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Lopes, Thais Sasso. "Padrões espaciais e temporais de ocorrência de anuros em riachos de Mata Atlântica e sua detecção por meio de DNA ambiental." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-20102016-142913/.
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O Brasil apresenta uma das maiores diversidade de espécies de anfíbios, sendo reconhecidas em torno de 500 espécies endêmicas no país, as quais são encontradas predominantemente em área de Mata Atlântica. O monitoramento da herpetofauna e conhecimento da dinâmica espacial e temporal destas espécies são informações básicas, porém, fundamentais ao desenvolvimento de outras áreas de pesquisa e conservação. Neste trabalho reunimos informações sobre ocorrência e abundância de três espécies típicas de riacho, Cycloramphus boraceiensis, Hylodes asper e Hylodes phyllodes e testamos o uso de DNA ambiental para detecção de comunidades de anuros. As amostragens ocorreram em um transecto de 100 a 115 m em quatro riachos no Núcleo de Picinguaba, localizado no Parque Estadual da Serra do Mar, São Paulo, Brasil. Coletas de abundância e uso do habitat ocorreram mensalmente de janeiro de 2007 a dezembro de 2010 e em meses alternados em 2011. Indivíduos pós-metamórficos foram amostrados por procura visual a montante de cada riacho, verificando-se todos os locais ao longo do leito. A localidade de cada indivíduo ativo e inativo foi mapeada e o uso do ambiente foi caracterizado em relação a seis parâmetros ecológicos. As amostras de DNA ambiental foram coletadas em 16 pontos em Abril de 2015. eDNA metabarcoding foi realizado com primer universal de anfíbios para uma região do gene mitocondrial (12S). Registramos um total de 6335 observações visuais. A abundância das três espécies variou entre e ao longo dos riachos, sendo que apenas a espécie Hylodes phyllodes foi registrada no riacho 2. Houve uma sazonalidade na abundância de Cycloramphus boraceiensis e Hylodes asper, sendo ambas espécies encontradas em maior número na estação chuvosa. As três espécies foram encontradas ativas majoritariamente em rochas úmidas ou molhadas, sem musgo e sem cobertura. Indivíduos inativos de Hylodes asper e H. Phyllodes foram encontrados majoritariamente em folhas secas sem musgo e sem cobertura. Por meio da técnica de eDNA metabarcoding, detectamos nove espécies, compatíveis com a amostragem tradicional. O DNA de espécies com fases do ciclo de vida atreladas aos riachos e com maior constância na amostragem tradicional foi detectado em maior proporção. Nossos estudos demonstraram que os resultados da amostragem tradicional e de eDNA metabarcoding fornecem informações fundamentais e complementares, sendo uma combinação de ambas metodologias potencialmente útil a futuros estudos de ecologiaBrazil ranks as the country with one of the highest amphibian species diversity. Streams in the Atlantic forest of southeastern Brazil have an important availability of microenvironments and harbors a particular richness in amphibian species. Monitoring herpetofauna and knowledge on their spatial and temporal dynamics provide primary information for ecological studies, and are essential to the development of other areas such as conservation biology. In this work we gather information on the occurrence and abundance of three torrent frogs, Cycloramphus boraceiensis, Hylodes asper and Hylodes phyllodes and examine the reliability of eDNA analysis to detect anuran communities. Samplings occurred within a 95 to 115 m transect in four streams in Núcleo Picinguaba, at the Parque Estadual da Serra do Mar, São Paulo, Brazil. Individual encounter number and their habitat were monthly recorded from January 2007 to December 2010 and every two months in 2011. We searched for post-metamorphic individuals while walking upstream for 30-60 min, checking all visually accessible spots in the streambed. The location of each active and inactive individual was mapped and its habitat use was characterized in relation to five ecological parameters. We collected eDNA samples at 16 sites on April, 2015. We used eDNA metabarcoding approach with a universal amphibian primer of a mitochondrial marker (12S) to detect amphibian communities. We recorded a total of 6335 visual observations. The three species abundance varied along and between streams and only Hylodes phyllodes were found in the stream 2. Abundance of C. boraceiensis and H. asper was significantly higher in the wet seasons. The three species were found active mainly in wet rocks, without moss and without cover. Inactive individuals of Hylodes asper and H. phyllodes were found mainly in dry leaves, without moss or cover. Through eDNA metabarcoding, we detected nine species, which were consistent with traditional survey results. DNA of riparian species and species with higher constancy in traditional surveys were detected in higher proportions. Our study showed that traditional survey and DNA metabarcoding results can be complementary and both methodologies can be combined in future ecology studies
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Garland, Lincoln. "Microhabitat ecology of small mammals on grassy road verges." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251021.
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Turvey, Shannon Lee. "The role of microhabitat associations in producing cross-taxa congruence." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/32496.
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Ecological interactions between taxa and environmental factors influencing the distribution of
multiple taxa are both thought to generate spatial concordance, or congruence, in diversity.
Observational studies have generally failed to find evidence for strong cross-taxa congruence
across sites, and examples of experimental studies testing for congruence as a result of an
underlying ecological mechanism are largely lacking. Here I present the results of an
experimental study employing downed wood additions in a BACI design to test for an
association of small mammals, carabid beetles, plants and amphibians with volume of downed
wood as a possible mechanism for congruence. In addition, I tested for congruence in species
richness and community similarity across these four groups. After one field season, there was
no significant effect of treatment on within-group abundance, species richness or diversity.
Species richness was not significantly correlated across taxa for any taxa pair. Small mammals,
carabids and plants showed weak but significant congruence in community similarity, while the
amphibian assemblage was not congruent with any other taxon. These results suggest that use
of downed wood by these four groups does not generate congruence in diversity at fine scales,
and that other ecological processes and sources of environmental variation may be more
important in generating congruence in assemblage similarity. Furthermore, the potential of one
taxon to act as an indicator of species-level diversity within another taxon may be limited.Forestry, Faculty of
Graduate
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Zimmerman, Brian J. "Microhabitat Use by the Redside Dace (Clinostomus Elongatus) in Ohio." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1250772332.
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Homan, Cassandra M. "Bottlenecks and Microhabitat Preference in Invasive Wall Lizard, Podarcis muralis." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1377868885.
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Mabray, Scott T. "Microhabitat Selection by Greater Sage-Grouse Hens in Southern Wyoming." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4160.
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Greater sage-grouse (Centrocercus urophasianus) populations have declined throughout the western United States over the past 3 decades. Habitat loss within the sagebrush steppe ecosystem is a major factor leading to sage-grouse population decline. Hen sage-grouse were captured, marked, and tracked during the summer of 2012 in southwestern and south-central Wyoming. I performed vegetation surveys, and avian point counts were performed at 1 early-season brood location, 1 late-season brood location, and an accompanying random location for each marked hen regardless of reproductive status. Multinomial models were run to determine what habitat variables were most informative in predicting site selection by hen sage-grouse. During early-brood season, hen sage-grouse with chicks selected sites that had high total shrub cover density; these areas also exhibited high densities of American kestrels (Falco sparverius). They did not avoid areas with common ravens (Corvus corax). Hen sage-grouse not accompanied by a brood selected sites with high total shrub cover and low densities of common ravens and American kestrels. During late-brood season, hen sage-grouse that
were accompanied by a brood selected sites with high shrub cover and low densities of small avian predators, such as black-billed magpies (Pica hudsonia) and American kestrels as well as medium-sized predators, such as common ravens, buteo hawks (Buteo spp.), and northern harriers (Circus cyaneus). Hens that were not accompanied by broods were more often found in sites with high total shrub cover and low densities of small avian predators, but selected sites with higher densities of medium-sized predators. Hen sage-grouse select areas with high total shrub cover during early and late-brood season regardless of their reproductive status. By avoiding predators and selecting areas with cover, hens with broods can reduce the risk of their chicks being depredated.
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Anderson, Jason J. "Microhabitat Use by the Meadow Vole, Microtus Pennsylvanicus (Ord), on a Reclaimed Grassland." Youngstown State University / OhioLINK, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=ysu999188325.
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Hubert, Jay Bradley. "INTERSPECIFIC COMPETITION AND MICROHABITAT SELECTION IN THE GOLDEN MOUSE (OCHROTOMYS NUTTALLI)." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/668.
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The golden mouse (Ochrotomys nuttalli), a state-threatened species in Illinois, is sympatric throughout most of its geographic range with the ubiquitous white-footed mouse (Peromyscus leucopus). The degree of interspecific competitive interaction between these species has been investigated by previous researchers, with often conflicting results. I live trapped and marked both species on two grids from 21 May 2008 through 8 May 2009. One grid was the control area; from the second grid I removed white-footed mice. Habitat on the grids was very similar for six measured habitat variables. My objectives were to document the extent of competition between the two species as indicated by a population density or behavioral response of golden mice to removal of white-footed mice on the experimental grid, and to determine if white-footed mouse presence or habitat variables affected the capture of golden mice. During 6,528 trap nights per grid, I captured a total of 22 individual O. nuttalli and 66 P. leucopus on the control grid, and 48 O. nuttalli and 202 P. leucopus on the removal grid. Compared to previous studies (Rose, 2008), the number of individual golden mice captured on my two sites (n = 70) was very large. Whereas I expected an increase in numbers and space use of golden mice upon removal of Peromyscus, the only statistically significant change was an apparent decrease in space use--there was no population density change. These results, which may indicate a lack of interspecific competition, are more likely the result of experimental design flaws, especially considering the following results. The likelihood of trapping a golden mouse at any given station on the control site was unaffected by any of the six habitat variables. White-footed mouse presence significantly decreased the likelihood of capturing golden mice on both sites. These results were the same for both elevated and ground traps. On the experimental site, golden mice changed from predominantly arboreal space use before Peromyscus removal to equal space use between arboreal and ground habitat after Peromyscusremoval. These results illustrate a spatially segregated habitat with competitively superior white-footed mice dominating the ground level microhabitat and golden mice staying predominantly in elevated microhabitat. My study, and others, demonstrate that golden mice in southern Illinois are likely habitat generalists (Morzillo et al., 2003), competitively inferior to Peromyscus(Feldhamer and Maycroft, 1992), and excluded from certain microhabitat; although it may be they actually prefer different microhabitats.
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Sailer, Gabriele. "The roles of local disturbance history and microhabitat parameters for stream biota." Diss., [S.l.] : [s.n.], 2005. http://edoc.ub.uni-muenchen.de/archive/00004500.
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Dennis, Paul Gareth. "How do rhizosphere bacteria interact with their environment at the microhabitat scale?" Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1444697/.
