The geometry of spatial analyses: Implications for conservation biologists

Most conservation biology is about the management of space and therefore requires spatial analyses. However, recent debates in the literature have focused on a limited range of issues related to spatial analyses that are not always of primary interest to conservation biologists, especially autocorrelation and spatial confounding. Explanations of how these analyses work, and what they do, are permeated with mathematical formulas and statistical concepts that are outside the experience of most working conservationists. Here, we describe the concepts behind these analyses using simple simulations to exemplify their main goals, functions and assumptions, and graphically illustrate how processes combine to generate common spatial patterns. Understanding these concepts will allow conservation biologists to make better decisions about the analyses most appropriate for their problems. © 2011 ABECO

Riqueza e Distribuição de Espécies de Borrachudos (Diptera: Simuliidae) na Região da Chapada Diamantina, BA

Taxonomically, blackflies (Simuliidae) are among the best-known aquatic insects in Brazil. However, information on their distribution is lacking for many regions. We sampled simuliids in 50 streams in the Chapada Diamantina region, State of Bahia, located in three distinct geographical areas, 20 at Lençóis, 18 at Mucugê, and 12 at Rio de Contas. We analyzed simuliid species richness and distribution in the Chapada Diamantina area as a whole, as well as in each of the three distinct geographical areas. We collected 20 species, three of which were not yet described and two were described after our sampling. The three areas are distinct in relation to environmental variables, mainly owing to differences in altitude and water pH. Four species were restricted to Rio de Contas, while four other species were restricted to Mucugê. Sixteen species were present in Mucugê and fifteen in Rio de Contas. Only twelve species were present in Lençóis, despite the higher sampling effort. Rio de Contas appears to be the area that harbors the highest species richness. Species richness was related to environmental factors only when evaluated on a small spatial scale (i.e. when each area was analyzed separately). Although we have not tested for causal relationships, our findings agree with other studies that showed that pH and altitude are important factors with which species richness and species distribution appear to be associated

O Vão do Paranã (GO) como área chave para conservação de macroinvertebrados bentônicos

Foi feita uma indicação de área prioritária para conservação da biota de invertebrados aquáticos na bacia hidrográfica do rio Paranã-GO, utilizando a comunidade de macroinvertebrados bentônicos como ferramenta de bioindicação. Os invertebrados foram coletados pela metodologia de avaliação rápida, utilizando redes manuais de abertura de malha de 2 mm durante 15 minutos de coleta ativa, em ambientes de correnteza com substrato pedregoso. A escolha da área foi feita seguindo três critérios:1- Raridade do táxon; 2- Representatividade e complementaridade dos pontos amostrados e 3- Conectividade. A área selecionada inclui trechos de rio com diferentes características hidrológicas, que refletemas diferentes características de composição da biota. A área prioritária para conservação proposta neste trabalho inclui três microbacias: as dos rios São Bartolomeu, Corrente e São Mateus. A área indicadaé uma região de expansão de atividades antrópicas e não está atualmente protegida por unidades de conservação federais ou estaduais. As informações geradas nesse trabalho podem subsidiar uma gestão mais eficiente para a conservação da biota aquática da bacia do rio Paranã

O Vão do Paranã (GO) como área chave para conservação de macroinvertebrados bentônicos

Foi feita uma indicação de área prioritária para conservação da biota de invertebrados aquáticos na bacia hidrográfica do rio Paranã-GO, utilizando a comunidade de macroinvertebrados bentônicos como ferramenta de bioindicação. Os invertebrados foram coletados pela metodologia de avaliação rápida, utilizando redes manuais de abertura de malha de 2 mm durante 15 minutos de coleta ativa, em ambientes de correnteza com substrato pedregoso. A escolha da área foi feita seguindo três critérios:1- Raridade do táxon; 2- Representatividade e complementaridade dos pontos amostrados e 3- Conectividade. A área selecionada inclui trechos de rio com diferentes características hidrológicas, que refletemas diferentes características de composição da biota. A área prioritária para conservação proposta neste trabalho inclui três microbacias: as dos rios São Bartolomeu, Corrente e São Mateus. A área indicadaé uma região de expansão de atividades antrópicas e não está atualmente protegida por unidades de conservação federais ou estaduais. As informações geradas nesse trabalho podem subsidiar uma gestão mais eficiente para a conservação da biota aquática da bacia do rio Paranã

Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters

Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scales of local stream sites, drainage basins and entire regions. We standardized the spatial extent of the study areas by resampling regional richness based on subsets of sites with similar extents. We examined differences in genus richness and assemblage abundance patterns between the regions using graphical and statistical modelling approaches. Results: We found that while genus accumulation and rank-abundance curves were relatively similar at the regional scale between Finland and Brazil, regional genus richness was higher in the latter but regional abundance much higher in the former region. These regional patterns for richness and abundance were reproduced by basin and local genus richness that were higher in Brazil than in Finland, and assemblage abundance that was much higher in Finland than in Brazil. The magnitude of the difference in genus richness between Brazil and Finland tended to increase from local through basin to regional scales. Main conclusions: Our findings suggest that factors related to evolutionary diversification might explain differences in genus richness between these two climatically different regions, whereas higher nutrient concentrations of stream waters might explain the higher abundance of insects in Finland than in Brazil.Peer reviewe

INFLUÊNCIA DO REGIME DE QUEIMADAS SOBRE A RIQUEZA E COMPOSIÇÃO FLORÍSTICA DE UMA SAVANA ISOLADA NA AMAZÔNIA - PELD OESTE DO PARÁ

