Determinants of Termite Species Taxonomic, Phylogenetic, and Functional Diversity in the Amazonian Forest

The distribution of species in space is determined by the species dispersal capacity, adaptation to environmental conditions, and response to predators and competitors. To determine the importance of dispersal limitation, environmental filtering, and species interactions on the distribution of species in the Brazilian Amazonian forest, I sampled termites in a large area of Brazil. I investigated patterns in species occurrence that could indicate competition and predation structuring termite communities, and analyzed the association of termite abundance and species richness with the density of ant predators. The spatial distribution of termites, and their association with climatic and edaphic conditions were also used to infer about the effects of dispersal limitation and environmental filtering. A total of 271 termite species and 4,389 colonies was found in the 148 transects sampled. Predator density was the strongest predictor of termite abundance and species richness at small spatial scales, but the turnover in termite species composition was mostly associated with measures of soil texture. At broad spatial scales, soil chemistry, climate, and isolation by distance were associated with termite abundance, species richness, and species composition. These results suggest that both species interactions, their association with the environment, and their dispersal capacity determine their distribution. Nevertheless, dispersal limitation seem to be stronger over large areas, whereas environmental filtering can act both at small and large geographic scales

Uma nova espécie de térmita do gênero Dihoplotermes Araujo (Blattaria, Isoptera, Termitidae) da floresta Amazônica Brasileira

Dihoplotermes, a previously monotypic genus, is now composed of two species. Dihoplotermes taurus sp. nov., a new Termitinae termite species, is illustrated and described based on morphological characters from soldiers, workers, and imago. The new species is distinguished from Dihoplotermes inusitatus Araujo by having a spine-like protuberance with blunt apex on the postmentum, the presence of a spine on the gizzard and the absence of dimorphic soldiers. Furthermore, the internal morphological characteristics of a Dihoplotermes worker are described for the first time. Both internal and external morphological characters were used to improve the characterization of the species.Dihoplotermes, que era um gênero monotípico, agora é composto por duas espécies. Dihoplotermes taurus sp. nov., uma nova espécie de cupim Termitinae, é descrita e ilustrada com base nos caracteres morfológicos dos soldados, operários e imago. A nova espécie se diferencia de Dihoplotermes inusitatus Araujo por apresentar uma protuberância em forma de espinho não pontiagudo no posmento, presença de um espinho na moela e ausência de soldados dimórficos. Além disso, são descritas pela primeira vez as características morfológicas internas de um operário de Dihoplotermes e utilizamos ambos caracteres morfológicos internos e externos para melhor caracterizar as espécies

Prezygotic resource-allocation dynamics and reproductive trade-offs in calymperaceae (Bryophyta)

PREMISE OF THE STUDY: Resource allocation is difficult to characterize in plants because of the challenges of quantifying gametes and propagules. We surveyed six sympatric, unisexual species in the family Calymperaceae (Bryophyta) to test for trade-offs in prezygotic sexual and asexual expression and density-dependent survivorship of female gametangia. METHODS: We tallied gametangial and asexual propagule output for 1820 shoots from 17 populations of six species at monthly intervals during one year (2010–2011) in a central Amazonian forest. Generalized linear mixed models were used to test for trade-offs in sexual and asexual expression and density-dependent senescence probability of gametangia. Precipitation and microsite variables were also included in the model. KEY RESULTS: For all species, sexual and asexual expression were positively correlated with mean monthly precipitation. Asexually expressing shoots produced significantly fewer gametangia than nonexpressing ones, and the probability of senescence increased with shoot density. Archegonium density per shoot was also consistently lower than the modeled optimum to maximize the number of receptive archegonia. CONCLUSIONS: Trade-offs among reproductive strategies and positive density-dependent senescence of female gametangia suggest that prezygotic sexual and asexual expression come at a tangible investment. However, the apparently inefficient resource-allocation dynamics in the production of female gametangia makes the possible advantages of squandering such investments unclear. One possibility is that the study populations, like those of many dioicous mosses, are skewed toward expressing females with low sporophyte production, which would suggest that asexual reproduction predominates and upstages efficient resource allocation in prezygotic investment. © 2016 Botanical Society of America