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The rhizosphere supports greater bacterial densities than root-free soil. Rhizosphere bacteria (RB) can affect plant health and nutrition however, attempts to manipulate introduced and/or indigenous communities to benefit plants are unreliable. Current evidence indicates that habitat factors strongly influence bacterial communities. In the rhizosphere many processes give rise to a high degree of habitat heterogeneity therefore, to understand how RB interact with their environment their ecology should be studied at the micro-spatial-scale. The objectives of this research were to develop a method for sampling RB at the microhabitat-scale, and to investigate techniques that can link these samples with key factors, such as substrate availability and pH. A novel method enabling non-destructive, micro-scale sampling of bacteria was developed. Its efficiency for removing bacteria from the root surface was similar to that of existing methods but offered greater accuracy in estimating RB densities. The novel method revealed that RB density was inversely proportional to distance from the apex of Brassica napus roots and that the composition of RB communities was highly variable at the micro-scale. Imaging of 14C-labelled root exudates revealed that RB density was not reflective of exudate availability but attempts to link RB with available C were unsuccessful. A key outcome of this work was the development of a strategy to combine micro sampling with microelectrode measurements. Microelectrodes revealed that pH at the root surface was highly variable at the micro-scale which, combined with similar observations for RB density/diversity, highlights the appropriateness of this scale for linking RB communities with their environment. This thesis considers the link between RB community structure, habitat and function and provides a detailed description of micro-sample analyses as well as a set of methods that will enable for the first time, the interactions between any surface-associated bacteria and their environment to be investigated at a microhabitat-scale.
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Farallo, Vincent R. "Notes from the Underground: Linking Microhabitat and Species Distributions of Plethodontid Salamanders." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou148156741016879.
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Moen, Daniel S., and John J. Wiens. "Microhabitat and Climatic Niche Change Explain Patterns of Diversification among Frog Families." UNIV CHICAGO PRESS, 2017. http://hdl.handle.net/10150/624675.
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A major goal of ecology and evolutionary biology is to explain patterns of species richness among clades. Differences in rates of net diversification (speciation minus extinction over time) may often explain these patterns, but the factors that drive variation in diversification rates remain uncertain. Three important candidates are climatic niche position (e.g., whether clades are primarily temperate or tropical), rates of climatic niche change among species within clades, and microhabitat (e.g., aquatic, terrestrial, arboreal). The first two factors have been tested separately in several studies, but the relative importance of all three is largely unknown. Here we explore the correlates of diversification among families of frogs, which collectively represent approximate to 88% of amphibian species. We assemble and analyze data on phylogeny, climate, and microhabitat for thousands of species. We find that the best-fitting phylogenetic multiple regression model includes all three types of variables: microhabitat, rates of climatic niche change, and climatic niche position. This model explains 67% of the variation in diversification rates among frog families, with arboreal microhabitat explaining approximate to 31%, niche rates approximate to 25%, and climatic niche position approximate to 11%. Surprisingly, we show that microhabitat can have a much stronger influence on diversification than climatic niche position or rates of climatic niche change.
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Lawson, Callum Robert. "From microhabitat to metapopulations : a model system for conservation under climate change." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/9557.
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Gomez, Patricia A. "Microhabitat preference of the introduced gecko Hemidactylus turcicus in an urban environment." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001213.
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Schwenke, Andrew C. "Riparian vegetation condition influences movement and microhabitat use by Mixophyes fasciolatus in South East Queensland." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/102339/4/Andrew_Schwenke_Thesis.pdf.
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Riparian vegetation has been impacted by urbanisation in many parts of Australia, resulting in population declines of numerous species of stream-associated frogs. This study was the first to investigate movement and microhabitat use of the stream-associated frog, Mixophyes fasciolatus, in sites that differed in the ecological condition of riparian vegetation in south-east Queensland. Twenty-nine frogs were tracked over a 48-hour period and their fine-scale movements and microhabitat use were examined and found to be related to riparian vegetation condition. These results have significant implications for the conservation management of this species.
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Jeske, Jan Torsten. "Microbial adaptations and controlling mechanisms of surface-associated microhabitat heterogeneity in aquatic systems." Doctoral thesis, Uppsala universitet, Limnologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-263206.
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Habitat heterogeneity is a driving factor for speciation and ecosystem functioning and is well studied in macro-ecology. Yet our understanding of microbial adaptations, and governing processes is incomplete. The here presented thesis aims at giving us a better understanding of patterns in micro-heterogeneity, and microbial adaptations to such heterogeneity with particular focus on surface-dominated, aquatic habitats. The most prominent microbial adaptation to surface associated mode of life is biofilm formation. Biofilms rely heavily on type IV pili. These pili systems are well studied in Bacteria, but largely unknown in Archaea. Therefore, the first part of this thesis focuses on resolving genetic and structural feature of the type IV like aap-pilus of the thermo-acidophilic Sulfolobus acidocaldarius. We found the aap-pilus to be indispensible for biofilm formation, and to be unparalleled in variability of its quaternary structure and cross regulation with other filaments. The second part of this thesis investigates particle colonization in the water column, focusing on diatoms as a model system, allowing an in situ assessment of different stages of particle colonization, and potential particle-specificity of the associated bacterial community. Opposing reports from marine systems, we did not observe diatom-specificity in the associated bacterial community. Instead we found bacterial community subsets, one likely originating from sediment resuspension, and the other being controlled by biofilm-forming populations (e.g. Flexibacter), able to attach to newly formed particle surfaces and subsequently facilitate secondary colonization by other bacteria. Finally, the habitat heterogeneity in top-layers of lake sediments were investigated in experimental microcosms. Cell-specific oxygen consumption rates were determined, to assess microbial activity across different scales. Individual activity rates differed strongly across all investigated scales, likely due to spatially heterogeneous distribution of nutrients with differing quality. Vice versa, the influence of microbial activity on micro-habitat-heterogeneity was investigated. We correlated sediment redox-state with bacterial community composition and populations. Our results indicate that habitat heterogeneity is generally beneficial for microorganism, and greater heterogeneity results in greater bacterial diversity. However, this heterogeneity-diversity relationship is limited and microorganisms actively stabilize their immediate redox environment to a preferred, community-specific, stable state, if cell abundances exceed a minimum threshold.
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Jarvis, Laurence Edward. "Microhabitat requirements of the great crested newt (Triturus cristatus) in a woodland area." Thesis, Open University, 2012. http://oro.open.ac.uk/54828/.
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The great crested newt Triturus cristatus is one of Europe's fastest declining amphibian species. This thesis aimed to increase our knowledge of the microhabitat use and ecology of great crested newts within a woodland area in the British Isles and suggest ways of improving measures for conservation. The study was conducted at Epping Forest Field Centre and surrounding deciduous woodland at High Beach, Epping Forest, which is situated to the north-east of London. Capture-mark-recapture of adults in four ponds over 5 years within a 1 km area revealed that great crested newts exhibited large fluctuations in detection probabilities, highlighting the importance of calculating detection before making inferences of population size or survival. Apparent annual survival was constant between ponds and years; male survival was 0.40 compared to 0.58 in females. Only 11 inter-pond movements were recorded. Many terrestrial juveniles occupied cover objects close to breeding ponds for many months of each year. Growth rates were fastest in smallest individuals (35.to 39 mm SVL) and juvenile body condition varied through each year. Juveniles had high monthly survival (0.56 to 0.77) and a low constant apparent annual survival of 0.19. Adult males exhibited lowest body condition index (BCI) in March and June while females had high BCI in March and lowest in April. Larger males with a higher body condition were more likely to possess taller crests. Experiments showed increased mortality in great crested newt embryos when raised in the presence of caged predatory sticklebacks compared to controls. Great crested newt larvae utilised vegetated microhabitats for a significantly greater proportion of the time when in the presence of caged predatory sticklebacks but not when faced with non-predatory crucian carp. Finally, great crested newt females exhibited a non-random distribution in egg laying. Individuals preferred to lay eggs on clean compared to occupied strips. These findings are discussed in relation to improving our understanding of great crested newt ecology and conservation.
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Wiley, Mark Joseph. "Usable Space and Microhabitat Characteristics for Bobwhites on Private Lands in Southwestern Ohio." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345548162.
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De, Angelo Jacquelyn Alexis. "Mangrove Shoreline Fish Assemblages of Oleta River State Park: Baseline Conditions in an Urban System." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/75.
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Oleta River State Park (ORSP), located in North Miami-Dade County is known as the most highly urbanized State Park in all of Florida. The present study was conducted as part of an ongoing seasonally-resolved survey of fish utilization of the mangrove shorelines of Biscayne Bay. Previous Unit Management Plans published by the Division of Recreation and Parks have lacked information concerning the park?s prominent mangrove forests along with its icthyofauna. The main purpose of this thesis was to provide a baseline characterization of the mangrove-fish assemblages and microhabitat trends of ORSP, against which future changes in and around the Park can be gauged. Fish assemblages inhabiting the mangrove shorelines were examined using a visual ?belt-transect? census method over 11 consecutive seasons. Microhabitat variables including salinity, water temperature, water depth, water clarity and distance from Baker?s Haulover Inlet were examined for possible correlations with fish metrics. Several significant differences were evident in the taxonomic richness (number of taxa per unit area) and densities of the five most abundant taxa within the shoreline habitats in terms of seasonal variation and microhabitat variable distribution along the river. Taxonomic richness was typically greater in survey sites located closer to Baker?s Haulover Inlet. Oleta River?s mangrove shoreline fish assemblages appear to reflect (1) proximity of the mangroves that they occupy to Baker?s Haulover Inlet; (2) temperature regime along the shoreline; and (3) the salinity gradient found within the river. Fish assemblage and microhabitat information collected here could serve as a ?baseline? in future investigations of the effects of further urbanization or the effects of other anthropogenic changes to Oleta River and its mangrove habitat, including possible changes to freshwater flow associated with the Comprehensive Everglades Restoration Plan.
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Firmino, da Silva Clebson. "Mixobiota de floresta atlântica: espécies ocorrentes em Elaeis Guineensis Jacq. (Arecaceae)." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/1995.
