped coastal habitat". Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/29896.
Testo completo
17
Niemelä, M. (Marika). "Biotic interactions and vegetation management on coastal meadows". Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514291234.
Testo completoAbstract (sommario):
Abstract
Conservation of rare habitats and species are central elements in the management of semi-natural grasslands of high biodiversity. Understanding the impacts of various abiotic and biotic interactions and management methods on threatened species is fundamental to their conservation. In the present study, effects of competition, plant parasitism, grazing and mowing were studied at the community level in Bothnian Bay coastal meadows and in greenhouse. This was the first time when the impacts of various biotic interactions on the critically endangered creeping alkali grass (Puccinellia phryganodes) have been explored in detail in one of its rare occurrences in the boreal vegetation zone in Europe. In addition, questions related to ecological and economical sustainability of cattle grazing on coastal meadows were examined.
Puccinellia phryganodes was found to suffer severely from competition with taller graminoids. Simulated and actual grazing by greylag goose, Anser anser, as well as infection by a hemiparasitic plant, Odontites litoralis, were found to indirectly benefit P. phryganodes by decreasing the competitive advantage of its competitors. In spite of the relatively intensive grazing by greylag goose in the field, P. phryganodes experienced a drastic decrease during four years in the grazed experimental quadrats and simultaneously the proportion of the taller graminoids increased substantially. Primary succession of coastal meadow vegetation was found to progress rapidly and continuous formation of suitable open habitats is therefore crucial for the subordinate species. Mowing was found to be an effective management method for some threatened plant species in coastal meadows, but not for P. phryganodes, which would probably benefit more, for example, from livestock grazing. Both lightly and rather intensively managed large open meadows could provide optimal habitats for the critically endangered lesser white fronted goose (Anser erythropus) as well as for the greylag goose.
The relatively low and variable yield of the coastal meadow vegetation compared to that of cultivated grasslands sets limits how management by cattle grazing can be implemented. Key factors for both the biodiversity management and livestock production in coastal meadows are timing of the grazing season, intensity of grazing and selection of suitable types of animals.
18
Fruchter, Jesse. "DO LARGE, INFREQUENT DISTURBANCES RELEASE ESTUARINE WETLANDS FROM COASTAL SQUEEZING?" OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/923.
Testo completoAbstract (sommario):
As disturbance frequencies, intensities, and types have changed and continue to change in response to changing climate and land-use patterns, coastal communities undergo shifts in both species composition and dominant vegetation type. Over the past 100 years, fire suppression throughout the Northern Gulf of Mexico coast has resulted in shifts towards woody species dominance at the expense of marsh cover. Over the next 100 years, sea levels will rise and tropical storm activity is projected to increase; resultant changes in salinity could reduce cover of salt-intolerant fresh marsh species. Together, the effects of fire suppression upslope and rising salinities downslope could "squeeze" fresh marsh species, reducing cover and potentially threatening persistence. To mitigate the effects of fire suppression, the use of prescribed fire as a management tool to mimic historic conditions is becoming increasingly widespread and will likely gain further popularity during the 21st century. Ecological shifts that will result from changing disturbance regimes are unknown. It was hypothesized that two recent hurricanes, Ivan and Katrina in 2004 and 2005, respectively, and a prescribed fire, in 2010, differentially affected species along the estuarine gradient and drove overall shifts away from woody dominance. Overall community composition did not change significantly in the intermediate and fresh marsh zones. However, significant changes occurred in the salt and brackish marshes and in the woody-dominated fresh marsh-scrub ecotone zones. Relative to 2004, woody species abundance decreased significantly in all zones in 2006, following Hurricanes Ivan and Katrina, and 2012, following the hurricanes and fire, though woody species regeneration in the marsh-scrub ecotone had begun to occur by 2012. It is hypothesized that interacting changes in fire and tropical storm regimes could release upslope areas from coastal squeezing.
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Taylor, Kelly Lynne. "Beach sediments : a source of dissolved organic carbon and nitrogen species to the coastal ocean /". Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/taylork/kellytaylor.pdf.
Testo completo
20
Vo, Van Thiep, Thi Yen Tran, Thi Huong Binh Nguyen e Ngoc Tam Huynh. "Growth characteristics of fish species Gerres filamentosus (Cuvier, 1829) in coastal zone, Quang Binh province". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190626.
Testo completoAbstract (sommario):
The research was conducted from October 2013 to March 2014 by using the method applied in the current ichthyology study by GV Nikolski, Pravdin IF, OF Xakun, NA Buskaia and Mai Dinh Yen. Fish samples were collected in the coastal area of Quang Binh province. The study results showed that Gerres filamentosus (Cuvier, 1829) had the length romf 52mm to 230mm, corresponding to the weight from 4g to 185g. The age structure of the fish was simple that consisted of four age groups (0+ - 3+), the annual growth rate was relatively fast, the growth equation following Von Bertalanffy was as: Lt = 234.4 x [1- e-0.35 (t + 0.996)], Wt = 373.4 x [1-e-0.0244 (t + 0.2388)] 3.0676Nghiên cứu được thực hiện từ tháng 10 năm 2013 đến tháng 3 năm 2014 bằng những phương pháp đang được áp dụng trong các nghiên cứu ngư loại hiện nay của G.V. Nikolski, I. F. Pravdin, O. F. Xakun, N. A. Buskaia và Mai Đình Yên, mẫu cá được thu tại vùng ven biển của tỉnh Quảng Bình. Kết quả nghiên cứu đã cho thấy cá Móm gai dài có chiều dài dao động từ 52mm – 230mm, tương ứng với khối lượng từ 4g – 185g. Cấu trúc tuổi cá Móm gai dài đơn giản, gồm 4 nhóm tuổi (0+ - 3+), tốc độ tăng trưởng hàng năm tương đối nhanh, phương trình sinh trưởng theo Von Bertalanffy có dạng Lt = 234,4 x [1-e-0,35(t + 0,996)], Wt = 373,4 x [1-e-0,0244(t + 0,2388)]3,0676
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Dames, Michael Henri. "Factors influencing estuarine and coastal connectivity of an estuarine-dependent fishery species, Pomadasys commersonnii (Haemulidae)". Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/62307.
Testo completo
22
Kirkwood, Donovan. "Establishment patterns of thicket and forest species in coastal dune landscapes of the southern Cape". Thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/26396.
Testo completo
23
Syaifullah, of Western Sydney Hawkesbury University e Faculty of Science and Technology. "Genetic variation and population structure within the Gudgeon genus Hypseleotris (Pisces-Eleotridae) in Southeastern Australia". THESIS_FST_XXX_Syaifullah_X.xml, 1999. http://handle.uws.edu.au:8081/1959.7/231.
Testo completoAbstract (sommario):
This study investigated the causes of high level of intra-and inter-population variation known to occur in the morphology of fish in the genus Hypseleotris Eleotride in southern Australia, particularly within the Murray-Darling river system. The three major objectives of the study were, identify the number and distribution of species,determine the genetic structure of the populations and analyse relationships between species and consider the process of speciation in this species complex. The investigation of morphological variation in Hypseleotris confirmed the presence of two well known species i.e. H. compressa and H. galli, in the coastal rivers and also of the inland species H. klunzingeri. Populations of Hypseleotris klunzigeri sensu lato in inland river were found to be very highly variable and analysis using discriminant functions and principle component analysis showed the widespread presence of three forms (A, B1 and B2). The analysis was confused by the presence of north/south clines and upstream/downstream variation in characteristic in each form. After these factors were removed, there was still a great deal of variation in each population. The presence of hybrids between each pair of inland species, identified by both morphological and genetic data, further confused the analysis and makes identification of all specimens to species in the field difficult. Examination of type material of H. Klunzingeri showed that this belonged to form B2. The other forms can be related to the undescribed species, Midgley's carp gudgeon and Lake's carp gudgeon. Keys to the species in the complex in southeastern Australia are given. The morphological and genetic data show that H. compressa and H. klunzingeri are sister species, primarily separated by the eastern uplands. Similarly, the coastal species, H. galli is related to form B1 and more distantly, to form A. Possible scenarios for the complex are given.Doctor of Philosophy (PhD)
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Grieger, Rebekah. "Resilience of Coastal Freshwater Wetland Vegetation to Climate Change". Thesis, Griffith University, 2021. http://hdl.handle.net/10072/410470.
