998 resultados para RICAN RAIN-FOREST
Resumo:
Upa Kimsey is a poorly known genus of Tiphiidae with seven species. This genus has records in forest areas and in this paper we present new records to four species. All specimens were collected by malaise traps in four areas of Atlantic Rain Forest and three of Atlantic Semi-deciduous forest, mainly from high and mid-elevations. The new records indicate that species of Upa are not as rare as others genera of Tiphiidae, which are virtually unknown in many Neotropical regions.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (< 40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha(-1) (range 6.6 to 112.4) to 8.0 Mg ha(-1) (-2.5 to 23.0).
Resumo:
A 30-year quantitative comparison of the bird community of a semideciduous forest remnant in the state of Sao Paulo. Few studies have evaluated long-term changes in avian abundance in forest remnants. To compare both species richness and abundance of the bird community in a forest fragment located in the municipality of Galia, state of Sao Paulo, southeastern Brazil, we surveyed forest birds using transect counts. We compared our results with a survey conducted 30 years earlier at the same locality and further classified bird species according to their food habits to eventually predict fluctuations of specific abundance. Although species with population declines predominated in the community, all trophic categories had species which increased their abundances. Most species prone to move around remnants decreased in abundance. We suggest that, regarding specific abundances, trophic categories may be equally affected as a result of fragmentation processes and that the forest regeneration of this remnant may have led to the loss of edge species. Species that suffered from abundance loss during this time period may become locally extinct in the near future.
Resumo:
The nests of Myrmelachista are found in tree trunk cavities and branches. The biology of these arboreal ants is still relatively unknown. We investigated the nesting behaviour of this genus in fallen dry twigs in the Atlantic rainforest of southeastern Brazil. Physical characteristics of the nests, colony demographics, presence of breeders and ant worker sizes were recorded. Samples were collected weekly for 12 months, along open, sunny and undisturbed trails within forest remnants. In all, 202 nests were collected and six species were recorded. Myrmelachista ruszkii had the highest population of immatures and the greatest number of nests found. Myrmelachista nodigera had the smallest workers, was the least populous and the colony was housed in the finest branches. These results expand the current knowledge about the diversity and biology of Myrmelachista in the Brazilian Atlantic forest, and describe polydomic nests and competitive behaviour of M. ruszkii.
Resumo:
Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species distributed in Amazonia and the Atlantic Forest. We used mitochondrial (414 bp of 12S, 575 bp of 16S genes) and nuclear DNA (785 bp of RAG-1) to investigate phylogenetic relationships and the timing of diversification within the genus. These molecular data were gathered from 23 specimens from 19 populations, including eight out of the 10 nominal species of the genus as well as Rhinella boulengeri. Analyses also included sequences of representatives of 18 other bufonid genera that were publically available. We also examined morphological characters to analyze differences within Dendrophryniscus. We found deep genetic divergence between an Amazonian and an Atlantic Forest clade, dating back to Eocene. Morphological data corroborate this distinction. We thus propose to assign the Amazonian species to a new genus, Amazonella. The species currently named R. boulengeri, which has been previously assigned to the genus Rhamphophryne, is shown to be closely related to Dendrophryniscus species. Our findings illustrate cryptic trends in bufonid morphological evolution, and point to a deep history of persistence and diversification within the Amazonian and Atlantic rainforests. We discuss our results in light of available paleoecological data and the biogeographic patterns observed in other similarly distributed groups. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
Lianas play a key role in forest structure, species diversity, as well as functional aspects of tropical forests. Although the study of lianas in the tropics has increased dramatically in recent years, basic information on liana communities for the Brazilian Atlantic Forest is still scarce. To understand general patterns of liana abundance and biomass along an elevational gradient (0-1,100 m asl) of coastal Atlantic Forest, we carried out a standard census for lianas a parts per thousand yen1 cm in five 1-ha plots distributed across different forest sites. On average, we found a twofold variation in liana abundance and biomass between lowland and other forest types. Large lianas (a parts per thousand yen10 cm) accounted for 26-35% of total liana biomass at lower elevations, but they were not recorded in montane forests. Although the abundance of lianas displayed strong spatial structure at short distances, the present local forest structure played a minor role structuring liana communities at the scale of 0.01 ha. Compared to similar moist and wet Neotropical forests, lianas are slightly less abundant in the Atlantic Forest, but the total biomass is similar. Our study highlights two important points: (1) despite some studies have shown the importance of small-scale canopy disturbance and support availability, the spatial scale of the relationships between lianas and forest structure can vary greatly among tropical forests; (2) our results add to the evidence that past canopy disturbance levels and minimum temperature variation exert influence on the structure of liana communities in tropical moist forests, particularly along short and steep elevational gradients.
