水保所知识产出(1956---)知识库

Water use efficiency (WUE) is an ecological indicator reflecting the link between carbon and water cycles in
terrestrial ecosystems, which is often affected by drought disturbance. However, knowledge about the influences
of soil moisture drought on WUE is still lacking. Therefore, this paper aims to quantify the lagged effect and
impact of soil moisture drought on terrestrial ecosystem WUE from 1982 to 2018 using ERA5 and Global Land
Surface Satellite (GLASS) datasets. Drought conditions are described by the soil moisture anomaly percentage
index (SMAPI). The lagged effect of drought on WUE is measured by the month with the maximum significant
correlation between SMAPI and WUE. The impact of drought on WUE is estimated through the relative change of
WUE during drought and non-drought periods. The results showed that: (1) Drought had an approximately 4-
month lagged effect on WUE, which was observed in 70.87% of the global vegetated areas. The lagged effect
of drought on WUE was a short period (1–4 months) for shrubland and sparse vegetation, middle and long
periods (5–12 months) for forest. (2) When drought occurred, WUE decreased by 36.95% in the Tibetan Plateau
and 24.93% in West Africa, while WUE in North Europe, Alaska/N.W. Canada, and West Asia increased by
14.64%, 8.83%, and 8.53%, respectively. The negative and positive impacts of drought on WUE in each vege-
tation type were commensurate. Our results provide useful information for understanding the response of
ecosystem carbon and water cycles to drought..