Testo completoAbstract (sommario):
Coastal wetlands are globally important ecosystems, valued for their provision of habitat, storm mitigation, water quality improvement, and carbon sequestration. Coastal wetlands are also one of the ecosystems most likely to be impacted by projected changes in climate, particularly changes associated with sea level rise, altered rainfall patterns, and changes to storm patterns and severity. Coastal freshwater wetlands (CFWs) are amongst the most understudied group of coastal wetlands and are characterised by freshwater dominated hydrology but can also experience periods of salinity associated with their proximity to the coast (i.e. as the result of storm surge and spring high tides). CFWs commonly occur as the most landward of coastal wetlands and many adjoin urban development, exposing them to anthropogenic impacts (nutrient enrichment, clearing, hydrology alteration). This position in the coastal landscape makes CFWs highly susceptible to salinity stress, particularly climate change induced sea level rise. Research investigating CFWs, their ecology, and responses to climate change threats, is greatly lacking, particularly for areas outside the United States of America (USA). This thesis investigates the resilience of CFWs to climate change and aims to address significant knowledge gaps by investigating: 1) the current knowledge of CFW responses to projected climate change globally; 2) the structure and composition of CFW vegetation in southeast Queensland and exploring drivers of vegetation patterns; 3) the role of soil seed banks in vegetation resilience for CFWs in southeast Queensland through contributions to vegetation dynamics; and 4) the regenerative potential and responses of CFW vegetation communities to altered hydrology and salinity regimes simulating sea level rise. To begin, I synthesised the current knowledge of CFW responses to projected changes in climate globally, through a systematic quantitative literature review, with the aim of identifying key knowledge gaps regarding geographic locations and research areas, with particular focus on four key aspects of climate change: sea level rise, altered rainfall, extreme events, increased temperature, and greenhouse gases. In Chapter 2, I reviewed published research on responses of CFWs in observational, experimental, and modelling studies within those four key aspects of climate change. This review identified that, despite the increasing research interest, knowledge of all aspects of climate change is lacking, particularly outside of the USA. Within the USA, while there is a significant body of research exploring the response of CFWs to impacts associated with rising sea levels, changes to rainfall patterns, and extreme events, the impacts of temperature and greenhouse gases remain unknown globally. Importantly, research investigating the response of CFWs to multiple climate drivers was identified as a significant knowledge gap.The research then focused on field and greenhouse studies of CFW vegetation communities in southeast Queensland, Australia to expand the knowledge of CFWs outside of the USA. Chapters 3 and 4 explored patterns in standing and soil seed bank vegetation assemblages and provides a baseline understanding of the structure and composition of these vegetation communities. In addition, I assessed local and regional environmental drivers (i.e. local hydrology, soil salinity, local land uses, projected sea level rise extent) of vegetation patterns and discussed potential changes to these drivers with climate change. To explore the effects of sea level rise on ground in CFWs, I conducted an in-situ hydrology and salinity manipulation experiment at an abandoned sugarcane farm which has a regenerating CFW vegetation community (Chapter 5). CFWs in southeast Queensland are important for their roles in nutrient cycling and habitat provision for endangered fauna species. My assessment of these vegetation communities (Chapter 3) also highlights that CFWs are home to a diverse vegetation assemblage including at least two flora species of national significance, flagging the biodiversity importance of these isolated wetland patches within a developed coastal landscape. Species composition was distinct between vegetation patches and a large proportion of variation between sites was associated with differences in local hydrology and salinity influence. The importance of hydrology and salinity as drivers of vegetation patterns suggests that climate change could dramatically impact the structure and composition of CFWs. The ability of CFWs to be maintained in the landscape under a changing climate is influenced by their regenerative capacity from soil seed banks or other propagule banks. In Chapter 4, I assessed the composition of CFW soil seed banks and explored potential drivers of vegetation patterns. Through this study, I again found that hydrology and salinity were strong drivers of patterns in soil seed bank composition, as well as, local land use which was associated with the proportion of exotic species. Similarity of soil seed banks to standing vegetation was low, suggesting that soil seed banks have a minimal role in maintaining standing vegetation communities in southeast Queensland CFWs. Rather, soil seed banks could provide a mechanism for vegetation change along four possible trajectories depending on the soil seed bank composition and abiotic conditions. Hydrology and salinity are important drivers of CFW vegetation composition identified in this thesis. In Chapter 5, I explored the impacts of altered hydrology and salinity regimes on CFW vegetation communities regenerating on abandoned agricultural land. Change in vegetation composition and structure was assessed in-situ at Yandina Creek Wetlands (YCW) where vegetation has naturally regenerated into communities typical of CFWs in southeast Queensland during 15 years since abandoment of sugarcane production. This regeneration potential is important given the projected constriction of CFWs between migrating seaward Changes were varied in each habitat surveyed, however, reductions in vegetation cover and species richness were observed over time in response to altered conditions in freshwater habitats. Conversely, vegetation cover increased in the saltmarsh, suggesting that this community is tolerant of the altered conditions and may expand within YCW. The changes observed at YCW suggest that widespread change is likely for many CFWs with increasing sea levels, but careful management could aid in maintaining these ecosystems in the coastal landscape. Overall, this thesis significantly furthers the understanding of CFWs and their vegetation patterns outside of the USA, and explores the future of these systems with climate change in southeast Queensland, Australia. The findings of this thesis highlight the importance of hydrology and salinity as drivers of vegetation patterns and indicates that dramatic and potentially rapid change in vegetation structure and composition will occur as a result of climate change. CFWs in southeast Queensland are important and highly variable vegetation communities, where loss of even single wetland patches could result in local species extirpation. It is unlikely that CFWs will remain in the landscape in their current state and continue to provide benefits from ecosystem services without significant management action. Even with such action, widespread loss or modification is likely and continued research is required to understand the full scope of climate change impacts.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text
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Chen, Hongwei. "Development of analytical methodologies for iodine species in gaseous and particulate phases of the coastal atmosphere". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976812096.
Testo completo
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Mach, Megan Elizabeth. "Research on marine coastal impacts to promote ecosystem-based management : nonnative species in northeast Pacific estuaries". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43117.
Testo completoAbstract (sommario):
Ecosystem-based management (EBM) offers a holistic evaluation of tradeoffs between human activities, but this offer rests upon a foundation of science. In this thesis, I assessed and advanced the knowledge-base for EBM in five ways, focusing on nonnative species in estuarine ecosystems.
In Chapter 2, I tested for the comprehensiveness of research that connects the impacts of anthropogenic activities to changes in ecosystem service production, employing a literature review of estuarine ecosystems. Research on these connections virtually never included the relationship of activities to ecosystem services production, presenting an impressive gap in research for evaluating tradeoffs using EBM.
I addressed the sufficiency of existing information regarding nonnative species in eelgrass beds in Chapter 3. I tested the relationship of nonnative species in British Columbia’s (BC) eelgrass beds with arrival pathways and environmental selection factors. There were few (12) nonnatives in BC’s eelgrass; all associated most commonly with aquaculture facilities and warm temperatures. Existing reports included the majority of nonnatives: only one species, the bamboo worm Clymenella torquata, represented a new record, as I described in Chapter 4.
Impacts of nonnatives are difficult to limit after invasion. In Chapter 5, I developed an approach for characterizing the potential economic impacts of nonnatives. I focused on European green crab, a nonnative species that has not yet arrived in Puget Sound, Washington. At a range of invasion densities and increasing calorie diets, I calculated a value-at-risk to shellfish harvest ranging from $1.6 - $41 million USD. Such calculations can aid in preparation for impending invasion by motivating prevention and mitigation efforts.
Nonnative management is often based on the available understanding of the impacts on native species. In Chapter 6, I assessed available research on the impact of nonnative seagrass, Zostera japonica, in northeast Pacific estuaries. My results suggested existing studies that quantitatively test Z. japonica impacts are insufficient to comprehensively assess the effects of this invasion. My dissertation research highlights the need for research to determine the ecosystem role of nonnatives in their invaded range through analysis of quantitative studies across broad scales.
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anderson, kaylee. "Using Linear Mixed Models to Analyze Native and Non-Native Species Abundances in Coastal Sage Scrub". Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/scripps_theses/807.
