摘要:以若尔盖退化高寒湿地为研究对象，连续3年（2015-2017年）于植被返青期（4-5月）、草盛期（7-8月）和枯黄期（10-11月）监测高原鼢鼠鼠丘密度、3个土层（0-10、10-20、20-30 cm）土壤理化性质、酶活性及微生物数量的季节动态，并分析土壤生物学特征与土壤环境间的季节相关性。结果表明：（1）各植被物候期，土壤pH值、容重指标均随土层加深而显著升高（P<0.05），土壤含水量、有机质、全氮、碱解氮、有效磷、速效钾、酶活性及微生物数量指标均随土层加深而显著降低（P<0.05）；（2）植被物候期对高寒鼠荒地非土丘土壤养分在不同土层的垂直分配有显著影响，对0-10 cm土层土壤生物学特征含量的影响程度显著大于10-20 cm和20-30 cm土层。（3）冗余分析（RDA）表明3个植被物候期，土壤生物学特征指标与土壤理化性质指标间显著相关（P<0.05），主成分分析（PCA）表明各指标在不同土层均呈现明显的季节性分布，数量特征表现为：枯黄期 > 返青期 > 草盛期。揭示了高寒鼠荒地高原鼢鼠季节性活动对土壤理化性质、酶活性及微生物数量的影响，为今后青藏高原鼠荒地的分级恢复治理提供理论依据。



Abstract:Plateau zoker (Myospalax baileyi) is a special subterranean rodent in the Qinghai-Tibet plateau, which built very complex burrow system to live and breed and made a lot of aboveground mounds on the alpine rangeland ecosystem. The mounds not only have a negative impact on edible pasture yield and rangeland landscape but also affect soil physicochemical properties and biological characteristics seriously. At present, there have been many studies of the vertical soil properties on plateau zoker mounds at different soil depths, but little knowledge on surrounding areas that not covered by the heaped mounds. Selecting rodents-damaged alpine rangeland as the study object, the seasonal dynamics of the density of plateau zokor mounds, the physical and chemical properties of three soil layers (at 0-10 cm, 10-20 cm, and 20-30 cm deep), the enzyme activities, and the thmicrobial population were closely monitored. While the seasonal correlation between the soil biological characteristics and the soil environmental conditions were analyzed from 2015 to 2017, in particular during the plant greenup period (GP) which normally takes place between April and May, the vigorous growth period (VGP) which occurs between July and August, and the withered period (WP) which occurs between October and November. The results indicated that: (1) The vegetation phenological phase, soil pH, and soil bulk density indices have shown a statistically significant increase with soil depth at the 0.05 level, whereas the decrease in soil water content, soil organic matter, total nitrogen, soil alkaline nitrogen, available phosphorus, available potassium, enzyme activity, and microbial quantity were statistically significant with the deepening of the soil layer at the 0.05 level of significance. (2) The vegetation phenological phase had a significant effect on the vertical distribution of soil nutrients at different soil layers, whereas the surrounding area that was not covered with the mounds by rodents activities. The impact of soil biological characteristics on the 10-20 cm soil layer was significantly greater than those of the 20-30 cm soil layer. (3) Redundancy analysis (RDA) showed that correlations between soil biological characteristics and soil environmental conditions, within three vegetation phenological phases, were statistically significant at the 0.05 level. Principal component analysis (PCA) showed that all indicators showed an obvious seasonal distribution trend. Moreover, the quantitative characteristics at different soil layers were as follows: WP > GP > VGP. This study reveals the effects of the seasonal activities of plateau zokor on the soil physicochemical properties, enzyme activities, and microbial population of the rodents-damaged alpine rangeland, and hope to provide a theoretical basis for the classification and restoration of the wetland degradation on the Qinghai-Tibet Plateau.





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