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Habitat structure and food resources for wildlife across successional stages in a tropical forest

Pinotti, Bruno T.; Pagotto, Camilla P.; Pardini, Renata
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.12%
Tropical forests are experiencing an increase in the proportion of secondary forests as a result of the balance between the widespread harvesting of old-growth forests and the regeneration in abandoned areas. The impacts of such a process on biodiversity are poorly known and intensely debated. Recent reviews and multi-taxa studies indicate that species replacement in wildlife assemblages is a consistent pattern, sometimes stronger than changes in diversity, with a replacement from habitat generalists to old-growth specialists being commonly observed during tropical forest regeneration. However, the ecological drivers of such compositional changes are rarely investigated, despite its importance in assessing the conservation value of secondary forests, and to support and guide management techniques for restoration. By sampling 28 sites in a continuous Atlantic forest area in Southeastern Brazil, we assessed how important aspects of habitat structure and food resources for wildlife change across successional stages, and point out hypotheses on the implications of these changes for wildlife recovery. Old-growth areas presented a more complex structure at ground level (deeper leaf litter, and higher woody debris volume) and higher fruit availability from an understorey palm...

Ecologia e conservação de aves em ambientes costeiros do Rio Grande do Sul

Accordi, Iury de Almeida
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
POR
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46.18%
Os ambientes costeiros se incluem entre os mosaicos de paisagens mais complexos e mais produtivos do mundo. As interações entre fatores ambientais bióticos e abióticos que ocorrem nestes ambientes geram padrões específicos de heterogeneidade que podem influenciar na composição de uma comunidade. A Planície Costeira do Rio Grande do Sul é formada por uma extensa planície que ocupa uma área de quase 50.000 km2 e se estende por 640 km cuja conformação geomorfológica originou um complexo mosaico de paisagens. Foram registradas nos últimos 30 anos 452 espécies continentais e costeiras e trinta e nove pelágicas na planície costeira ou ao largo dela. Outras 22 espécies só possuem registros históricos. Embora a composição das espécies na planície costeira seja razoavelmente bem conhecida, a estrutura das assembléias que fazem parte do mosaico de ambientes da planície costeira só recentemente começou a ser descrita, As assembléias de aves que ocupam o mosaico formado pelos ambientes paralelos alinha de praia ainda não foram objeto de nenhum estudo. Além das assembléias, pelo menos 56 espécies costeiras e continentais que ocupam a planície costeira requerem atenção específica, seja por estarem ameaçadas ou por não serem ainda suficientemente conhecidas no Rio Grande do Sul. Visando investigar aspectos da ecologia e conservação de assembléias e de populações de aves na planície costeira do Rio Grande do Sul...

Disentangling the influences of habitat structure and limnological predictors on stream fish communities of a coastal basin, southeastern Brazil

Ferreira, Fabio Cop; Silva, André Teixeira Da; Gonçalves, Cristina Da Silva; Petrere Jr., Miguel
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: 177-186
ENG
Relevância na Pesquisa
46.18%
Em ambientes de riacho, fatores relacionados à estrutura dos habitats e limnologia interagem regulando os padrões de transferência de energia e matéria, afetando a composição da comunidade de peixes. Em bacias costeiras do sudeste do Brasil as características limnológicas e estrutura dos habitats diferem entre riachos de águas claras e pretas. Os primeiros são compostos por uma variedade de tipos de substrato, possuem velocidades de corrente mais elevadas e baixa condutividade, enquanto os últimos apresentam substrato arenoso, baixas velocidades de corrente e águas escuras e ácidas. Neste trabalho analisamos a importância relativa da estrutura dos habitats e das variáveis limnológicas como preditores dos padrões de composição em comunidades de peixes de riachos. Oito riachos de primeira a terceira ordem foram amostrados na planície costeira da bacia do rio Itanhaém. Capturamos 34 espécies e verificamos que a composição das comunidades foi influenciada por fatores estruturais e limnológicos, sendo os primeiros mais importantes. Uma fração de variação que não pode ser totalmente decomposta, deve-se à influência conjunta da limnologia e estrutura dos habitats. Algumas das espécies restritas aos riachos de águas pretas provavelmente apresentam adaptações fisiológicas e comportamentais para lidar com os baixos níveis de pH. Quando foram examinados somente os riachos de águas claras...

Relações entre complexidade de habitat e comunidade de peixes de costão rochoso

Silveira, Marcelo
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Dissertação de Mestrado Formato: 88 p.| il., grafs., tabs.
POR
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46.23%
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, Florianópolis, 2010; Uma das causas atribuídas à reconhecida diversidade dos peixes recifais é a complexidade estrutural do ambiente em que vivem. Assim, diversas variáveis de complexidade de habitat têm sido propostas para caracterizar a complexidade estrutural dos recifes, bem como diferentes metodologias para acessá-las. Entretanto a maioria das proposições aconteceu em recifes de corais, existindo ainda muitas dúvidas sobre a diferença da funcionalidade da complexidade de habitat entre recifes rochosos e coralíneos. Nesse contexto o presente estudo (1) abordou a complexidade de habitat em costões rochosos com uma perspectiva sobre metodologias (quantitativas e qualitativas) utilizadas para acessá-la e quantificá-la nesses ambientes; (2) testou o potencial de três diferentes variáveis de complexidade de habitat (rugosidade, número e tamanho de tocas) em explicar variações de densidade, biomassa e riqueza de espécies de peixes de costão rochoso; e (3) avaliou o potencial da variável ambiental profundidade em explicar variações de densidade e riqueza de espécies em diferentes localidades da costa brasileira dispostas em gradiente latitudinal. Constatamos que atenção especial deve ser dada na aplicação em recifes rochosos de metodologias de avaliação da complexidade do habitat de recife de corais. Recomendamos a utilização de estimativas visuais (metodologia qualitativa) para tais avaliações em recifes rochosos...

The bioassessment of fish and macroinvertebrates in a Mediterranean-Atlantic climate: Habitat assessment and concordance between contrasting ecological samples

Monaghan, KA; Soares, AMVM
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.22%
Human intervention and drought conditions in Mediterranean rivers may necessitate the collection of organisms from a different habitat type to that specified by the original bioassessment protocol; it is therefore critical to understand the consequences of adaptive sampling strategies in these lotic systems. In a survey of 31 streams (2nd-4th order) in northern Portugal we collected separate macroinvertebrate samples from running-water and standing-water habitats and fish samples from a delineated reach, inclusive of all habitat types. In addition to collecting habitat data specific to macroinvertebrates and fish we conducted a generalized River Habitat Survey (RHS) and derived scores designed to report habitat quality and habitat degradation. Ecological data were described in terms of taxonomic structure, functional organization and by biotic indices and interpreted in relation to habitat data, comparing samples within and between sites for concordance. Macroinvertebrates from respective habitats differed in their relationship with habitat variable with running-water samples more strongly related to substrate and water quality and standing-water samples more strongly reflecting habitat characteristics at the reach scale. Running- and standing-water samples from the same-site varied widely...

Habitat Structural Effect on Squamata Fauna of the Restinga Ecosystem in Northeastern Brazil

DIAS,EDUARDO J.R.; ROCHA,CARLOS F.D.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
Relevância na Pesquisa
56.09%
In this work, we surveyed data on richness and composition of squamatan reptiles and habitat structural effect in nine areas of restinga ecosystem in the State of Bahia, northeastern Brazil. The “restinga” ecosystems are coastal sand dune habitats on the coast of Brazil. Our main hypothesis is that the Squamata fauna composition along these restinga areas would be modulated by habitat structural. After 90 days of field sampling we recorded approximately 5% of reptile species known in Brazil. The composition of Squamata assemblages varied mainly based on the presence or absence of lizards of the genera Ameivula and Tropidurus. Our data showed that habitat structure consistently affected the composition of local Squamata fauna, especially lizards.

Disentangling the influences of habitat structure and limnological predictors on stream fish communities of a coastal basin, southeastern Brazil

Ferreira,Fabio Cop; Silva,André Teixeira da; Gonçalves,Cristina da Silva; Petrere Jr.,Miguel
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
Relevância na Pesquisa
46.18%
In stream environments habitat structure and limnological factors interact regulating patterns of energy and material transfer and affecting fish communities. In the coastal basins of Southeastern Brazil, limnological and structural characteristics differ between clear and blackwaters streams. The former have a diversity of substrate types, higher water velocities, and lower water conductivity, while the latter have sandy substrate, tea-colored and acidic waters, and low water velocities. In this study, we verified the relative importance of habitat structure and limnological variables in predicting patterns of variation in stream fish communities. Eight first to third order streams were sampled in the coastal plain of Itanhaém River basin. We captured 34 fish species and verified that community structure was influenced by physical habitat and limnology, being the former more important. A fraction of the variation could not be totally decomposed, and it was assigned to the joint influence of limnology and habitat structure. Some species that were restricted to blackwater streams, may have physiological and behavioral adaptations to deal with the lower pH levels. When we examined only the clearwater streams, all the explained variation in fish community composition was assigned to structural factors...