Testo completoAbstract (sommario):
Coastal Sage Scrub (CSS) is a low scrubland plant community native to the coasts of California, housing many threatened and endangered species. Due to the invasion of non-native plants, many areas of CSS have type converted to annual grasslands and the fire frequency has accelerated; fire in turn, may facilitate further invasion, leading to a loss of biodiversity. While many studies document post-fire succession in these communities, pre-fire data are rarely available for comparison, especially data on seedling emergence. I analyzed post-fire recovery of a type-converted grassland community, comparing seedling emergence data for the first and third year after fire to the three years preceding the fire. Non-native species abundances declined more after the fire than did native abundances. This pattern was still present in 2015, three years post-fire. Two native species, Amsinckia menziesii var. intermedia (Amsinckia) and Phacelia distans (Phacelia), were subjects of seed addition treatments pre-fire, but I found no evidence that past seeding increased their abundances post-fire. Amsincki did recover to its pre-fire density three years after the fire, while the density of Phacelia declined over 75% in both the year immediately post-fire and three years after the fire. However, a third native species, Lupinus bicolor (Lupinus), was both much more abundant and also more spatially widespread both immediately after the fire and two years later. This supports the hypothesis that Lupinus is stored in the soil seed bank and the fire may have given this species the opportunity to recover by lowering abundances of non-native competitors. This analysis will inform future conservation efforts by improving our understanding of how seed banks impact the post-fire recovery of native species.
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Barton, Regina A. "Stopover ecology of five species of migratory songbirds at a coastal site in the Pacific flyway". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13682.
Testo completoAbstract (sommario):
Master of ScienceDepartment of Biology
Brett K. Sandercock
The migratory period is a critical time for birds. Population declines in long-distance migratory birds have been associated with trophic mismatches among climate change, timing of food availability, and timing of migratory movements. Studies on migratory songbirds have been limited to eastern North America and Europe, and migration strategies of birds may differ along the Pacific flyway. We evaluated the stopover ecology of five species of migratory songbirds at a coastal site in northern California. We found variation in changes in timing of spring migration, but consistent changes in timing of autumn migration over a 22-year period. Timing of spring migration advanced for Swainson’s Thrushes (Catharus ustulatus) and Yellow Warblers (Setophaga petechia), was compressed for Pacific-slope Flycatchers (Empidonax difficilis) and Wilson’s Warblers (Cardellina pusilla), but was protracted for Orange-crowned Warblers (Oreothlypis celata). In contrast, timing of autumn migration was delayed for Pacific-slope Flycatchers, Orange-crowned Warblers, and Yellow Warblers, but was protracted for Wilson’s Warblers. Warm, wet conditions were associated with advanced spring migration, and warm, dry conditions were associated with delayed autumn migration. Changes in timing of migration related to climate conditions were strongest for Pacific-slope Flycatchers and Orange-crowned Warblers. Stopover duration of our five study species was longer than songbirds in eastern flyways, and on average, was longer in spring than autumn. Pacific-slope Flycatchers and Yellow Warblers had longer stopovers in spring, whereas Swainson’s Thrushes and Wilson’s Warblers stopped had longer stopovers in autumn. Birds captured at low body mass had longer stopovers in spring and autumn. Migratory birds in western North America may have different migration strategies because of differences in climate and geography, but more study is needed to discover migratory routes and compare our results to other stopover sites along the Pacific flyway. Understanding differences in migration strategies of different populations of the same species are important in directing conservation efforts, especially in light of ongoing climate change.
29
Vasquez, Edward. "Growth Characteristics and Salt Tolerance of Two Reciprocally Invasive Grass Species Found in Coastal Salt Marshes". Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/195039.
Testo completoAbstract (sommario):
An invasive variety of the common reed Phragmites australis, the M haplotpye, has been implicated in the spread of this species into North American salt marshes normally dominated by the salt marsh grass Spartina alterniflora (smooth cordgrass). Phragmites australis is spreading into North American coastal marshes that are experiencing reduced salinities, while Spartina spp. are spreading into northern European brackish marshes that are experiencing increased salinities. We compared the salt tolerance and other growth characteristics of the invasive, M haplotype with two native haplotypes (F and AC) in greenhouse experiments. The M haplotype retained 50% of its growth potential up to 0.4 M NaCl, whereas the F and AC haplotypes did not grow above 0.1 M NaCl. The M haplotype produced more shoots per gram of rhizome tissue and had higher relative growth rates than the native haplotypes on both freshwater and saline water treatments. The M haplotype also differed from the native haplotypes in shoot water content and the biometrics of shoots and rhizomes. The results offer an explanation for how the M haplotype is able to spread in coastal salt marshes and support the conclusion of DNA analyses that the M haplotype is a distinct ecotype of P. australis.We then compared the growth, competitive ability, salt tolerance and osmotic adjustment of M haplotype P. australis and S. alterniflora along a salinity gradient in greenhouse experiments. Spartina alterniflora produced new biomass up to 0.60 M NaCl, whereas P. australis did not grow well above 0.2 M NaCl. When the two species were grown in mixed cultures, P. australis was less affected by competition than S. alterniflora at lower salinities but the competitive advantage reversed above 0.2 M NaCl. The greater salt tolerance of S. alterniflora compared to P. australis was due to its ability to use Na+ for osmotic adjustment in the shoots. On the other hand, at low salinities P. australis was more competitive because it produced more shoots per gram of rhizome tissue than S. alterniflora. These studies illustrate how ecophysiological differences shift the competitive advantage from one species to another along a salinity gradient.
30
Sundblad, Göran. "Spatial Modelling of Coastal Fish – Methods and Applications". Doctoral thesis, Uppsala universitet, Limnologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132620.
Testo completoAbstract (sommario):
Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. Information on the distribution of resources and conservation values are also highly needed in marine management as coastal areas are increasingly influenced by human activities. In this thesis, large-scale field data is used to explore how strong environmental gradients found on multiple scales in the coastal areas of the Baltic Sea influence fish habitats. The underlying concepts are based in the field of species distribution modelling, whereby habitat maps can be produced using environmental layers in a geographic information system. Distribution modelling is further used to address both ecological and applied questions by examining effects of habitat limitation on fish population sizes and to evaluate management actions aimed at habitat conservation. I show that specific habitat requirements for fish species of both freshwater and marine origin can be described using environmental variables and that species-environment relationships can be used to predict the distribution of early life-stages of fish in the Baltic Sea archipelagos. Further, predicted habitat availability of a specific life-stage was directly related to adult population size of Eurasian perch Perca fluviatilis, signifying that the abundance of large predatory fish can be limited by specific recruitment habitats. Lastly, by predicting the distribution of an assemblage of coastal fish species and their associated habitats, an assessment of a network of marine protected areas was performed. Results revealed large gaps in the current network and identified areas suitable for future protection. By demonstrating how current habitat protection can be improved by including critical habitats for coastal fish population sizes this thesis points to the benefits of integrating nature conservation and fisheries management. Based on these findings I conclude that species distribution modelling provides a suitable analytical framework for assessing the habitat requirements of organisms. An increased understanding of habitat-population relationships and an ability to accurately map ecologically important features will be of great value for an ecosystem-based marine management. Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 709
31
Vo, Van Thiep, Thi Yen Tran, Thi Huong Binh Nguyen e Ngoc Tam Huynh. "Growth characteristics of fish species Gerres filamentosus (Cuvier, 1829) in coastal zone, Quang Binh province: Short communication". Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29094.
Testo completoAbstract (sommario):
The research was conducted from October 2013 to March 2014 by using the method applied in the current ichthyology study by GV Nikolski, Pravdin IF, OF Xakun, NA Buskaia and Mai Dinh Yen. Fish samples were collected in the coastal area of Quang Binh province. The study results showed that Gerres filamentosus (Cuvier, 1829) had the length romf 52mm to 230mm, corresponding to the weight from 4g to 185g. The age structure of the fish was simple that consisted of four age groups (0+ - 3+), the annual growth rate was relatively fast, the growth equation following Von Bertalanffy was as: Lt = 234.4 x [1- e-0.35 (t + 0.996)], Wt = 373.4 x [1-e-0.0244 (t + 0.2388)] 3.0676.Nghiên cứu được thực hiện từ tháng 10 năm 2013 đến tháng 3 năm 2014 bằng những phương pháp đang được áp dụng trong các nghiên cứu ngư loại hiện nay của G.V. Nikolski, I. F. Pravdin, O. F. Xakun, N. A. Buskaia và Mai Đình Yên, mẫu cá được thu tại vùng ven biển của tỉnh Quảng Bình. Kết quả nghiên cứu đã cho thấy cá Móm gai dài có chiều dài dao động từ 52mm – 230mm, tương ứng với khối lượng từ 4g – 185g. Cấu trúc tuổi cá Móm gai dài đơn giản, gồm 4 nhóm tuổi (0+ - 3+), tốc độ tăng trưởng hàng năm tương đối nhanh, phương trình sinh trưởng theo Von Bertalanffy có dạng Lt = 234,4 x [1-e-0,35(t + 0,996)], Wt = 373,4 x [1-e-0,0244(t + 0,2388)]3,0676.
