Forest Fragment In Brazil Research Articles

Effectiveness of sampling methods and further sampling for accessing spider diversity: a case study in a Brazilian Atlantic rainforest fragment

Abstract The current biodiversity crisis makes the quantification of the diversity and the description of organism distribution particularly pressing. Biological inventories are among the most effective ways to improve the knowledge about local biota, but they can be very time and money‐consuming. The determination of adequate sampling effort and the selection of cost‐effective collecting methods are critical issues. In this article, a spider diversity inventory in an Atlantic semi‐deciduous forest fragment in Brazil was used to compare the efficiency of three collecting methods in two different seasons in order to propose an optimised sampling protocol. The worthiness of increasing sampling effort in the target area and similar tropical ecosystems was estimated and evaluated in terms of its cost‐effectiveness. For a better sampling of the spider community, it is suggested that a proportion of 55, 29 and 16% of total sampling hours should be dedicated to nocturnal hand collecting (NHC), pitfall traps and beating trays, respectively, in the rainy season. If only one method can be applied, the most efficient in terms of species per sampling is the NHC. A completeness of 70% of the estimated spider species richness (as predicted by the Chao1 estimator) was observed in the complete inventory and increasing sampling effort in the studied area may be highly ineffective when the costs involved are considered. Other studies in similar tropical rainforest areas also presented completeness around 70%, which might be a threshold from which the sampling effort necessary to raise the observed species richness substantially starts to be ineffective.

Functional Extinction of Birds Drives Rapid Evolutionary Changes in Seed Size

Local extinctions have cascading effects on ecosystem functions, yet little is known about the potential for the rapid evolutionary change of species in human-modified scenarios. We show that the functional extinction of large-gape seed dispersers in the Brazilian Atlantic forest is associated with the consistent reduction of the seed size of a keystone palm species. Among 22 palm populations, areas deprived of large avian frugivores for several decades present smaller seeds than nondefaunated forests, with negative consequences for palm regeneration. Coalescence and phenotypic selection models indicate that seed size reduction most likely occurred within the past 100 years, associated with human-driven fragmentation. The fast-paced defaunation of large vertebrates is most likely causing unprecedented changes in the evolutionary trajectories and community composition of tropical forests.

Use of space by frugivorous bats (Chiroptera: Phyllostomidae) in a restored Atlantic forest fragment in Brazil

We studied patterns in the use of space for foraging and roosting by two frugivorous bat species in a five-year-old restored Atlantic forest located in a fragmented landscape in southeastern Brazil. Ten individuals of Carollia perspicillata and eleven individuals of Artibeus lituratus were monitored through radio-telemetry in five sampling sessions. Each session lasted 3–8days for each individual, with an average of 25.4±10 locations for each C. perspicillata individual and 19±4.4 for each A. lituratus individual. We described an average range of 124.4ha and an average commuting distance of 1158.8m for A. lituratus and an average range and commuting distance of 32ha and 489m, respectively, for C. perspicillata. We demonstrated a consistent pattern in habitat use and movements for both studied species, where they strictly used forests (restored or not) for day roosting, roosting in the foliage of trees located only in secondary forest remnants and restored areas, while restored areas were their main feeding habitat. We demonstrate that newly restored forests can be readily incorporated as foraging and roosting habitats by these species, and that C. perspicillata alters its roosting behavior in relation to preferred food availability. These results, when combined with data on the diet of the studied species, show consistent evidence of the potential that bats have to improve species diversity of anthropogenic plantings with their own natural seed dispersal.

Dietary Flexibility of the Brown Howler Monkey Throughout Its Geographic Distribution

