Rozprawy doktorskie na temat „Habitat modification”
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Rangeley, Robert W. (Robert William). "Habitat selection in juvenile pollock, Pollachius virens : behavioural responses to changing habitat availability". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28648.
Pełny tekst źródłaGray, Michael Andrew. "The ecological impacts of habitat modification on tropical biodiversity". Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440791.
Pełny tekst źródłaBrush, Janell Marie. "Wetland avifauna usage of littoral habitat prior to extreme habitat modification in Lake Tohopekaliga, Florida". [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0014260.
Pełny tekst źródłaMuench, Ann Marie. "Aquatic vertebrate usage of littoral habitat prior to extreme habitat modification in Lake Tohopekaliga, Florida". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008580.
Pełny tekst źródłaMaran, Audrey Marie. "The effect of anthropogenic habitat modification on insect-mediated ecosystem services". Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594488419133855.
Pełny tekst źródłaWesenbeeck, Bregje Karien van. "Thresholds and shifts : consequences of habitat modification in salt-marsh pioneer zones /". PURL, 2007. http://www.arlis.org/docs/vol1/A/433191982.pdf.
Pełny tekst źródłaFALASCHI, MATTIA. "INTERACTIVE EFFECTS OF HABITAT MODIFICATION AND INVASIVE ALIEN SPECIES ON AMPHIBIAN BIODIVERSITY". Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/822579.
Pełny tekst źródłaSICURELLA, BEATRICE CARLOTTA. "Analysis of the consequences of climate change and habitat modification on migratory birds". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/69740.
Pełny tekst źródłaPillay, Pradeep. "The ecological and evolutionary assembly of competitive communities in dynamic landscapes /". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101164.
Pełny tekst źródłaFischer, Jason L. "Fish community response to habitat alteration: impacts of sand dredging in the Kansas River". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13601.
Pełny tekst źródłaDepartment of Biology
Craig Paukert
In-stream dredging is a common practice in rivers worldwide that can affect fish and fish habitat. We investigated the magnitude of these alterations and their influence on the fish community of the Kansas River, a large sand bed river. Fishes were collected monthly from June 2010 to June 2011 in Edwardsville and Lawrence, KS from 12, 1-km reaches (three actively dredged, two historically dredged that have not been dredged in at least one month, and seven control reaches) with bottom trawls, seines, and electrofishing. Water depths and velocities were measured with an acoustic doppler current profiler and interpolated in ArcGIS at all 12 reaches. Actively dredged reaches had proportionally more deep water habitat (> 3 m) and lower velocity (< 0.15 m/s) near the river bed than control reaches (P < 0.01 and P = 0.04, respectively). However, the mean proportion of shallow water habitat (< 0.5 m), high velocities near the river bed (> 0.30 m/s), low velocity habitat (< 0.25 m/s), and high velocity habitat (> 0.75 m/s) were similar among all reach types (Ps > 0.05). A canonical correspondence analysis was used to characterize relationships among habitat variables, reach types (actively dredged, historically dredged, and control), and catch per unit effort (CPUE) of fishes in the Kansas River. Mean velocity and depth explained a significant amount of variation in species CPUE; however, reach type was not a significant factor for any of the gear types for any season. Our results show that dredging in Great Plains Rivers can increase depths, but alterations to fish community structure was not evident, likely because many of these fishes are adapted to a range of habitat conditions and are highly mobile.
Groshens, Thomas P. "An assessment of the transferability of habitat suitability criteria for smallmouth bass, Micropterus dolomieu". Thesis, Virginia Tech, 1993. http://hdl.handle.net/10919/44601.
Pełny tekst źródłaThe purpose of this study was to determine if habitat suitability criteria developed in the summer months for sma11mouth bass were transferable among streams representing different eco regions.
Habitat suitability criteria were developed for depth, mean column velocity, cover and substrate for two size classes of sma1lmouth bass, 100-199mm and >200mm, in the North Anna River and Craig Creek, Virginia.