32
Klinka, Karel, Pal Varga e Christine Chourmouzis. "Select CD : computer support system for making tree species and reproduction cutting decisions in the coastal forest of BC". Forest Sciences Department, University of British Columbia, 1999. http://hdl.handle.net/2429/672.
Testo completoAbstract (sommario):
"SELECT CD is a site-specific, decision-support tool for selecting ecologically viable tree species, reproduction
cuttings, and regeneration methods in the coastal forest (CDF, CWH, and MH zones). SELECT CD integrates
information from several existing guides with new information from literature and recent research into a single,
user-friendly resource. SELECT CD also includes a rich library of visuals and an illustrated glossary of technical
terms."
33
Stewart, Jaclyn Grace. "Matrix Model Analysis of a Coastal Northern California Subpopulation of the Western Snowy Plover (Charadrius alexandrinus nivosus)". Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1513.
Testo completoAbstract (sommario):
Shorebirds are increasingly threatened by introduced predators, invasive grasses, and human disturbance. Matrix models can be used to predict population growth and assess management options. The Pacific coast population of the western snowy plover, Charadrius alexandrinus nivosus, is listed as threatened under the Endangered Species Act, largely due to high rates of nest predation. A matrix model for the entire Pacific coast metapopulation of western snowy plovers was published in 1999 by Nur et al., but population growth has not been comprehensively reassessed since, even after development of a recovery plan (USFWS 2007) and extensive management intervention. I built and analyzed a matrix model for one subpopulation of western snowy plovers previously considered a sink habitat—Recovery Unit 2 in northern California, comprising Humboldt, Mendocino, and Del Norte counties. Based on my model, growth rate (lambda) is 1.05—countering a previous finding that Recovery Unit 2 is a sink—compared to 1.036 for the Nur et al. (1999) metapopulation model. I found that sensitivities and elasticities for each vital rate were similar between the two models; adult survival had the greatest effect on lambda, followed by juvenile survival, and fecundity had the least effect. Even though fecundity was lower for my model than Nur et al.’s (1999), adult survival was higher, which had a larger impact on population growth. In terms of management strategies, predator control, habitat restoration, and restriction of human activity should continue as outlined in the recovery plan, so as to continue the trend of positive growth for the coastal breeding population. Future directions involve performing population viability analyses for other recovery units to reassess the state of western snowy plovers compared to 1999.
34
Lozada, M. Tannya. "Plant communities in land-use systems of coastal Ecuador diversity patterns, endemism, and species turnover at landscape scale /". [S.l.] : [s.n.], 2006. http://webdoc.sub.gwdg.de/diss/2006/lozada.
Testo completo
35
Machon, Julia. "Sensory adaptations in shrimp from deep hydrothermal vents : Comparison of chemo‐ and thermo-sensory abilities in the vent species Mirocaris fortunata and the coastal species Palaemon elegans". Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS145/document.
Testo completoAbstract (sommario):
Les crevettes Alvinocarididae sont emblématiques des sources hydrothermales de la Dorsale Médio-Atlantique, mais les mécanismes qui leur permettent de détecter leur habitat sont énigmatiques. Il est supposé que les signatures chimique et thermique du fluide hydrothermal leur servent de repères pour s’orienter. Les facultés chimio- et thermosensorielles de l’espèce hydrothermale Mirocaris fortunata et de l’espèce côtière Palaemon elegans ont été étudiées avec plusieurs approches. Des traits structuraux du système sensoriel périphérique et central ont été comparés pour inférer sur les facultés olfactives de chaque espèce. L’expression du récepteur ionotropique IR25a dans les organes chimiosensoriels a été mesurée. Une technique d’électroantennographie a été mise au point afin de tester la détection de composés chimiques de fluide hydrothermal par les crevettes. Plusieurs expériences à pression atmosphérique et in situ ont été réalisées afin d’étudier le comportement des espèces hydrothermale et côtière exposées à une odeur de nourriture, du sulfure ou des températures relativement chaudes. L’ensemble des résultats montre que M. fortunata présente un système chimio- et thermosensoriel fonctionnel et apporte des bases substantielles pour approfondir les connaissances sur les adaptations sensorielles en milieu hydrothermal profondAlvinocaridid shrimp are an emblematic taxon at hydrothermal vents on the Mid-Atlantic Ridge, but how they locate active vents and detect their habitat is still enigmatic. They might use the chemical and thermal signatures of the hydrothermal fluid as orientation cues. The chemo- and thermosensory abilities of the hydrothermal species Mirocaris fortunata and the coastal species Palaemon elegans were investigated using various approaches. Structural features of the peripheral and central nervous system were used as rough estimates of their olfactory abilities. The co-ionotropic receptor IR25a, involved in chemodetection, was identified and located in the antennal appendages. A new electroantennography method was developed to test the detection of hydrothermal fluid chemicals. Several attraction tests were conducted at atmospheric and in situ pressure to investigate the behavior of the vent and shallow-water species when exposed to a food odor, sulfide and warm temperatures. Altogether, these results provide advances in the knowledge of the chemosensory biology of vent shrimp, and a substantial background for future researches on sensory adaptations to the hydrothermal environment
36
Stiles, Judith H. "The red imported fire ant, Solenopsis invicta, in early-successional coastal plain forests: tests of distribution and interaction strength". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/46488.
Testo completoAbstract (sommario):
The red imported fire ant, Solenopsis invicta, is an abundant and aggressive component of early-successional communities in the southeastern United States. After disturbance, it rapidly invades new habitats, and once there, it has strong competitive and predatory effects on the existing arthropod community. In upland coastal plain pine forests at the Savannah River Site in South Carolina, I conducted two studies of fire ant ecology. In my first study (chapter 1), I investigated the way in which fire ants colonize early-successional road and powerline cuts through forests, and I tested whether some of these linear habitats provided better fire ant habitat than others. I found that fire ant mound density (#/ha) was similar in narrow dirt roads and in wider roads with the same intermediate level of mowing disturbance, and that density was lower in wide powerline cuts where the vegetation is only removed every five years. Furthermore, mound density was greatest near the edges of cleared roads and powerline cuts and was also greater on the northern sides of roads and powerline cuts where there was less shading from the adjacent forest. Results from this study suggest that allowing increased shading from adjacent forest vegetation, especially along northern roadside edges, would limit the suitability of road and powerline cuts as fire ant habitat, thereby slowing invasion. In my second study (chapter 2), I examined the impact of fire ants on arthropod and plant species in early-successional forest gaps. In a tritrophic system, I tested whether the top-down effect of insect herbivore consumption by fire ants was strong enough to cascade through two trophic levels and improve plant growth and fitness. I compared this potential effect to that of other arthropod predators in the community. I found that fire ants controlled the level of tissue damage to plant leaves by herbivores, but that the damage was not severe enough to influence plant growth or fitness. Fire ants had stronger negative interactions with insect herbivores than other predators in the community, and for this reason, fire ants can be considered keystone predators. This project provides further evidence that fire ants successfully invade even small patches of early-successional habitat that exist within larger matrices of uninhabitable, late-successional forest, and that once there, they have a dramatic effect on the arthropod community. Restricting the amount of early-successional habitat within southeastern forests, either as permanent road and powerline cuts or as temporary gaps, would limit the potential for strong and detrimental effects by the invasive fire ant.Master of Science
37
Von, Schaumburg Dana Marie. "A Study of Post-Fire Recovery in Invaded Coastal Sage Scrub at the Bernard Field Station". Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/338.
