Non-growing/growing season non-uniform-warming increases precipitation use efficiency but reduces its temporal stability in an alpine meadow
Fusong Han, Chengqun Yu, Gang Fu
Abstract
There are still uncertainties on the impacts of season-non-uniform-warming on plant precipitation use efficiency (PUE) and its temporal stability (PUE stability ) in alpine areas. Here, we examined the changes of PUE and PUE stability under two scenes of non-growing/growing season non-uniform-warming (i.e., GLNG: growing-season-warming lower than non-growing-season-warming; GHNG: growing-season-warming higher than non-growing-season-warming) based on a five-year non-uniform-warming of non-growing/growing season experiment. The GLNG treatment increased PUE by 38.70% and reduced PUE stability by 50.47%, but the GHNG treatment did not change PUE and PUE stability . This finding was mainly due to the fact that the GLNG treatment had stronger influences on aboveground biomass (AGB), non-growing-season soil moisture (SM NG ), temporal stability of AGB (AGB stability ), temporal stability of non-growing-season air temperature ( T a_NG_stability ), temporal stability of growing-season vapor pressure deficit (VPD G_stability ) and temporal stability of start of growing-season (SGS stability ). Therefore, the warming scene with a higher non-growing-season-warming can have greater influences on PUE and PUE stability than the warming scene with a higher growing-season-warming, and there were possibly trade-offs between plant PUE and PUE stability under season-non-uniform-warming scenes in the alpine meadow.