Criteria that accurately describe habitat selection by a species or guild in a system different from where the criteria were developed are said to be transferable to that system. The transferability of suitability criteria between the North Anna River and Craig Creek, as well as depth and velocity criteria from Minnesota, the Huron River, Michigan and the Upper James River, Virginia, to the North Anna River and Craig Creek were tested using a 2x2 contingency table analysis.
Depth criteria for the smaller sizes of sma1lmouth bass did not transfer well between regions; 4 of the 8 transferability tests (50%) failed. Depth criteria for larger sma1lmouth bass transferred to the North Anna River and Craig Creek in all cases.
Velocity criteria developed for the smaller size classes did not transfer well among regions; only 3 of the 8 transferability tests were positive. Likewise, velocity criteria for larger sizes of smallmouth bass did not transfer well; only 1 of 8 tests were positive.
General criteria were developed for depth and mean column velocity by averaging the suitability values reported from this and 3 other studies. General depth and velocity criteria transferred well to the North Anna River and Craig Creek for both the larger and smaller size classes of smallmouth bass; all depth tests were positive and 3 of 4 velocity tests were positive. The improved success of transferability warrants investigation of developing general criteria for smallmouth bass.
Cover criteria for both size classes of smallmouth bass were transferable from the North Anna River to Craig Creek but not vice versa. Substrate heterogeneity criteria were not transferable between the North Anna River and Craig Creek for either size class of smallmouth bass. Criteria developed for the percentage of substrate particles >15cm (smallmouth bass >200mm only) were transferable from Craig Creek to the North Anna River but not vice versa.
The transferability of habitat suitability criteria among regions was inconsistent and it is recommended that site-specific criteria be developed for each stream to which habitat assessments are applied. Additionally, nose velocities used were more consistent between the North Anna River and Craig Creek than were mean column velocities used. Hence, it is recommended that information on nose (focal point) velocities be incorporated into habitat studies to more accurately describe smallmouth bass velocity requirements.
Master of Science
Breitfuss, Mark, i n/a. "The Effects of Physical Habitat Modification for Mosquito Control, Runnelling, on Selected Non-Target Saltmarsh Resources". Griffith University. Australian School of Environmental Studies, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20031126.074304.
Pełny tekst źródłaBreitfuss, Mark. "The Effects of Physical Habitat Modification for Mosquito Control, Runnelling, on Selected Non-Target Saltmarsh Resources". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367526.
Pełny tekst źródłaThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
Register, Sarah M. "Breeding biology and habitat associations of cerulean warblers in southern Indiana". Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1372052.
Pełny tekst źródłaDepartment of Biology
Lequerica, Tamara Manuel Eduardo. "Urbanisation and environmental modification as drivers of insect community diversity and composition in Sydney, Australia". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18178.
Pełny tekst źródłaPenedos, Cláudia Patrícia Tavares. "A comparative analysis of fish communities associated to Zostera noltii beds before a major vegetation collapse and during the natural habitat recovery". Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13347.
Pełny tekst źródłaSeagrass beds provide higher biomass, abundance, diversity and productivity of ichthyofaunal communities than non-vegetated substrata. During 2008, the seagrass beds of Zostera noltii located in the lower Mira estuary (SW Portugal) disappeared completely. However, during 2009, slight symptoms of natural recovery were observed, a process which has since evolved intermittently. The main goal of this study was to investigate the temporal and spatial distribution patterns of the composition and structure of the ichthyofaunal communities under two distinct habitat ecological conditions: “before” the collapse, characterized by mature vegetation of the seagrass beds, and “after” recovery, corresponding to natural habitat recovery process of the seagrass beds. The following hypotheses were tested: there would be significant differences of the fish communities between i) the period “before” the habitat loss and “after”, during the natural recovery; and ii) seagrass beds and main channel under both ecological conditions. The temporal and spatial distribution patterns of the fish species composition and abundance were clearly different before the habitat loss and after, during the natural recovery. “Before” the collapse the main channel and seagrass beds showed significant differences between the habitats, on the contrary, during the natural recovery it was not possible to distinguish both communities, which were much similar to those of the non-vegetated areas in the 1980s. Generally, fish communities of Z. noltii seagrass beds in the 1980s were more rich and diverse and with higher abundance of individuals. Apparently, disappearance of Z. noltii seagrass beds led to the disappearance or decrease in abundance of resident fish species in that habitat, which have not return to the system or recover the respective populations even after the beginning of the recovery of Z. noltii seagrass beds. This study also revealed that this system has registered an increased colonization from species with subtropical affinity, which might be related to gradual temperature increase at a global scale. However, modifications due to the collapse and recovery of the Z. noltii seagrass beds seemed to surpass the effects resulting from climate changes
N/A
Onken, Kai Sven. "Effects of native freshwater mussels and leaf debris on benthic macroinvertebrate abundance and diversity : A field experiment with Margaritifera margaritifera in Vasslabäcken, Örebro county". Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84485.