Resumo:
The Australian palm Archontophoenix cunninghamiana was introduced into Brazil as an ornamental species, and became a dangerous invader of remnant Atlantic forest patches, demanding urgent management actions that require careful planning. Its fruits are greatly appreciated by generalist birds and its sudden eradication could be as harmful as its permanence in the native community. Our hypothesis was that A. cunninghamiana phenology and fruit traits would have facilitated the invasion process. Hence the aim of the study was to characterize the reproductive phenology of the palm by registering flowering and fruiting events, estimating fruit production, and evaluating fruit nutritional levels. Phenological observations were carried out over 12 months and analyzed statistically. Fruit traits and production were estimated. Pulp nutritional levels were determined by analyzing proteins, lipids, and carbohydrates. Results showed constant flowering and fruiting throughout the year with a weak reproductive seasonality. On average, 3651 fruits were produced per bunch mainly in the summer. Fruit analysis revealed low nutrient contents, especially of proteins and lipids compared with other Brazilian native palm species. We concluded that the abundant fruit production all year round, and fruit attractivity mainly due to size and color, :may act positively on the reproductive performance and effective dispersion of A. cunninghamiana. As a management procedure which would add quality to frugivore food resources we suggest the replacement of A. cunninghamiana by the native palm Euterpe edulis, especially in gardens and parks near to Atlantic forest fragments.
Resumo:
Assessment of the suitability of anthropogenic landscapes for wildlife species is crucial for setting priorities for biodiversity conservation. This study aimed to analyse the environmental suitability of a highly fragmented region of the Brazilian Atlantic Forest, one of the world's 25 recognized biodiversity hotspots, for forest bird species. Eight forest bird species were selected for the analyses, based on point counts (n = 122) conducted in April-September 2006 and January-March 2009. Six additional variables (landscape diversity, distance from forest and streams, aspect, elevation and slope) were modelled in Maxent for (1) actual and (2) simulated land cover, based on the forest expansion required by existing Brazilian forest legislation. Models were evaluated by bootstrap or jackknife methods and their performance was assessed by AUC, omission error, binomial probability or p value. All predictive models were statistically significant, with high AUC values and low omission errors. A small proportion of the actual landscape (24.41 +/- 6.31%) was suitable for forest bird species. The simulated landscapes lead to an increase of c. 30% in total suitable areas. In average, models predicted a small increase (23.69 +/- 6.95%) in the area of suitable native forest for bird species. Being close to forest increased the environmental suitability of landscapes for all bird species; landscape diversity was also a significant factor for some species. In conclusion, this study demonstrates that species distribution modelling (SDM) successfully predicted bird distribution across a heterogeneous landscape at fine spatial resolution, as all models were biologically relevant and statistically significant. The use of landscape variables as predictors contributed significantly to the results, particularly for species distributions over small extents and at fine scales. This is the first study to evaluate the environmental suitability of the remaining Brazilian Atlantic Forest for bird species in an agricultural landscape, and provides important additional data for regional environmental planning.
Resumo:
With fast growth rates and clonal reproduction, bamboos can rapidly invade forest areas, drastically changing their original structure. In the Brazilian Atlantic Forest, where recent mapping efforts have shown that woody bamboos dominate large areas, the present study assessed the differences in soil and vegetation between plots dominated (>90% of bamboo coverage) and not dominated (<10% of coverage) by the native Guadua tagoara. Surface soil was physically and chemically analyzed, and trees at three size classes (seedling, sapling, and adult) were counted, identified and measured. New inventories were conducted to assess recruitment, mortality, and damage rates. Bamboo plots had more fertile soils (higher bases saturation and lower potential acidity) due to the preferential occurrence of G. tagoara on more clayey soils. Bamboo-dominated plots had lower density of adult trees (diameter >5 cm) and lower species density. In addition, overall tree diameter distribution was very different between environments, with bamboo plots having greater concentration of small-sized trees. Such differences are probably related to the general tendency of higher mortality, recruitment, and damage rates in bamboo plots. Greater physical (wind and bamboo-induced damages) and physiological stress (heat and light) in bamboo plots are probable causes of bamboo-dominated plots being more dynamic. Finally, we discuss the differences between Atlantic and Amazonian Guadua-dominated forests, causes, and possible consequences of bamboo overabundance to the Atlantic Forest conservation. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
Litterfall and litter decomposition are vital processes in tropical forests because they regulate nutrient cycling. Nutrient cycling can be altered by forest fragmentation. The Atlantic Forest is one of the most threatened biomes in the world due to human occupation over the last 500 years. This scenario has resulted in fragments of different size, age and regeneration phase. To investigate differences in litterfall and leaf decomposition between forest successional phases, we compared six forest fragments at three different successional phases and an area of mature forest on the Atlantic Plateau of Sao Paulo, Brazil. We sampled litter monthly from November 2008 to October 2009. We used litterbags to calculate leaf decomposition rate of an exotic species, Tipuana tipu (Fabaceae), over the same period litter sampling was performed. Litterfall was higher in the earliest successional area. This pattern may be related to the structural properties of the forest fragments, especially the higher abundance of pioneer species, which have higher productivity and are typical of early successional areas. However, we have not found significant differences in the decomposition rates between the studied areas, which may be caused by rapid stabilization of the decomposition environment (combined effect of microclimatic conditions and the decomposers activities). This result indicates that the leaf decomposition process have already been restored to levels observed in mature forests after a few decades of regeneration, although litterfall has not been entirely restored. This study emphasizes the importance of secondary forests for restoration of ecosystem processes on a regional scale.