Testo completoAbstract (sommario):
Coastal sage scrub (CSS), a lowland plant community native to California, is home to many rare, threatened, or endangered plants and animals. Fire, a natural feature of CSS, is essential for maintaining species diversity. However, the invasion of non-native grasses has altered the fire regime in CSS, increasing fire frequency and fire season length and decreasing fire intensity. Changes in the historical fire regime may in turn cause feedbacks that favor non-native species, resulting in the loss of biodiversity in invaded CSS sites. Numerous studies have examined patterns of post-fire succession in CSS; however, the role that the pre-fire seed bank and the relative abundance of natives to non-natives play in vegetation regrowth and community recovery is unclear. A lack of adequate pre-fire data on community composition makes testing hypotheses about the role of seed banks in post-fire recovery challenging. I propose to study recovery of the plant community in two differentially invaded CSS sites (East and West field) following a fire at the Bernard Field Station in September 2013. Data collected at the two sites from 2009-2013 reveal that non-native grass cover was significantly higher than native cover at both sites, though the West field had slightly higher native forb cover. Furthermore, the invasive grass Bromus diandrus almost entirely dominated the East field. Vegetation cover in the West field was more diverse with the abundance of other non-natives (Bromus hordeaceus, Bromus madritensis, Vulpia myuros) and natives (Amsinckia menziesii, Lupinus spp.) significantly higher than in the East field. To determine the effects of these pre-fire differences on recovery processes, I will carry out a randomized block experiment with four treatments (control, native seed addition, non-native grass removal, and both native seed addition and removal of non-native grasses). Twelve blocks will be evenly divided between the East and West fields. I propose to measure relative seedling abundance for both native and non-native species after each significant rainstorm over a three-year study period. I hypothesize that the composition of seed banks pre-fire will predict vegetation regrowth post-fire. Specifically, I predict that, under control conditions, B. diandrus will dominate the East field post-fire given its high abundance pre-fire. Further, I predict that regrowth in controls plots in the West field will be more variable given its more diverse seed bank pre-fire. Lastly, I predict that native forbs will exhibit the greatest degree of recovery in plots where active restoration methods (seeding and non-native grass removal) are employed; the effects of these restoration methods should be strongest in the East field because the pre-fire vegetation community was more heavily weighed towards non-native species. This study will add crucial knowledge to our understanding of how the pre-fire seed bank in CSS affects its recovery post-fire, which may inform future conservation efforts to ensure the continued health and protection of CSS sites around California.
38
Olivier, Pieter Ignatius. "Patterns of species diversity in coastal forests : case studies on tree and bird assemblages in KwaZulu-Natal, South Africa". Thesis, University of Pretoria, 2014. http://hdl.handle.net/2263/46216.
Testo completoAbstract (sommario):
Habitat loss and fragmentation drives the current extinction crisis. The processes through which it affects biodiversity, however, are complex and poorly understood. This is especially true for spatially complex regions that comprise a mosaic of land-use types, which often range from protected areas to dense human settlements. In such human-modified landscapes, it is important to determine the extent and impact of changing land-use patterns on biodiversity if we are to meet conservation targets or regain ecosystem services. My analyses of coastal forests in KwaZulu-Natal suggest that extensive loss of forests (82%) incurred an extinction debt, modelled to match the 11 bird species now listed as threatened locally. Forest fragments are now also smaller, fewer, further apart and more encroached by human land uses than in the past. Yet, species interactions with the gradient of habitat conditions that now surround forest fragments may have forestalled the realisation of predicted extinctions. I found that natural matrix habitats adjacent forest fragments (e.g. grasslands and woodlands) may facilitate dispersal, enable species spillover from forest fragments, and buffer forest interiors from changes in abiotic conditions associated with high contrast matrix habitats (e.g. agricultural plantations). However, when natural matrix habitats were transformed, these processes were disrupted, which suggest that the effect of landscape change on coastal forest diversity may stretch beyond forest loss per se and the deterministic extinctions predicted by conventional species-area relationships.
Next, I determined that the response of different bird species to habitat fragmentation parameters (i.e. area, connectivity and matrix habitats), depended on life-history traits such as body size, feeding guild and habitat specialization. Extinction risk was, however, not a function of species traits or the fragmentation parameter species responded to. This means that a conservation approach that only focuses on restoring a single fragmentation parameter (e.g. area) may not be successful in halting predicted extinctions, simply because multiple factors may determine extinction risk in coastal forests.
The interpretation of biodiversity patterns in fragmented landscapes may, however, also be influenced by spatial scale. I therefore used a fractal-based sampling design to test how sampling at fine, intermediate and coarse scales influences (1) beta diversity of and (2) inferences from the modelled contribution of niche- versus dispersal-based assembly processes in structuring tree and bird assemblages. I showed that inferences from beta diversity are scale dependent. As a result, studies with similar sampling effort and temporal sampling protocol, but with different sampling grains are likely to report dissimilar ecological patterns, which may ultimately lead to inappropriate conservation strategies.
This thesis provides information of how land-use changes impact on biodiversity patterns and derived processes in a human-modified landscape. It also highlights some conservation opportunities in the coastal forest landscape mosaic, where conservation and restoration actions should focus on both forest fragments and on the surrounding matrices. The conservation of natural matrices may buffer forest communities from impacts associated with high contrast habitat edges, enhance natural plant regeneration through species spillover, provide important linkages between forest fragments, boost regional diversity and allow coastal forests to track environmental change under changing climatic conditions.Thesis (PhD)--University of Pretoria, 2014.
tm2015
Zoology and Entomology
PhD
Unrestricted
39
Banks, Christopher Mark. "New Zealand Calanoid Copepod Invasions: Has Artificial Lake Construction Facilitated Invasions, and are our Coastal Waters Uninvaded?" The University of Waikato, 2007. http://hdl.handle.net/10289/2269.
Testo completoAbstract (sommario):
Non-indigenous species have become a global issue of increasing importance in recent years, with many causing significant environmental and economic damage. Identifying locations vulnerable to invasion allows for focus of management efforts towards prevention of invasions at those locations. In order to determine whether constructed water bodies, such as reservoirs, ornamental lakes or retired mines, are more easily invaded environments than natural water bodies, owing to decreased biotic resistance, the distributions of native and non-indigenous freshwater calanoid copepod species in the North Island were examined. Calanoid copepods in ports and other coastal environments were also examined, in order to determine whether ports are more frequently invaded owing to increased propagule supplies from visiting ships and other sources. The distributions of the native freshwater calanoid copepod species Boeckella hamata, B. propinqua, B. delicata and B. tanea are confined in the North Island of New Zealand to specific technostratigraphic terranes when natural waters only are examined, and as such each species can be considered to have a native range. The recently colonised calanoid copepod species Boeckella minuta (6 locations), Skistodiaptomus pallidus (3 locations) and Sinodiaptomus valkanovi (2 locations) are to date confined to constructed water bodies. Boeckella symmetrica (2 locations) may be confined to constructed water bodies, but the status of one location is unclear. Boeckella triarticulata, a species common in the South Island, is known only from a single farm dam in the North Island. The native species Boeckella hamata, B. propinqua and B. delicata were found to occur in constructed waters, but only B. propinqua was found in constructed water bodies outside their natural ranges (9 locations). Calamoecia lucasi is found in lakes throughout most of the North Island, and is not confined to any one terrane. My results indicate that constructed water bodies are more easily invaded by non-indigenous species than natural water bodies, represents a potential pathway for future invaders to establish, and provides locations for species to spread. In order to determine whether recently established freshwater calanoid copepod species have the potential to spread from their present habitats into other water bodies, the prosomal lengths of non-indigenous calanoid copepod species were measured and compared with those for native species. The results suggest that dietary overlap should prevent the non-indigenous species present to date from spreading into any water bodies with established Boeckella populations, although Sinodiaptomus valkanovi and Boeckella triarticulata could potentially spread to lakes containing only Calamoecia lucasi. Data on the co-occurrences of native freshwater calanoid copepod species support the theory of dietary exclusion, as Boeckella species have not been found to coexist. In order to test whether New Zealand marine environments have been invaded by non-indigenous calanoid copepods, and whether ports have been more regularly invaded than non-port areas, calanoid copepods were sampled from various coastal locations around the North Island. With the possible exception of Sulcanus conflictus, no non-indigenous species were found, indicating that non-indigenous marine calanoid copepod species are not establishing in New Zealand despite a history of invasion elsewhere.
40
Dupré, Cecilia. "Regional and local variation in plant species richness". Doctoral thesis, Uppsala universitet, Institutionen för evolutionsbiologi, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-691.
Testo completoAbstract (sommario):
In this thesis, I examine the variation in plant species richness along gradients of productivity and disturbance in grasslands and forest habitats in southern Sweden, and I compare the documented patterns with theoretical predictions. Moreover, I evaluate the relative importance of habitat quality and habitat configuration for the occurrence of field layer species in deciduous forests. Finally, I present a new method for the determination of the regional species pool. To examine regional and local variation in plant species richness, I gathered data on species composition in plots of different size (0.001 - 1000 m2) in three vegetation types (deciduous forests, dry grasslands and coastal meadows) in four regions of southern Sweden (Öland, Gotland, Småland and Uppland). As predicted by the species pool hypothesis, differences in small-scale species richness of deciduous forests and dry grasslands were correlated with differences in the size of the regional species pool. Moreover, among plots large-scale diversity was predictive of small-scale diversity. Species diversity showed a hump-shaped relationship with productivity in forests, and was related to environmental heterogeneity and the size of the 'habitat-specific' species pool. In the two types of grassland examined, grazed sites were richer in species than abandoned sites. Moreover, both species composition and the representation of plants with different life-history characteristics differed between grazed and abandoned sites. As predicted by the intermediate disturbance hypothesis, species richness was highest at intermediate levels of grazing in coastal meadows. However, all the above patterns were scale-dependent, and not observed at all plot sizes. The occurrence of field layer species in deciduous forests was more strongly related to habitat quality (mainly soil factors) than to habitat configuration (forest area and isolation). Across species, low seed production, clonal reproduction and habitat specificity were negatively associated with isolation.
41
Harris, April. "Differential Response of Barrier Island Dune Grasses to Species Interactions and Burial". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4097.
Testo completoAbstract (sommario):
Dune grasses are integral to biogeomorphic feedbacks that create and alter foredunes and barrier island stability. In a glasshouse study, Ammophila breviligulata Fern. and Uniola paniculata L. were planted together and subjected to sand burial to quantify morphological and physiological response. Ammophila breviligulata physiological and morphological performance declined when planted with U. paniculata but U. paniculata was not affected when planted with A. breviligulata. Burial had a positive effect on A. breviligulata and U. paniculata as indicated by electron transport rate and total biomass at the end of the experiment. Due to their different growth strategies, A. breviligulata and U. paniculata form continuous versus hummocky dunes, respectively. As global temperatures rise and U. paniculata migrates into A. breviligulata dominated habitat, A. breviligulata performance may diminish, and changes in dune form could result in altered island stability via increased overwash. Foredune community structure could also change due to the shift in dominant species which could alter dune succession.
42
Róis, Ana Sofia da Silva Valbordo. "Strategies for conservation of rare and endemic species: characterization of genetic and epigenetic variation and unusual reproductive biology of coastal species from Limonium ovalifolium and Limonium binervosum complexes (Plumbaginaceae)". Doctoral thesis, ISA/UL, 2014. http://hdl.handle.net/10400.5/7352.
Testo completoAbstract (sommario):
Doutoramento em Biologia - Instituto Superior de AgronomiaLimonium Mill. (Plumbaginaceae) is among the best represented genus in coastal habitats. In Continental Portugal, two taxonomically complex groups, diploid Limonium ovalifolium and tetraploid Limonium binervosum complexes are present, and species within these complexes present morphological similarities. These species are threatened as a result of negative anthropic impacts in coastal areas. The aims of the study presented in here were to collect information on chorology, karyology, natural population genetic and epigenetic variation, and reproductive biology of those species. A comparison of populations’ chromosome numbers revealed the presence of aneuploid individuals in species of both complexes. Male micro- sporogenesis and gametogenesis analyses showed regular meiosis and viable pollen grains formation in diploids as opposed to tetraploids. Floral heteromorphisms studies, pollination experiments and cytoembryological analyses demonstrated facultative apomixis in diploids and obligate apomixis in tetraploids. Analysis of methylation sensitive amplification polymorphisms revealed modest genetic and epigenetic differentiation among species populations’. Phylogeographic studies using chloroplast DNA marker sequences demonstrated a large amount of haplotype sharing indicating hybridization among species. This thesis offers deeper insights into these taxonomic complexes for better design conservation strategies in situ and ex situ, and a basis for ongoing and future research projects dealing with the expression of apomixis as well as genome evolution in Limonium spp.
43
Hacker, Molly. "ASSESSING SEED BANK CONTRIBUTION TO LANDWARD EXPANSION OF COASTAL WETLAND COMMUNITIES AND RESPONSES TO FIRE AND TRANSLOCATION ALONG COENOCLINE". OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2332.
Testo completoAbstract (sommario):
Land loss is a major threat to coastal wetlands of the northern Gulf of Mexico due to the impacts and interactions of sea level rise, regional subsidence, and anthropogenic changes to land cover and sediment supply. Here, coastlines are rapidly converting to open water due to an inability of coastal systems to keep pace with sea level rise via marsh migration due to barriers in the landscape, including dense shrub encroachment from fire suppression of inland communities. Fire may play an important role in promoting resiliency by in two ways, first by reducing or removing woody encroachment, allowing species to be released to migrate inland, second, by promoting primary productivity of herbaceous vegetation, which in turn, may promote vertical expansion. Where elimination of barriers is not possible (i.e., roads, industry and infrastructure), assisted migration of coastal communities landward (via translocation) may be also be a viable solution to bypass these barriers. This research is focused on the potential contribution of seed banks in landward migration of species, the role that fire plays in compositional change, and how seed banks compare to translocated communities when introduced into new environments. Here, seed bank dynamics were assessed and compared to aboveground vegetation of naturally regenerating and reciprocally transplanted (translocated) sods through time, with and without fire. The objectives of this study were to examine: 1) richness and abundance of species in the seed bank among vegetation zones of the coastal transition gradient; 2) effect of fire on expression of the soil seed bank; 3) emergence patterns and the degree of mixing/dispersion of dominant species within the seed bank among zones; 4) similarity of species composition of seed bank to that of the standing vegetation, pre- and post-fire; 5) similarity of species composition of the seed bank to that of the inter-zonally transplanted sods, with and without fire; and 6) fire behaviors through fuel loads and fire temperatures across zones. Results demonstrate the effect of zone on the composition, species richness and propagule density of the seed bank, and differences in similarity of the composition of the seed bank and standing vegetation. Fire did not appear to affect the composition of the seed bank. Ordinations indicate that seed bank communities are more widely distributed than standing vegetation assemblages. An overlap of communities was observed in each zone of the seed bank except salt marsh. Reciprocally transplanted sods that were burned prior to translocation were more similar to seed bank composition than no-fire transplants. Similarity, related to habitat preference, was most retained when sods were transplanted one zone away, and when transplanted upslope. A series of Procrustes analyses was conducted for combinations of seed bank treatments to standing vegetation of naturally regenerated and reciprocally transplanted plots of varying survey periods. Results showed that seed bank composition was most similar to the standing vegetation of the same survey period, and least similar for no-fire seed bank to transplanted plots surveyed 15 months after transplant. That the no-fire transplant plots were less similar to seed bank than burned transplant plot indicate that similarity between the seed bank and standing vegetation may be retained with fire. Comparisons of the Jaccard’s Similarity Coefficient of transplanted plot to seed bank with and without fire showed that overall, plots that had been burned were more similar to their source plots than those that had not been burned, across all zones. This study provides insight to zonation patterns of the seed bank across the coastal coenocline of the northern Gulf of Mexico, and compositional similarity of the seed bank to both naturally generated and reciprocally transplanted propagules, in order to understand the how these communities respond to sea level rise, how they may be managed with fire, and how plant species respond to conditions across zone, thereby the potential contribution of the seed bank to landward migration and the promotion of resiliency of coastal communities through facilitation of lateral migration in response sea level rise.
44
Schirmel, Jens [Verfasser]. "Arthropods in a changing environment : a multi-level and -species approach to diversity and ecology in coastal heathlands / Jens Schirmel". Greifswald : Universitätsbibliothek Greifswald, 2011. http://d-nb.info/1013465237/34.
Testo completo
45
Maggs, Jade Quinton. "Movement of coastal fishery species in Southern Africa: research trends, characterisation of behaviours and a case study on fishery implications". Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/60574.
