Characteristics of Soil Enzymatic Activity during Forage Green-up Period of Alpine Grasslands in the Eastern Qilian Mountain Areas
YANG Cheng-de1,CHEN Xiu-rong1,LONG Rui-jun2,MAN Yuan-rong1,ZHANG Zhen-fen1,ZHANG Jun-zhong1 (1.Pratacultural College,Gansu Agricultural University/Key Laboratory of Grassland Ecosystem,Ministry of Education/Sino-U.S.Center for Grazingland Ecosystem Sustainability,Lanzhou,Gansu Province 730070,China;2.College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou,Gansu Province 730020,China)
Soil enzymatic activities have drawn a lot attentions from researchers worldwide because they can serve as the assessing measure on soil quality,agrotechnical efficiency,and changing index of soil quality.In this experiment,the activities of soil enzymes(including catalase,urease,and neutral phosphatase) and their correlations with soil physical-chemical properties were studied of seven alpine grassland types,e.g.Rhododendrons simsii Planch.brushland(DJ),Salix cupularis Rehd.brushland(GL),Dasiphora fruticosa(L.) Rydb.brushland(JL),Polygonum viviparum L.grassland(ZY),gramineous steppe(HC),swamp grassland(ZZ),and Kobresia capillifolia(Decne.) C.B.Clarke grassland(SC),in the Eastern Qilian Mountains areas of the Qinghai-Tibetan Plateau in order to understand their ecological distribution characteristics and its relationship to soil properties.The results show that the activities of soil catalase,urease and neutral phosphatase were different among sampling sites and varied from 0.37 to 0.49 mL·g-1 min-1、0.24 to 0.42 mg·g-1 24 h-1,and 1.14 to 3.03 mg·g-1,espectively.The urease activity and neutral phosphatase activity at upper soil layer were higher than those at the lower layer.Soil catalase activity and neutral phosphatase activity at grassland were higher than those at brushland,but the soil urease activity was opposite.Soil enzymatic activity showed differently significant correlation with soil water content,bulk density,pH value,microbial biomass carbon,microbial biomass nitrogen,and microbial biomass phosphorus at different sampling sites.For example,soil urease activity had significantly negative correlation with soil water content and pH value at 0.05 or 0.01 levels at ZY,ZZ and SC,but no significant correlation at other grassland types with disagreement between JL and ZZ which had approximate quantity of soil organic matter.Therefore,taking soil urease activity as the soil fertility index has its limitation.
【Fund】： 甘肃省自然科学基金(096RJZA003);; 退化草原植被恢复与碳固定之间的研究(052456CHA-GS-Y-4)资助
【CateGory Index】： S812
【CateGory Index】： S812