Pouco se conhece sobre os efeitos de longo prazo do fogo sobre a composição florística das savanas amazônicas isoladas. Dados do regime de queimadas foram coletados entre 1997 e 2017 e relacionados à composição florística em parcelas de 3,75 hectares distribuídos por 10.000 hectares de savana na região de Alter do Chão-PA, como parte das pesquisas desenvolvidas pelo PELD Oeste do Pará. As análises foram realizadas para o conjunto total de espécies e para os hábitos de plantas em particular (árvores, arbustos, gramíneas + ciperáceas, ervas dicotiledôneas e lianas). Registramos 115 espécies de plantas, em 43 famílias e 90 gêneros, sendo 24 espécies de árvores, 43 de arbustos, 37 de ervas (incluindo as gramíneas) e 11 de lianas. Trinta e uma espécies estavam presentes em mais de 90 % das parcelas, com maior frequência relativa de Trachypogon spicatus (L.f.) Kuntze, Chamaecrista ramosa (Vogel) H.S.Irwin & Barneby, Rhynchospora hirsuta (Vahl) Vahl e Paspalum carinatum Humb. & Bonpl. ex Flüggé. Nossas análises sugerem que o fogo promoveu mudanças na vegetação da savana estudada, reduzindo a riqueza de espécies e modificando sua composição independentemente dos hábitos avaliados (exceto gramíneas). No entanto, a detecção dessas mudanças só foi possível através da obtenção de uma longa série de dados de fogo e medidas da vegetação realizadas em campo. Por isso, a manutenção de Projetos Ecológicos de Longa Duração é fundamental para que seja possível prever e manejar os padrões em curso, resultando na melhoria da gestão da paisagem e conservação da biodiversidade das savanas amazônicas isoladas.INFLUENCE OF THE FIRE REGIME ON THE SPECIES RICHNESS AND FLORISTIC COMPOSITION OF AN ISOLATED AMAZONIAN SAVANNA - PELD OESTE DO PARÁ: Little is known about the long-term effects of fire on the floristic composition of isolated Amazonian savannas. Data from the burn regime were collected between 1997 and 2017 and related to the floristic composition in plots of 3.75 hectares spread over 10.000 hectares of savanna in the Alter do Chão-PA region, as part of the research developed by PELD Oeste do Pará. Analyzes were performed for the total species and for each plant habitat in particular (trees, shrubs, grasses + forbs, dicotyledonous herbs and lianas). We recorded 115 plant species in 43 families and 90 genera, being 24 tree species, 43 shrub species, 37 herbaceous species (including grasses and forbs) and 11 liana species. Thirty-one species were present in more than 90 % of the plots, with the highest relative frequency of Trachypogon spicatus (L.f.) Kuntze, Chamaecrista ramosa (Vogel) H. Irwin & Barneby, Rhynchospora hirsuta (Vahl) Vahl and Paspalum carinatum Humb. & Bonpl. ex Flüggé. Fire have promoted changes in the vegetation of the studied savanna, reducing species richness and modifying its composition independently for each plant habitat (except grasses). However, the detection of these changes was only possible through a long series of fire data and vegetation measurements carried out in the field. Therefore, the maintenance of Long Term Ecological Projects is essential to predict and manage current patterns, which results in improved landscape management and biodiversity conservation of the isolated Amazonian savannas

How far can we go in simplifying biomonitoring assessments? An integrated analysis of taxonomic surrogacy, taxonomic sufficiency and numerical resolution in a megadiverse region

The need for biodiversity conservation is increasing at a rate much faster than the acquisition of knowledge of biodiversity, such as descriptions of new species and mapping species distributions. As global changes are winning the race against the acquisition of knowledge, many researchers resort to the use of surrogate groups to aid in conservation decisions. Reductions in taxonomic and numerical resolution are also desirable, because they could allow more rapid the acquisition of knowledge while requiring less effort, if little important information is lost. In this study, we evaluated the congruence among 22 taxonomic groups sampled in a tropical forest in the Amazon basin. Our aim was to evaluate if any of these groups could be used as surrogates for the others in monitoring programs. We also evaluated if the taxonomic or numerical resolution of possible surrogates could be reduced without greatly reducing the overall congruence. Congruence among plant groups was high, whereas the congruence among most animal groups was very low, except for anurans in which congruence values were only slightly lower than for plants. Liana (Bignoniaceae) was the group with highest congruence, even using genera presence-absence data. The congruence among groups was related to environmental factors, specifically the clay and phosphorous contents of soil. Several groups showed strong spatial clumping, but this was unrelated to the congruence among groups. The high degree of congruence of lianas with the other groups suggests that it may be a reasonable surrogate group, mainly for the other plant groups analyzed, if soil data are not available. Although lianas are difficult to count and identify, the number of studies on the ecology of lianas is increasing. Most of these studies have concluded that lianas are increasing in abundance in tropical forests. In addition to the high congruence, lianas are worth monitoring in their own right because they are sensitive to global warming and the increasing frequency and severity of droughts in tropical regions. Our findings suggest that the use of data on surrogate groups with relatively low taxonomic and numerical resolutions can be a reliable shortcut for biodiversity assessments, especially in megadiverse areas with high rates of habitat conversion, where the lack of biodiversity knowledge is pervasive. (c) 2012 Elsevier Ltd. All rights reserved.PhD scholarship from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq