Global patterns, trends, and drivers of water use efficiency from 2000 to 2013

摘要: Water use efficiency (WUE; gross primary production [GPP]/evapotranspiration [ET]) estimates the tradeoff between carbon gain and water loss during photosynthesis is an important link of cycles. Understanding spatiotemporal patterns drivers WUE helpful for projecting responses ecosystems to climate change. Here we examine patterns, trends, at global scale from 2000 2013 using gridded GPP ET data derived Moderate Resolution Imaging Spectroradiometer (MODIS). Our results show that has average value 1.70 g C/kg H2O with large spatial variability 14-year period. exhibits latitude. also varies much elevation: it first remains relatively constant as elevation 0 1000 m then decreases dramatically. generally increases precipitation specific humidity increase; whereas after reaching maxima temperature solar radiation increases. In most land areas, temporal trend positively correlated over period; while a negative relationship related warming dimming. On average, shows increasing 0.0025 C·kg−1 H2O·yr−1 globally. global-scale assessment implications improving our understanding linkages cycles better