03262naa a2200301 a 450000100080000000500110000800800410001902400390006010000160009924501070011526000090022250004620023152019060069365000160259965300460261565300350266165300150269665300090271165300100272065300370273070000140276770000180278170000180279970000160281770000140283370000160284777300970286310591972021-03-11       2019    bl uuuu     u00u1 u    #d7 a10.1016/j.ecolind.2018.09.0462DOI1 aTEXEIRA, M.  aFunctional syndromes as indicators of ecosystem change in temperate grasslands.h[electronic resource]  c2019  aArticle history: Received 27 December 2017// Received in revised form 21 August 2018// Accepted 24 September 2018. Acknowledgments: This research was supported by CONICET (Argentina), Universidad de Buenos Aires (Argentina), and FONCyT (Argentina). This work was carried out with the aid of a grant from the Inter-American Institute for Global Change Research (IAI) CRN III 3095, which is supported by the US National Science Foundation (Grant GEO-1128040).  aAbstract: The lack of an organizing conceptual framework to address ecosystem changes reduces our capacity to distinguish biophysical from direct human impacts on grassland dynamics. This is particularly important for subhumid temperate grasslands, one of the world's most threatened biomes. We identified and mapped 4 functional syndromes of grassland change at the wettest end of its worldwide distribution, the Campos in Uruguay. Syndromes were defined by differences in precipitation use efficiency (PUE, ANPP/precipitation), and in precipitation marginal response (PMR, slope of the linear regression between ANPP and precipitation) between two periods (1981-1995 and 2001-2011). Temporal trends in aboveground net primary production (ANPP, obtained by splicing two sources of NDVI, LTDR and MOD13Q1) were also characterized. To rule out the effect of precipitation we analyzed temporal trends of the residuals from the relationship between ANPP and annual precipitation (RESTRENDS). Functional syndromes associated with increases in seasonality or in the abundance of annual vegetation (?PMR > 0, ?PUE < 0, ?14,000 km 2) and vegetation cover loss (?PUE < 0 and ?PMR < 0, > 5000 km 2) were the most abundant. ANPP trends were significantly negative in 3.7% of the area (2475 km 2) and only positive in 0.3%. However, RESTRENDS were significant in 11% of the area (> 7700 km 2), and mostly negative (in ?7200 km 2). Most of these negative trends and residual trends were associated to seasonality increase and vegetation loss syndromes. These patterns were consistent with observed changes in the region. We highlight that this conceptual framework is suitable for describing patterns of change and potential causes. Moreover, it provides policymakers with a novel tool to guide management and conservation policies, pointing to sites where intervention (i.e. conservation, restoration) is needed.  aECOSISTEMAS  aABOVEGROUND NET PRIMARY PRODUCTION (ANPP)  aECOSYSTEM FUNCTIONAL SYNDROMES  aGRASSLANDS  aLTDR  aMODIS  aPRECIPITATION USE EICIENCY (PUE)1 aVERON, S.1 aIRISARRIA, G.1 aOYARZABAL, M.1 aSTAIANO, L.1 aBAEZA, S.1 aPARUELO, J.  tEcological Indicators, 2019gv. 96, p.600-610.Doi: https://doi.10.1016/j.ecolind.2018.09.046