黄土高原水蚀风蚀交错区5种典型草地群落土壤酶活性的研究

Soil Enzymatic Activities of Five Typical Grassland Communities in Water-wind Erosion Crisscross Region on the Loess Plateau

以长芒草(Stipa bungeana)、苜蓿-长芒草-铁杆蒿(Medicago sativa-S.bungeana-Artemisia sacrorum)、苜蓿-铁杆蒿(M.sativa-A.sacrorum)、长芒草-铁杆蒿(S.bungeana-A.sacrorum)和苜蓿-长芒草(M.sativa-S.bungeana)5种弃耕后自然演替形成的草地群落为研究对象,通过分析不同群落中土壤淀粉酶、脲酶、蔗糖酶和碱性磷酸酶活性的分布,进一步阐释黄土高原水蚀风蚀交错区弃耕农地不同植被恢复过程对土壤酶活性的影响。结果表明:除土壤淀粉酶外,土壤脲酶、蔗糖酶和碱性磷酸酶活性均受地上植物群落的显著影响,并且土壤脲酶、蔗糖酶和碱性磷酸酶活性均随土层的加深而逐渐减小。长芒草群落土壤酶活性低且土壤养分和生物量均低于其他4个群落,表明弃耕后以单一种为优势种的草地群落植被恢复效果并不理想。4种土壤酶活性与土壤养分因子存在显著相关性,表明土壤酶活性可以指示土壤质量的变化。

In this study, 5 different types of grassland communities （Stipa bungeana, Medicago sativa-S. bungeana-Artemisia sacrorum, M. sativa-A, sacrorum, S. bungeana-A, sacrorum and M. sativa-S, bungeana） developed as the form of natural succession after farmland abandoned in water-wind erosion criss- cross region were selected as the research object to analyze the distribution of urease, invertase, alk-phos- phatase and diastase, and to reveal the effect of different vegetation restoration on soil enzyme activities in water-wind erosion crisscross region on the Loess Plateau. Results showed that soil enzyme activities var- ied significantly in different grassland communities except for diastase. Activities of urease, invertase and alk-phosphatase all decreased with the increasing soil depth. Soil nutrients and biomass in S. bungeana grassland were the lowest among the 5 grssland communities, and the minimum values of soil enzymatic activities were all found in it, which indicated that the effect of restoration by single vegetation was not i- deal. There were significant correlations between soil enzyme activities and soil nutrients, which revealed that soil enzyme activities could indicate the change of soil quality.