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Previous issue date: 2006Realizou-se um estudo sobre as espécies de Myxomycetes que ocorrem em Elaeis guineensis Jacq. (dendezeiro), visando contribuir para o conhecimento sobre os representantes deste grupo que estão associados com palmeiras no Brasil. A incidência, abundância, diversidade taxonômica (espécie/gênero) dos esporocarpos em estipes, folhas, brácteas, inflorescências e frutos (vivos ou mortos) de dendezeiros foi analisada em 20 indivíduos presentes em três fragmentos de Floresta Atlântica da Reserva Ecológica do Gurjaú, Cabo de Santo Agostinho, Pernambuco (08º10 00 e 08º15 00 S; 35º02 30 e 35º05 00 WGr.). Calculou-se a abundância relacionando-se o número de espécimes do táxon e o total de espécimes obtidos, e enquadrou-se cada espécie como rara (0,5-1%), ocasional (2-4%), comum (5-7%) ou abundante (superior a 7%). Exsicatas foram depositadas no Herbário UFP. As espécies foram listadas em ordem alfabética por subclasse. Apresenta-se a distribuição conhecida para o Brasil para cada espécie e os registros para palmeiras neste país. O dendezeiro mostrou ser um excelente substrato para o desenvolvimento de mixomicetos. Todas as subclasses, cinco das seis ordens e 50% das famílias reconhecidas para este grupo foram registradas. Com este estudo, 22 espécies foram acrescentadas à lista de mixomicetos associados com dendezeiro no Brasil; destas, Ceratiomyxa sphaerosperma, Didymium anellus e Physarum gyrosum não haviam sido referidas como ocorrendo em palmeiras neste país. Nos ambientes estudados, as Physaraceae são as mais freqüentes, seguidas pelas Trichiaceae. Hemitrichia serpula, Arcyria cinerea e Physarum compressum são espécies comumente encontradas em E. guineensis, confirmando sua preferência em se associar com palmeiras. Conclui-se que a mixobiota do dendezeiro é diversificada, ocorrendo à esporulação preferencialmente em órgãos mortos
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Machado, Renata Figueira. "USO DO HABITAT POR PEQUENOS MAMÍFEROS EM UM MOSAICO DE FLORESTA - CAMPO NO EXTREMO SUL DA FLORESTA ATLÂNTICA." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/5319.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe macro and microhabitat use by small-mammal was investigated in an Atlantic Forest- Pampa mosaic. A grid with 88 traps was used, being 27 installed in the understory every two traps placed on the ground, which were 70 m apart of each other. The fieldwork was carried out in 17 monthly phases, during five days, from June 2011 to October 2012, totalizing a sampling effort of 7480 trap-nights. An analysis of variance was used to verify differences in richness, total abundance and abundance of each species among grassland, edges and forest. The same analysis was performed to test if the body mass of each species differs between the vegetation types. Eleven environmental variables measured were summarized through a principal component analysis (PCA). Subsequently, a multiple linear regression analysis was performed between richness and total abundance of each species and the first two axes of PCA. The environmental variables were also correlated to the abundance of small mammal through an analysis of redundancy (RDA). Analysis of variance showed no difference in total abundance and richness for any vegetation types. However, abundance of Oligoryzomys nigripes differed significantly (Q = 1.88, P = 0.0009), being higher in grassland. Considering body mass, there was a significant difference for Akodon montensis (Q = 1824, P = 0.046) and O. nigripes (Q = 1262.1, P = 0.001). The first axis of the PCA, were associated Didelphis albiventris and O. nigripes (r = 0.06, P = 0.022, r = 006, P = 0.018, respectively), and related to variables that characterize forest environments (higher density of woody vegetation). Analysis of variance showed that environmental complexity is not the main factor influencing the richness and abundance of species in the studied area, but there were differences in the pattern of individual distribution according to age, since adults selected best environments than young. The PCA and RDA showed significant effect of microhabitat variables on species occurrence. The presence of A. montesis was influenced by zoochorous dispersion and number of epiphytes, while D. albiventris and O. nigripes were related to forested environments, with greater trees abundance, DAP and litter. The last ones were also correlated with open environments, being D. albiventris related to ferns and distance of water and O. nigripes related to grasses.
A distribuição macro e micro-espacial de pequenos mamíferos não-voadores em uma área de mosaico entre Floresta Atlântica e Pampa foi investigada. Foi utilizada uma grade com 88 armadilhas, 27 foram instaladas no sub-bosque a cada duas armadilhas instaladas no solo, as quais distavam 70 m uma da outra. Foram realizadas 17 fases mensais de campo, durante cinco dias, de junho de 2011 a outubro de 2012, totalizando um esforço amostral de 7480 armadilhas-noite. Uma análise de variância (ANOVA) foi utilizada para verificar se existem diferenças na riqueza, abundância total e abundância de cada espécie entre as fitofisionomias de campo, borda e interior de floresta. Também foi testada a existência de diferenças na massa corporal dos indivíduos para cada espécie, entre essas fitofisionomias. Onze variáveis ambientais mensuradas foram resumidas através de uma análise de componentes principais (PCA). Posteriormente, foi realizada uma análise de regressão linear múltipla entre a riqueza e a abundância total e de cada espécie e os dois primeiros eixos do PCA. As variáveis ambientais brutas foram relacionadas com a abundância de mamíferos por meio de uma análise de redundância (RDA). A análise de variância não mostrou diferença na riqueza e abundância total das espécies para nenhuma das fitofisionomias. Oligoryzomys nigripes foi mais abundante na fitofisionomia de campo (Q = 1,88, P = 0,0009). Quanto à massa corporal, houve diferença significativa para Akodon montensis (Q = 1824, P = 0,046) e O. nigripes (Q = 1262,1, P = 0,001). O primeiro eixo da PCA, associado com Didelphis albiventris e O. nigripes estiveram associadas (r = 0,06; P = 0,022; r = 006; P = 0,018, respectivamente), foi relacionado às variáveis que caracterizam ambientes florestais. A análise de variância mostrou que a complexidade ambiental não é o principal fator que influencia a riqueza e a abundância das espécies na área estuda, porém houve diferenças no padrão de distribuição dos indivíduos conforme a idade, com indivíduos adultos selecionando ambientes distintos dos jovens. A RDA mostrou que a abundância de A. montesis foi influenciada pela dispersão zoocórica e número de epífitas, já D. albiventris e O. nigripes foram relacionados a ambientes florestados, com maior número de árvores, DAP e folhiço. Esses últimos foram correlacionados também a ambientes campestres, com D. albiventris se relacionando a locais com presença de samambaias e distantes da água e O. nigripes a ambientes com alta abundância de gramíneas.
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Mikaelyan, Aram [Verfasser], and Andreas [Akademischer Betreuer] Brune. "Microhabitat-specificity of the hindgut microbiota in higher termites / Aram Mikaelyan. Betreuer: Andreas Brune." Marburg : Philipps-Universität Marburg, 2014. http://d-nb.info/1052995004/34.
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Bates, Colin Robert. "Macroalgae as microhabitat : seaweed traits and wave action as predictors of invertebrate epifaunal diversity." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31214.
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In many coastal environments, anthropogenic stressors yield changes in seaweed biodiversity. Here, I describe three studies addressing how such floristic changes might affect provision of habitat by seaweeds for small mobile invertebrate epifauna. In chapter 2, I used observational and manipulative (transplant) experiments to test how changes in seaweed biodiversity influenced biodiversity of associated invertebrates. I found that invertebrate epifaunal richness and abundance were not affected by changes in seaweed biodiversity. Invertebrate assemblage structure was, in most cases, not influenced by changes in seaweed composition; only when algal assemblages were composed of monocultures of species with 'foliose' morphologies did I observe a change in invertebrate assemblage structure. Correlations between algal functional composition and invertebrate assemblage structure were observed, but not between algal species composition and invertebrate assemblage structure. These results suggest that changes in seaweed biodiversity will have implications for invertebrate epifauna only under specific scenarios of algal change. In Chapter 3, I tested the performance of host taxonomic relatedness and functional (i.e. morphological) group affiliation as predictors of associated invertebrate epifauna. Neither general framework performed well; invertebrate assemblages found on congeneric host species were as similar as those found on hosts classified in different kingdoms, and taxon richness and abundance of invertebrates varied substantially within seaweed functional groups. Species identity was identified as a key predictor of the performance of seaweeds as hosts for invertebrate epifauna. In chapter 4, I examined the context dependence of these host identity effects by testing how host morphological complexity and maximum wave velocity interacted to determine local invertebrate diversity. Three types of host species were identified: (a) morphologically `simple' thalli that were minimally utilized as habitat under any of the tested wave regimes, (b) thalli that were coarsely branched and were utilized by invertebrates under relatively benign wave conditions but became less utilized under higher wave action, and (c) 'complex' algal hosts that supported diverse invertebrate assemblages under all tested wave conditions. Together, these studies support the view that invertebrates that use seaweeds as habitat are host-generalists, and therefore consequences for invertebrates of changes in seaweed biodiversity are likely to be minimal.Science, Faculty of
Botany, Department of
Graduate
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Villeneuve, Valérie. "Algues benthiques du haut Arctique canadien, microhabitat et évaluation des facteurs de contrôle chimiques." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/MQ53987.pdf.
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Boyce, Sean. "Microhabitat selection and characterization of the Woolly Beech Scale, «Cryptococcus fagisuga», in Southern Quebec." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40686.
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Beech bark disease is a widespread and fatal disease of the American beech, (Fagus grandifolia Ehrh.), initiated by an infestation by the woolly beech scale insect, (Cryptococcus fagisuga Lind.). This infestation is characterized by spatial patterns in the number of beech scale colonies within trees by both aspect and height. I studied these patterns by monitoring differences in microhabitat quality within trees over four months (June-September) at two forests in Montreal, Canada. Spatial patterns in bark temperature, bark resistance to puncture, moisture content, and roughness were compared to patterns in beech scale colonization as determined by colony counts at the start and end of the study. Additionally, stemflow collars were attached to some trees to experimentally determine the effect of stemflow on beech scale colonization patterns. Beech scale colonies were found to be significantly more numerous on the north side of trees, as well as higher up (2.5-2.8 m aboveground) the bole of trees. Seasonal bark temperature was 0.5oC higher at 2.5 m aboveground. Seasonal bark moisture content was significantly higher further up the bole of trees by an average of 3%. The north aspects of tree boles were found to be significantly more resistant to puncture. Diverting stemflow moisture away from the north aspect of trees did not change the bark moisture content, but did cause a significant reduction in scale colonization. The effects of transient stemflow moisture as a source of moisture or as a dispersing agent for beech scale nymphs may explain the higher scale populations on the north side of trees. My results demonstrate that beech scale populations vary spatially with microhabitat quality.La maladie corticale du hêtre est une maladie répandue et mortelle du hêtre à grandes feuilles (Fagus grandifolia Ehrh.). Une infestation par le puceron laineux du hêtre, (Cryptococcus fagisuga Lind.) représente la première étape dans la progression de la maladie (Ehrlich 1934). Sa propagation sur l’arbre est affectée par l’exposition et la hauteur. Nous avons caractérisé ces patrons spatiaux en mesurant la température, la résistance, la rugosité et l'humidité de l'écorce des arbres. Ces mesures ont été prises dans deux forêts de la région de Montréal, Québec entre Juin et Septembre à deux hauteurs différentes (1.3 et 2.5 m) et du côté nord et sud des arbres. Nous avons également installé des colliers aux arbres pour empêcher l'écoulement sur le tronc du côté nord des arbres. Les pucerons étaient plus nombreux sur le côté nord et plus haut (2.5-2.8 m du sol) sur l’arbre . La température moyenne de l’écorce était 0.5oC plus élevée à 2.5 m. Le contenu en eau de l’écorce était 3% plus élévé à la hauteur de 2.5 m. Le résistance de l’écorce était plus haute sure les côtés nord des arbres. Les collets ont diminué la colonisation par le puceron laineux pendant l'été d’environ 80%. Nos résultats suggèrent que l’écoulement sur le tronc est une source d'humidité importante pour l'insecte, ou une méthode de transport, qui peut expliquer les plus grandes populations observées du côté nord des arbres. En bref, nos résultats démontrent que les populations du puceron laineux du hêtre varient avec la qualité du microhabitat.