Testo completoAbstract (sommario):
Movement of fishes is an integral part of their daily life, but has significant implications for fishery management. As with nearly all coastal countries, South Africa relies on coastal fisheries as a renewable resource, but many stocks have been overexploited for decades. Although it has long been recognised that an understanding of fish movement is necessary for effective management, it is with some difficulty that the subject has been studied in the past. In recent years, however, improvements in technology have provided the means for more in-depth investigations into fish movement. This research has revealed a range of complex movement behaviours. Movement in fishes occurs on a variety of temporal and spatial scales leading to the characteristic patterns of distribution and abundance observed in marine ecosystems. Fishes move nearly constantly in search of food, shelter or reproductive opportunities. Observations of behaviours such as long-term site fidelity, longdistance migration and natal homing are enabling ecologists to understand patterns of distribution and abundance within a species' range. Fish movement around the South African coast has been studied on numerous occasions but this has largely been confined to studies on single species. Movement behaviour of multiple species has been studied, but this has been limited to spatially localised marine protected area research. There has been little attempt in southern Africa to synthesize interspecific movement behaviour over wide spatial scales.Unprecedented concern over the biological effects of overexploitation, together with rapid technological advances in biotelemetry, have provided the impetus for much research, on a global scale, into the movement of marine animals. I reviewed 101 marine and estuarine fish movement studies from southern Africa, published from 1928 to 2014, with the aim of synthesising research trends and findings. Trends showed an increasing emphasis on fish movement research in publications in the sub-tropical and warm-temperate biogeographic regions along the south and east coasts of southern Africa. Although 63% of publications featured only marine studies, research into fine-scale habitat use in estuaries has been on the increase, concomitant with increasing accessibility of biotelemetry. Overall, 26 fish families were identified in the surveyed literature with regionally endemic sparids featuring in 32% of the publications. Ten movement themes were identified in the surveyed literature, including broad-scale movement patterns, which featured in 68% of studies, followed by fine- scale habitat usage (33%) and protected areas (26%). The most prominent phenomenon, emerging from this research, is that of partial migration, which describes the occurrence of resident and migratory behaviour within a coexisting animal population. Substantial progress has also been made in unravelling the complexities of fine-scale movements in marine reserves and habitat usage in estuaries. While this knowledge has enabled more effective management of South Africa's multi-user, multi-species fisheries, focus should now be directed at improving our understanding of the commonalities in movement behaviour, the associated driving forces behind this behaviour and the extent of movement across reserve boundaries. Mark-recapture data, collected over the past 30 years by the Oceanographic Research Institute’s Cooperative Fish Tagging Project (ORICFTP), were used to investigate broad- scale movement patterns of 30 prominent coastal fishery species (Chapter 4). Fishes were tagged with plastic dart tags along the coastline of southern Africa from Angola to Mozambique. This exercise yielded more than 10000 recaptures. The 30 chosen species represented 14 families, although 12 species belonged to a single family (Sparidae). Overall, 67% of recaptures were reported from the original tagging locality and 73% were recorded within 5 km of the tagging locality. The remaining observations extended from 6-3000 km. Movements were assigned to four distance bins (0-5 km, 6-50km, 51-500km and >500 km) and modelled with an ordinal logistic regression. Species, life-stage (juvenile/adult) and time- at-liberty were included as predictor variables. Model coefficients were then included in a cluster analysis, which produced two primary groupings of species (Category I and II), with two sub-groupings (Category IIa and IIb). Category I species were characterised by wide-ranging movements, greatest median recapture length and highest trophic levels. Category II species were characterised by residency, lower median recapture length and lower trophic levels. These findings have implications for fisheries management. Exploitation of resident species may lead to localised depletion, but their diffuse spatial distribution may offer some resilience. In contrast, even localised targeting of migratory species may pose a population level risk if individuals are known to aggregate. Life-cycle diversity or intra-population variability describes the existence of alternative strategies or tactics among coexisting individuals within an animal population (Chapter 5). Partial migration is a specific case of life-cycle diversity where coexisting groups exhibit either resident or migratory (wide-ranging) behaviour within a single population. Mark- recapture data collected under the auspices of the ORICFTP were used to investigate the occurrence and nature of life-cycle diversity in the movement behaviour of five non- diadromous fish species around the coastline of southern Africa. Among the five species were three teleosts (Category I and IIa) and two elasmobranchs (Category I). A fish was considered to have remained resident if recaptured within 0-5 km after 365 days at liberty. A fish was considered to have undertaken a wide-ranging movement if recaptured more than 50 km away from the release site in 365 days or less. A total of 1848 individuals from the five study species were recaptured during the study, of which 73% of the observations were classified as being resident. Binomial logistic regression confirmed that species, life-stage (juvenile/adult) and ecoregion were significant (p < 0.001) predictors of the probability of wide-ranging behaviour. A Gaussian model confirmed that species and ecoregion were also significant (p < 0.001) predictors of direction and distance of wide-ranging movement. However, the direction and distance of wide-ranging movements in juveniles did not differ significantly (p > 0.05) to that of adults. The median growth rate was mostly greater in wide- ranging individuals; however, this was only statistically significant (p < 0.05) in two cases. These findings provide unequivocal evidence of life-cycle diversity in five fish species, with vastly different life-histories. This ecological phenomenon may provide species resilience at the population level and needs to be considered in fisheries management initiatives. The movement of fishes is a fundamental aspect to consider when designing fishery management regimes. Unfortunately, traditional management strategies have often disregarded movement behaviour to the detriment of fish populations (Chapter 6). As a case study, the management of Lichia amia (Category I: wide-ranging) was evaluated in the context of its movement behaviour. Long-term catch-per-unit-effort (CPUE) datasets were examined for three South African recreational fishery sectors. The CPUE was standardised using generalized linear models (delta-Gamma/hurdle approach) to reduce the effect of factors other than abundance. Factors that were available for this purpose were year, month and locality/zone. Year was included in every model as the primary objective was to detect trends in abundance over time. Although standardised CPUE for all sectors showed an overall long-term decline, there was considerable variability in trends between the different recreational sectors and between datasets. Contrasting trends between competitive shore angling and general shore angling datasets were ascribed to hyperstability in competitive CPUE data. Hyperstability in this case was mostly influenced by rapidly improving technology, techniques and communication networks amongst competitive anglers. Month and locality were significant factors explaining the probability of catching L. amia. This suggests that the predictable aggregatory behaviour of this species could further compound the observed CPUE hyperstability. Although the CPUE responded positively for six years after implementation of the first minimum size and bag limits, and for one year after the decommercialisation of the species, these regulations and their amendments failed to arrest a long-term decline in the CPUE despite the ample evidence for hyperstability. It is clear from this case study that the predictable nature of wide-ranging behaviour in L. amia has made the population vulnerable to exploitation. This has led to the demise in the population, which could have been worse if not for the occurrence of intra-population variability in its movement behaviour, which may provide some measure of resilience.
46
Gong, Wen-Bin, e 龔文斌. "Amphibian species distribution model in Coastal Range". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13136260022239530134.
Testo completoAbstract (sommario):
碩士國立東華大學
自然資源與環境學系
99
Since 1999, the NDHU Amphibian Conservation Laboratory has conducted ecological monitoring of Anuran in Coastal Range. Given that most areas of the Range are undeveloped primary forests where people can hardly get to, we used MAXENT to know the potential geographic distribution of frogs and to find the biodiversity hotspots throughout the Coastal Range. These results will provide basic data in for further monitoring and conservation on amphibians. In this study, we used the climate layers (spatial resolution of 40 square meters) that included Mean Temperature of warmest month, Mean Temperature of coldest month, Precipitation of Wettest Quarter, Precipitation of Driest Quarter, Annual Mean Temperature, Annual Precipitation, altitude and warmth index. The results showed that frogs in Coastal Range could be classified into 5 categories: (1) General in the north but fragmental in the others. (2) Only in the south. (3) Only in the central and southern parts. (4) General throughout the Coastal Range. (5) Only in the north. The most useful climate variables is were Annual Mean Temperature and Annual Precipitation. According to the types of climate variables, frogs in Coastal Range could be categorized into four groups. The first group is consisted of B. bankorensis, Rh. aurantiventris and R. swinhoana; the second group is comprised H. chensis and M. inornata, and the third one included K. eiffingeri and Rh. moltrechti. All the other frogs which are not mentioned above belonged to the fourth groups. In regard to the climate variables and species occurrence response curve, different species had different preferences for habitats. The main limiting factor was temperature and precipitation, and that was also related to the seasons and the habitats chosen by frogs. We calculated the amount of frog species in each grid, and made the grid containing 13-17 species a hotspot. Now the hotspots are located in the northern part of Coastal Range, low elevation areas including Ruisui county to Yuli township, Changbin county, and Fuli county to Luye county. We overlapped the hotspots on the current conservation area in Coastal Range, and it turned out that only 0.7% of the hotspots were protected. We suggest that besides the follow-up monitoring on hotspots, the plans for conservation measures are important as well.
47
Conduto, Telma Lúcia Pereira dos Santos Coelho. "Trophic connectivity in coastal habitats supporting fishery species". Doctoral thesis, 2017. http://hdl.handle.net/10400.1/10792.
