春季休牧时间对藏嵩草型草甸植物种群生态位的影响  

Effects of rest grazing in spring on the niche of plant population in Carex tibetikobresia meadow

作　　者：谢乐乐 王晓丽[1] 王彦龙[1] 马玉寿[1] 周选博 XIE Lele;WANG Xiaoli;WANG Yanlong;MA Yushou;ZHOU Xuanbo(State Key Laboratory of Plateau Ecology and Agriculture,Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学畜牧兽医科学院,省部共建三江源生态与高原农牧业国家重点实验室,西宁810016

出　　处：《西北植物学报》2024年第11期1801-1810,共10页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金项目(32260327);青海省自然科学青年基金项目(2022-ZJ-979Q)。

摘　　要：【目的】探究春季休牧对藏嵩草型草甸植物生态位的影响,为草地恢复以及生物多样性保护提供数据支撑和理论指导。【方法】在返青期设置放牧和4个休牧时间处理(20,30,40,50 d),于控制试验第2年7月中旬对植物群落进行调查,并将休牧时间作为环境梯度,研究藏嵩草草甸植物种群生态位特征。【结果】休牧30,40,50 d莎草科的重要值和地上总生物量比放牧显著增加,但毒害草的重要值呈相反趋势;莎草科、禾本科、阔叶型可食草的地上生物量在休牧50 d增加最显著,分别增加了220.99%、69.73%和139.37%;藏嵩草、藏异燕麦、垂穗披碱草和紫羊茅的生态位宽度值(N_(B))最大(0.999),而圆叶毛茛的NB最小(0.889);生态位重叠值(N_(O))大于0.990的有55对,占总数的26.10%,N_(O)小于0.75的有3对,占总数的1.43%。【结论】春季较长的休牧时间促进莎草科和禾本科植物的生长,抑制毒害草的生长;从生态位角度分析,藏嵩草草甸物种的重要值越高,其生态位宽度越大,更有利于优良牧草的生长,可有效促进草地恢复。[Objective]The study aims to explore the influence of spring rest grazing on the niche of Carex tibetikobresia meadow plants,and to provide data and theoretical guidance for grassland restoration and biodiversity protection.[Methods]Grazing and four grazing-off time treatments(20,30,40,and 50 d)were set during the green-returning period.Plant community was investigated in the middle of July of the second year,and the grazing-off time were taken as the environmental gradient to study the niche of plant populations in the C.tibetikobresia meadow.[Results]After 30,40,and 50 days of rest grazing,the importance value and aboveground biomass of Cyperaceae were significantly increased compared to grazing,while the importance value of poisonous weeds showed the opposite trend.The aboveground biomass of Cyperaceae,Gramineae,and broad-leaved edible grasses were increased most significantly after 50 days of rest grazing,increasing by 220.99%,69.73%,and 139.37%,respectively.The niche width(NB)of C.tibetikobresia S.R.Zhang,Helictotrichon tibeticum(Roshev)Holub,Elymus nutans Griseb,and Festu-ca rubra were the largest(0.999),while that of Ranunculus indivisus(Maxim.)Hand.-Mazz.was the smallest(0.889).There were 55 pairs with niche overlap value(N_(O))greater than 0.990,accounting for 26.10%of the total,and 3 pairs with N_(O)less than 0.75,accounting for 1.43%.[Conclusion]Longer rest grazing time in spring promotes the growth of Cyperaceae and Gramineae,and inhibites the growth of poi-sonous weeds.The higher the importance value of C.tibetikobresia meadow species,the wider its niche width,which is more conducive to the growth of excellent pasture and can effectively promote the restora-tion of grassland.

关 键 词：藏嵩草型草甸 休牧时间 重要值 生态位宽度 生态位重叠 

分 类 号：Q948[生物学—植物学]