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Sakai, Osamu. "Personality of a clonal gecko Lepidodactylus lugubris: developmental mechanism and relation to microhabitat use." Kyoto University, 2019. http://hdl.handle.net/2433/242641.
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Nishi, Hirotaka. "Divergence of Euhadra land snails associated with differentiation in microhabitat, shell morphology and behavior." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136804.
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Debortoli, Jully Anne. "Preferência de monogenéticos por microhabitat branquial em jundiá Rhamdia quelen sob condições de laboratório." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/handle/123456789/107329.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2013.Made available in DSpace on 2013-12-05T23:49:42Z (GMT). No. of bitstreams: 1 321480.pdf: 474485 bytes, checksum: 740a5ce5064047e1a848613752299430 (MD5) Previous issue date: 2013
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Hunter, Anne Katherine. "Longitudinal Patterns of Community Structure for Stream Fishes in a Virginia Tailwater." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/31656.
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I examined the abundance, composition, and distribution of 34 fishes within the first 24 km below Philpott Dam on the Smith River, a hydropeaking system in Virginia. Fish were sampled at 12 sites over 8 time periods ranging from 2000 to 2002 across April, June, and October. I evaluated spatial and temporal change in fish community characteristics. Species demonstrated persistent trends in abundance, diversity, and composition throughout the duration of the study. Fish abundance and diversity generally increased with increasing distance from the dam. Fish composition changed minimally across seasons and years, indicating consistent fish assemblages. Distributional patterns suggested a strong response to thermal gradients and presence of tributaries. I concluded that temperature and tributary location directly influence fish community patterns in the Smith River and that the patterns are persistent over space and time.
I characterized spawning microhabitat use and availability, and tested transferability of spawning microhabitat criteria for Etheostoma flabellare and Nocomis leptocephalus, two of the most common species in the Smith River. E. flabellare preferentially selected small and large cobble size rocks for their spawning rock. N. leptocephalus selected areas with slower demersal and mean water column velocities in which to build their mounds. Transferability tests were conducted using spawning microhabitat criteria from the unregulated Roanoke River (Smith 1999). The logistic regression model developed for E. flabellare by Smith (1999), using information on the diameter of the spawning rock, silt, and embeddedness, transferred with most success with over half of the spawning sites and available sites correctly classified in the Smith River.Master of Science
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Melo, Lilian Sayuri Ouchi de [UNESP]. "A similaridade no uso do microhabitat por girinos (Amphibia, Anura) reflete processos ecológicos ou filogenéticos?" Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/110980.
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000799449.pdf: 2022440 bytes, checksum: 61bf7f3ec81de445521cb6b8518efe4a (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Inúmeros processos tem sido sugeridos para explicar a estruturação de comunidades, como por exemplo competição, predação, dispersão, deriva continental, filtragem ambiental, especiação. A compreensão da influência desses processos em escala local é capaz de possibilitar uma melhor compreensão dos determinantes da composição e riqueza de espécies em comunidades, especialmente as bem delimitadas fisicamente, como é o caso das comunidades de girinos. Nosso objetivo neste estudo foi investigar a influência de características ambientais na estruturação de comunidades de girinos em corpos d'água lênticos e lóticos. Realizamos as amostragens em uma área de Mata Atlântica no sudeste do Brasil. Este trabalho está dividido em dois capítulos. No primeiro capítulo verificamos quais características ambientais dos microhabitats de corpos d'água lênticos e lóticos influenciam positivamente a riqueza de espécies. Além da riqueza, avaliamos ainda a composição de espécies nos microhabitats, testando se ela é determinada pelas características ambientais ou um reflexo da estrutura espacial dos corpos d'água. No segundo capítulo, investigamos a relação entre os gradientes ambientais contínuos e descontínuos - considerando as características ambientais de corpos d'água lênticos e lóticos - com a diversidade taxonômica, filogenética e funcional de girinos em escala local. Os resultados do primeiro capítulo demonstram que a riqueza de espécies nos microhabitats dos corpos d’água lênticos e lóticos foi influenciada, respectivamente, pela quantidade de vegetação e de areia. A vegetação aquática influenciou positivamente a riqueza, provavelmente por proporcionar maior quantidade de alimento e de refúgios contra predadores. Nos ambientes lóticos, a relação positiva da riqueza de espécies com o substrato arenoso provavelmente decorre da seleção de microhabitats com menor correnteza, onde a areia fica ...
Inumerous processes have been suggested to explain the community structure, such as competition, predation, dispersal, continental drift, environmental filtering, speciation. To comprehend the influence of these processes on a local scale provide a better understanding of the composition and species richness determinants in communities, especially physically well defined communities, as is the case of the communities of tadpoles. Our goal in this study was to investigate the influence of environmental characteristics in communities structures of tadpoles in lotic and lentic water bodies. We conducted sampling in an area of Atlantic Rain Forest in southeastern Brazil. This work is divided into two section. In the first chapter we verified which environmental microhabitat characteristics of lotic and lentic water bodies positively influence species richness. Besides species richness, we evaluated species composition in microhabitats, testing if it is determined by the environmental characteristics of microhabitats or a consequence of water bodies spatial structure. In the second chapter, we seek to investigate the relationship between continuous and discontinuous environmental gradients - considering the environmental characteristics of lotic and lentic water bodies - with the taxonomic, phylogenetic and functional diversity of tadpoles on a local scale. The results of the first chapter show that species richness in microhabitats in lentic and lotic water bodies was influenced, respectively, by the amount of vegetation and sand. The aquatic vegetation had a positively relationship with tadpoles richness, probably due to the greater amount of food and refuge from predators provided. In lotic environments, the positive relationship of species richness with sand probably due to the selection of microhabitats with lower currents, where the sand is accumulated. In contrast, species composition in lentic and lotic microhabitats was mainly ...
FAPESP: 12/09243-0
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Van, Overdijk Colin D. A. "Microhabitat selection by the amphipods Echinogammarus ischnus and Gammarus fasciatus in laboratory and field experiments." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0033/MQ62296.pdf.
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Melo, Lilian Sayuri Ouchi de. "A similaridade no uso do microhabitat por girinos (Amphibia, Anura) reflete processos ecológicos ou filogenéticos? /." São José do Rio Preto, 2014. http://hdl.handle.net/11449/110980.
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Orientador: Denise de Cerqueira Rossa-FeresBanca: Ricardo Janinni Sawaya
Banca: Fabrício Barreto Teresa
Resumo: Inúmeros processos tem sido sugeridos para explicar a estruturação de comunidades, como por exemplo competição, predação, dispersão, deriva continental, filtragem ambiental, especiação. A compreensão da influência desses processos em escala local é capaz de possibilitar uma melhor compreensão dos determinantes da composição e riqueza de espécies em comunidades, especialmente as bem delimitadas fisicamente, como é o caso das comunidades de girinos. Nosso objetivo neste estudo foi investigar a influência de características ambientais na estruturação de comunidades de girinos em corpos d'água lênticos e lóticos. Realizamos as amostragens em uma área de Mata Atlântica no sudeste do Brasil. Este trabalho está dividido em dois capítulos. No primeiro capítulo verificamos quais características ambientais dos microhabitats de corpos d'água lênticos e lóticos influenciam positivamente a riqueza de espécies. Além da riqueza, avaliamos ainda a composição de espécies nos microhabitats, testando se ela é determinada pelas características ambientais ou um reflexo da estrutura espacial dos corpos d'água. No segundo capítulo, investigamos a relação entre os gradientes ambientais contínuos e descontínuos - considerando as características ambientais de corpos d'água lênticos e lóticos - com a diversidade taxonômica, filogenética e funcional de girinos em escala local. Os resultados do primeiro capítulo demonstram que a riqueza de espécies nos microhabitats dos corpos d'água lênticos e lóticos foi influenciada, respectivamente, pela quantidade de vegetação e de areia. A vegetação aquática influenciou positivamente a riqueza, provavelmente por proporcionar maior quantidade de alimento e de refúgios contra predadores. Nos ambientes lóticos, a relação positiva da riqueza de espécies com o substrato arenoso provavelmente decorre da seleção de microhabitats com menor correnteza, onde a areia fica ...
Abstract: Inumerous processes have been suggested to explain the community structure, such as competition, predation, dispersal, continental drift, environmental filtering, speciation. To comprehend the influence of these processes on a local scale provide a better understanding of the composition and species richness determinants in communities, especially physically well defined communities, as is the case of the communities of tadpoles. Our goal in this study was to investigate the influence of environmental characteristics in communities structures of tadpoles in lotic and lentic water bodies. We conducted sampling in an area of Atlantic Rain Forest in southeastern Brazil. This work is divided into two section. In the first chapter we verified which environmental microhabitat characteristics of lotic and lentic water bodies positively influence species richness. Besides species richness, we evaluated species composition in microhabitats, testing if it is determined by the environmental characteristics of microhabitats or a consequence of water bodies spatial structure. In the second chapter, we seek to investigate the relationship between continuous and discontinuous environmental gradients - considering the environmental characteristics of lotic and lentic water bodies - with the taxonomic, phylogenetic and functional diversity of tadpoles on a local scale. The results of the first chapter show that species richness in microhabitats in lentic and lotic water bodies was influenced, respectively, by the amount of vegetation and sand. The aquatic vegetation had a positively relationship with tadpoles richness, probably due to the greater amount of food and refuge from predators provided. In lotic environments, the positive relationship of species richness with sand probably due to the selection of microhabitats with lower currents, where the sand is accumulated. In contrast, species composition in lentic and lotic microhabitats was mainly ...