Resumo:
This study evaluated whether processing non-timber forest products (NTFPs) and establishing trade partnerships between forest communities and companies enhance the outcomes of NTFP commercialization. In particular, we evaluated whether product processing, partnerships, or their combination was associated with a number of outcomes related to the well-being of forest inhabitants and forest conservation. We based our analyses on ethnographic and quantitative data (i.e., survey and systematic observations) gathered at seven communities from five societies of the Brazilian and Bolivian Amazon. Our results indicated that product processing and partnerships do not represent a silver bullet able to improve the results of NTFP commercialization in terms of well-being and conservation indicators. Compared with cases without interventions, households adopting partnerships but not product processing were most often associated with improved economic proxies of well-being (total income, NTFP income, food consumption and gender equality in income). In comparison, the combination of product processing and partnerships was associated with similar outcomes. Unexpectedly, product processing alone was associated with negative outcomes in the economic indicators of well-being. All of the investigated strategies were associated with less time spent in social and cultural activities. With respect to forest conservation, the strategies that included a partnership with or without processing produced similar results: while household deforestation tended to decrease, the hunting impact increased. Processing alone was also associated with higher levels of hunting, though it did not reduce deforestation. Our results indicate that establishing partnerships may enhance the outcomes of NTFP trade in terms of the financial outcomes of local communities, but practitioners need to use caution when adopting the processing strategy and they need to evaluate potential negative results for indicators of social and cultural activities. With respect to conservation, the three strategies are promising for reducing deforestation, but more pervasive impacts, such as hunting, might increase.
Resumo:
The cyanobacterial community colonizing phyllosphere in a well-preserved Brazilian mangrove ecosystem was assessed using cultivation-independent molecular approaches. Leaves of trees that occupy this environment (Rhizophora mangle, Avicennia schaueriana and Laguncularia racemosa) were collected along a transect beginning at the margin of the bay and extending upland. The results demonstrated that the phyllosphere of R.similar to mangle and L.similar to racemosa harbor similar assemblages of cyanobacteria at each point along the transect. A.similar to schaueriana, found only in the coastal portions of the transect, was colonized by assemblages with lower richness than the other trees. However, the results indicated that spatial location was a stronger driver of cyanobacterial community composition than plant species. Distinct cyanobacterial communities were observed at each location along the coast-to-upland transect. Clone library analysis allowed identification of 19 genera of cyanobacteria and demonstrated the presence of several uncultivated taxa. A predominance of sequences affiliated with the orders Nostocales and Oscillatoriales was observed, with a remarkable number of sequences similar to genera Symphyonemopsis/Brasilonema (order Nostocales). The results demonstrated that phyllosphere cyanobacteria in this mangrove forest ecosystem are influenced by environmental conditions as the primary driver at the ecosystem scale, with tree species exerting some effect on community structure at the local scale.
Resumo:
Two new species of Gastrotheca are described from northeastern Minas Gerais and southern Bahia, in the Atlantic Forest of Brazil. Data on morphology, calls, mitochondrial, and nuclear DNA are provided. Allied to G. fissipes and G. megacephala, the new taxa provide evidence for a higher diversity of species of Gastrotheca than previously thought at the Atlantic Forest. The data also suggest that G. pulchra, another Atlantic Forest taxon, is more closely related to non-Atlantic Forest species than to the remaining analyzed Brazilian Gastrotheca species. This implies that the Gastrotheca at the Brazilian coastal forests have at least two independent origins.
Resumo:
The identification of northern and southern components in different vertebrate species led researchers to accept a two-component hypothesis for the Brazilian Atlantic forest (BAF). Nevertheless, neither a formal proposal nor a meta-analysis to confirm this coincidence was ever made. Our main objective here was therefore to systematically test in how many vertebrate components the BAF could be divided by analysing existing empirical data. We used two approaches: (1) mapping and comparing the proposed areas of vertebrate endemism in the BAF and (2) analysing studies mentioning spatial subdivisions in distinct forest-dependent vertebrates within the biome, by the use of panbiogeography. The four large-scale endemism area components together with the six small-scale panbiogeographical ones allowed the definition of three BAF greater regions, subdivided into nine vertebrate components, latitudinally and longitudinally organized. Empirical time estimates of the diversification events within the BAF were also reviewed. Diversification of these vertebrates occurred not only in the Pleistocene but also throughout the Miocene. Our results confirm the BAF's complex history, both in space and time. We propose that future research should be small-scale and focused in the vertebrate components identified herein. Given the BAF's heterogeneity, studying via sections will be much more useful in identifying the BAF's historical biogeography. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 39-55.