放牧管理模式对高原鼢鼠(Eospalax baileyi)鼠丘形态特征的影响

为明晰放牧对高原鼢鼠（Eospalax baileyi）造丘活动的影响，于2019年5月、8月和10月分别对禁牧（No grazing，NG）、生长季休牧（Rest grazing in growing season，RG）、传统放牧（Traditional grazing，TG）和连续放牧（Continuous grazing，CG）4种放牧管理模式样地下高原鼢鼠的新鼠丘（2个月内形成）半径、高度、表面积和体积等进行测定，并分析其表面积、体积与土壤和植被生物量间的关系。结果发现：放牧管理模式显著影响了高原鼢鼠鼠丘形态特征，且具有季节性差异。NG下鼠丘的半径、表面积和体积最大，而CG下鼠丘的体积和表面积显著变小（P<0.05），在8月和10月，鼠丘半径在CG样地显著小于其他3种放牧模式样地（P<0.05）；8月TG下鼠丘高度最高，而5月和10月NG下鼠丘高度最高，鼠丘高度在CG样地显著小于NG样地（P<0.05）。冗余分析2个排序轴几乎全部解释了土壤因子及地下生物量与鼠丘特征之间的关系，但各放牧管理模式下影响因子不同，NG样地的土壤容重（P<0.05）、土壤紧实度（P<0.01）和莎草科植物的地上生物量（P<0.01），RG样地的地下生物量（P<0.01）、土壤紧实度（P<0.01）和豆科植物的地上生物量（P<0.01），TG样地的禾本科和豆科植物的地上生物量（P<0.01），CG样地的土壤水分、地下生生物量、土壤紧实度（P<0.05）和莎草科植物的地上生物量（P<0.01）均显著影响了鼠丘的形态特征。可见，放牧会影响高原鼢鼠的鼠丘形态特征，进而对草地的演替产生不同的影响。

Effects of grazing management regimes on mound morphological characteristics of plateau zokors (Eospalax baileyi)

The rodent damage by plateau zokor in the process of alpine meadow grazing is a key problem in its utilization and management. Grazing is one of the most important ways to use grassland. Grazing management regimes, as a utilization system index to control grazing intensity, maintain livestock quantity and grassland ecosystem balance, which have different influences on grassland community structure, grassland productivity, soil structure, and nutrient properties. The plateau zokor (Eospalax baileyi) is a kind of underground rodent endemic to the Qinghai-Tibet Plateau, the embodiment of their different functions is the key to judge the "benefit and harm". Their continuous earthmoving and mound building is also one of the important manifestations of their harm,and the size of the mound building and the change of the excavated soil properties are the key factors affecting the grassland. Therefore, it is of great significance for rodent control and grassland management and utilization by elucidating the changes of mound characteristics in alpine meadow under different grazing management systems. In order to clarify the effect of grazing management regimes on the mound-building activity of plateau zokors, the radius, height, surface area and volumes of new mounds (formed within 2 months) under four kinds of grazing management regimes, namely no grazing (NG), rest grazing in the growing season (RG), traditional grazing (TG), and continuous grazing (CG) plots, were measured in May, August, and October 2019, and the relationship between surface area and volume and soil and vegetation biomass was analyzed. The results showed that the grazing management regimes significantly affected the morphological characteristics of mounds with seasonal differences. The radius, surface area and volume of mounds under no grazing regime were the largest, while the volume and surface area of mounds under continuous grazing regime decreased significantly (P<0.05), and the radius of mounds under the continuous grazing regime was significantly less than that of other three grazing regimes in August and October (P<0.05); the height of mounds under traditional grazing regime was the largest in August, while they were the largest under no grazing regime in May and October, and they were significantly less under continuous grazing regime than that under no grazing regime (P<0.05). The two sequencing axes of redundancy analysis almost entirely explained the relationship of mounds with environmental factors and underground biomass. However, the influencing factors were different under different grazing management regimes. There were great effects on the characteristics of zokor mounds from soil bulk density (P<0.05), soil compactness (P<0.01) and aboveground biomass of cyperaceae plants (P<0.01) under no grazing regimes. There were great effects on the characteristics of zokor mounds from underground biomass (P<0.01), soil compactness (P<0.01) and aboveground biomass of leguminosae plants(P<0.01) under rest grazing in growing season regime. There were great effects on the characteristics of zokor mounds from aboveground biomass of gramineae and leguminosae plants (P<0.01) under traditional grazing regimes, and there were great effects on the characteristics of zokor mounds from soil moisture, underground biomass, soil compactness (P<0.05) and aboveground biomass of cyperaceae plants(P<0.01) under continuous grazing regimes. Grazing can affect the mound-building activity of plateau zokors, and then had different effects on the succession of grassland.