Testo completoAbstract (sommario):
The transfer of production along coastal habitats from migration of organisms and natural or anthropogenically caused environmental conditions create complex food webs between habitats.
A species is rarely independent from the resources of other habitats as nutrients and food supply flow easily in the aquatic environment developing strong habitat connections between food webs. These multiple trophic interactions are very susceptible to variability in the environmental conditions of the habitat that supplies the energy source. All this justifies additional investigation on coastal habitat specific food webs interactions and key energetic connections that extent from primary producers to top consumers.
Given the easy access and importance to achieve sustainability of species and their supporting habitats, explicitly for fisheries species that maintain local economy, this thesis aims to study energy sources, prey and consumers that transcend habitats in the eastern Algarve coastal area.
A General Introduction highlights the functioning of coastal food webs and the flow of nutrients and food with the movement of organisms between distinct habitats in the coastal area. The constant changes in the coastal landscape and the variability in environmental conditions create a knowledge gap in the functional role of different habitats in the complex web of coastal trophic interactions and secondary production that support coastal fisheries. Temporal and spatial variability in trophodynamics of fisheries species was performed with trophic markers: fatty acids and stable isotopes. These biomarkers determine the importance of the outwelling of terrestrial organic matter in trophic webs of adjacent coastal habitats and if movement of consumers results in the transfer of energy sources between habitats.
This introduction describes the most relevant aspects in trophic markers biochemistry and applications in ecology and detailed analytical procedures for the following chapters, as well as quality control of analysis. Applications in ecological studies are exemplified from the identification of energy sources, including terrestrial organic matter, microphytobenthos and different groups of phytoplankton that support the food webs of a wide variety of aquatic consumers.
Chapter 2 demonstrates how the wide range of primary producers and energy sources is reflected in the diet of coastal fish, estuarine fish and offshore fish. The relative contribution of energy sources determined the importance of upriver foraging behavior of marine fish for the transport of marine production upriver and the importance of the estuarine environment as feeding ground for coastal fishes. Estuary primary producers and vascular plants were recognized as a potential source of energy for mid estuary fishes against marine phytoplankton and microphytobenthos for coastal fishes.
Chapter 3 describes the role of terrestrial organic matter as energetic source for fish food webs in the estuary and adjacent coastal area. Organic detrital material of terrestrial origin flows in rivers towards coastal areas in a dynamic and continuous process but nevertheless it had a minor role in this connectivity between the estuarine and coastal trophic webs.
Chapter 4 evaluates several tissues of a cephalopod from the benthic coastal environment to define inter-tissue comparisons. Tissues with the same function represented the trophic markers in similar proportions and were ineffective to determine temporal and spatial diet variability. Mantle and digestive gland were the chosen tissues for the sequent analyses.
Chapter 5 demonstrates the main sources of nutrition in the diet of Octopus vulgaris from the coastal benthic environment. Here are described potential trophic pathways to other habitats, including the role of terrestrial production. This chapter explains the temporal variability in the contribution of the different production sources for the octopus food web in the area of the fishery and demonstrates octopuses depend mainly on local primary sources. The trophic markers supported a trophic web based in dinoflagellate production in the marine environment.
Chapter 6 shows the feeding behavior of the cephalopod O. vulgaris towards the input of allochthonous prey and how human interactions create a trophic coupling between the benthic and pelagic environment. The opportunistic behavior of this cephalopod was demonstrated for a food resource absent from the natural diet.
Chapter 7 is the general discussion from the overall results and conclusions of the case studies in this thesis under the subject of habitat trophic connectivity of coastal fishery species. Pros and cons of the chosen techniques are discussed as well as issues arising from the sample sizes and pooling of samples. Further research and techniques will improve studies on trophic dynamics and connectivity in these ecologically and economically important benthic habitats.
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Hong, Shu-Ting, e 洪淑婷. "Effects of Gaps on Coastal Tree Species for Reforestation". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/96104705245725467838.
Testo completoAbstract (sommario):
碩士國立中興大學
森林學系所
100
To offer the reference of mixed forest or forest understory regeneration for coastal forest in northwest Taiwan, we directed at two objective to study: First, we investigated stand condition in coastal forest in Xinfeng section, Hsinchu county and Kekegang section, Taoyuan county, then estimated the essentiality of regeneration and the adaptive species; second, we selected seeds of the Cerbera manghas, Terminalia catappa and Calophyllum inophyllum as sowing materials, then sowed the seeds at Xinfeng field, and nursery as the control group. Moreover, we investigated transplanting seedlings at large gap in Kekegang section. To explore the adaptation of these experimental species in the different gap environment and the results of forestation of these species further. The results of stand condition: Casuarina spp. were the major species but they showed signs of deterioration. Celtis sinensis might have an opportunity of becoming a stable population but it was deficient in quantity. This suggested that artificial manner could promote the assignments of regeneration. Furthermore, Hibiscus tiliaceus and Pandanus odoratissimus showed the greater growth performance so it could plant in the understory to construct a multistoried forest The experiment results of the sowing seedlings and the transplanting seedlings: In the nursery’s seedling, the characteristics of morphology indicated the C. manghas and T. catappa had better growth at the full light, C. inophyllum had better growth at the relative light environment of 20 % to the full light; the characteristics of photosynthesis indicated the C. manghas and T. catappa showed the greater net photosynthetic rate at the full light, and C. inophyllum had similar values between the light environment treats; the characteristics of chlorophyll fluorescence indicated the C. manghas was slightly influenced at the full light but it was still healthy according to Fv/Fm of predawn, T. catappa and C. inophyllum were not influenced. Summarizing the above results, seedlings of three species were suitable at the light environment of 20 % to the full light, but C. inophyllum couldn’t have better growth at the full light. Contrast to the field’s seedling further, sowing seedlings of the C. manghas performed lower germination percentage and morphological sections than the nursery’s seedlings, and lower survival rate at large gap. This indicated that C. manghas might not adapt to high light in harsh environments. Germination percentage of the T. catappa and C. inophyllum was very low. Summarizing the sowing seedlings results, C. manghas was suitable for sowing to small gap which were in the light of 20 % to 40 % and T. catappa was suitable for sowing to gap or open site which were above the light of 20 % when implementing understory regeneration for coastal forest, but it required on the premise that effectively improvement of the germination percentage; moreover, C. manghas and T. catappa had good adaptation, hence they were also suitable for planting. C. inophyllum was also suitable in the same light environment with T. catappa, but it was more proper for planting. The other transplanting seedlings could be used for regeneration in the region. To improve successful probability, it suggested that transplanting seedlings planted in the interior of stand from the start.
49
Tseng, Shu-Ying, e 曾淑瀛. "Shewanella species in the coastal water and aquaculture of Taiwan". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/65110009066401153735.
Testo completoAbstract (sommario):
碩士國立中興大學
獸醫學系暨研究所
101
Shewanella is a facultatively anaerobic gram-negative bacillus. It is a saprophytic, marine organism which is often associated with opportunistic infections. Most reported cases had history of sea water exposure or seafood consumption. Recently, case reports of Shewanella infection have increased. Many of them were found in the Asian region and Taiwan. The study aims to investigate the occurrence, distribution, and diversity of Shewanella spp. in Taiwan coastal water and aquaculture. In total, 80 aquaculture samples and 25 water samples were collected. Shewanella was identified to species level using 16S-rRNA sequences. More characteristics were analyzed using auxiliary biochemical, growth, and hemolytic tests. A total of 64 Shewanella strains were isolated from aquaculture samples, included S. haliotis, S. algae, S. chilikensis, S. marisflavi, S. aquimarina and S. loihica. 22 Shewanella strains were isolated from water samples, included S. haliotis, S. algae, S. marisflavi, S. aquimarina, S. loihica, S. putrefaciens and S. baltica. The majority of Shewanella species amongst the Shewanella isolates were S. algae, S. haliotis and S. putrefaciens. Most Shewanella isolates are able to grow at 37℃, in the presence of 6.5% NaCl and exhibit hemolysis on sheep blood agar. Further studies are required to identify its virulence factors and role in diseases. Our results suggest that aquaculture are reservoirs of opportunistic pathogenic microorganisms to aquatic organisms and humans and a better understanding of the microbial ecology of the aquaculture will provide insights to the possible health hazards from these microorganisms.
50
Cody, Elizabeth. "Hawaiian coastal wetlands : germination and early growth of five native Hawaiian coastal species and the invasive Batis maritima". Thesis, 2006. http://hdl.handle.net/10125/20456.
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