Habitat loss and fragmentation constrain the survival of most forest-living mammals, particularly strictly arboreal primates. Because fragment size directly affects food availability, primate survival in small fragments may depend on dietary flexibility. Here, we review the literature on the diet of 29 wild groups of Alouatta guariba clamitans inhabiting forest fragments in Brazil and Argentina. We identify general feeding patterns and analyze the influence of fragment size and latitude on diet composition. Brown howlers presented a diet composed of 402 plant species belonging to 227 genera and 80 families. Rarefaction curves suggest that the richness of top food species is similar among groups living in larger (>100 ha), medium (11-100 ha) or small (1-10 ha) fragments. On average, only 12% of the plant species used as food sources by a given group was also consumed by groups from other sites. The shorter the distance between sites, the higher the diet similarity among groups. Despite their diet flexibility, brown howlers spent >80% of the total feeding records on 6-24 species belonging to genera such as Ficus, Zanthoxylum, and Eugenia. Leaves and fruits were the plant items most consumed (65% and 22% of the total feeding records, respectively). Leaf consumption was not affected by fragment size, but it was inversely related to latitude, which may be linked to an increase in the concentration of secondary metabolites in leaves at higher latitudes. We suggest that the ability of brown howlers to exploit a large number of plant food species, including native and exotic trees, shrubs, vines, and lianas, is an important trait that contributes to their survival in highly fragmented habitats along the Atlantic forest. Similar meta-analyses of data from other howler species are necessary to test whether such dietary flexibility is a genus-wide pattern.

Nesting Biology of the Yellow-Olive Flatbill (Tyrannidae, Elaninae) in Atlantic Forest Fragments in Brazil

Abstract The Yellow-olive Flatbill (Tolmomyias sulphurescens) is a small insectivorous passerine inhabiting Neotropic forests. Its breeding biology is poorly known despite its abundance and conspicuousness. We describe the nesting biology of Yellow-olive Flatbills from Atlantic Forest fragments in Belo Horizonte County, Minas Gerais State, southeastern Brazil. Eighty nests were monitored every 3–5 days from August to January between 1995 and 2000. Active nests were found from mid-September through late December with a peak from mid October through late November. First clutches were usually laid during the first rains, but prior to the main peak in annual rainfall. The Yellow-olive Flatbill builds closed, pencile nests on tree branches along streams or roads, principally of dark fungal (Marasmius sp.) fibers. Clutch size ranged from two to four white eggs. Incubation was irregular and hatching was asynchronous. Incubation and nestling periods were 20 and 23 days, respectively. Nesting success across all 5 ...

Phytoseiidae (Acari) in forest fragments in the State of São Paulo, Brazil

Mites of the family Phytoseiidae have been extensively studied as biological control agents of various pests. However, knowledge of these mites in plants of forest fragments in Brazil is still incomplete. The aim of this study was to study the occurrence of Phytoseiidae in forest fragments in the Northwestern of State of São Paulo. Samplings were collected from 18 forest fragments, including 102 plant species belonging to 47 plant families. We recorded 46 phytoseiid species belonging to 17 genera and three subfamilies. Two new species are described, Amblyseius biotafapesp sp. nov. and Amblyseius novagranadensis sp. nov. Trichilia casaretti and Actinostemon communis harbored the largest numbers of species, 29 and 22, respectively. Some species recorded in this study have been frequently reported on cultivated plants. Besides the biological importance of knowing the phytoseiid mite fauna in these forests, survey studies can provide information to support projects on integrated pest management.

Food habits of sympatric opossums coexisting in small Atlantic Forest fragments in Brazil

The diets of sympatric species of opossums coexisting in small (<10 ha) Atlantic Forest fragments were studied at Poço das Antas Biological Reserve, southeastern Brazil. Food items consumed by Caluromys philander and Didelphis aurita were investigated through the analysis of faecal contents, and compared with the diet of Micoureus demerarae analysed in a previous study. The major diet components for all three species were arthropods and fruits, with a high richness of items of both feeding categories; feathers were also found in the diet of D. aurita. The most frequent insect orders overall were Hymenoptera and Coleoptera, and most seeds were from plants of secondary vegetation such as Cecropia and Piper. The diets showed little variation along time and space for all three species. Diets were also similar among species, except for a larger consumption of Arachnida and Diplopoda and a smaller consumption of Lepidoptera by D. aurita when compared to M. demerarae. Diversity of food items was lower for C. philander when compared with either other species. There was a high feeding niche overlap between species, suggesting that differentiation in diet composition would not be enough to allow coexistence of the three species in small fragments. Coexistence may rather be allowed by vertical segregation and/or by differences in prey size.

