Evidence of Competition Between Two Canopy Ant Species: Is Aggressive Behavior Innate or Shaped by a Competitive Environment?

Competition occurs in all ecological communities, although it has not always been experimentally tested as a structuring force in the distribution of species. We tested the hypothesis that the aggressiveness exhibited by Camponotus rufipes changes according to the pressures of a competitive environment. This is a dominant species in the montane forest of the Itacolomi State Park, Brazil, where Camponotus sericeiventris does not occur. Using bait traps in a field site where both species occur, (“Juiz de Fora” site) we showed that C. sericeiventris was able to remove C. rufipes workers at the same bait. In the laboratory, we used dyadic encounters to test workers from both species taken from colonies found in areas where both occur and where only C. rufipes was found. Camponotus rufipes from Itacolomi fought significantly less and was killed during the first few minutes in 60% of the events. On the other hand, the workers that co-existed with C. sericeiventris in the field were more aggressive, but less efficient fighters than the latter. This investigation demonstrated existence of competition between C. rufipes and C. sericeiventris, and also the lower aggressiveness of C. rufipes' individuals that did not co-exist in the field with C. sericeiventris

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

Efeitos da heterogeneidade ambiental e da sazonalidade em assembléias de formigas (hymenoptera: formicidae) no Parque Estadual do Rio Doce, MG.

Este trabalho objetivou explorar os padrões de distribuição das assembléias de formigas em resposta aos tipos estruturais de florestas no Parque Estadual do Rio Doce, MG. Foram comparadas bordas antropomórficas do parque e ecótones naturais, tais como orlas de lagoas com florestas, e florestas em bom estado de preservação. Investigou-se se a riqueza, a abundância de formigas e a composição de espécies modificam-se de acordo com os tipos estruturais de vegetação. Esperava-se maior riqueza de espécies no interior de mata alta, comparada com mata baixa ou ecótones. Além disso, testaram-se os efeitos da sazonalidade sobre as assembléias de formigas encontradas em cada vegetação estudada. Cada tipo vegetacional foi amostrado com no mínimo um transecto de 150 m de comprimento, somandose 30 armadilhas pit-fall por transecto. Duas amostragens foram feitas, uma na estação seca (setembro de 2001) e outra na estação úmida (janeiro de 2002). Para ambas as estações, a mata alta apresentou a menor média de riqueza e abundância de formigas, fato que corrobora a predição de que ecótones podem apresentar maior diversidade alfa. A riqueza e abundância média de formigas não foram diferentes entre mata baixa e orla de lagoa, ou entre esses habitats e borda de floresta. Os resultados obtidos sugerem que a perda de espécies devido ao desflorestamento provavelmente é maior do que se pensava anteriormente, e que para se compreender os padrões de diversidade e distribuição de espécies de insetos em ecossistemas tropicais deve-se levar em conta um desenho amostral mais compreensivo.This work aimed to explore the response of ant species assemblage to contrasting types of forests in a semideciduous stationary rainforest, in the Parque Estadual do Rio Doce, South Eastern Brazil. We compared antropomorphic borders of this park and natural ecotones, such as lake margins continuous with forests, as well as preserved forests far from ecotones. We investigated whether grounddwelling ant species richness, abundance and composition would change according to forest types and ecotones. We expected greater species richness in interior tall forest, compared with low forest or ecotone habitats. In addition, we tested the effect of climate seasonality on ant assemblages found in each studied vegetation type. Each forest type was surveyed based on a minimum transect sampling unit of 150 m long summing up 30 pit-falls per unit. Two sampling events, one in dry season(September of 2001) and another in the rainy season (January of 2002) were performed. For both seasons, tall forest presented greater total number of ant species, however lower mean ant species and abundance per trap than other forest types, thus corroborating the prediction that ecotones might present high alpha diversity. Mean species richness and abundance did not differ between interior low forest and lake edge, or between these habitats and reserve border. In general, species composition were not clearly defined by forest types. Results here found suggest that species loss or community dominance by generalist species, eventually due to deforestation, is probably a much greater problem than previously thought. However, to understand patterns of insect species diversity and distribution in tropical ecosystem should be taken in account much more comprehensive, spatially explicit sampling designs

Preliminary contribution to the knowledge of Coleoptera Buprestidae from Atlantic rainforest regions of Rio Doce and Itacolomi Parks of Minas Gerais. The genera Agrilus Curtis, 1825, Autarcontes Waterhouse, 1887, and Geralius Harold, 1869.

A checklist of species belonging to Agrilus Curtis, 1825, AutarcontesWaterhouse, 1887, and Geralius Harold, 1869 genera found in Rio Doce and Itacolomi Estadual Parks is given. 19 species are listed, 5 of which are new for the science and here described: Agrilus pirilampo n. sp., A. disorientatus n. sp., A. coal n. sp., A. rarestriatus n. sp., A. taediosus n. sp. Most species were found in one sampling season and reflect a quite favourable rainforest for xylophagous species. The high dominance of Leguminosae large tree species could be related to this pattern

Gymnetis pudibunda, um elo funcional entre o dossel e o solo das florestas.

Submitted by Ana Caroline Calderaro ([email protected]) on 2016-08-02T12:30:51Z No. of bitstreams: 1 ARTIGO_GymnetisPudibundaElo1.pdf: 551431 bytes, checksum: ec0a91a4b9e7b4ce2e51a2866c75bc88 (MD5)Approved for entry into archive by Oliveira Flávia ([email protected]) on 2016-08-02T14:08:43Z (GMT) No. of bitstreams: 1 ARTIGO_GymnetisPudibundaElo1.pdf: 551431 bytes, checksum: ec0a91a4b9e7b4ce2e51a2866c75bc88 (MD5)Made available in DSpace on 2016-08-08T14:40:37Z (GMT). No. of bitstreams: 1 ARTIGO_GymnetisPudibundaElo1.pdf: 551431 bytes, checksum: ec0a91a4b9e7b4ce2e51a2866c75bc88 (MD5) Previous issue date: 201

Genetic, morphological and spatial characterization of two populations of Mabea fistulifera mart. (Euphorbiaceae), in different successional stages.

Two populations of Mabea fistulifera (Euphorbiaceae) located at Rio Doce State Park (Minas Gerais, Brazil) in places characterized as in different successional stages, were investigated through genetic and ecological traits. Twenty randomly chosen individuals from each population had its genetic data assessed by 43 RAPD markers and were also evaluated through five morphologic traits and its spatial distribution. Both Shannon’s index and AMOVA reveled that most of the genetic variation was found between individuals within populations and about 9% of variation was located between populations. Moreover, populations differed genetically, but presented similar values of genetic diversity. Morphologic data showed differences between populations. Significant correlations among matrix of genetic, geographic and morphologic distances were obtained considering both populations, and spatially closer individuals were more similar genetically, characterizing genetic substructured populations