The role of limnological variables and habitat complexity in impacted tropical streams as regulatory factors on the flagellate protozoa community

Camargo,Janielly Carvalho; Vieira,Ludgero Cardoso Galli; Velho,Luiz Felipe Machado
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
56.12%
OBJECTIVE: To contribute to the knowledge of patterns of spatial and seasonal distribution of composition and species richness of flagellate protozoa in tropical impacted streams and to identify which variables (physical and chemical or descriptor variables of habitat complexity) control these attributes in these environments. METHODS: Samplings were performed in 10 tropical streams (5 urban and 5 rural) in two periods (summer and winter). Limnological variables were determined on the field (except for the concentration of nutrients), the habitat macrostructure was visually estimated in situ, using a quadrat and the species identification was performed in vivo, under optical microscope. RESULTS: In total, 106 taxa were identified, the order Euglenida was that contributed most to the species richness, probably due to the high tolerance to environmental changes. Multivariate analyses (ANOSIM and MDS) evidenced significant spatial and seasonal differences both for composition and species richness. The Bioenv and Mantel Test indicated that the patterns of composition and richness were controlled by physical and chemical variables indicative of water quality (pH, electrical conductivity, and concentration of nutrients). However, the species richness was also influenced by the habitat structural complexity and by its stability...

Environmental gradient in reservoirs of the medium and low Tietê River: limnological differences through the habitat sequence

Smith,Welber Senteio; Espíndola,Evaldo Luis Gaeta; Rocha,Odete
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
Relevância na Pesquisa
56.12%
AIM: The reservoirs of the medium and low Tietê River are disposed as a "cascade series", in which time, physiographic features and influence from drainage basins present differences that determine variability in their dynamics. These reservoirs are submitted to different impacts from the urban centres which they drain, and also from agricultural activities.Considering these features, the aim of this work was to characterize the Medium and Low Tietê river stretches by limnological analysis (including water and sediments) considering dry and rainy seasons evaluating changes along the reservoirs sequence. METHODS: Based on physical and chemical measurements on water and sediments from 16 points along the reservoirs and in the river mouth of the main tributaries, it was possible to make an environmental characterization of the study area. RESULTS: This was performed focusing on water, sediment, habitat structure and time scale. Generally, the data showed a reduction in the values of the analyzed parameters along the reservoirs sequence. Moreover, it was possible to identify differences between the dry and rainy seasons for water and sediment parameters. Concerning habitat structure, there is a gradient along the river, which shows that the environmental quality improves from the river head to the river mouth. Differences in macrophyte composition...

Small-Scale Habitat Structure Modulates the Effects of No-Take Marine Reserves for Coral Reef Macroinvertebrates

Dumas, Pascal; Jimenez, Haizea; Peignon, Christophe; Wantiez, Laurent; Adjeroud, Mehdi
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 15/03/2013 EN
Relevância na Pesquisa
46.19%
No-take marine reserves are one of the oldest and most versatile tools used across the Pacific for the conservation of reef resources, in particular for invertebrates traditionally targeted by local fishers. Assessing their actual efficiency is still a challenge in complex ecosystems such as coral reefs, where reserve effects are likely to be obscured by high levels of environmental variability. The goal of this study was to investigate the potential interference of small-scale habitat structure on the efficiency of reserves. The spatial distribution of widely harvested macroinvertebrates was surveyed in a large set of protected vs. unprotected stations from eleven reefs located in New Caledonia. Abundance, density and individual size data were collected along random, small-scale (20×1 m) transects. Fine habitat typology was derived with a quantitative photographic method using 17 local habitat variables. Marine reserves substantially augmented the local density, size structure and biomass of the target species. Density of Trochus niloticus and Tridacna maxima doubled globally inside the reserve network; average size was greater by 10 to 20% for T. niloticus. We demonstrated that the apparent success of protection could be obscured by marked variations in population structure occurring over short distances...

