Fruits and frugivory in neotropical primates and in Amazonian flooded and unflooded forests

The richness and resilience of tropical forest ecosystems are best described by the myriad of ecological interactions linking co-occurring species together. The many functions previously served by ecological links are often only detected once these links are lost. Of particular interest in this regard are the mutualistic networks between fruiting plants and vertebrate frugivores, whose interdependent relationship is fundamental to the functioning of tropical forests. This thesis examined these fruitfrugivore interactions at two contrasting scales, and using two different approaches. On a landscape scale in western Brazilian Amazonia, the focus was on a community-wide assessment, with particular attention paid to the differences between two highly divergent but adjacent species-rich forest types, seasonally-flooded várzea forests and unflooded terra firme forests. As part of this comparison, the powerful role of the annual flood pulse was shown to determine both spatial patterns of forest structure and temporal patterns of fruit production. The strong influence of this seasonal cycle was apparent in the adaptive traits observed in plants and animals, with corresponding effects upon their networks of interactions. The role of frugivore body size as an important trait in relation to the degree of frugivory within consumers was emphasised via one of the most extensive compilations on the feeding ecology of any frugivorous vertebrate taxon. By amassing the observations of feeding records accumulated over several decades of neotropical primate field research, and accounting for the highly variable levels of sampling effort among primate species, the prevalence of frugivory at the mid-high spectrum of body mass was confirmed. This continental-scale metaanalysis also revealed that, despite representing arguably the most observable and wellstudied group of vertebrate frugivores in tropical forests worldwide, most primate species were heavily undersampled in terms of the richness of fruits known to occur in their diets. These astounding gaps in our cumulative knowledge highlight the challenges faced in assembling comprehensive fruit-frugivore networks for entire communities, where the diets of most consumers are even more poorly understood than for primates. This is particularly pertinent in the face of ever-increasing threats to ecosystems comprised of, and sustained by, these complex webs of interactions

Generating spatially and statistically representative maps of environmental variables to test the efficiency of alternative sampling protocols

Accurate assessment of environmental variables is vital to understanding the global issues of land-use change and climate change, but is hindered by their high spatial and temporal heterogeneity. Extensive surveys are needed to model such large-scale problems, with their success dependent on adequate sampling protocols. We present a robust method for designing efficient sampling protocols for environmental variables. The SIMAP method involves the following steps: 1) Selecting sites that cover a representative range of spatial variability, 2) Intensive and spatially-accurate surveys within sites, 3) construction of continuous Maps that replicate the spatial and statistical variation of the surveys, 4) Accuracy simulations based on sampling of these maps and 5) determining a sampling Protocol for subsequent broader surveys. To illustrate the method, we used estimation of soil C stocks in mixed-species tree plantings and pastures to estimate carbon sequestration following reforestation. Soil C was surveyed intensively from these two land uses at several farms that covered a large rainfall gradient to provide contrasting datasets. In this example, sampling simulations showed that a systematic design generally required one less sample than a restricted-random design to achieve the same accuracy, while a simple-random design required substantially more samples. We found taking a minimum of 30 soil samples was needed for both bulk density and C concentration to accurately estimate soil C content within a 1-ha plot in a pasture or tree planting, which suggests many previous surveys of soil C were sampled inadequately. The SIMAP method could be readily applied to a range of abiotic and biotic variables, with the construction of maps allowing most sampling intensities and designs to be tested. Adequate sampling intensities differ widely among environmental variables, so the SIMAP method enables researchers to determine which variables require more investment. For many variables, costs may be minimised while maintaining a high accuracy of the sampling design via bulking of well-mixed samples prior to analysis.Shaun C. Cunningham, Stephen H. Roxburgh, Keryn I. Paul, Antonio F. Patti, Timothy R. Cavagnar

Annals [...].

Pedometrics: innovation in tropics; Legacy data: how turn it useful?; Advances in soil sensing; Pedometric guidelines to systematic soil surveys.Evento online. Coordenado por: Waldir de Carvalho Junior, Helena Saraiva Koenow Pinheiro, Ricardo Simão Diniz Dalmolin