03025naa a2200337 a 450000100080000000500110000800800410001902200140006002400420007410000140011624501380013026000090026850000900027752019320036765000130229965000190231265000210233165000250235265000120237765300290238965300230241865300090244165300500245065300290250065300310252970000150256070000170257570000160259270000180260877300610262610502002018-09-27       2010    bl uuuu     u00u1 u    #d  a1654-109X7 a10.1111/j.1654-109X.2009.01051.x2DOI1 aBAEZA, S.  aSpatial variability of above-ground net primary production in Uruguayan grasslandsbA remote sensing approach.h[electronic resource]  c2010  aArticle history: Received 4 November 2008;  accepted 16 July 2009. Published in 2010.  aAbstract: Question: How does above-ground net primary production (ANPP) differ (estimated from remotely sensed data) among vegetation units in sub-humid temperate grasslands? Location: Centre-north Uruguay.  Methods: A vegetation map of the study area was generated from LANDSAT imagery and the landscape configuration described. The functional heterogeneity of mapping units was analysed in terms of the fraction of photosynthetically active radiation absorbed by green vegetation (fPAR), calculated from the normalized difference vegetation index (NDVI) images provided by the moderate resolution imaging spectroradiometer (MODIS) sensor. Finally, the ANPP of each grassland class was estimated using NDVI and climatic data. Results: Supervised classification presented a good overall accuracy and moderate to good average accuracy for grassland classes. Meso-xerophytic grasslands occupied 45% of the area, Meso-hydrophytic grasslands 43% and Lithophytic steppes 6%. The landscape was shaped by a matrix of large, unfragmented patches of Meso-xerophytic and Meso-hydrophytic grasslands. The region presented the lowest anthropic fragmentation degree reported for the Rio de la Plata grasslands. All grassland units showed bimodal annual fPAR seasonality, with spring and autumn peaks. Meso-hydrophytic grasslands showed a radiation interception 10% higher than the other units. On an annual basis, Meso-hydrophytic grasslands produced 3800 kg dry matter (DM) ha 1 yr  1 and Meso-xerophytic grasslands and ithophytic steppes around 3400 kg  DM ha 1  yr 1 . Mesoxerophytic grasslands had the largest spatial variation during most of the year. The ANPP temporal variation was higher than the fPAR variability. Conclusions: Our results provide valuable information for grazing management (identifying spatial and temporal variations of ANPP) and grassland conservation (identifying the spatial distribution of vegetation units).  aESPECIES  aIDENTIFICACION  aPASTIZAL NATURAL  aSISTEMAS GEOGRAFICOS  aURUGUAY  aLAND-COVE CLASSIFICATION  aNATIVE GRASS-LANDS  aNDVI  aNORMALIZED DIFFERENCE VETETATION INDEX (NDVI)  aRADIATION-USE EFFICIENCY  aRIO DE LA PLATA GRASSLANDS1 aLEZAMA, F.1 aPIÑEIRO, G.1 aALTESOR, A.1 aPARUELO, J.M.  tApplied Vegetation Science, 2010gv. 13, no. 1 p. 72-85.