Habitat structure alters top-down control in litter communities

Kalinkat, Gregor; Brose, Ulrich; Rall, Björn Christian
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.21%
The question whether top-down or bottom-up forces dominate trophic relationships, energy flow, and abundances within food webs has fuelled much ecological research with particular focus on soil litter ecosystems. Because litter simultaneously provides habitat structure and a basal resource, disentangling direct trophic and indirect non-trophic effects on different trophic levels remains challenging. Here, we focussed on short-term per capita interaction strengths of generalist predators (centipedes) on their microbi-detritivore prey (springtails) and addressed how the habitat structuring effects of the leaf litter modifies this interaction. We performed a series of laboratory functional response experiments where four levels of habitat structure were constructed by adding different amounts of leaf litter to the experimental arenas. We found that increased leaf litter reduced the consumption rate of the predator. We interpreted this as a dilution effect of the augmented habitat size provided by the increasing leaf litter surface available to the species. Dilution of the prey population decreased encounter rates, whereas the capture success was not affected. Interestingly, our results imply that top-down control by centipedes decreased with increasing resource supply for the microbi-detritivore prey (i.e. the leaf litter that simultaneously provides habitat structure). Therefore...

Os efeitos da estrutura de habitat sobre as comunidades de aranhas em uma floresta de caatinga do nordeste brasileiro; Habitat structure effects over spider communities in a caatinga forest from brazilian northeast

Araújo, Nicholas Sebastian Aires de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ecologia; Bioecologia Aquática Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ecologia; Bioecologia Aquática
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.24%
The inherent complexity of natural communities is a challenge to our understanding about how the habitat influences the abundance, local distribution and species diversity. The habitat can influence community structure in multiple ways and elucidate these relationships has provoked a lot of debate in ecology. The habitat heterogeneity hypothesis states that an increase in habitat heterogeneity (number of habitats) leads to an increase in species diversity in the landscape due to an expansion in niche dimensions. This study aims to identify whether this hypothesis is valid for the spiders that inhabit a locality in the Caatinga of northeastern Brazil. Cursorial and arboreal spiders were sampled in 30 plots within an area of Caatinga together with measures of environmental complexity, habitat heterogeneity and environmental parameters related to multiple aspects of vegetation architecture and species composition of woody plants. Stepwise multiple regressions were used to define which local environmental parameters best explain the variation in arboreal and cursorial spiders richness. Then a NMDS (Nonmetric multidimensional scaling) was used to reduce the number of predictive variables to those who are the most important and best represent the variation in spiders richness associated with the environment they were sampled. The results show a clear segregation between the guilds of arboreal and cursorial spiders...

A influência da estrutura do hábitat sobre a composição da avifauna em praças públicas; The influence of habitat structure on birds composition in public square

Marques, Renata Leal
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
56.12%
Existe um aumento reconhecido das paisagens dominadas por populações humanas que não pode ser ignorado na busca da conservação da biodiversidade. O conhecimento dos impactos que a urbanização pode ter sobre comunidades de aves pode permitir a identificação de importantes ferramentas para melhor planejar os hábitats urbanos de modo que esse grupo possa sobreviver nesses ambientes. A vegetação presente nas cidades, principalmente nos espaços públicos abertos, como praças, exerce um importante papel ao incrementar a biodiversidade. Assim, foram avaliadas as respostas da comunidade de aves à estrutura do hábitat, à localização e à perturbação humana em 40 praças de diferentes regiões da cidade de Uberlândia-MG. A observação da avifauna foi realizada por meio de registros visuais com varreduras detalhadas em toda a praça e nas ruas adjacentes, de março a novembro de 2009, entre 6:30h e 13:00h. Foram realizados registros do número de espécies e de indivíduos. O substrato e o estrato vertical utilizados, a atividade comportamental executada e o recurso explorado pelas aves foram anotados. Em cada praça foram realizadas medidas da área total; da riqueza e do número de indivíduos vegetais classificados nas alturas de 0...

Historical configuration of habitat influences the effects of disturbance on mobile invertebrates

Goodsell, P.; Connell, S.
Fonte: Inter-research Publicador: Inter-research
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
Relevância na Pesquisa
46.21%
Mobile animals can be affected by disturbance because of changes to the structure of their habitat. Few studies, however, recognise the potential for the historical configuration of habitat (e.g. density prior to disturbance) to affect the way animals respond to the disturbance. Furthermore, there is a tendency for ecologists to study or manipulate only the most severe disturbances, but such events are less likely to be common. We tested the hypothesis that the density of Ecklonia radiata before disturbance affects the response of assemblages of mobile invertebrates to different severities of disturbance. Differences in the severity of disturbance caused changes in the structure of assemblages, but this response varied depending on the historical configuration of habitat. The magnitude by which assemblage structure differed between undisturbed and disturbed habitats was greater where habitats were historically sparse rather than dense. We emphasise the importance of assessing a range of severities of disturbance and demonstrate the importance of habitat configuration prior to the disturbance, particularly for animals with close association to their habitat.; Paris J. Goodsell and Sean D. Connell; Copyright © 2005 Inter-Research.

