纳板河自然保护区土壤酶对不同海拔、坡向的响应

在纳板河自然保护区内分海拔和坡向采集土样，测定分析了尿酶、蛋白酶、蔗糖酶、过氧化氢酶4种主要土壤酶活性和主要养分指标的变化。结果表明:土壤有机质、水解氮含量随海拔升高显著增加；阳坡全氮含量随海拔升高呈现由中间向两端减小的趋势，阴坡全氮含量随海拔升高波动增加；土壤速效磷含量随海拔呈现由中间向两端减小趋势；蛋白酶活性高海拔 > 低海拔，海拔对表层过氧化氢酶活性影响较小，脲酶、蔗糖酶活性随海拔呈现波动。土壤有机质、全氮、水解氮、速效磷含量阳坡 > 阴坡；土壤蛋白酶、过氧化氢酶、蔗糖酶活性阴坡 > 阳坡，各土层土壤脲酶活性阳坡 > 阴坡。各养分含量及酶活性表层 > 中下层。土壤酶活性与各肥力因子间相关关系显著，各土壤酶活性间相关性显著。有机质、全氮、全磷是影响蛋白酶活性的主导因子，速效磷和水解氮为次要因子；全磷、速效磷、水解氮为影响脲酶活性的主要因子，有机质、全磷、速效钾为次要因子。主成分分析结果表明蛋白酶和脲酶活性作为保护区土壤肥力指标具有可行性。

Response of Soil Enzymes to Different Elevations and Aspects in Naban Basin Nature Reserve

We collected soil samples in River nature reserve on the basis of elevation and slope, analyzed the variations of the urine enzyme, protease, sucrose, catalase four main soil enzyme activity and the change of main nutrient indexes. The results showed that soil organic matter, the hydrolysis nitrogen content increased significantly with the increase of altitude; on sunny slope, total nitrogen contents showed the trends of decreasing with the increase of altitude from middle to both ends, and in shady slope, total nitrogen content increased with the increase of altitude; soil available P contents showed the decreasing trends with the increase of altitude from middle to both ends; protease activity was higher in low altitude than that in the high altitude, the surface catalase activity was less influenced by elevation, urease and sucrose activity fluctuated along with the elevation; soil organic matter, total nitrogen, hydrolyzed nitrogen, available phosphorus content were higher on the sunny slope than those on the shady slope; soil protease, sucrose, catalase activities were higher on shady slope than those on the sunny slope, soil urease activities in the soil layers were higher on sunny slope than those on the shady slope. The nutrient content and enzyme activity were higher in the surface that those in the deep layers. Correlation between soil enzyme activity and the fertility factor was significant, correlation between each soil enzyme activities were significant. Organic matter, total nitrogen, total phosphorus were the major factors influencing the activities of protease, followed by available phosphorus and hydrolysis nitrogen; total phosphorus, available phosphorus, hydrolyze nitrogen were the main factors affecting the activity of urease, followed by organic matter, total phosphorus, available potassium. Principal component analysis results showed that the protease and urease activity identified as of soil fertility index was feasible in the nature reserve area.