Defining a termite sampling protocol for ecological studies: An effective method to increase statistical power

Protocols for sampling soil fauna are usually designed to increase the number of species found when one or a few plots are heavily sampled. However, no previous study has evaluated how the number of plots sampled affect the power of statistical tests associating community composition and the environment. We test the effect of the number of transects (plots) and the sampling effort in each transect on the representation of trophic groups and on the association of termite species composition with environmental variables. Data were collected in 30 250m-long transects located in central Amazonia. Each transect was subdivided into 10 non-contiguous sections of 5 m × 2 m each (separation of 22 m between sections). We rarefied the data to determine arrangement of transects and sections that 1) best characterizes the distribution of species in trophic groups and 2) maximizes the chances to detect true associations between termite species composition and environmental predictor variables. When more than six transects (plots) were sampled with at least five non-contiguous sections each, the distribution of trophic groups was similar to the known distribution for the area. However, the detection of the association between termite species composition and environmental variables was more easily detected by increasing the number of transects sampled (plots) than the sampling effort per transect. Our results suggest that spreading sampling effort into at least 15 transects (plots) improves the ability to detect trophic groups and the performance of regression tests associating the composition of species with the environment. © 2019 Elsevier Masson SA

Borboletas (Lepidoptera: Hesperioidea e papilionoidea) de fragmentos de floresta ombrófila mista, rio grande do sul, Brazil

The landscape of Campos de Cima da Serra region, at North of Rio Grande do Sul State, is fragmented and its biodiversity threatened due the impact of human activities. This study investigated the butterfly fauna in fragments of Mixed Ombrophilous Forest native vegetation (VN) and anthropic area (AA) at Soledade and Mormaço municipalities. 1,181 butterflies were registered and distributed in 125 species, after 108 net-hours through active search sampling with entomological net. VN registered 72 species and 470 individuals, while AA had 89 and 711, respectively. Heliconius erato phyllis (Fabricius, 1775), Biblis hyperia nectanabis (Fruhstorfer, 1909) and Dryas iulia alcionea (Cramer, 1779) were the three most abundant species in general and in AA, while Strephonota elika (Hewitson, 1867), H. erato phyllis and Morpho helenor achillides C. Felder & R. Felder, 1867 were the most abundant in VN. Thirty-three species are considered new records for Mixed Ombrophilous Forest in Rio Grande do Sul State. The results show the contribution of butterfly rapid inventories as source of subsidies to biodiversity conservation

Mesofauna do solo em diferentes sistemas de uso da terra no alto Rio Solimões, AM

The mesofauna has an important function in the soil and it is represented mainly by Acari Oribatida and Collembola. We report the first data on the density and diversity of the soil mesofauna in Benjamin Constant, Amazonas State, Brazil. The following systems were evaluated: primary forest, secondary forest, agroforestry system, cultivated areas and pastures. A total of 101 samples were collected 100 m apart from each other and specimens were collected by using Berlese-Tullgren method. The highest density was registered in secondary forest (29,776 specimens.m-2). Acari Oribatida was the dominant group (7.072 specimens.m-2) in the pasture, suggesting that mites show higher capacity of adaptation to disturbed environments and/or due to the presence of gregarious species. The density of Collembola (5,632 specimens.m-2) was higher in secondary forest. Formicidae was the dominant group (27,824 specimens.m-2) and its highest density occurred in the secondary forest (12,336 specimens.m-2). Seven species and ten morphospecies of Isoptera and three species of Symphyla were identified. The highest density and diversity were found in secondary forest. One supposes that the low density of mesofauna found in all of the studied systems is being influenced by soil structure and composition as well as litter volume. For SUT, the composition of taxonomic groups in the cultivated areas is similar to the one found in primary forest, while the groups found in the agroforestry system are similar to those in the pasture, which may help to decide on land use strategies