岷江上游典型森林生态系统土壤酶活性初步研究

对四川岷江上游4种典型森林(连香树、马尾松、云杉、桦树)土壤酶活性及其化学性质的研究表明:土壤酶(脲酶、过氧化氢酶、蛋白酶、蔗糖酶)活性均随着土层深度的增加而呈现递减趋势,上层(0~20cm)是下层(20~40cm)的2~6倍;脲酶和过氧化氢酶与土壤微生物量碳氮、有机碳和全氮呈极显著相关(P<0.01);蔗糖酶为土壤微生物量碳氮、有机碳和全氮呈极显著相关(P<0.01);蛋白酶与微生物量氮、有机碳、全氮都未达到显著相关(P>0.05),但与微生物量碳呈显著相关(P<0.01);土壤酶对土壤微生物量碳氮的直接通径系数和决策系数排列顺序均为:脲酶>蔗糖酶>过氧化氢酶>蛋白酶;对土壤有机碳、全氮的直接通径系数和决策系数排列顺序均为:脲酶>过氧化氢酶>蔗糖酶>蛋白酶。

Preliminary Studies on Soil Enzymes Activities of Typical Forest Ecosystem in Minjiang Areas

Study on soil enzymes activities and chemical properties of 4 kinds of typical forest ecosystems(Cercidiphyllum japonicum, Pinus massoniana, Picea asperata, Betula utilis)in Minjiang areas showed: Soil enzymes activities decreased with soil depth increasing. Soil enzymes (urease, hydrogen peroxides, invertase, protease) activities of top layer (0~20 cm) were higher than deep layer (20~40 cm) by 2~6 times. MB-C&N, soil organic carbon and total nitrogen were significantly correlated with urease activity and hydrogen peroxides activity (P<(0.01)). The correlations were significantly between invertase activity and MB-C&N, soil organic and total nitrogen (P<0.01), though the direct effects were negative between invertase activity and MB-N, soil organic carbon and total nitrogen. MB-N, soil organic carbon and total nitrogen were not significantly correlated with protease activity (P>0.05), and MB-C was significantly correlated with protease activity (P<0.01). The order of direct path coefficients and decision-making coefficients was urease>invertase >hydrogen peroxides>protease between soil enzymes and MB-C&N. The order of direct path coefficients and decision-making coefficients was urease>hydrogen peroxides>invertase> protease between soil enzymes and soil organic carbon and total nitrogen.