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1.
Environ Manage ; 61(4): 687-699, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29404739

RESUMO

The multiple scale of stream networks spatial organization reflects the hierarchical arrangement of streams habitats with increasingly levels of complexity from sub-catchments until entire hydrographic basins. Through these multiple spatial scales, local stream habitats form nested subsets of increasingly landscape scale and habitat size with varying contributions of both alpha and beta diversity for the regional diversity. Here, we aimed to test the relative importance of multiple nested hierarchical levels of spatial scales while determining alpha and beta diversity of caddisflies in regions with different levels of landscape degradation in a core Cerrado area in Brazil. We used quantitative environmental variables to test the hypothesis that landscape homogenization affects the contribution of alpha and beta diversity of caddisflies to regional diversity. We found that the contribution of alpha and beta diversity for gamma diversity varied according to landscape degradation. Sub-catchments with more intense agriculture had lower diversity at multiple levels, markedly alpha and beta diversities. We have also found that environmental predictors mainly associated with water quality, channel size, and habitat integrity (lower scores indicate stream degradation) were related to community dissimilarity at the catchment scale. For an effective management of the headwater biodiversity of caddisfly, towards the conservation of these catchments, heterogeneous streams with more pristine riparian vegetation found within the river basin need to be preserved in protected areas. Additionally, in the most degraded areas the restoration of riparian vegetation and size increase of protected areas will be needed to accomplish such effort.


Assuntos
Agricultura , Biodiversidade , Meio Ambiente , Insetos , Rios , Animais , Brasil , Ecossistema , Humanos , Qualidade da Água
2.
Environ Monit Assess ; 188(7): 441, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27353133

RESUMO

Selective logging has become a major source of threats to tropical forest, bringing challenges for both ecologists and managers to develop low-impact forestry. Reduced-impact logging (RIL) is a prominent activity accounting for such forestry practices to prevent strong forest disturbances. Our aims were to evaluate the effects of RIL on insect communities of forested streams from Eastern Amazon and to test the hypothesis of negative effects of RIL on species richness, abundance, and functional feeding groups of aquatic insect assemblages. Neither of the evaluated metrics of the studied assemblages were negatively affected by RIL. Environmental metrics, such as substrate heterogeneity, woody canopy cover, and hill slope height, varied more among RIL streams than in reference streams, indicating a gradient according to logging impacts, and are suitable candidates to monitor RIL impacts in Amazonian streams. In addition, the PHI index also varied among REF and RIL, according to age class and year of logging, which could reflect trends to recover the forest structure after logging in a time frame of only 10 years. We conclude that RIL impacts have not had detrimental impacts on insect communities, but have changed little of the environmental conditions, especially of the riparian vegetation around streams.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Agricultura Florestal , Florestas , Insetos/crescimento & desenvolvimento , Animais , Biodiversidade , Brasil , Ecossistema , Insetos/classificação
3.
Biota neotrop. (Online, Ed. port.) ; 11(2): 347-355, Apr.-June 2011. mapas, tab
Artigo em Português | LILACS | ID: lil-596888

RESUMO

Trichoptera comprise one of the most diverse and abundant group among aquatic insects in stream ecosystems around the world. Currently, about 500 species are known from Brazil, but only sixteen species have been recorded from the State of Mato Grosso. The present article provides a list of known species and new records of caddisflies collected in the eastern region over the past 10 years and incorporated in the entomological section of the Coleção Zoobotânica "James A. Ratter" of University of Mato Grosso State, Nova Xavantina (CZNX). Specimens were recorded from tributaries of the Rio Xingu and of the Rio das Mortes and from lakes and rivers of the Bananal floodplain. Altogether, 30 species are reported, being seven new records from Mato Grosso. Achoropsyche duodencimpunctata (Navás, 1916), Amazonatolica hamadae Holzenthal & Pes, 2004, Nectopsyche nigricapilla (Navás, 1920), Nectopsyche quatourguttata (Navás, 1922), Macronema hageni Banks, 1924, Macrostemum santaeritae (Ulmer, 1905) and Cyrnellus fraternus (Banks, 1905) are new records from the State. Nectopsyche quatourguttata and N. nigricapilla configure the first records to Brazil. Additionally, Blepharopus diaphanus Kolenati, 1859, Macrostemum arcuatum (Erichson, 1848), Macrostemum ulmeri (Banks, 1913) are new regional records and provide additional material to species distribution from State.


A ordem Trichoptera compreende uma das mais diversas e abundantes ordens dentre todos os grupos de insetos aquáticos encontrados em rios ao redor do mundo. Atualmente, cerca de 500 espécies são conhecidas no Brasil, mas apenas 16 espécies foram registradas para o Estado de Mato Grosso. O presente estudo apresenta uma lista das espécies conhecidas e novos registros, a partir de material coletado na região leste do estado nos últimos 10 anos e incorporado à seção entomológica da Coleção Zoobotânica "James A. Ratter" da Universidade do Estado de Mato Grosso, Nova Xavantina (CZNX). Foram registrados espécimes de tributários do Rio Xingu e do médio Rio das Mortes e em lagos e rios da planície de inundação do Bananal. Ao todo são reportadas 30 espécies, sendo sete novos registros para o Estado de Mato Grosso. Achoropsyche duodencimpunctata (Navás, 1916), Amazonatolica hamadae Holzenthal & Pes, 2004, Nectopsyche nigricapilla (Navás, 1920), Nectopsyche quatourguttata (Navás, 1922), Macronema hageni Banks, 1924, Macrostemum santaeritae (Ulmer, 1905) e Cyrnellus fraternus (Banks, 1905) são novos registros para Mato Grosso. Nectopsyche quatourguttata e N. nigricapilla são registradas pela primeira vez para o Brasil. Adicionalmente, Blepharopus diaphanus Kolenati, 1859, Macrostemum arcuatum (Erichson, 1848) e Macrostemum ulmeri (Banks, 1913) configuram novos registros regionais e provêem material adicional para a distribuição das espécies no Estado.

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