Physical disturbance and subtidal habitat structure on open rocky coasts: Effects of wave exposure, extent and intensity

Wernberg-Moller, T.; Connell, S.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
56.16%
Canopy-forming algae occur across of range of energy environments (i.e., wave sheltered to exposed coasts) where disturbances are frequent (i.e., gap formation) and benthic patterns largely reflect variation in post-disturbance processes. Disturbances vary in extent (area affected) and intensity (degree of damage), and this may affect recolonisation at local scales. On an open oceanic coast, we tested whether habitat structure (patches of canopy algae) differed between heavy and relatively lighter wave exposure (sheltered vs. exposed sides of islands), and whether wave exposure affected the response of prominent habitat-formers to varying disturbance regimes (different sizes of partial and complete canopy removal). Observations of naturally occurring patterns showed sheltered coasts to be characterised by small patches of fucoids, whereas exposed coasts were characterised by large patches of kelp. Canopy-gaps were larger at exposed than sheltered coasts, and mixed canopies constituted > 24% of the subtidal rocky habitat independently of wave exposure. Experimental disturbances showed the local density of kelps to affect recovery through greater recruitment to partial clearings (80% canopy removal). Fucalean algae, on the other hand...

Avian Habitat Preference in Tropical Forest Restoration in Southern Costa Rica

Reid, J. Leighton; Harris, J. Berton C.; Zahawi, Rakan A.
Fonte: Association of Tropical Biology Publicador: Association of Tropical Biology
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
56.1%
An important question for tropical forest restoration is whether degraded lands can be actively managed to attract birds. We censused birds and measured vegetation structure at 27 stations in young (6–9‐yr old) actively and passively restored pasture and old growth forest at Las Cruces Biological Station in southern Costa Rica. During 481 10‐min point counts, we detected a high diversity—186 species— of birds using the restoration area. Surprisingly, species richness and detection frequency did not differ among habitats, and proportional similarity of bird assemblages to old growth forest did not differ between restoration treatments. Bird detection frequency was instead explained by exotic grass cover and understory stem density—vegetation structures that were not strongly impacted by active restoration. The similarity of bird assemblages in actively and passively restored forest may be attributed to differential habitat preferences within and among feeding guilds, low structural contrast between treatments, or the effect of nucleation from actively restored plots into passively restored areas. Rapid recovery of vegetation in this recently restored site is likely due to its proximity to old growth forest and the lack of barriers to effective seed dispersal. Previous restoration studies in highly binary environments (i.e....

Effects of riparian vegetation on the structure of the marginal aquatic habitat and the associated fish assemblage in a tropical Brazilian reservoir

Beltrão,Gabriel de Barros Moreira; Medeiros,Elvio Sergio Figueredo; Ramos,Robson Tamar da Costa
Fonte: Instituto Virtual da Biodiversidade | BIOTA - FAPESP Publicador: Instituto Virtual da Biodiversidade | BIOTA - FAPESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
56.2%
Riparian zones represent areas of strong biological, physical and chemical interaction between terrestrial and aquatic ecosystems. These areas are usually typified by high diversity of fauna, flora and environmental processes. The present study evaluates the littoral habitat structure and its fish fauna related to associations between presence and absence of natural riparian vegetal cover, in a reservoir in northeastern Brazil. Sampling was performed on marginal areas where riparian vegetation was present and where it had been removed for the plantation of sugar cane. For each type of marginal area three replicate sites were sampled during the wet season. Data on the habitat structure (submerged elements and substrate composition), fish and water quality were collected. The data was analyzed using Shannon-Wiener's diversity index and Pielou's equitability. Non-metric Multidimensional Scaling and the Multi-Response Permutation Procedure were used to evaluate similarities between sites. The structure of the habitat was more diverse in sites were natural riparian vegetation was still present. Muddy substrate was more abundant in areas with riparian vegetation whereas sandy substrate was more abundant in areas where riparian vegetation had been removed. Measured physico-chemical parameters and nutrients remained nearly constant across all sites. Metynnis lippincottianus and Crenicichla menezesi were more associated with the habitat in areas where riparian vegetation was removed...