Mestre
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Rocha, Clarisse Rezende. "Utilização de microhabitat por três espécies de roedores cricetídeos em um cerrado do Brasil central." reponame:Repositório Institucional da UnB, 2007. http://repositorio.unb.br/handle/10482/3397.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ecologia, Programa de Pós-Graduação em Ecologia, 2007.Submitted by Fernanda Weschenfelder (nandaweschenfelder@gmail.com) on 2009-11-26T15:04:09Z No. of bitstreams: 1 2007_ClarisseRezendeRocha.PDF: 1573350 bytes, checksum: de4b9ef998b233632ebe78772c8a5aa9 (MD5)
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O objetivo deste trabalho foi analisar a utilização de microhabitat por Calomys tener, Necromys lasiurus e Thalpomys lasiotis e os fatores que mais influenciam a abundância destas três espécies de cricetídeos em áreas abertas de campo com murundus. O estudo foi realizado na Estação Ecológica de Águas Emendadas, Planaltina, DF, entre julho e setembro de 2004. Foram estabelecidas duas grades com 100 pontos de amostragem cada, em que foram colocadas armadilhas e para os quais foram registrados os dados de oito variáveis de microhabitat e das capturas dos roedores. A abundância de Calomys tener foi associada negativamente com o número de árvores e positivamente com a quantidade de gramíneas e de número de cupinzeiros. Foi encontrada diferença significativa entre as variáveis de microhabitat utilizadas por esta espécie quando comparados os machos com as fêmeas. Necromys lasiurus apresentou abundância diretamente proporcional à densidade de árvores no microhabitat. Thalpomys lasiotis apresentou associação negativa com o diâmetro de árvore e associação positiva com a variável distância da árvore mais próxima, o que indica ter associação inversamente proporcional à densidade de árvores. Calomys tener e T. lasiotis parecem ter maior especificidade aos gradientes de microhabitat quando comparado com N.lasiurus, considerada uma espécie generalista de habitats. A Análise de Correspondência Canônica sugeriu que as variáveis de microhabitat não são bons indicadores para predizer a composição da comunidade em áreas de campo cerrado com murundus durante a estação seca, entretanto foi encontrado que estas variáveis são de fato selecionadas pelos indivíduos e espécies. _______________________________________________________________________________ ABSTRACT
The aim of the present study was to investigate the utilization of microhabitat by Calomys tener, Necromys lasiurus and Thalpomys lasiotis, and the factors that affect the abundance of these cricetid species in open areas of fields with “murundus”, a kind of vegetation of the Central Brazil Cerrado. The study was conducted in a conservation area (Estação Ecológica de Águas Emendadas), Planaltina town, Federal District, from July to September, 2004. Population densities of the three animal species and eight microhabitats variables were recorded in two grids with 100 trapping station each. Calomys tener was negatively associated to the number of trees and positively to grass percentage and numbers of termite nest. It was found a significant difference among used microhabitat variables for this species by comparing males and females. For Necromys lasiurus the most important variables were proximity between trees and number of trees. Thalpomys lasiotis was negatively associated to tree diameters and had a positive association to proximity between trees. Calomys tener and T. lasiotis seemed to have more specificity to microhabitat gradients than N. lasiurus. Canonical Correspondence Analyses suggest that microhabitat variables are not good to predictors of community’s composition in “murundus” fields of the Cerrado areas, during the dry season. However, it was found that these microhabitats variables are in fact selected by individuals and species.
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Viljoen, Jan-Adriaan. "Distribution of leaf dissection and sclerophylly along microhabitat gradients in pteridophytes of the Cape peninsula." Bachelor's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/25976.
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Plant species with small leaves and sclerophylls have been reported to occur mainly on dry, low-nutrient soils in situations of high insolation. However; a number of physiological functions have been proposed for the two sets of traits. Ferns are well-suited to the study of leaf structure and its impact in different environments, as they show remarkable variation in leaf dissectedness and sclerophylly, and are able to inhabit a variety of marginal habitats. In this study, ecological and leaf trait data were collected for 17 fern species occurring in Skeleton Gorge, Table Mountain, in the Western Cape. Correlations between the traits and regressions of leaf traits on potential environmental determinants was carried out using both species averages and phylogenetically independent contrasts. The habitat and leaf traits were also subjected to a test of evolutionary trait conservatism. Sclerophyllous plants were found to be have thicker leaves, containing less chlorophyll, but sclerophylly was poorly correlated with leaf dissection. Plants occurring in high-light environments tended to be more sclerophyllous and have more dissected leaves, although these environments also were nutrient-poor. Leaf dissection appears to be primarily a means of dissipating heat by convection, rather than evaporative cooling, but it may also improve nutrient acquisition in low-nutrient soils. Sclerophylly in these ferns was not directly associated with nutrients; instead low sclerophylly seems to be favoured in low-light environments, perhaps because of lower metabolic costs or to reduce self-shading.
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Jacob, Suellen A. "Effects of microhabitat and temporal factors on foraging behavior of white-footed mice (Peromyscus leucopus)." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337888535.
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Boley, Ryan Michael. "Relative species abundance and microhabitat preferences of larval Scaphirhynchus sturgeon in the middle Mississippi River." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/195.
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The pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (S. platorynchus) are benthic freshwater fishes that are sympatric throughout the range of the pallid sturgeon. Pallid sturgeon was listed as endangered under the Endangered Species Act in 1990, while shovelnose is common throughout the range. Previous abundance studies estimate the ratio of adult pallid to shovelnose sturgeon to be on the order of 1:82 in the middle Mississippi River, respectively. Despite adult abundances, reproduction and/or recruitment of pallid sturgeon larvae is undocumented in the middle Mississippi River. The current study aims to confirm the presence of pallid sturgeon reproduction and estimate the relative species abundances of larval pallid, shovelnose and hybrid sturgeon in the middle Mississippi River. Since larval pallid, shovelnose and hybrid sturgeon are virtually identical morphologically, the use of DNA markers was required for species designations; sixteen previously developed microsatellite loci were used in this study. Of the 583 larval Scaphirhynchus sturgeon collected from the middle Mississippi River, 581 were shovelnose, one was a hybrid and one was a pallid. This study was the first to genetically confirm the presence of pallid sturgeon reproduction in the middle Mississippi River. Differences in species ratios between adult and larval Scaphirhynchus sturgeon could be explained by three potential hypotheses; life history characteristics accentuate species ratios between adult and larval stages, pallid are experiencing low reproduction and/or low recruitment, or pallid larvae reside in different microhabitat locations compared to shovelnose.
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Nitta, Carlos Hiroshi. "Uso de hábitat por tatus em área de floresta de restinga do sul do Brasil." Universidade do Vale do Rio dos Sinos, 2008. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3128.
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Os tatus (Cingulata: Dasypodidae), apesar da diversidade de espécies, 21 espécies, e ampla distribuição, da Argentina até a metade sul dos EUA, passando pela América Central, as informações sobre a utilização dos ambientes por estes animais é escassa. A escavação e utilização de buracos no solo é uma característica ecológica relevante para o grupo, podendo estas estruturas serem consideradas indicadores conspícuos da presença desses animais. No presente estudo investiguei a densidade, direção, morfometria e microhabitat das tocas, em diferentes tipos de formação vegetal. O trabalho foi desenvolvido durante 13 meses (Out/06 a Nov/07) no Parque Estadual de Itapuã, na Grande Porto Alegre, RS, Brasil. O tatu-galinha (Dasypus novemcinctus) parece ser a espécie mais abundante neste local, onde ainda ocorre ao menos uma outra espécie, tatu-de-rabo-mole-grande (Cabassous tatouay). As características físicas e ambientais de 72 tocas, no campo (n = 31), mata (n = 22) e Restinga (n = 19), encontradas foram analisadas. A densidade de tocas não variou significativamente entre estes ambientes. Embora o tatu-galinha seja apontado como uma espécie de áreas florestadas no presente estudo, as áreas abertas foram utilizadas com a mesma intensidade que mata e restinga. Dentre as variáveis ambientais o número de árvores e porcentagem de cobertura de solo por arbustos tiveram influência no número de tocas encontradas em mata. A direção das tocas foram predominantemente sul nas áreas de floresta (mata e restinga) e significativamente diferentes das áreas de campo (campoXmata p = 0,002; campoXrestinga p = 0,001). Sugerindo que esta espécie possa mudar o comportamento e aumentar o nicho na ausência ou relaxamento de predadores e competidores.
Armadillos ( Cingulata : Dasypodidae ), despite the diversity of species , 21 species , and wide distribution , from Argentina to the southern half of the United States through Central America, information on the use of animals in these environments is scarce. The excavation and using holes in the ground is an important ecological nature of the group, these structures may be considered conspicuous indicators of the presence of these animals. In the present study I have investigated the density, direction, morphometric and microhabitat of the burrows in different types of plant formation. The study was conducted during 13 months (Oct/06 to Nov/07) in Itapuã State Park, in Porto Alegre , RS , Brazil . The nine-banded armadillo (Dasypus novemcinctus) seems to be the most abundant species at this site, which is still at least one other species, the greater naked-tailed armadillo (Cabassous tatouay). The physical and environmental characteristics of 72 holes, fields (n = 31), forest (n = 22) and Restinga (n = 19), found were analyzed. The density of burrows did not vary significantly between these environments. Although the nine-banded is touted as a kind of wooded areas in the present study, the open areas were used with the same intensity that forest and dunes. Among the environmental variables the number of trees and percentage of ground cover shrubs influenced the number of burrows found in the woods. The direction of the burrows were predominantly southern areas of forest (forest and Restinga) and significantly different from field areas (fieldXforest p = 0.002; fieldXrestinga p = 0.001). Suggesting that this species can change behavior and increase the niche or relaxation in the absence of predators and competitors.
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Larrieu, Laurent. "Les dendro-microhabitats : facteurs clés de leur occurrence dans les peuplements forestiers, impact de la gestion et relations avec la biodiversité taxonomique." Thesis, Toulouse, INPT, 2014. http://www.theses.fr/2014INPT0130/document.
