Metacommunity patterns of Amazonian Odonata: The role of environmental gradients and major rivers

Background. We identified and classified damselfly (Zygoptera) and dragonfly (Anisoptera) metacommunities in Brazilian Amazonia, relating species distribution patterns to known biological gradients and biogeographical history. We expected a random distribution of both Zygoptera and Anisoptera within interfluves. At the Amazonian scale, we expected Anisoptera metacommunities to be randomly distributed due to their higher dispersal ability and large environmental tolerance. In contrast, we expected Zygoptera communities to exhibit a Clementsian pattern, limited by the large Amazonia rivers due to their low dispersal ability. Methods. We used a dataset of 58 first-to-third order well-sampled streamlets in four Amazonian interfluves and applied an extension of the Elements of Metacommunity Structure (EMS) framework, in which we order Zygoptera and Anisoptera metacommunities by known spatial and biogeographic predictors. Results. At the Amazonian scale, both Zygoptera and Anisoptera presented a Clementsian pattern, driven by the same environmental and biogeographical predictors, namely biogeographic region (interfluve), annual mean temperature, habitat integrity and annual precipitation. At the interfluve scale, results were less consistent and only partially support our hypothesis. Zygoptera metacommunities at Guiana and Anisoptera metacommunities at Tapajós were classified as random, suggesting that neutral processes gain importance at smaller spatial scales. Discussion. Our findings were consistent with previous studies showing that environmental gradients and major rivers limit the distribution of Odonata communities, supporting that larger Amazonian rivers act as barriers for the dispersal of this group. In addition, the importance of habitat integrity indicates that intactness of riparian vegetation is an important filter shaping metacommunity structure of Amazonian stream Odonata.This work was supported by the Coordination for the Improvement of Higher Education Personnel—CAPES (120147/2016-01), Brazil National Council for Scientific and Technological Development—CNPq (303252/2013-8, 574008/2008-0, 305542/2010-9,478884/2008-7, 314523/2014-6), Brazilian Agriculture Research Corporation EMBRAPA (SEG 02.08.06.005.00), the UK Darwin Initiative (17023), The Nature Conservancy and the Natural Environment Research Council—NERC (NE/F01614X/1 and NE/G000816/1)

Distribuição de Cladocera ao longo de um gradiente ambiental no ecótono Cerrado-Amazônia : um estudo preliminar

Objetivo: Nosso objetivo neste estudo é entender a distribuição de espécies de Cladocera ao longo de um gradiente ambiental em florestas e paisagens agrícolas no sul da Amazônia. Métodos Coletamos comunidades de Cladocera e variáveis ambientais em cinco riachos e verificamos suas associações com uma Análise de Redundância. Resultados Acroperus tupinamba, Alonella dadayi e Kisakiellus aweti foram mais associados a locais com maior cobertura do dossel. Já Anthalona neotropica, Anthalona verrucose e Flavalona iheringula ocorreram exclusivamente no local com maior profundidade de talvegue. Conclusões Se estes resultados forem confirmados, as comunidades de Cladocera de riachos são afetadas por mudanças no uso da terra. Mais estudos nessa linha são extremamente necessários para reduzir essa lacuna de conhecimento.Aim Our objective in this study is to understand Cladocera species distribution along an environmental gradient in forest and cropland landscapes in the southern Amazon. Methods We collected Cladocera communities and environmental variables from five streams and verified their associations with a Redundancy Analysis. Results Acroperus tupinamba, Alonella dadayi e Kisakiellus aweti were mostly associated to sites with higher canopy cover. Anthalona neotropica, Anthalona verrucose and Flavalona iheringula occurred exclusively in site with more thalweg depth. Conclusions If these results are confirmed Cladocera stream communities are affected by changes in land use. Further studies in this line are extremely necessary to reduce this knowledge gap

Metacommunity patterns of Amazonian Odonata: the role of environmental gradients and major rivers

