首页|放牧方式和施肥梯度对高寒草甸群落生产力和物种丰富度的影响

放牧方式和施肥梯度对高寒草甸群落生产力和物种丰富度的影响

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通过比较青藏高原东部高寒草甸植物群落的地上生物量、物种丰富度及其相关关系对两种放牧方式和4种施肥梯度的响应,分析了放牧方式和施肥梯度对该类草甸群落的影响.结果表明,放牧显著增加了物种丰富度(P<0.001),减小了群落生物量,增加了杂类草在生物量中的比重,抑制了禾草类物种的生长,而施肥则显著降低了物种丰富度(P<0.001),但是增加了群落生物量,抑制了杂类草类的生长,增加了禾草类在生物量中的比重.在全年放牧的所有施肥区,物种丰富度均未呈现显著变化(P>0.05),而在全年封育的所有施肥区,物种的丰富度均显著下降(P<0.001),这表明放牧是主效应,施肥效应被放牧效应所掩盖.在放牧处理或施肥处理下的所有试验小区中,群落生物量和物种丰富度均呈负相关关系,且这种负相关程度随着施肥水平增加或封育禁牧而显著增强.本研究还发现在该地区牧场中进行适度的氮肥撒施可以既不影响物种的丰富度,又能增加群落的生产力,而且可以提高优质牧草在群落中的比重,这是一种最佳的群落性能,能够承载更多的牲畜进而带来更高的经济效益且不会导致当地草原的退化,适宜在该地区牧场中进行推广.
Effects of grazing and fertilization on community productivity and species richness in eastern alpine meadow of Tibetan plateau
The community productivity,species richness and their interaction response to grazing and fertilization were analyzed in eastern alpine meadow of Tibetan Plateau with four nitrogen fertilizer levels and two grazing levels.Fertilization significantly reduced (P <0.001) the species richness and inhibited the growth of forbs group but increased the aboveground biomass and promoted the growth of grasses group,while grazing significantly increased (P <0.001) the species richness and promoted the growth of forbs group but decreased the aboveground biomass and inhibited the growth of grasses group.In the plots with both fertilized and grazed,there was no significant changes for species richness,whereas there were significant reductions (P<0.001) in the fertilized plots without grazing.These results suggested that grazing was the main factor and the effects of fertilization was covered up by the grazing.There was a negative relationship between species richness and community biomass in the plots two only with grazing or fertilization.The moderate nitrogen fertilization can increase community productivity and the ratio of forage without effects on species richness.This management was optimal for loading more stocks to achieve more profits without degradation of grassland which can be applied in the local grassland.ested that moderate fertilization in the grassland of the study site would increase community productivity and have little effect on species richness.The reasonable solution is suitable for generalization in the local pasture.

functional groupcommunity biomassspecies richnessfertilizationgrazingalpine meadow

张春花

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甘肃民族师范学院,甘肃合作747000

功能群 群落生物量 物种丰富度 施肥 放牧 高寒草甸

国家自然科学基金

41430749

2014

草业科学
中国草原学会 兰州大学草地农业科技学院

草业科学

CSTPCDCSCD北大核心
影响因子:0.854
ISSN:1001-0629
年,卷(期):2014.31(12)
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