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Les microhabitats portés par les arbres (dendro‐microhabitats), comme les cavités, sont nombreux dans les forêts naturelles. Une revue de la littérature a révélé qu'ils sont des ressources d'habitat évolutives, temporaires, et déterminantes pour la bio‐complexité des écosystèmes forestiers. Leur étude est cependant récente et les connaissances sont par conséquent fragmentaires. En forêt exploitée, les dendro‐microhabitats sont des objets sylvicoles simples et bien catégorisés, souvent comme des défauts de l'arbre dévaluant sa valeur commerciale. Comment concilier alors le maintien d'objets écologiques cruciaux et les objectifs économiques de production de bois de haute qualité marchande ? Ce travail de thèse avait comme objectifs d'une part de contribuer à une meilleure qualification du rôle écologique des dendro‐microhabitats pour la biodiversité et, d'autre part, de fournir des éléments de réponse pratiques aux gestionnaires d'espaces forestiers soucieux d'intégrer la conservation d'une diversité d'espèces dans leur gestion courante. Il a nécessité la mise en place de 1028 placettes dans 210 forêts françaises dans lesquelles nous avons observé environ 55 000 arbres. Nous avons étudié les relations entre les dendromicrohabitats et la richesse et la composition spécifiques de neuf taxons. Dans le cadre de l'analyse des caractéristiques‐clés de l'arbre et du peuplement pour les dendro‐microhabitats, nous avons montré que l'association des variables essence et diamètre explique respectivement 26 % et 31 % de la variance de l'occurrence des dendro‐microhabitats et de leur diversité dans les hêtraies‐sapinières inexploitées depuis plus de 100 ans. Nous avons défini des seuils de diamètre significatifs pour l'occurrence et la diversité des dendro‐microhabitats portés par le Hêtre (Fagus sylvatica L.) et le Sapin pectiné (Abies alba Mill.). D'autre part, la densité de dendro‐microhabitats et le volume de bois mort ainsi que leurs diversités respectives sont relativement constants tout au long du cycle sylvigénétique des forêts mixtes de montagne. Les feuillus secondaires jouent un rôle crucial dans la régulation de ces stocks en les complétant dans les phases où les dryades fournissent peu de dendro‐microhabitats et de bois mort. Un minimum de 10 hectares est nécessaire pour observer toute la diversité des dendro‐microhabitats. Dans les forêts exploitées, nous avons observé des patrons d'occurrence des dendro‐microhabitats drastiquement différents de ceux observés dans les forêts inexploitées depuis plus d'un siècle : les dendro‐microhabitats y sont toujours moins diversifiés et la densité relative de chaque type est modifiée. Après arrêt de l'exploitation, la reconstitution des stocks de dendro‐microhabitats est lente dans les forêts feuillues de plaine. Un arrêt de l'exploitation pendant 30 années est insuffisant pour observer une reconstitution du stock de dendro‐microhabitats dans tous les contextes et pour changer significativement les communautés de Coléoptères saproxyliques. En mesurant la contribution des dendro‐microhabitats à la biodiversité, nous avons observé que la densité d'arbres porteurs de cavités et de sporophores de champignons lignivores est une variable structurante pour la composition des assemblages et la richesse spécifique des Coléoptères saproxyliques. La densité d'arbres porteurs de dendro‐microhabitats et d'arbres porteurs spécifiquement de bois dur sans écorce ou de sporophore de polypores est significativement corrélée à la richesse spécifique des polypores. Le degré d'ouverture du peuplement ou les conditions climatiques locales affectent, dans certains cas, ces relations. Afin d'harmoniser les futurs protocoles de recherche sur les dendro‐microhabitats et de faciliter le partage des données, nous avons proposé une typologie hiérarchique de référence des dendro‐microhabitatsTree microhabitats, such as cavities, are diverse and abundant in natural forests. A literature review revealed that they are dynamic and temporary key habitat resources for the complexity of forest ecosystems. However, since their study is recent, they are still poorly known. In harvested forest, tree microhabitats are well categorized as silvicultural items, mostly as wood defaults decreasing its commercial value. Therefore, how to reconcile the retention of ecological objects crucial for biodiversity and the production of high‐quality timber? This PhD thesis aimed, on the one hand, at participating to better qualify the ecological roles of tree microhabitats for forest biodiversity and, on the other hand, at giving practical recommendations to forest managers who integrate the conservation of species diversity in their usual management. 1028 plots were set up in 210 French forests to observe about 55,000 trees. We studied the relationships between tree microhabitats and species richness and composition of 9 taxa. Through the analysis of key features for tree microhabitats at the tree and stand levels, we showed that tree species and diameter at breast height explain 26 and 31 % of the variations in microhabitat occurrence and diversity, respectively, in beech‐fir forest unlogged for more than 100 years. We highlighted significant diameter thresholds for the occurrence and diversity of microhabitats borne by beech (Fagus sylvatica L.) and silver fir (Abies alba Mill.). Furthermore, tree microhabitat density, deadwood volume and their diversity were shown to be roughly constant throughout the silvigenetic cycle in mountain mixed forests. Secondary tree species play a crucial role in the regulation of deadwood and microhabitat pools, especially during the phases where the dryad trees supply a low amount of microhabitats and deadwood. A surface of unharvested forest more than 10 hectares in area is necessary to observe the whole microhabitat diversity. Microhabitat occurrence patterns in logged forests were drastically different from those observed in forests unlogged for more than one century: tree microhabitats were systematically less diverse and the relative density of microhabitat types was modified. Moreover, the restoration of tree microhabitat pools was slow in set‐aside plain broadleaved forests. More than 30 years without harvests were not sufficient to observe the restoration of the tree microhabitat pool and significant changes in saproxylic beetle communities in all forest contexts. We measured the contribution of tree microhabitats to biodiversity, and we observed that the density of cavity‐ and fungus‐bearing trees were significant drivers for species richness and composition of saproxylic beetle assemblages. The density of trees bearing microhabitats, especially bark losses, significantly influenced the species richness of polypores. The stand openness and local climatic conditions affected these relationships in several forest‐taxon cases. We proposed a reference hierarchical typology of tree microhabitats in order to harmonize survey protocols and to facilitate data sharing in the future. Furthermore, we improved the consideration of tree microhabitats in an integrated management tool, i.e. the Potential Biodiversity Index (PBI). We also included the tree microhabitat pool into a simulation model of mountain forest dynamics (Samsara 2). Apart from being relevant management tools in conservation biology, tree microhabitats stand for natural microcosms available to further fundamental ecological researches. We hope that our work will help foresters to have a new insight on their managed forests
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Tolimieri, Nicholas. "Effects of microhabitat characteristics and spatial scale on recruitment and adult abundance in Caribbean reef fishes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq30297.pdf.
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Virillo, Carolina Bernucci. "Influência do microhabitat e da densidade e distância de vizinhos na demografia de populações espécies arbóreas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315004.
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Orientador: Flavio Antonio Maes dos SantosTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Os mecanismos responsáveis pela alta diversidade de espécies arbóreas em florestas tropicais têm sido alvo de intenso debate na literatura, e dentre os inúmeros mecanismos propostos, dois deles têm encontrado relativo suporte empírico: a dependência de densidade e a diferenciação de nichos. O objetivo deste trabalho foi investigar a ocorrência destes mecanismos na Floresta Ombrófila Densa Atlântica, que apresenta uma enorme diversidade de espécies vegetais, que variam em abundância, e uma grande diversidade de habitats, o que faz deste bioma um local apropriado para buscar evidências da ocorrência desses mecanismos. Foi investigada a influência da densidade de coespecíficos, da vizinhança e do microhábitat na demografia de quatro espécies arbóreas, e esperava-se que estes fatores atuassem de maneira conjunta na determinação da demografia das espécies estudadas. Em cinco áreas de 0,25 ha, duas na Floresta Ombrófila Densa de Terras Baixas (TB) e três na Floresta Ombrófila Densa Submontana (SM), foram marcados e medidos os indivíduos destas espécies, e um recenso foi realizado após dois anos para obtenção de taxas de mortalidade e recrutamento. Indivíduos com PAP (perímetro a altura do peito) > 15 cm foram acompanhados mensalmente para a avaliação da fenologia reprodutiva e do incremento diamétrico. Foi avaliada a influência da densidade de indivíduos e da distância e número de vizinhos coespecíficos na demografia das espécies. Também foi avaliada a relação da demografia com habitats específicos, dados pela declividade e pela porcentagem de abertura de dossel, assim como da fenologia reprodutiva e do incremento diamétrico com a cota de altitude e com o índice de iluminação da copa (IC). Para nenhuma das espécies estudadas foi encontrada relação entre a densidade total de indivíduos e as taxas de mortalidade e de recrutamento. Entretanto, nas áreas de maior abundância, foram encontradas associações entre os indivíduos mortos e os demais indivíduos da população, assim como diminuição da agregação conforme se considera classes de tamanho maiores, que podem ser interpretadas como evidências dos processos dependentes de densidade, indicando que os processos dependentes de distância ou densidade só se mostram importantes em situações de densidade elevada. Houve relação do número de indivíduos com a declividade para a maioria das espécies, mas foram poucas as relações significativas com a abertura de dossel. A mortalidade, o recrutamento e o crescimento dos indivíduos com PAP < 15 cm apresentaram poucas relações significativas com as variáveis ambientais (IDP e abertura do dossel), provavelmente devido ao baixo número de eventos registrados. Para duas das espécies, a fenologia reprodutiva se relacionou com a cota de altitude, mas não com o IC, indicando um aspecto da preferência de hábitat. Já o incremento diamétrico variou muito dentro de uma mesma cota altitudinal, se relacionando, para duas das espécies, com o IC, mas para as outras duas espécies nem a altitude e nem a iluminação das suas copas explicou a variação observada no crescimento. Recomenda-se que um maior número de variáveis ambientais sejam utilizadas para caracterizar os microambientes quando se busca evidências de preferências de hábitat. É provável que os mecanismos estudados não sejam mutuamente exclusivos e que eles atuem em conjunto na determinação dos processos demográficos populacionais, e assim influenciando conjuntamente na manutenção da grande diversidade de espécies arbóreas em florestas tropicais.
