Soil-associated drivers of plant traits and functional composition in Atlantic Forest coastal tree communities

The severe deforestation of Brazil’s Atlantic Forest and the increasing effects of climate change underscore the need to understand how tree species respond to climate and edaphic factors. To identify the most important environmental drivers of coastal Atlantic Forest diversity and functional composition, we studied 42 plots of coastal Atlantic Forest (restinga), which has a high diversity of plant communities and spans strong environmental gradients. We examined how forest physiognomy and functional composition respond to changes in the environment, hydraulic, and soil properties. We tested different hypotheses relating the roles of nutrients and soil water availability in driving shifts in tropical forest diversity and functioning. We collected wood samples and leaves from ˜85% of the plant species identified in the forest inventory and estimated the community-weighted tree height, aboveground biomass, basal area of individual plants, specific leaf area, wood density, and the total tree biomass per community by the sum of all trees’ aboveground biomass per plot. We measured water table depth and 24 physicochemical soil parameters. Hypotheses relating to these factors were formalized via both generalized additive models and piecewise structural equation models and null models of community assembly. Increasing drought, as reflected by increasing water table depth, coarse sand, and soil concentration of aluminum (>6 cmol/kg), was found to be a primary driver of shifts in all measured functional traits. Water table depth was found to be the main environmental driver of restinga species diversity, but shifts in species richness were largely decoupled from functional richness and functional dispersion. Our results suggest that decreases in soil water availability are a central driver of local phenotype–environment matching and that increasing water limitation increases the role of environmental filtering on multiple traits. Our results show that drought leads to a strong convergence (standardized effect size < −1.95) in forest function and leads to shifts to smaller statured forest in particular. These findings reveal important differences in the drivers of forest structure and functioning, suggesting that changes in local spatial variation in soil and moisture variables will be a central issue in restinga management and conservation. © 2021 The Authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Armadilhas fotográficas na amostragem de mamíferos: considerações metodológias e comparação de equipamentos Use of camera traps in mammal sampling: methodological considerations and comparison of equipments

A utilização de armadilhas fotográficas em estudos desenvolvidos no Brasil é recente. O alto custo dos equipamentos e os constantes gastos com material de consumo podem, em alguns casos, limitar o número de unidades e o tempo de amostragem. O presente estudo objetivou discutir questões metodológicas visando otimizar a utilização do equipamento no inventário de mamíferos, além de comparar dois modelos de armadilhas fotográficas. O estudo foi desenvolvido na Estação Biológica de Santa Lúcia, no centro-norte do estado do Espírito Santo entre janeiro de 2002 e novembro de 2003, utilizando três Wildlife Pro Camera© (WPC) e quatro DeerCam©. Constatou-se a importância da realização de amostragens em diferentes fitofisionomias, tendo sido observadas variações na composição da comunidade registrada em cada ambiente. Foi detectada uma correlação significativa entre número de espécies registradas e esforço de amostragem empregado em cada trilha, ressaltando o registro de 60% ou mais dos táxons amostrados em trilhas com esforço > 250 armadilhas-dia. Houve predomínio de registros noturnos (67%), embora o número de espécies registradas durante a noite tenha sido semelhante ao obtido ao longo do dia. Quando as armadilhas foram colocadas em pares, apenas 27% das fotografias foram simultâneas. Os equipamentos utilizados apresentaram diferenças significativas na durabilidade e eficiência na amostragem de mamíferos, tanto dentro como entre as marcas testadas.<br>The use of camera traps is quite recent in Brazil. The high cost of equipments and constant expenses with supplies can, in some circumstances, limit the number of units to be deployed and sampling effort. The present study discusses methodological issues aiming at optimizing the use of these traps in mammalian inventories and also provides a comparison of two brands of equipments. The study was carried out in Santa Lúcia Biological Station (SLBS) in Center-north Espirito Santo state between January 2002 and November 2003, using three Wildlife Pro Camera© (WPC) units and four DeerCam© units. We realized the importance of sampling in different phitophysiognomies as they varied in mammal community. We detected a significant correlation between species richness and sampling effort in each trail, observing that 60% or more of species richness recorded in SLBS was obtained when sampling effort was > 250 camera-trap nights/trail. Nocturnal records predominated (67%) although the number of recorded species was similar between night and day. When camera traps were set in pairs, only 27% of records were simultaneous. The tested units showed significant differences in durability and efficiency, both within and between brands