Process interactions on catenas have supported grazing adapted ecosystems and sustained biodiversity values in the source zone of the Yellow River in western China for millennia.In recent decades,anthropogenic disturb...Process interactions on catenas have supported grazing adapted ecosystems and sustained biodiversity values in the source zone of the Yellow River in western China for millennia.In recent decades,anthropogenic disturbance and climate change have threatened the integrity of these systems,impacting upon environmental values and their capacity to sustain local livelihoods.Collaborations between local experts and a team of international researchers during a workshop and field excursion to this area in July 2019 developed a cross-disciplinary,process-based model of alpine meadow catenas.This paper relates the contemporary health of these grassland-wetland systems to their‘best achievable state’under prevailing boundary conditions,differentiating stages of degradation and recovery in relation to climate and land use changes.Recovery is underway for alpine meadow catenas at Maqin.Reduced land use pressures(stocking rates)and longer growing seasons have enhanced grasslandwetland conditions.However,recovery prospects are limited for local areas of extremely degraded grasslands(heitutan),as breached abiotic thresholds have resulted in soil and nutrient loss and reduced capacity for water retention.While lagomorphs and rodents act as ecosystem engineers when alpine meadows are in a healthy state,irruptions locally increase the proportion of bare ground and inhibit recovery potential.Management options that support recovery of alpine meadows are presented for differing stages of degradation.展开更多
基金funded by the Qinghai Science and Technology Department(Grant No.2020-ZJ-904)the National Natural Sciences Foundation of China(Grant No.31872999)+4 种基金the 111 Project(Grant No.D18013)Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK1002)Changjiang Scholars and Innovative Research Team in University,MOE(Grant No.IRT_17R62)local authorities for their support for this workUniversity of Auckland for their commitment to the Three Brothers Project。
文摘Process interactions on catenas have supported grazing adapted ecosystems and sustained biodiversity values in the source zone of the Yellow River in western China for millennia.In recent decades,anthropogenic disturbance and climate change have threatened the integrity of these systems,impacting upon environmental values and their capacity to sustain local livelihoods.Collaborations between local experts and a team of international researchers during a workshop and field excursion to this area in July 2019 developed a cross-disciplinary,process-based model of alpine meadow catenas.This paper relates the contemporary health of these grassland-wetland systems to their‘best achievable state’under prevailing boundary conditions,differentiating stages of degradation and recovery in relation to climate and land use changes.Recovery is underway for alpine meadow catenas at Maqin.Reduced land use pressures(stocking rates)and longer growing seasons have enhanced grasslandwetland conditions.However,recovery prospects are limited for local areas of extremely degraded grasslands(heitutan),as breached abiotic thresholds have resulted in soil and nutrient loss and reduced capacity for water retention.While lagomorphs and rodents act as ecosystem engineers when alpine meadows are in a healthy state,irruptions locally increase the proportion of bare ground and inhibit recovery potential.Management options that support recovery of alpine meadows are presented for differing stages of degradation.