Pełny tekst źródłaOrganismer i komplexa ekosystem interagerar inte bara med andra organismer utan också med sin miljö, samt påverkar ekosystemfunktioner. I akvatiska ekosystem påverkar filtrerare ekosystemfunktioner genom att överföra energi och näringsämnen från vattnet till det bentiska samhället. De filtrerande unionoida musslorna kan ha stora effekter på närsalter och biodeposition i vattendrag, vilket påverkar primär- och sekundärproduktionen. I ett 90-dagars fältbursförsök under vintern 2019-2020 testades effekterna av den starkt hotade sötvattenspärlemusslan (Margaritifera margaritifera) och löv på bentiska samhällen. Makroevertebrater provtogs i burarna och undersöktes på lab. Det fanns inga signifikanta effekter av musslor, löv eller deras interaktion på makroevertebraters tätheter och diversitet för de flesta grupper. Tätheter av Simulidae var dock lägre i burar med musslor jämfört med burar utan musslor. Förekomsten av musslor i vattendrag kan därför påverka ekosystemets funktion, här visat som en möjlig effekt på mellanartskonkurrens mellan filtrerare.
Lewis, Cassandra Kasun. "The effects of habitat fragmentation on Amorpha canescens, a prairie forb, and its associated herbivores". Thesis, University of Iowa, 1999. https://ir.uiowa.edu/etd/5396.
Pełny tekst źródłaGonsalves, Sydney Marie. "Green Roofs and Urban Biodiversity: Their Role as Invertebrate Habitat and the Effect of Design on Beetle Community". PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/2997.
Pełny tekst źródłaTomblin, David Christian. "Ecological niche responses of small mammals to gypsy moth disturbance". Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06302009-040517/.
Pełny tekst źródłaLuck, Gary W. "Landscape differences in the ecology of the Rufous Treecreeper Climacteris Rufa". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2000. https://ro.ecu.edu.au/theses/1546.
Pełny tekst źródłaPaull, David James Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "Habitat fragmentation and the southern brown bandicoot Isoodon obesulus at multiple spatial scales". Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2003. http://handle.unsw.edu.au/1959.4/38698.
Pełny tekst źródłaWhytock, Robin C. "Optimising habitat creation for woodland birds : the relative importance of local vs landscape scales". Thesis, University of Stirling, 2018. http://hdl.handle.net/1893/27298.
Pełny tekst źródłaDavis, Adrian Louis Victor. "Climatic change, habitat modification and relative age of dung beetle taxa (Coleoptera: Scarabaeidae, Hydrophilidae, Histeridae, Staphylinidae) in the South-Western Cape". Doctoral thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/8424.
Pełny tekst źródła1. Two study sites near Pretoria in the Transvaal were located in a summer rainfall climatic area, type 113d (Walter & Lieth 1964), on deep and in both open woodland and grassland. 2. Eleven study sites in the south-western Cape were distributed between two winter rainfall climatic areas, type IV in the Cape of Good Hope Peninsula and type III(IV)a (Walter & Lieth 1964) on the west coast. The west coast could be divided into two subregions, the coastal belt of deep calcareous sand and the Darling Hills comprising predominantly sandy soils with a higher clay fraction. Vegetation at the sites formed a gradient from low, dense pasture to taller sparser shrubland; The five pasture sites were distributed between all three subregions whereas the six shrubland sites were located only in the Cape of Good Hope Peninsula and on the west coastal belt. 3. Pitfall traps baited with cattle dung were used to sample dung beetle fauna over 24h periods once a week in the Transvaal, irrespective .of weather (three traps/site), and on three sunny occasions per month in the south-western Cape (ten traps/site) for one year. 4. A further 13 study sites used for back-up studies in the south-western Cape were concentrated into three localities, three in the Cape of Good Hope Peninsula, six on the west coastal plain and four-in the Darling Hills. These sites comprised different combinations of pasture (five sites) and shrubland (eight sites) habitats. Five traps at each site were baited on one 24h occasion each month over six months.
