Grassland ecological protection compensation and reward policy is the largest-scale investment concerning themost extensive areas since foundation of the PRC. It will be the long-term implementationpolicy for grasslan...Grassland ecological protection compensation and reward policy is the largest-scale investment concerning themost extensive areas since foundation of the PRC. It will be the long-term implementationpolicy for grassland ecological protection. In this study,based on macro-perspective, the policy effects ofgrasslandproductivity, ecological protection, animal husbandryoutput, pastoralists＇ income were ana- lyzed. The resultsshow that, afterimplementation of the policy, naturalgrass production and grasslandtheoretical stocking rateincreased. The averagenatural grasslandlivestockoverloading ratedecreased significantly, comprehensivenationalgrasslandvegetation coverageis increasing. Besides, adult cattleandbeef yield arefluctuated. Sheep head, adult sheep, sheep production, milk productionincreasedin varying degrees. The per capita netincomeof farmers and pastoralists, livestock income, the proportion oflivestockincomewere higher than those beforeimplementation of the policy.展开更多
Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We...Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We addressed the climatic niche shift of G.quadriradiata and evaluated how this could contribute to its invasion in China.We used the Maxent model to predict the potential distribution of G.quadriradiata using its native and invaded range occurrences and climatic variables.Principal component analysis was conducted to measure climatic niche shifts of G.quadriradiata during its invasion in China.The models revealed only 32.7%niche overlap between the native and invasive populations.The niche similarity of the two populations was significantly low(Schoener’s D=0.093,P<0.005),suggesting the occurrence of a niche shift.The envelop and center of the realized climatic niche in China has shifted to lower temperature and less precipitation compared to that in its native range.The majority of invaded areas in southern China are in the stabilizing zone,whereas the colonization and adaptation zones are predicted to be at the leading edge of G.quadriradiata invasion in northern China.This suggests that the regional distribution of G.quadriradiata may be in a quasi-equilibrium state,and that the species continues to invade environmentally suitable areas.Alterations in G.quadriradiata’s niche would help to explain why this species is so invasive in China.展开更多
基金Supported by National Natural Science Funds of China(71503251)The Agricultural Science and Technology Innovation Program(ASTIP-IAED-2015-01)China forage and grass research system(CARS-35-22)~~
文摘Grassland ecological protection compensation and reward policy is the largest-scale investment concerning themost extensive areas since foundation of the PRC. It will be the long-term implementationpolicy for grassland ecological protection. In this study,based on macro-perspective, the policy effects ofgrasslandproductivity, ecological protection, animal husbandryoutput, pastoralists＇ income were ana- lyzed. The resultsshow that, afterimplementation of the policy, naturalgrass production and grasslandtheoretical stocking rateincreased. The averagenatural grasslandlivestockoverloading ratedecreased significantly, comprehensivenationalgrasslandvegetation coverageis increasing. Besides, adult cattleandbeef yield arefluctuated. Sheep head, adult sheep, sheep production, milk productionincreasedin varying degrees. The per capita netincomeof farmers and pastoralists, livestock income, the proportion oflivestockincomewere higher than those beforeimplementation of the policy.
基金supported by the National Natural Science Foundation of China(32071520,31600445 and 31570425)the Natural Science Basic Research Plan in Shaanxi Province of China(2020JM-286)+2 种基金the Central University Innovation Team Project(GK202001006)the Fundamental Research Funds for the Central Universities(GK202103072 and 2020CSLY014)the Research Funds of Shaanxi Association for Science and Technology,and the Research Funds of Xi’an Association for Science and Technology(202113).
文摘Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We addressed the climatic niche shift of G.quadriradiata and evaluated how this could contribute to its invasion in China.We used the Maxent model to predict the potential distribution of G.quadriradiata using its native and invaded range occurrences and climatic variables.Principal component analysis was conducted to measure climatic niche shifts of G.quadriradiata during its invasion in China.The models revealed only 32.7%niche overlap between the native and invasive populations.The niche similarity of the two populations was significantly low(Schoener’s D=0.093,P<0.005),suggesting the occurrence of a niche shift.The envelop and center of the realized climatic niche in China has shifted to lower temperature and less precipitation compared to that in its native range.The majority of invaded areas in southern China are in the stabilizing zone,whereas the colonization and adaptation zones are predicted to be at the leading edge of G.quadriradiata invasion in northern China.This suggests that the regional distribution of G.quadriradiata may be in a quasi-equilibrium state,and that the species continues to invade environmentally suitable areas.Alterations in G.quadriradiata’s niche would help to explain why this species is so invasive in China.
