不同放牧管理模式下高寒草甸鼢鼠鼠丘土壤种子库特征

Soil seed bank characteristics of zokor moundsunder different grazing managementregimes in alpine meadow

摘要:

为明确放牧管理模式对高寒草甸鼢鼠鼠丘土壤种子库特征的影响,于2019年10月和2020年5月,分别采集禁牧、生长季休牧、传统放牧和连续放牧4种长期放牧管理模式下鼠丘土壤种子库,分析其密度、组成、多样性及与植被群落物种之间的相似性。结果发现:放牧显著影响鼢鼠鼠丘土壤种子库特征。与禁牧相比,连续放牧(5月)与生长季休牧(10月)模式下鼠丘的土壤种子库密度显著增加(P＜0.05);丰富度指数、多样性指数和优势度指数在连续放牧(5月)和生长季休牧(10月)管理模式下最高,禁牧模式下最低。优势度指数在传统放牧模式下最高,禁牧模式下最低,大小顺序为TG＞RG＞CG＞NG。Sorensen相似性分析发现,5月和10月鼠丘土壤种子库与植被群落物种之间的相似性指数均在连续放牧管理模式下最大,分别为0.58(5月)和0.57(10月),大小次序为CG＞RG＞TG＞NG(5月)和CG＞TG＞RG＞NG(10月)。放牧会影响鼠丘土壤种子库特征,进而对鼠丘斑块的演替产生影响。

Abstract:

In order to understand the effect of grazing management regimes on soil seed bank characteristics of zokor (Eospalax sp.) mounds,the soil seed banks under four kinds of long-term grazing management regimes,namely,no grazing (NG),rest grazing in growing season (RG),traditional grazing (TG),and continuous grazing (CG) plots,were characterized.Soil samples were collected in October 2019 and May 2020.The density,composition and diversity of the plant species of each vegetation community were analyzed and compared among the seed banks of the four management regimes .The results showed that grazing regimes significantly affected the soil seed bank characteristics of zokor mounds.Compared with no grazing,the soil seed bank density of zokor mound was significantly (P＜0.05) increased under continuous grazing (May) and rest grazing in growing season (October).The species richness index,diversity index,and dominance index were the highest under continuous grazing and resting grazing in growing season management regimes,and the lowest under no grazing regime.The evenness index was the highest under traditional grazing,and the lowest under no grazing with the specific order TG＞RG＞CG＞NG.Sorensen similarity analysis showed that the similarity index between soil seed banks and vegetation communities of continuous grazing management was the highest in May (0.58) and October (0.57).The similarity indices were ranked as CG＞RG＞TG＞NG (May) and CG＞TG＞RG＞NG (October).The results demonstrated that grazing regimes could affect the characteristics of the soil seed bank of zokor mounds,which in turn influence the evolution of the mound patches.