Tatchley, Cerian. "Wildlife impacts of, and public attitudes towards, small wind turbines". Thesis, University of Stirling, 2015. http://hdl.handle.net/1893/22894.
Pełny tekst źródłaSmith, Scott M. "The influence of submerged aquatic vegetation on trophic relationships of largemouth bass". Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/74542.
Pełny tekst źródłaMaster of Science
Ricciardi, Anthony. "The role of the zebra mussel (Dreissena polymorpha) in structuring benthic macroinvertebrate communities in the St. Lawrence River /". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34438.
Pełny tekst źródłaThe capacity for Dreissena to displace native freshwater mussels (Family Unionidae) in the St. Lawrence River was examined over a four year period by quadrat sampling at selected sites. Dreissena preferentially colonized unionid mussels in the river. Mean infestation loads (number of zebra mussels per unionid mussel) in the St. Lawrence were 10-100 times lower than in the Great Lakes,.but resulted in similar high mortality. Severe declines in unionid species richness and abundance occurred in areas of the river that supported dense Dreissena populations ($>$4,000 mussels/m$ sp2).$ Analysis of data from the Great Lakes-St. Lawrence River system suggests that mass mortality and extirpation of unionid populations typically occurs within 4-5 years following initial colonization of unionids by Dreissena, and that Dreissena infestation will increase the future tate of extinction of North American unionids by nearly 10-fold.
Siegel, James Joshua 1956. "An evaluation of the minimum habitat quality standards for birds in old-growth ponderosa pine forests, northern Arizona". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276951.
Pełny tekst źródłaDevoucoux, Pierrick. "Conséquences et impacts prévisibles d'une perte d'habitat majeure sur une espèce menacée aux exigences écologiques complexes : effets de la mise en place du contournement ferroviaire à grande vitesse Nîmes-Montpellier sur la dynamique de la population d'Outarde canepetière des Costières de Nîmes". Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2285/document.
Pełny tekst źródłaUrbanization and increasing transport infrastructure construction are known as the main cause of biodiversity loss. By habitat loss and landscape fragmentation they cause, these structures impact populations. Our work sought to assess, on a case of complex ecological requirements, foreseeable impacts of the establishment of a High Speed Line (HSL) and their consequences. We studied the population of Little Bustard Tetrax Tetrax of the Costières nîmoise area. Within its own range scale, this population is an exception: it reaches locally unusually high densities and develops distributions patterns never met previously. We sought to identify local variations in distribution and their correlation with habitat parameters in a wide range of spatial scales, to model the expected distribution patterns and expected impacts of future infrastructure
Driver, Patrick, i n/a. "The role of carp (Cyprinus carpio L) size in the degradation of freshwater ecosystems". University of Canberra. School of Resources, Environmental and Heritage Sciences, 2002. http://erl.canberra.edu.au./public/adt-AUC20050404.110223.
Pełny tekst źródłaBank, Michael S. "Mercury Bioaccumulation and Habitat Relations of Lotic and Lentic Amphibians from Acadia National Park, Maine, USA". Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/BankMS2005.pdf.
Pełny tekst źródłaMagoba, Rembuluwani Norman Nicholas. "Effect of invasion and clearing of alien riparian vegetation on benthic macroinvertebrate and adult odonata assemblages in Soutpansberg rivers". Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/1800.
