Global patterns of extreme drought-induced loss in land primary production: Identifying ecological extremes from rain-use efficiency

Abstract

Quantifying the ecological patterns of loss of ecosystem function in extreme drought is important to understand the carbon exchange between the land and atmosphere. Rain-use efficiency [RUE; gross primary production (GPP)/precipitation] acts as a typical indicator of ecosystem function. In this study, a novel method based on maximum rain-use efficiency (RUE) was developed to detect losses of ecosystem function globally. Three global GPP datasets from the MODIS remote sensing data (MOD17), ground upscaling FLUXNET observations (MPI-BGC), and process-based model simulations (BESS), and a global gridded precipitation product (CRU) were used to develop annual global RUE datasets for 2001-2011. Large, well-known extreme drought events were detected, e.g. 2003 drought in Europe, 2002 and 2011 drought in the U.S., and 2010 drought in Russia. Our results show that extreme drought-induced loss of ecosystem function could impact 0.9% ± 0.1% of earth's vegetated land per year and was mainly distributed in semi-arid regions. The reduced carbon uptake caused by functional loss (0.14 ± 0.03 PgC/yr) could explain >70% of the interannual variation in GPP in drought-affected areas (p ≤ 0.001). Our results highlight the impact of ecosystem function loss in semi-arid regions with increasing precipitation variability and dry land expansion expected in the future.

Precipitation amount and event size interact to reduce ecosystem functioning during dry years in a mesic grassland

“…RUE, as the ratio of net primary productivity to precipitation, is an integrative metric of ecosystem functioning that can be informative for quantifying impacts of future precipitation change on terrestrial ecosystem functioning (Du et al, 2018;Huxman et al, 2004). In par ticular, more variable rainfall patterns-characterized by fewer and larger rainfall events-are forecast to be overlaid by increased in terannual precipitation variability and extremity (Cook et al, 2015;IPCC, 2013;Swain et al, 2018).…”

Rapid recovery of ecosystem function following extreme drought in a South African savanna grassland

“…Empirical data and model projections suggest that regional‐scale droughts are increasing in frequency, duration, and magnitude across the globe (Dai , Trenberth , Cook et al ). These more severe and prolonged droughts have the potential for large and long‐lasting effects on ecosystem structure and function (Du et al , Sankaran and Staver ). To maintain function in response to extreme drought, ecosystems must exhibit either high resistance during drought (e.g .…”

Performance evaluation of the CHIRPS precipitation dataset and its utility in drought monitoring over Yunnan Province, China

“…It is followed by hydrological and agricultural droughts because all three other types of drought are attributable to a continued period of insufficient precipitation (Adamson and Bird 2010). At the beginning of the twenty first century, large-scale extreme droughts occurred throughout the world, causing huge economic losses (Du et al 2018). According to statistics from the Bulletin of Flood and Drought Disasters in China, national annual losses induced by drought reached approximately 88 billion RMB during 2006-2017.…”