摘要
为探讨放牧强度对短花针茅荒漠草原植物群落结构及生态位的影响,并进一步探究优势植物生态位宽度与种群特征的关系,以不放牧(NG)为对照(CK),设置轻度放牧(LG)、中度放牧(MG)和重度放牧(HG)3个处理,载畜率分别为0.91(只羊/hm^(2))、1.82(只羊/hm^(2))和2.71(只羊/hm^(2))。于2020年8月植物生长高峰期对短花针茅荒漠草原植物物种重要值、生态位宽度、生态位重叠以及物种种群特征与生态位宽度的关系进行分析。结果表明:CK、LG、MG和HG群落中物种数分别为18、15、12和5,表明随着载畜率增加,群落中物种数减少;与CK相比,LG提高了优势种短花针茅、无芒隐子草等的生态位宽度,降低了半灌木冷蒿和木地肤的生态位宽度,而MG和HG降低了优势种的生态位宽度;与CK相比,LG显著降低了群落中物种生态位重叠平均值,而MG和HG显著增加了群落中物种生态位重叠平均值;建群种短花针茅的生态位宽度与种群特征均无显著相关性,优势种无芒隐子草的生态位宽度与其密度和生物量呈显著正相关,银灰旋花与无芒隐子草相同。综上所述,载畜率为0.91只羊/hm^(2)是荒漠草原较为适宜的放牧强度,有利于优质牧草生长。
This study aimed to explore the effects of grazing intensity on plant community structure and niche of Stipa breviflora desert steppe and further investigate the relationship between niche breadth and population characteristics of dominant plants.Four treatments were conducted in the present study,no grazing as the control group(CK),and the three experimental treatments:light grazing(LG),moderate grazing(MG),and heavy grazing(HG),with a grazing intensity of 0.91 sheep/hm^(2),1.82 sheep/hm^(2)and 2.71 sheep/hm^(2),respectively.We analyzed the population importance value,niche breadth,niche overlap,and the relationship between population characteristics and niche breadth of dominant plants in S.breviflora desert steppe at the growth peak in August 2020.The results showed that the number of species in CK,LG,MG,and HG treatments were 18,15,12,and 5,respectively,indicating that the number of species decreased with the increasing grazing intensity.LG treatment increased the niche breadth of dominant species(S.breviflora and Cleistogenes songorica)and reduced that of Artemisia frigida and Kochia prostrata.However,MG and HG treatments decreased the niche breadth of dominant species.Moreover,the average niche overlap of the community was significantly reduced under the LG treatment and increased dramatically umder the MG and HG treatments compared with the CK group.There were no significant correlations between niche breadth and population characteristics of the constructive species S.breviflora.The niche breadth of the dominant species C.songorica was positively correlated with plant density and biomass,the same as Convolvulus ammannii.In summary,a grazing intensity of 0.91 sheep/hm^(2)was more suitable for the desert steppe,which was conducive to the growth of high-quality forage grass.
作者
王琪
郑佳华
张峰
乔荠瑢
赵萌莉
张军
WANG Qi;ZHENG Jia-hua;ZHANG Feng;QIAO Ji-rong;ZHAO Meng-li;ZHANG Jun(College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Hohhot 010011,China;Key Laboratory of Grassland Resources,Ministry of Education,Inner Mongolia Agricultural University,Hohhot 010011,China;College of Science,Inner Mongolia Agricultural University,Hohhot 010018,China)
出处
《中国草地学报》
CSCD
北大核心
2022年第10期1-9,共9页
Chinese Journal of Grassland
基金
国家自然科学基金项目(32160332)
内蒙古自治区自然科学基金项目(2020ZD03)。
关键词
载畜率
短花针茅荒漠草原
群落结构
生态位宽度
生态位重叠
Grazing intensity
Stipa breviflora desert steppe
Community structure
Niche breadth
Niche overlap