A Comparative Study of Habitat Complexity, Neuroanatomy, and Cognitive Behavior in Anolis Lizards

Powell, Brian James
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
Relevância na Pesquisa
46.24%

Changing environmental conditions may present substantial challenges to organisms experiencing them. In animals, the fastest way to respond to these changes is often by altering behavior. This ability, called behavioral flexibility, varies among species and can be studied on several levels. First, the extent of behavioral flexibility exhibited by a species can be determined by observation of that species' behavior, either in nature or in experimental settings. Second, because the central nervous system is the substrate determining behavior, neuroanatomy can be studied as the proximate cause of behavioral flexibility. Finally, the ultimate causation can be examined by studying ecological factors that favor the evolution of behavioral flexibility. In this dissertation, I investigate behavioral flexibility across all three levels by examining the relationship between habitat structure, the size of different structures within the brain and total brain size, and behavioral flexibility in six closely-related species of Puerto Rican Anolis lizards. Anolis lizards provide an excellent taxon for this study as certain species, including those used here, are classified as belonging to different ecomorphs and are morphologically and behaviorally specialized to distinct structural habitat types.

In order to determine the presence of behavioral flexibility in Anolis...

Influence of habitat structure on Pristimantis species (Anura: Craugastoridae) in a bamboo-dominated forest fragment in southwestern Amazonia; Influência da estrutura do habitat sobre espécies de Pristimantis (Anura: Craugastoridae) em um fragmento florestal dominado por bambu no sudoeste da Amazônia

López-Rojas, Jhon Jairo; Souza, Moisés Barbosa; Morato, Elder Ferreira
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiróz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiróz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 30/06/2015 ENG
Relevância na Pesquisa
66.3%
Structural and determinate factors for the composition of assemblages of species are diverse. Two theories attempt to explain the pattern of species composition in assemblies using different approaches—i.e., Niche Theory and Neutral Theory. Anurans have complex responses to habitat structure. Species of Pristimantis are good indicators for conservation because they are organisms with direct development. The effect of habitat structure on species of Pristimantis in a bamboo-dominated remnant forest located in southwestern Amazonia is analyzed herein. Active visual and auditory searches in 10 plots of the Biodiversity Research Program (PPBio) were conducted between November 2012 and May 2013. Four hundred and sixty individuals of five species were recorded: Pristimantis altamazonicus, P. diadematus, P. fenestratus, P. reichlei, and P. skydmainus. Neither spatial distance nor the structure of the habitat of the plots affected the composition of Pristimantis. The first axis of PCA explained 45.6% variation of the characterization habitat structure, correlated significantly with the number of Pristimantis, species increasing with trees between 10 ≤ dbh < 30 cm and decreased with density of bamboo. The increase in litter depth and canopy cover influenced in the occurrence of P. reichlei...

Contrasting effects of sampling scale on insect herbivores distribution in response to canopy structure

Neves,Frederico S.; Sperber,Carlos F.; Campos,Ricardo I.; Soares,Janaína P.; Ribeiro,Sérvio P.
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
46.23%
Species diversity of insect herbivores associated to canopy may vary local and geographically responding to distinct factors at different spatial scales. The aim of this study was to investigate how forest canopy structure affects insect herbivore species richness and abundance depending on feeding guilds´ specificities. We tested the hypothesis that habitat structure affects insect herbivore species richness and abundance differently to sap-sucking and chewing herbivore guilds. Two spatial scales were evaluated: inside tree crowns (fine spatial scale) and canopy regions (coarse spatial scale). In three sampling sites we measured 120 tree crowns, grouped in five points with four contiguous tree crowns. Insects were sampled by beating method from each crown and data were summed up for analyzing each canopy region. In crowns (fine spatial scale) we measured habitat structure: trunk circumference, tree height, canopy depth, number of ramifications and maximum ramification level. In each point, defined as a canopy region (coarse spatial scale), we measured habitat structure using a vertical cylindrical transect: tree species richness, leaf area, sum of strata heights and maximum canopy height. A principal component analysis based on the measured variables for each spatial scale was run to estimate habitat structure parameters. To test the effects of habitat structure upon herbivores...