Influence of edge and fire-induced changes on spatial distribution of small mammals in Brazilian Atlantic forest fragments

The spatial distribution of small mammals in relation to distance from forest edges, before and after fire, was studied in Atlantic Forest fragments in Brazil. None of nine species was captured exclusively on either edges or forest interior. Before the fire only the rodents Akodon cursor and Oecomys con-color were captured more often at the edge than randomly expected. After the fire only A. cursor remained associated with edges; it had increased in number and penetrated farther than before into the forest fragments. The marsupial Micoureus demerarae became more restricted to the forest interior than randomly expected. These results suggest that small mammal species tolerant to habitat changes induced by edge effects and fire have better chances to survive in forest fragments.

Isolamento e identificação de fungos micorrízicos rizoctonióides associados a três espécies de orquídeas epífitas neotropicais no Brasil

Distúrbios causados pelo homem têm resultado no aumento do risco de extinção de diversos táxons de orquídeas nativas da Mata Atlântica no Brasil. Na natureza, orquídeas utilizam obrigatoriamente fungos endomicorrízicos para a germinação de sementes e desenvolvimento da plântula, ao menos nos primeiros estádios do seu ciclo de vida. Assim, fungos micorrízicos associados ao sistema radicular de orquídeas nativas vêm sendo isolados, caracterizados e armazenados para uso em futuros programas de conservação de espécies de orquídeas, por meio da germinação simbiótica. Três isolados de fungos micorrízicos rizoctonióides foram obtidos do sistema radicular de três espécies de orquídeas neotropicais, Gomesa crispa, Campylocentrum organense e Bulbophyllum sp., de três diferentes fragmentos de Mata Atlântica no Brasil. Estudos taxonômicos, baseados na condição nuclear, morfologia da hifa vegetativa e ultra-estrutura do septo dolipórico, revelaram que os isolados pertencem aos gêneros Ceratorhiza e Rhizoctonia. Esse é o primeiro relato do isolamento de fungos micorrízicos associados ao sistema radicular dessas espécies de orquídeas neotropicais. Aspectos relativos à taxonomia e ao uso desses isolados no contexto de um programa de conservação de orquídeas nativas são discutidos.

Determinants of differential extinction vulnerabilities of small mammals in Atlantic forest fragments in Brazil

From the nested structure often found in biological communities, it could be expected that the order of species loss after forest fragmentation would be predictable to some extent. This could expose the factors that would cause differential vulnerability of species to local extinctions in forest fragments. In this study, small mammals were sampled in eight small forest fragments and a larger area of Atlantic forest in Brazil for seven years. Multiple regression showed that tolerance to the matrix of grassy vegetation which separated the fragments was the main determinant of the vulnerability to local extinction, whereas other attributes of the species – fecundity, body weight, longevity, population density prior to the fragmentation, and degree of arboreality – were not good predictors of extinction vulnerability. Therefore, the connectivity of forest fragments is of paramount importance for the conservation of mammalian populations in Atlantic forest fragmented landscapes.

Massive Seed Predation of Pseudobombax grandiflorum (Bombacaceae) by Parakeets Brotogeris versicolurus (Psittacidae) in a Forest Fragment in Brazil1

ABSTRACTHere we report massive seed predation of Pseudobombax grandiflorum (Bombacaceae) by Botogeris versicolurus (Psittacidae) in a forest fragment in Brazil. The intensity of seed predation was very high when compared to other studies in continuous forest, perhaps resulting from a scarcity of resources in such areas. This scarcity may limit the range of parrot's diet to a few plant species. It suggests that studies of Psittacidae seed predation may be important for conservation of some plants in fragments.

Frequency of movements of small mammals among Atlantic Coastal Forest fragments in Brazil

Rates of interfragment movements were estimated for small mammals inhabiting a group of eight Atlantic Coastal Forest fragments, surrounded by grassland matrix, in order to understand the degree to which each species' population was isolated. Didelphis aurita showed the greatest movement rate (19.4% of recaptures showing interfragment movements), followed by Metachirus nudicaudatus (10.0%), Philander frenata (7.5%), Nectomys squamipes (3.6%), Micoureus demerarae (1.2%) and Akodon cursor (0.25%). Interfragment movements were not detected for Caluromys philander, Oecomys concolor and Oligoryzomys nigripes. Species can be placed along a continuum which goes from species that are represented by a single population in the whole study area, through those with metapopulations, to species that have isolated populations in each fragment. Ability to move among fragments was not related to abundance in the matrix; nevertheless, such ability helps to explain the persistence of species in fragments otherwise too small to support viable populations.