Abstract: The mechanisms that are responsible for the high tree species diversity in tropical forests have been intensively debated on literature, and among the several proposed mechanisms, two of them have been relatively empirically supported: the density-dependence and the niche differentiation. The aim of this work was to investigate the occurrence of these mechanisms on the Atlantic Ombrophilous Dense Forest, that has a huge plant species diversity, that vary on their abundance, and a high diversity of habitats, what makes this biome an appropriate place to seek for the existence of these mechanisms. We investigated the influence of conspecific density, neighborhood and microhabitat on the demography of four tree species, and we expected these factors to act together on determining the demography of the studied species. On five 0.25 ha area, two on the Lowland Ombrophilous Dense Forest and three on the Lower-montane Ombrophilous Dense Forest, we tagged and measured all the plants of the studied species; the plants were re-censused after two years so we obtained the mortality and recruitment rates. Plants with perimeter at breast height (PBH) > 15 cm were monthly observed to evaluate their reproductive phenology and diameter increment. We evaluated the influence of the density of plants and the number and distance of conspecific neighbors on the demography of the studied species. We also evaluated the relationship of the demographic rates with specific habitats, given by canopy openness and declivity, and of the reproductive phenology and diameter increment with the altitude and the crown illumination index (IC). We found no relationship between the total density of individuals and the mortality or recruitment rates, but on the areas of high abundance we found associations between the dead plants and the other plants of the populations, as well as lower aggregation as we considered bigger size classes, which could be interpreted as evidences of the density dependent processes, indicating that the density or distance-dependent processes are important only on high density situations. We found significant relationships between the number of individuals and declivity for the majority of species, but there were few significant associations with the canopy openness. Mortality, growth and recruitment of plants PBH < 15 cm have few significant correlations with environmental variables (declivity and canopy openness), probably because of the low number of events registered. For two of the studied species, the reproductive phenology was related to the altitude but not with IC, indicating one aspect of the habitat preference. The diameter increment showed great variation on the same altitude, and for two species it was related with IC, but for the other two neither the altitude nor the IC explained the observed variation on growth. We recommend the use of more environmental variables to characterize the microenvironments when seeking for evidence of habitat preference. It's possible that the studied mechanisms are not mutually exclusive and that they act together on determining the demographic processes, and so, influencing together the maintenance of the high tree species diversity on tropical forests.
Doutorado
Mestre em Biologia Vegetal
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Farquhar, Michael Robert. "Interspecific interactions of the sea urchin Parechinus angulosus and the effect of variations in microhabitat availability." Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1005406.
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Intertidal populations of the sea urchin Parechinus angulosus were examined at seven sites along the south and east coasts of South Africa. At the five southerly sites, P. angulosus occurred in allopatry, while, at the two northerly sites, it occurred in sympatry with several species of Indopacific sea urchins. At the five southerly sites, there was a significant correlation of number of sea urchins per pool with the surface area of the overhang in that pool. This relationship broke down for P. angulosus at the two northerly sites, where there was a significant correlation between these two factors for Stomopneustes variolaris. The density of populations of P. angulosus at the two northerly sites, although not significantly different from all five southerly sites, were considerably lower. There was a significant difference between the mean size of populations at the seven sites. Although no direct evidence is available, a competitive interaction between these two species is proposed to explain the observed patterns of microhabitat utilization and densities. Two series of manipulative experiments were conducted at Kowie Point, where P. angulosus occurs in sympatry, The first, involved urchin removals from three experimental sites. The percentage cover of four functional algal groups was monitored in three experimental and three unaltered control sites over a three month period in spring (Sept. - Dec.) 1993. Two 100 point 0,25m² random point quadrats were thrown at each of the six sites at approximately monthly intervals over the experimental period. Since initial cover of algae varied at the six sites, ANOVA's of the change in percentage cover of four functional algal groups were used to determine treatment effects. No treatment effects were identified for any of the four functional algal groups. There was a strong negative correlation between the percentage cover of foliose algae and encrusting coralline algae, suggesting the possibility of a competitive relationship between them. The second, involved the experimental manipulation of microhabitat availability. The blocking of overhangs, by means of cement filled bags, resulted in an approximate 50% decrease in the total number of urchins in the two experimental pools, and the two control pools without overhangs. However, in the control pool with overhangs there was a slight increase in the number of urchins over the same period. Clearly, the presence of suitable shelters, is a prerequisite for the maintenance of dense intertidal population of P. angulosus. It is proposed that, due to the exposed nature of the South African coast, intertidal populations of P.angulosus are restricted to inhabiting suitable shelters from which they emerge to feed on passing drift algae. The implications of these findings are discussed in terms of current ecological literature.
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Mergo, John Carl. "Studies on the life history, development, occurrence, and microhabitat of Microcotyle spinicirrus, (Monogenea: Microcotylidae) Maccallum 1819 /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487588939090221.
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Cross, Amy Suzanne. "MICROHABITAT USE BY GOLDEN MICE (OCHROTOMYS NUTTALLI) AND WHITE-FOOTED MICE (PEROMYSCUS LEUCOPUS) IN SOUTHERN ILLINOIS." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1094.
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Similarities between golden mice (Ochrotomys nuttalli) and white-footed mice (Peromyscus leucopus) have been well-studied in both field and laboratory settings. Often sympatric, these species share similar habitat, as well as other resources, yet previous researchers have found little evidence for interspecific competition. Niche partitioning may reduce direct competition through specialization of resource use. Although the golden mouse is considered a resource specialist, it is likely that the degree of habitat specialization differs by locality, and thus, the degree of interspecific competition with similar species is variable. To determine the extent to which microhabitat use differs between golden mice and white-footed mice, I measured 16 and 15 microhabitat variables during the leaf-on and leaf-off seasons, respectively, in Jackson County, Illinois. Trapping took place on 3 grids from March 2010 to September 2011. The ratio of individual golden mice (n = 74) to white-footed mice (n = 85) was unusually high during this study. Microhabitat use models were constructed for both species during both seasons using logistic regression by comparing microhabitat at trapping stations where each species was captured vs. stations without captures. Few variables described habitat occupied by golden mice. Overall, dense vegetation up to 2.0 m was most important for golden mice and ground-level structures such as logs were most important for white-footed mice. Captures and noncaptures were predicted with a high degree of accuracy by logistic regression (81.5-90.3%). Discriminant function analysis was used to identify which microhabitat variables optimally discriminated between habitat used by golden mice, white-footed mice, and neither species. More variables discriminated between species during the leaf-on season than the leaf-off season although discriminating variables during leaf-off were more important overall. Habitat where either species was captured was combined and compared against habitat where no mice were captured; microhabitat used by mice was statistically distinct within the study area. Captures and noncaptures were classified correctly more than would be expected by chance by discriminant function analysis but moderate classification success values indicated microhabitat differences between species were subtle. Microhabitat and elevated trap use varied between seasons for both species, but neither species used ground or elevated traps more than expected during the leaf-on season. Spatial segregation was more apparent during the leaf-off season when golden mice used elevated traps more than expected and white-footed mice used ground traps more than expected. Overall results suggest that golden mice exhibited a great deal of plasticity in microhabitat use seasonally, and are more habitat generalists than previous literature would suggest. Although some spatial segregation was apparent between golden mice and white-footed mice, there was no evidence for avoidance between species, which implies a lack of interference competition. It is likely that other life-history factors (such as metabolic rate, nest building, or sociality) in combination with microhabitat and vertical partitioning allow coexistence between these species rather than microhabitat segregation alone.
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Silva, Adilson de Oliveira. "Análise comparativa dos nichos espacial e alimentar de anuros em áreas de Caatinga e Mata Atlântica de Sergipe, Brasil." Universidade Federal de Sergipe, 2014. https://ri.ufs.br/handle/riufs/4404.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorDistinct environmental characteristics can directly affect community structure, they offer varying conditions and resources, which allows each area to establish different groups of species. In this study we analyzed two amphibian assemblages between October 2012 and September 2013 in two areas with different degrees of environmental heterogeneity, one in the Caatinga (Monument Natural Grota do Angico - MNGA ) and the other in the Atlantic Rainforest (Refugio de Vida Silvestre Mata do Junco - RVSMJ), both in the state of Sergipe. We used information about the spatial and food niches and their relationships with ecological and historical factors. We analyzed 1,332 records (999 - RVSMJ 333 - MNGA) of 28 species (22 - RVSMJ and 15 - MNGA, nine common to both areas). The food and space niche overlap was relatively high in both study sites. Nine types of microhabitats were used by the species being the most common, regardless of the area, soil (45.1 %), water (23.7 %) and leaflitter (8.6%). The most important preys in their diets were Formicidae and Coleoptera in both areas. Individuals in the Atlantic rainforest were relatively smaller than those of the Caatinga area suggesting differentiated investments between reproduction and growth between the areas. The results suggest that the assemblages from both areas are influenced by historical or phylogenetic factors only in the use of space assets. Their diets are strongly influenced by the availability of resources the environment offers.
Características ambientais distintas podem afetar diretamente a estruturação das comunidades, pois oferecem recursos e condições variadas, o que permite que em cada área, grupos diferenciados de espécies se estabeleçam. Nesse estudo duas taxocenoses de anfíbios anuros foram analisadas entre outubro de 2012 e setembro de 2013, em duas áreas com diferentes graus de heterogeneidade ambiental, uma na Caatinga (Monumento Natural Grota do Angico MNGA) e outra de Mata Atlântica (Refugio da Vida Silvestre Mata do Junco RVSMJ), ambas no estado de Sergipe. Foram utilizadas informações sobre os nichos espacial e alimentar e suas relações com fatores ecológicos e históricos. Foram tomados 1.332 registros (999 - RVSMJ e 333 - MNGA) pertencentes a 28 espécies (22 RVSMJ e 15 MNGA, sendo nove comuns as duas áreas). A sobreposição de nicho espacial e alimentar foi relativamente alta em ambas as áreas. Nove tipos de microhábitats foram utilizados pelas espécies sendo os mais comuns, independente da área, solo (45,1%), água (23,7%) e folhiço (8,6%). As presas mais importantes das dietas foram Formicidae e Coleoptera em ambas as áreas. Os indivíduos da Mata Atlântica foram relativamente menores que os da Catinga sugerindo investimentos diferenciados em reprodução e crescimento entre as áreas. Os resultados obtidos sugerem que as taxocenoses de ambas as áreas são influenciadas por fatores históricos ou filogenéticos somente na utilização dos recursos espaciais. Suas dietas são fortemente influenciadas pelas disponibilidades de recursos que o ambiente oferece.
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Ditterich, Franziska [Verfasser], and Ellen [Akademischer Betreuer] Kandeler. "Microbial community structure and function is shaped by microhabitat characteristics in soil / Franziska Ditterich ; Betreuer: Ellen Kandeler." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2016. http://d-nb.info/1118571665/34.
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Landry-Cuerrier, Manuelle. "From habitat to energetics : eastern chipmunk burrow microhabitat selection and fine-scale variation in winter torpor expression." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112530.
