Effects of aridity on ecosystem functioning through plant
diversity
The negative effects of aridity on ecosystem functioning were mainly
mediated by a reduction in plant species richness, in this study, which
was in accordance with earlier studies at local to global scales
(Delgado-Baquerizo et al. 2013; Wang et al. 2014;
Brookshire & Weaver 2015; DurĂ¡n et al. 2018). Global grasslands
are mainly distributed in arid and semiarid regions, and water
availability is the most important limiting factor for grassland
structure and ecosystem functioning (Harpole et al. 2007; Merboldet al. 2009). Drought is predicted to become more severe in many
places across the globe (Dai 2013; Sherwood & Fu 2014; Trenberthet al. 2014). In arid environment, water availability is the main
driver of biological activities, and thus, an increase in aridity would
have substantial effects on ecosystem structure and biogeochemical
cycles (Austin et al. 2004; Schwinning & Sala 2004;
Delgado-Baquerizo et al. 2013; Wang et al. 2014). The
present findings indicate that adverse climatic conditions have direct
and indirect negative effects on aboveground plant biomass production
and SOC and that the deterioration of ecosystem functions was mostly
mediated by a reduction in plant diversity. This finding suggests that
the preservation of plant biodiversity can buffer decreased ecosystem
functioning due to climate change.