Pełny tekst źródłaBenthic macroinvertebrates (sampled using South African Scoring System, SASS5) and adult male Odonata (sampled with close-focus binoculars) were recorded on two streams and a river of Soutpansberg, with the aim of determining the effect of invasion and removal of alien riparian vegetation on their assemblages. A secondary aim was to establish the importance of dragonflies as indicators of degree of disturbance in rivers. Forty two aquatic macroinvertebrate families and 33 adult Odonata species were recorded at a total of 71 sampling units. Three distinct riparian vegetation types were selected (natural, alien and cleared). Cleared vegetation refers to clearing of invasive alien trees, allowing regrowth of natural vegetation. Natural and cleared vegetation supported more benthic macroinvertebrate families compared to alien vegetation. Certain families that were lost to alien vegetation were recorded from natural vegetation. The highest SASS5 score was recorded from natural vegetation, followed by cleared vegetation, and the lowest was from alien vegetation. The highest number of adult Odonata was recorded at cleared vegetation, with alien and natural vegetation supporting the least number of Odonata species. Vegetation type, stream flow and microhabitats were statistically identified as the most influential variables for benthic macroinvertebrate assemblages. For adult Odonata assemblages, vegetation type, shade and temperature were the most important environmental variables. Species assemblages of adult Odonata can be used as indicators of environmental condition of rivers. The clearing of alien riparian vegetation clearly benefits the indigenous benthic macroinvertebrates as conditions are restored to their natural state. It also benefits dragonfly species richness, but if natural succession proceeds to a shaded tree canopy, the effect becomes similar to that of habitat shaded by alien vegetation. The impact of alien vegetation is to reduce sun-loving invertebrate species, especially dragonflies, with lesser impact on shade-loving species.
Ferner, Matthew C. "Environmental Modification of Chemosensory Interactions between Predators and Prey: The World According to Whelks". Diss., Connect to this title online, 2006. http://etd.gatech.edu/theses/available/etd-04102006-140436/.
Pełny tekst źródłaTitle from PDF t.p. (viewed on Oct. 28, 2006). Weissburg, Marc, Committee Chair ; Dusenbery, David, Committee Member ; Hay, Mark, Committee Member ; Webster, Donald, Committee Member ; Blanton, Jackson, Committee Member. Includes bibliographical references (p. 108-119).
Hutchison, Melissa Alice Sarah. "Interactions between habitat fragmentation and invasions: factors driving exotic plant invasions in native forest remnants, West Coast, New Zealand". Thesis, University of Canterbury. School of Biological Sciences, 2009. http://hdl.handle.net/10092/3218.
Pełny tekst źródłaLau, Jamie K. "Impacts of channelization on stream habitats and associated fish assemblages in east central Indiana". Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1319547.
Pełny tekst źródłaDepartment of Biology
Hugo, Christine Denise. "The influence of fire and plantation management on Wetlands on the Tsitsikamma plateau". Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1464.
Pełny tekst źródłaDixon, Katherine Marguerite, i n/a. "Biodiversity along a gradient of modification : plant invertebrates and reptile diversity in mid-altitude tall tussock (Chionochloa rigida) grasslands, eastern Central Otago, New Zealand". University of Otago. Department of Botany, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070130.154858.
Pełny tekst źródłaStoner, Elizabeth W. "Human-driven Benthic Jellyfish Blooms: Causes and Consequences for Coastal Marine Ecosystems". FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1516.
Pełny tekst źródłaShacks, Vincent. "Habitat vulnerability for the Nile crocodile (Crocodylus niloticus) in the Okavango Delta, Botswana". Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1651.
Pełny tekst źródłaMercado, Alida. "Ground beetle (Coleoptera:Carabidae) communities along a successional gradient in southwestern Quebec and notes on the range expansion of introduced species". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97966.
Pełny tekst źródłaGoodman, James R. "Artificial avian nest predation in a Kansas tallgrass prairie". Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1129624.
Pełny tekst źródłaDepartment of Natural Resources and Environmental Management
Neef, Götz-Georg. "Comparative phylogeography of five swallowtail butterfly species (Lepidoptera: Papilionidae) in South Africa : ecological and taxonomic implications". Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013574.
Pełny tekst źródłaKiskaddon, Erin Paige. "Feeding Patterns and Trophic Food Web Dynamics of Armases cinereum Across a Mangrove/Upland Ecotone". Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6525.
