Description: Questions The study of naturally discontinuous forest systems could help further our understanding of the relative roles of abiotic factors and spatial connectivity in influencing species turnover and plant metacommunity structure compared to continuous forest formations where local communities are often arbitrarily defined and where ‘mass effects’ and source-sink dynamics tend to confound the roles of dispersal and environment. Here we study a tropical montane landscape where old-growth evergreen forest occurs as patchy formations in a matrix of natural grasslands, to test the influence of environment and connectivity on species turnover and woody plant metacommunity structure . Location The study area consists of the western and southern regions of the Upper Nilgiri Plateau in the Western Ghats of Southern India, a global biodiversity hotspot . Methods We sampled 85 vegetation plots located across a 600 km2 landscape, assembled environmental data, constructed contrasting spatial connectivity models, including models for the effects of topography on structural connectivity, and used RDA-based variation partitioning to assess the relative influence of environment and space on woody plant metacommunity structure . Results Considering several environmental and multi-scale spatial predictors, we could explain half the variation in plant community structure. Environmental and habitat factors such as precipitation, temperature seasonality, elevation, fragment size and landscape context play a dominant role and explain 42% of variation. Spatial predictors based on Euclidean distance performed better than those that accounted for topographical resistance. Spatial predictors accounted for only 9% of the variation in plant metacommunity structure . Conclusion Our results support the species sorting paradigm of metacommunity structure, as abiotic effects and biotic interactions play dominant roles in influencing community structure and species turnover in these old growth forests with a comparatively small influence of spatial connectivity. Effective management of woody species diversity would therefore require conservation of these forests across the range of environmental conditions under which they occur . This article is protected by copyright. All rights reserved.

Description:    A 108-year (1901–2008) downscaling of the twentieth-century reanalysis (20CR) using the Regional Spectral Model (RSM) has been conducted for the southeastern United States (SEUS) at a horizontal grid resolution of 10 km. This 108-year product, named as the Florida Climate Institute-Florida State University Land–Atmosphere Reanalysis for the southeastern United States at 10-km resolution version 1.0 [FLAReS1.0], has primarily been developed for anticipated application studies in hydrology, crop management, ecology, and other interdisciplinary fields in the SEUS. The analysis of this downscaled product reveals that it ameliorates the issue of artificial discontinuity in the precipitation time series of the 20CR from the variations inherent to RSM. This centennial scale product allows us to begin examining decadal scale variations of the regional features of the SEUS. The fidelity of the low-frequency variations of the winter rainfall associated with the Atlantic Multi-decadal Oscillation (AMO) and the Pacific Decadal Oscillation is reasonably well captured in FLAReS1.0. In fact, the modulation of the El Niño-Southern Oscillation (ENSO) teleconnection with the SEUS rainfall by AMO in the downscaled product is also validated with observations. The ENSO-associated variations of accumulated rainfall from landfalling hurricanes in the SEUS are also well simulated in the downscaled climate simulation. It is to be noted that the success of this dynamical downscaling is also because the global reanalysis of 20CR showed comparable fidelity in these low-frequency variations of the SEUS climate. This method of dynamic downscaling global reanalysis with inclusion of spectral nudging at large wavelengths (in this case ≥500 km) toward the driving global reanalysis (20CR) is sometimes referred as a form of regional reanalysis. Content Type Journal Article Category Original Article Pages 1-9 DOI 10.1007/s10113-012-0372-8 Authors V. Misra, Department of Earth, Ocean and Atmospheric Science, Florida State University, P.O. Box 3064520, Tallahassee, FL 32306-4520, USA S. M. DiNapoli, Center for Ocean-Atmospheric Prediction Studies, Florida State University, 2035 E. Paul Dirac Dr., 200 RM Johnson Bldg, Tallahassee, FL 32306-2840, USA S. Bastola, Center for Ocean-Atmospheric Prediction Studies, Florida State University, 2035 E. Paul Dirac Dr., 200 RM Johnson Bldg, Tallahassee, FL 32306-2840, USA Journal Regional Environmental Change Online ISSN 1436-378X Print ISSN 1436-3798

Description: Questions As biodiversity losses increase due to global change and human-induced habitat destruction, the relationships between plant traits and ecosystem properties can provide a new level of understanding ecosystem complexity. Using a functional response–effect approach, we show that multiple components of the carbon cycle are determined by a few plant traits, which in turn are strongly affected by environmental conditions. Location Salt marshes, northwest Germany. Methods We explored responses of morphological, chemical and biomass-related plant traits to environmental drivers and examined their effects on carbon cycle properties, i.e. above-ground biomass, above-ground net primary productivity and decomposition. The combined analysis between environmental parameters, functional traits and ecosystem properties used structural equation modelling (SEM). Results Important response and effect traits were leaf dry matter content (LDMC) and below-ground dry mass (BDM, responding to groundwater level and salinity) and leaf C:N ratio (responding to inundation frequency). Inundation and salinity led to increased allocation to below-ground biomass and salt stress adaptation in leaves, which translated into increased decomposition rates. Release from these abiotic controls resulted in standing biomass accumulation, which was controlled by LDMC and canopy height as key traits. Conclusions These findings demonstrate the interacting effects of non-consumable environmental factors and soil resources on morphological, chemical and biomass traits, which affected carbon cycle properties. Loss of species from the community has the potential to change the relationships between environment and vegetation-based ecosystem properties and therefore elicit effects on the multifunctionality of the entire and adjacent ecosystems. Studying relationships between plant traits and ecosystem properties can provide new insight into ecosystem complexity. We ask how plant species traits respond to environmental conditions and how key effect traits determine carbon related ecosystem properties in salt marshes of NW-Germany. Our study reveals interacting effects of environmental factors on morphological, chemical and biomass traits and gives recommendations for conservation management.