摘要
放牧和异常降水对荒漠草原生态系统产生了显著的影响,群落物种组成及多样性因降水和载畜率的改变而变化。然而不同载畜率下荒漠草原植物群落物种组成及多样性对异常降水的响应尚不明晰。本研究以内蒙古短花针茅(Stipa breviflora)荒漠草原为研究对象,调查并分析不同载畜率(绵羊,CK:不放牧、LG:0.93、MG:1.82和HG:2.71羊单位hm^(-2)半年^(-1))放牧区植物群落物种组成及其数量特征。结果表明:降水增加对群落数量特征和物种多样性促进作用显著,但对群落物种优势度指数有显著抑制作用;降水增加使得不同功能属性物种数目增多,引起建群种物种综合优势度降低,从而改变群落物种组成及多样性;不同功能属性物种对载畜率的响应存在差异,群落物种组成及多样性在响应异常降水变化时,降水与载畜率之间协同变化和相互制约,但直根系C3植物和群落总密度的变化主要受载畜率影响。异常降水可影响长期过度放牧引起的生态系统过程,对草地生态系统恢复有积极作用。
Desert grassland ecosystem was significantly effected by the grazing and abnormal precipitation,resulting in the composition and diversity of plants posed changes under the variation of precipitation and stocking rates.However,the response mechanism of species is not yet clear in the desert steppe.In this study,the composition and diversity of plants were investigated in the Stipa breviflora desert steppe of Inner Mongolia under different stocking rates(CK,without grazing,light grazing[LG,0.93 sheep unit hm^(-2)half∙a-1],moderate grazing[MG,1.82 sheep unit hm^(-2)half∙a^(-1)],heavy grazing[HG,2.71 sheep unit hm^(-2)half∙a^(-1)])to reveal the effects of precipitation and grazing on plant communities.The results indicated that(1)the increase of precipitation significant improved the community quantitative and diversity of species,but has a greatly inhibitory effect on the species dominance index,(2)it also enhanced the number of species with different functional attributes,but reduced the Stipa breviflora summed dominance ratio(SDR)and lead to the variation of composition and diversity of community species,and(3)the synergistic and mutually restrictive changes were found between precipitation and stocking rates and the C3 plants and total density were major affected by the stocking rates,which indicated the responses to stocking rates varied among species under different functional attributes.The abnormal precipitation can affect the ecosystem process that influenced by a long-term overgrazing and has a positive effect on the restoration of the grassland ecosystems.
作者
李江文
何邦印
张晓曦
回虹燕
李彩
韩国栋
LI Jiangwen;HE Bangyin;ZHANG Xiaoxi;HUI Hongyan;LI Cai;HAN Guodong(College of Life Sciences,Yan′an University,Yan′an 716000,China;Shaanxi Key Laboratory of Chinese Jujube(Yan′an University),Yan′an 716000,China;Key Laboratory of Grassland Resources of the Ministry of Education of China,Hohhot 010020,China)
出处
《生态学报》
CAS
CSCD
北大核心
2023年第15期6433-6442,共10页
Acta Ecologica Sinica
基金
国家自然科学基金项目(31770500)
草地资源可持续利用教育部科技创新团队(IRT_17R59)
陕西省自然科学基础研究项目(2021JQ-623)
延安大学科研计划资助项目(YDBK2019-18)。
关键词
异常降水
荒漠草原
载畜率
群落
物种多样性
abnormal precipitation
desert steppe
stocking rate
community
species diversity