Pełny tekst źródłaMangachena, Joy Rumbidzai. "Response of bird assemblages to the invasion and clearing of alien trees in the Western Cape, South Africa". Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2583.
Pełny tekst źródłaInvasive alien plant species pose a major threat to global biodiversity by displacing native vegetation and transforming habitats. In South Africa, invasive alien plants have become a major component of most habitats. River systems are particularly affected owing to their dynamic nature and to anthropogenic activities. This has resulted in fynbos riparian scrub vegetation being replaced mainly by Acacia and Eucalyptus species, with serious ecological and economic impacts. The presence of alien trees along river banks leads to a reduction in native plant species richness and their high water consumption adds on to the existing water challenges in an already dry country. However, with regards to native fauna, it largely remains unknown both at small or large spatial scale, whether alien trees provide additional habitat which increases biodiversity, or if their presence leads to a reduction of native biodiversity. Impacts on water supply have led to large-scale clearing of invasive alien trees from riparian zones by the government through the Working for Water (WfW) programme. Monitoring and evaluation studies carried out after clearing are not well-rounded and mostly focus on vegetation response to clearing. Although some of these studies have reported successful restoration through passive methods, ecosystem recovery remains partial. There is evidently a lack of information regarding the response of animal communities to invasive alien plant clearing. Therefore, the main objective of this thesis was to investigate bird assemblage response to alien tree invasion and clearing. As a study system, I used the riparian area of the Berg River within the fynbos biome of the Cape Floristic Region, South Africa. The area historically consisted of renosterveld vegetation characterised by a matrix of shrubs and a high diversity of geophytes but relatively poor avifaunal diversity. This area is heavily affected by invasive alien trees and shrubs including Eucalyptus camaldulensis. I employed bird assemblages as an indicator, and used fixed-point bird counts to compare bird species richness and bird abundance between invaded and near-pristine habitats. Invasion by E. camaldulensis significantly reduced bird species richness and abundance. In particular, nectarivores and frugivores, which play important mutualistic roles in the fynbos, were reduced and unexpectedly; there were fewer raptors in invaded areas. I proceeded to carry out a space for time substitution, comparing plant and bird assemblages in invaded sites, near-pristine sites and in sites cleared in 2005, 2007, 2008 and 2014. A general increase in bird species richness and bird abundance with time since clearing exists with bird assemblages in cleared sites being similar to those in near-pristine sites. However, bird assemblages in cleared sites have not yet fully recovered a decade after clearing and four native plant species are still absent. In the third part of my thesis I assessed the impacts of invasive alien plants on bird assemblages at a larger spatial scale. The different responses shown by bird assemblages to invasive alien plant cover depended on the intensity of invasion, spatial scale and other land uses. From a bird’s eye view, this study supports the current clearing by WfW given the significant negative effects of invasive alien plants on bird diversity both at plot and large spatial scales. However, passive restoration is unsuccessful in restoring the full complement of plants and birds, therefore, active restoration should be considered. To limit the cost, I suggest a focused restoration approach of selected keystone tree species which can assist to establish a functional native ecosystem.
Stephenson, Thomas Robert. "Mule deer response to military activity in southeast Colorado". Thesis, This resource online, 1989. http://scholar.lib.vt.edu/theses/available/etd-07292009-090244/.
Pełny tekst źródłaTrani, Margaret Katherine. "Landscape pattern analysis related to forest wildlife resources". Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-06062008-144910/.
Pełny tekst źródłaCabrera-García, Leonardo. "Linking social and ecological dynamics for bird conservation : protecting the endangered Sierra Madre sparrow in Chichinautzin, Mexico". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102793.
Pełny tekst źródłaCommunity-based biodiversity conservation efforts have been recently recognized as an important option for safeguarding ecosystems while reducing land use conflicts arising from the material, cultural and spiritual needs of local inhabitants. Community involvement is particularly critical for conservation in anthropogenic habitats. Few studies have linked the ecological impacts of community land use practices with the auto-ecological requirements of dependent bird species. In this study I examine the conservation possibilities for the endangered Sierra Madre sparrow (Xenospiza baileyi) by considering three basic elements: the ecological requirements of the bird, the effects of traditional land use practices in shaping the habitat, and the economic and social conditions that influence current and future land use decisions. I draw on ecological field studies, on traditional ecological knowledge systems, and studies of the political ecological context that influences local practices.