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This thesis evaluates, in free-ranging eastern chipmunks (Tamias striatus), burrow site selection, the effect of burrow microhabitat on individual behaviour and winter torpor expression, as well as resource and climate determinants of fine-scale variation in winter torpor expression and energetics. This was accomplished by characterizing burrow microhabitat, performing behavioural observations, and monitoring winter torpor expression. Among several burrow microhabitat variables related to food availability, predation risk, and hibernacula microclimate, availability of woody debris was the best predictor of burrow site use. Anti-predator benefits associated with availability and use of woody debris are potentially more important than those associated with burrow microhabitat features that are either too spatially invariant (soil temperatures) or too spatially and temporally variant (food sources). Abundance of tree-seeds drastically reduced winter torpor, increasing considerably winter energy consumption, and local density of seed-producing trees was responsible for fine-scale spatial variation in torpor expression. The potential range in winter torpor expression and energy consumption was constrained by microclimate, whereas observed patterns of winter torpor and energy consumption were highly variable and determined primarily by local food abundance.
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Guerra, Giraldez Mabel. "Alteración en la elección de microhabitat de Acyrtosiphon pisum (Hemiptera: Aphididae) parasitado por Aphidius ervi (Hymenoptera: Braconidae)." Tesis, Universidad de Chile, 2000. http://www.repositorio.uchile.cl/handle/2250/106673.
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Duchemin, Gérald. "Ecologie des foraminifères benthiques du Golfe du Morbihan et de la Grande Vasière : variabilité temporelle et microhabitat." Angers, 2004. http://www.theses.fr/2004ANGE0014.
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Cette thèse sur l'écologie des foraminifères benthiques présente deux volets, l'un sur un schorre du Golfe du Morbihan, et l'autre sur le plateau continental du Golfe de Gascogne (dans le cadre du PNEC Golfe de Gascogne). L'objectif de cette thèse est, dans les deux environnements, d'éclaircir le comportement des foraminifères vis-à-vis des variations environnementales. Dans le schorre du Golfe du Morbihan, nos observations indiquent que les faunes de foraminifères présentent une forte variabilité à court terme (semaine) et une succession bien établie de microhabitats sur les 9 premiers centimètres de sédiment. De plus, cette étude met en lumière des phénomènes peu étudiés, comme d'éventuelles migrations et/ou le transport de foraminifères, l'effet refuge de la végétation et le probable impact de la pluviosité. Sur le plateau continental, les faunes de foraminifères sont principalement assujetties aux variations de flux de matière organique. Ces apports déterminent la composition, la distribution spatiale et les variations saisonnières de densité des faunes de foraminifères benthiquesThis thesis on benthic foraminiferal ecology presents two parts, one on a high marsh of the Gulf of Morbihan, and the other on the continental shelf of the Bay of Biscay (in the context of the French national program PNEC). The aim of this thesis is the same for both environments: to define the foraminiferal behaviour in response to the environmental variations. In the high marsh of the Gulf of Morbihan, our observations indicate that foraminiferal faunas present a strong short-term (weekly) variability and a well established microhabitat succession in the first 9 cm of sediment. Furthermore, this study highlights some poorly known phenomena, such as possible migrations and/or transport of foraminifera, the refuge effect of the vegetation and the potential impact of the rainfall. On the continental shelf, foraminiferal faunas are mainly under the influence of the variations of matter organic fluxes. These fluxes determine the composition, the spatial distribution and the seasonal variations of density of the benthic foraminiferal faunas
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Legras, Elaine C. "Microhabitat is critical for sugar pine seedlings emergence and survival in a xeric Jeffrey pine dominated forest /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1455660.
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Thesis (M.S.)--University of Nevada, Reno, 2008."May, 2008." Includes bibliographical references (leaves 39-44). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2009]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Ortiz, Durà Jesús. "Response of the benthic macroinvertebrate community to a point source in La Tordera stream (Catalonia, NE Spain)." Doctoral thesis, Universitat de Girona, 2005. http://hdl.handle.net/10803/7901.
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Vam monitoritzar paràmetres físics i químics, macroinvertebrats bentònics, clorofil·la a, productors primaris i matèria orgànica durant un any (2001-2002) per examinar els efectes d'una font puntual sobre la composició taxonòmica, la estructura de la comunitat, l'organització funcional, la utilització de l'habitat i la estoquiometria al riu la Tordera (Catalunya).Aigües avall de la font puntual, concentració de nutrients, cabal i conductivitat eren majors que al tram d'aigües amunt, mentre que oxigen dissolt era menor. La densitat de macroinvertebrats era més elevada al tram d'aigües avall però la biomassa era similar als dos trams. La riquesa taxonòmica al tram de dalt era un 20% més alt que al tram de baix. Els anàlisis d'ordenació separen clarament els dos trams en el primer eix, mentre que els dos trams presentaven una pauta temporal similar en el segon eix. La similaritat entre els dos trams en composició taxonòmica, densitats i biomasses després de les crescudes d'abril i maig de 2002, indiquen que les pertorbacions del cabal poden actuar com a un mecanisme de reinici de la comunitat bentònica i jugar un paper important per a la restauració d'ecosistemes fluvials.
Els dos trams presentaven una biomassa de perifiton, plantes vasculars, CPOM i FPOM similars, mentre que clorofil·la a, algues filamentoses, molses i SPOM eren majors al tram d'aigües avall. La densitat relativa de trituradors era menor sota la font puntual mentre que col·lectors i filtradors van ser afavorits. La biomassa relativa de trituradors també era menor sota la font puntual, però la biomassa de col·lectors i depredadors va augmentar. Les relacions entre densitat de grups tròfics i els seus recursos eren rarament significatives. La relació s'explicava millor amb la biomassa de macroinvertebrats. Els dos trams compartien la mateixa relació per raspadors, col·lectors i filtradors però no per trituradors i depredadors.
La densitat i la biomassa de macroinvertebrats es trobaven positivament correlacionades amb la quantitat de recursos tròfics i la complexitat d'habitat, mentre que la riquesa taxonòmica es trobava negativament relacionada amb paràmetres hidràulics. La influència dels substrats inorgànics prenia menor rellevància per a la distribució dels macroinvertebrats. Els anàlisis d'ordenació mostren com les variables del microhabitat de major rellevància eren CPOM, clorofil·la a, algues filamentoses i velocitat. La cobertura de sorra només era significativa per al tram d'aigües amunt i les molses, al d'aigües avall. El número de correlacions significatives entre macroinvertebrats i les variables del microhabitat era més elevat per al tram de dalt que per al de baix, bàsicament per diferències en composició taxonòmica. La biomassa de macroinvertebrats va aportar una informació semblant a la obtinguda per la densitat.
Perifiton i molses tenien uns continguts de nutrients similars en els dos trams. Els %C i %N d'algues filamentoses també eren similars en els dos trams però el %P sota la font puntual era el doble que al tram de dalt. Les relacions estoquiomètriques en CPOM, FPOM i SPOM eren considerablement menors sota la font puntual. Els continguts elementals i relacions van ser molt variables entre taxons de macroinvertebrats però no van resultar significativament diferents entre els dos trams. Dípters, tricòpters i efemeròpters presentaven una estoquiometria similar, mentre que el C i el N eren inferiors en moluscs i el P en coleòpters. Els depredadors presentaven un contingut en C i N més elevat que la resta de grups tròfics, mentre que el P era major en els filtradors. Els desequilibris elementals entre consumidors i recursos eren menors en el tram d'aigües avall. A la tardor i l'hivern la major font de nutrients va ser la BOM mentre que a la primavera i a l'estiu va ser el perifiton.
We monitored physical and chemical parameters, benthic macroinvertebrates, chlorophyll a, primary producers, and organic matter for one year (2001-2002) to assess the effect of a point source input on the taxa composition, community structure, functional organization, microhabitat distribution, and elemental stoichiometry in La Tordera stream (Catalonia, NE Spain).
Below the point source, nutrient concentrations, discharge, and specific conductance were higher than at the upstream reach, while dissolved oxygen decreased. Total macroinvertebrate density was higher at the downstream reach than at the upstream reach. The two reaches did not differ in macroinvertebrate total biomass. On average, taxa richness at the upstream reach was 20% higher than at the downstream reach. Ordination analysis clearly separated the samples of the two reaches in the first axis and corroborated the effect of the point source on the benthic community. The two reaches followed a similar temporal pattern with respect to the distribution of taxa along the second axis. Higher similarities between the two reaches in taxa composition, densities and biomass after the spates of April and May 2002, suggest that flooding events may act as a reset mechanism for benthic communities and play an important role in stream restoration.
The two reaches did not differ in standing stocks of periphyton, vascular plants, CPOM and FPOM. Chlorophyll a, filamentous algae, mosses, and SPOM concentrations were increased by the point source. Relative density of shredders was reduced at the downstream reach, whereas gatherers and filterers were enhanced. Relative biomass of shredders decreased below the point source as well, but gatherers diminished and predators increased. The relationships between density of functional feeding groups and their presumed food resources were rarely significant. The relation between consumers and their food resources was best explained through macroinvertebrate biomass. The two reaches had the same relationship for scrapers, gatherers, and filterers, but differed for shredders and predators.
Macroinvertebrate density and biomass were positively correlated with food resources and complexity of habitat architecture while taxa richness was negatively correlated with hydraulic parameters. Inorganic substrate exerted a lesser influence on macroinvertebrate distribution. Ordination analysis revealed that the microhabitat variables of major relevance at the two reaches were CPOM, chlorophyll a, filamentous algae, and maximum water velocity. Sand coverage was only retained at the upstream reach and moss, at the downstream reach. The number of significant correlations between macroinvertebrates and microhabitat variables was higher at the upstream reach than at the downstream reach mainly because of higher taxa richness. Macroinvertebrate biomass provided similar information to that obtained from density in our study case.
Periphyton and mosses had similar nutrient contents in the two reaches. The %C and %N filamentous algae was also similar in the two reaches, but %P below the point source was two times higher than that at the upstream reach. Stoichiometric ratios for CPOM, FPOM, and SPOM decreased considerably below the point source. Elemental contents and ratios were highly variable among macroinvertebrate taxa but did not differ significantly between the two reaches, indicating homeostatic regulation. Dipterans, caddisflies, and mayflies had similar elemental contents and stoichiometry, whereas C and N were lower in mollusks and P in beetles. Predators had the higher C and N contents, while %P was higher in filterers and lower in scrapers. Elemental imbalances between consumers and resources were amended at the downstream reach relative to the upstream reach. Macroinvertebrates represented, on average, relatively low nutrient storage in the ecosystem. At the upstream reach, autochthonous production represented the major input of nutrients into the ecosystem food web, whereas the major source of P for heterotrophic production at the downstream reach was represented by allochthonous inputs.