Background We identified and classified damselfly (Zygoptera) and dragonfly (Anisoptera) metacommunities in Brazilian Amazonia, relating species distribution patterns to known biological gradients and biogeographical history. We expected a random distribution of both Zygoptera and Anisoptera within interfluves. At the Amazonian scale, we expected Anisoptera metacommunities to be randomly distributed due to their higher dispersal ability and large environmental tolerance. In contrast, we expected Zygoptera communities to exhibit a Clementsian pattern, limited by the large Amazonia rivers due to their low dispersal ability. Methods We used a dataset of 58 first-to-third order well-sampled streamlets in four Amazonian interfluves and applied an extension of the Elements of Metacommunity Structure (EMS) framework, in which we order Zygoptera and Anisoptera metacommunities by known spatial and biogeographic predictors. Results At the Amazonian scale, both Zygoptera and Anisoptera presented a Clementsian pattern, driven by the same environmental and biogeographical predictors, namely biogeographic region (interfluve), annual mean temperature, habitat integrity and annual precipitation. At the interfluve scale, results were less consistent and only partially support our hypothesis. Zygoptera metacommunities at Guiana and Anisoptera metacommunities at Tapajós were classified as random, suggesting that neutral processes gain importance at smaller spatial scales. Discussion Our findings were consistent with previous studies showing that environmental gradients and major rivers limit the distribution of Odonata communities, supporting that larger Amazonian rivers act as barriers for the dispersal of this group. In addition, the importance of habitat integrity indicates that intactness of riparian vegetation is an important filter shaping metacommunity structure of Amazonian stream Odonata

Efeito de borda sobre a camada de serapilheira em área de cerradão no leste de Mato Grosso

A fragmentação da vegetação ocasiona efeito de borda, alterando o microclima, a composição das espécies e suas interações bióticas e abióticas. A serapilheira é crucial para a ciclagem de nutrientes nas florestas. O objetivo deste artigo foi verificar a influência de borda de vegetação nos atributos da camada de serapilheira em área de cerradão, testando a hipótese de que a distância da borda está diretamente relacionada com a biomassa e a proporção de folhas na camada de serapilheira. Foram coletadas amostras da camada de serapilheira em transeções de 95m em cinco áreas de cerradão do leste mato-grossense. Foi estimado um total de 6.724,44 kg/ha-1 de serapilheira, sendo 72,2% folhas, 27,8% ramos, 0,07% frutos e 0,004% flores. A distância da borda apresentou relação positiva e significativa com a espessura, massa seca, volume e massa de fração foliar da serapilheira. Essas informações contribuem para o entendimento de um componente pouco estudado em áreas de cerradão, demonstrando que a fragmentação dessas áreas altera a estrutura da camada de serapilheira, podendo causar prejuízos a funções e serviços ecossistêmicos, com possíveis reflexos futuros na diversidade de espécies

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Do landfills affect the environmental quality of nearby streams?

When inappropriately disposed, solid waste may contaminate the soil, water and air, leading to severe negative impacts on biodiversity. The Brazilian National Policy for Solid Waste (PNRS) requires municipalities to ensure the environmental quality of landfills. Accordingly, our objective was to evaluate the community of aquatic insects in a stream with stretches downstream and upstream of a sanitary landfill. Our hypothesis was that there will be no differences in insect community between the stretches (downstream and upstream) on the basis of the premise that landfills abiding by the PNRS do not cause environmental damage to nearby areas. There was no change in any aspect of the composition of the macroinvertebrate community as a result of the landfill. The only changes observed in the macroinvertebrate communities occurred between the dry and rainy seasons, which were related to the seasonality and consequent changes in the environmental conditions of the water over the year. Our study, although limited, showed primary and pioneering evidence that the PNRS can contribute positively to the conservation of the biotic quality of aquatic environments, further reinforcing the need for immediate implementation of the PNRS throughout the country.Quando mal depositados, os resíduos sólidos contaminam o solo, a água e o ar, causando sérios problemas para a conservação da biodiversidade. A Política Nacional de Resíduos Sólidos (PNRS) prevê que os municípios garantam a qualidade ambiental nas regiões dos aterros sanitários. Neste contexto, nosso objetivo foi avaliar comunidades de insetos aquáticos de um riacho com trechos a jusante e montante de um aterro sanitário. Nossa hipótese é que não haverá diferenças na comunidade entre os trechos (jusante e montante) partindo da premissa que aterros que seguem a PNRS não causam danos ambientais nas áreas adjacentes. Não houve alteração em qualquer aspecto da comunidade relacionada ao aterro sanitário. A única mudança observada na comunidade ocorreu entre as estações seca e chuvosa, que se relacionam com a sazonalidade e suas mudanças nas condições ambientais da água ao longo do ano. Nosso estudo, embora breve, mostra evidências primárias e pioneiras de que o PNRS pode contribuir positivamente para a conservação da qualidade biótica dos ambientes aquáticos, reforçando ainda mais a necessidade de sua implementação imediata em todo o país