The studies were carried out from 2000-2003 and employed a combination of ethnographic, participative and spatial-ecological approaches to address human-land interactions and their impacts on the sparrow habitat. Social data were obtained through nine workshops which included site visits, transect walks, participatory mapping, oral histories and semi-structured interviews. Ecological data were obtained from landscape ecology analysis, vegetation post-disturbance assessments and detailed bird's nest-site selection analysis.
Results indicate that local people, principally herders, hold a rich knowledge of fire use to achieve diverse purposes, including pasture renewal, grassland maintenance and grass species selection, and prevention of dangerous fires. In order to accomplish their goals, herders have established rotational fire and grazing regimes that consider timing, frequency, location and extent of these disturbance-based practices. This rotational system was found to benefit the Sierra Madre sparrow by maintaining the grassland at the scales needed by the sparrow for nesting. Multiscale habitat recommendations for the species' conservation were derived from this socio-ecological interaction and dynamics.
Unfortunately, external conservation perspectives and interests and internal land tenure conflicts have altered this rotational regime and local perspectives on resource management that threaten the resilience of this social-ecological system. Consequently, traditional ecological knowledge on grassland management can be on risk of disappearing and, with it, important native grasses and grasslands are being made vulnerable. The survival of the Sierra Madre sparrow in particular and of associated biodiversity in general, is in peril if these conflicts are not solved in a relatively short time. A community-based fire co-management program is recommended to promote integrative bird conservation-local development scenarios.
Holgate, Katheryn T., i University of Lethbridge Faculty of Arts and Science. "The effects of cattle grazing on the breeding biology of riparian forest birds". Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1999, 1999. http://hdl.handle.net/10133/349.
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Sharratt, Norma. "Response of aquatic macroinvertebrate and aerial odonate assemblages to the removal of invasive alien trees in the Western Cape". Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50440.
Pełny tekst źródłaENGLISH ABSTRACT: Invasive alien trees, especially Acacia species, are a great threat to biodiversity in South African rivers. The national Working for Water Programme is addressing the alien problem by removing alien trees from river margins. The concern is that this may be creating even further disturbance by affecting water quality and habitats. In particular, how is this affecting rare and endemic species? Benthic macro invertebrates and aerial odonates were assessed along five Western Cape rivers in alien-invaded, cleared and natural sites between December and March. The aim was to assess the effect of both alien invasion and alien clearing on aquatic invertebrates. Odonata, being easily sampled, were also assessed as they are severely affected by the lack of understorey plants in shaded, alien-invaded sites. Odonata and benthic macroinvertebrates were treated as two separate studies and no attempt was made to correlate the results obtained from both studies. SASS5, a qualitative, rapid bioassessment technique, based on the sensitivity of the families present, was used as a measure of river health and, indirectly, of water quality. SASS indicated a decline in water quality conditions after alien clearing, a likely response to the greater insolation as well as erosion of cleared banks, resulting in elevated temperatures and suspended solids and lowered oxygen levels. Community responses to alien disturbance and other environmental factors were analysed using PRIMER and CANOCO software. Assemblages of Odonata were found to provide a rapid, cost-effective means of assessment and monitoring. Potential indicator and detector species were also identified using the lndicator Value method. Assemblage patterns of aquatic invertebrates, however, were dominated by between-river and seasonal effects. Therefore, while SASS detected overall changes in river health, without identifying the cause, potential aquatic detector taxa were identified that may be useful for linking general disturbance to alien invasion or clearing. All indicator and detector taxa identified in both studies can be used for long-term monitoring and for identifying biodiverse areas for clearing or protection. In both studies, sensitive, endemic taxa were lost after clearing, being replaced by more tolerant, widespread taxa. Recovery of the biota appears to follow the recovery succession of the vegetation, with most sensitive or endemic taxa only appearing after the recovery of indigenous plants. A number of recommendations are made regarding the restoration of both water quality (particularly with respect to shade and soil erosion) and biotope availability (particularly in terms of the recultivation of indigenous plants) in order to achieve biodiversity objectives. The role of catchment management, prioritisation procedures and long-term monitoring are also discussed.
