异常降水对不同载畜率下荒漠草原物种丰富度及优势度的影响  

Effects of abnormal precipitations on plant species richness and dominance under different stocking rates

作　　者：李江文 何邦印 回虹燕 张晓曦 李彩 韩国栋 LI Jiangwen;HE Bangyin;HUI Hongyan;ZHANG Xiaoxi;LI Cai;HAN Guodong(College of Life Sciences,Yan’an University,Yan’an 716000,Shaanxi,China;Shaanxi Key Laboratory of Chinese Jujube(Yan’an University),Yan’an 716000,Shaanxi,China;Key Laboratory of Grassland Resources of the Ministry of Education of China,Hohhot 010020,China)

机构地区：[1]延安大学生命科学学院,陕西延安716000 [2]陕西省红枣重点实验室(延安大学),陕西延安716000 [3]草地资源教育部重点实验室,呼和浩特010020

出　　处：《生态学杂志》2023年第7期1610-1617,共8页Chinese Journal of Ecology

基　　金：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)资助。

摘　　要：放牧对草地生态系统物种组成及多样性产生显著影响,荒漠草原对降水变化具有高度敏感性。本研究基于内蒙古短花针茅(Stipa breviflora)荒漠草原多年放牧试验平台,通过调查不同载畜率下植物群落物种组成及数量特征,分析异常降水对不同载畜率下荒漠草原物种丰富度及优势度的影响。结果表明:试验地共发现物种50种,其中,丰水年出现48种,干旱年出现29种。丰水年群落数量特征、物种丰富度显著高于干旱年,丰水年短花针茅综合优势度显著低于干旱年。群落数量特征随载畜率的增加而降低,物种丰富度与载畜率呈线性负相关,与降水量呈非线性正相关。短花针茅综合优势度与载畜率呈线性正相关,与降水量呈非线性负相关,物种丰富度与短花针茅综合优势度呈线性负相关。异常降水和放牧均对荒漠草原物种丰富度及优势度产生显著影响,轻度放牧有利于维持荒漠草原物种丰富度。本研究结果可以为荒漠草原科学管理及合理放牧利用提供依据。Grazing has significant effects on species composition and diversity of grasslands.Desert steppe is highly sensitive to the variations of precipitation.Based on a multi-year grazing experimental platform of Stipa breviflora desert steppe in Inner Mongolia,we investigated species composition and its quantitative characteristics and explored the effects of abnormal precipitation on species richness and dominance under different stocking rates.The results showed that a total of 50 species were recorded in the research site,of which 48 species were recorded in wet year and 29 species in dry year.The community quantitative characteristics and species richness in wet years were significantly higher than those in dry year,while the dominance of S.breviflora in wet year was significantly lower than that in dry year.The community quantitative characteristics decreased with increasing stocking rates.Species richness had a linear negative correlation with stocking rate,but a nonlinear positive correlation with pre-cipitation.The dominance of S.breviflora had a linear positive correlation with stocking rate,and a nonlinear nega-tive correlation with precipitation.Species richness had a linear negative correlation with the summed dominance ratio of S.breviflora.Both abnormal precipitation and grazing had significant impacts on species richness and domi-nance in desert steppe.Light grazing was beneficial to maintain plant species richness.This study provides basis for scientific management and rational grazing in desert steppe.

关 键 词：载畜率 物种丰富度 物种综合优势度 异常降水 荒漠草原 

分 类 号：S812[农业科学—草业科学]