AFRIKAANSE OPSOMMING: Uitheemse, indringerbome, veral Acacia spesies, is 'n groot bedreiging vir biodiversiteit in Suid- Afrikaanse riviere. Die nasionale Werk vir Water-projek spreek hierdie probleem aan deur uitheemse bome van rivieroewers te verwyder. Die kommer is dat water kwaliteit en habitatte sodoende verder versteur kan word. Byvoorbeeld, hoe word endemiese en bedreigde spesies geraak? Akwatiese makroinvertebrate en volwasse Odonata in vyf Wes-Kaapse riviere is tussen Desember en Maart bestudeer en gemonster in natuurlike gebiede, in gebiede waar indringerbome teenwoordig is, en in gebiede waar hulle verwyder is. Die doel was om die effek van indringerverwante impakte op akwatiese invertebrate vas te stel. Odonata is ook bestudeer omdat hulle maklik gemonster kan word en omdat hulle ernstig geraak word deur indringers. Die uitheemse plantegroei oorskadu die oewers en verhoed die groei van inheemse oewerplante. Die bentiese makro-invertebrate en Odonata is as twee aparte studies behandel en geen poging is gemaak om die resultate van die twee te vergelyk nie. SASSS, 'n kwalitatiewe, bioasseseringsmetode wat op die sensitiwiteit van die aanwesige families baseer word, is gebruik om waterkwaliteit op 'n indirekte manier te bepaal. SASS het aangedui dat daar 'n afname in waterkwaliteit is nadat indringerplante verwyder is. Dit is moontlik as 'n gevolg van groter blootstelling aan sonskyn en erosie van rivieroewers wat veroorsaak dat temperature en die hoeveelheid gesuspendeerde materiaal verhoog word, en dat suurstof konsentrasies verminder word. Die gevolge van indringerplante en ander omgewingsfaktore op akwatiese gemeenskappe is met PRlMER en CANOCO sagteware ontleed. Groepering van Odonata kan gebruik word om op 'n maklike en koste-effektiewe manier om die impak van indringerplante en hul verwydering te bepaal en te monitor. Aanwyserspesies is ook deur middel van die 'Indicator Value' metode geïdentifiseer. Die verspreidingspatrone van invertebraatspesies word deur geografiese en seisoenale effekte oorheers. Dus, terwyl SASS veranderinge in waterkwaliteit kan aantoon, sonder om die oorsaak daarvan te identifiseer, kan aanwyserspesies gebruik word om meer spesifieke impakte deur indringerplantegroei, of indringerverwydering, te bepaal en te monitor. Hulle kan ook gebruik word om gebiede met hoë biodiversiteit vir bewaring of indringerverwydering te identifiseer. Beide studies dui aan dat sensitiewe en endemiese taksa na indringerverwydering verlore gaan, en vervang word met meer geharde, wydverspreide taksa. Herstel van die biota volg op die herstel van die plant gemeenskappe, en die mees sensitiewe of endemiese taksa herstel eers nadat die inheemse plantegroei herstel het. 'n Aantal aanbevelings in verband met die restorasie van waterkwaliteit (veral in terme van die hoeveelheid skaduwee en erosie) en die beskikbaarheid van biotope (veral in terme van inheemse plante) om biodiversiteitsdoelwitte te bereik word gemaak. Die rol van opvanggebied bestuur, voorrang prosedures en lang termyn monitering word ook bespreek.
Hausmann, Franziska. "The Utility of Linear Riparian Rainforest for Vertebrates on the Atherton and Evelyn Tablelands, North Queensland". Thesis, Griffith University, 2004. http://hdl.handle.net/10072/365964.
Pełny tekst źródłaThesis (Masters)
Master of Philosophy (MPhil)
Australian School of Environmental Studies
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