林分密度对柏木人工林土壤养分及酶活性的影响

Effects of Stand Densities on Soil Nutrients and Enzyme Activities of Cupressus funebris Plantations

【目的】探索不同密度柏木(Cupressus funebris)人工林土壤养分含量及酶活性的变化趋势及其特征。【方法】以35~55年生柏木人工林为对象,研究不同林分密度(密度分别为4160、992、452株/公顷)下0~40 cm土层的土壤养分含量及酶活性变化。【结果】柏木人工林土壤养分含量及酶活性均随土层深度的增加呈降低趋势,具有明显的表聚现象。随着林分密度的降低,土壤养分含量呈先降低后增加的趋势,土壤全氮、全磷、全钾、碱解氮、速效钾在452株/公顷林分密度下含量最高;磷酸酶和蔗糖酶活性整体呈增加的趋势,且在452株/公顷林分密度下活性最大。相关分析结果显示:蔗糖酶、磷酸酶与土壤养分指标关系密切。【结论】适宜的林分密度有利于柏木人工林土壤养分的积累,能有效提高土壤肥力。

【Objective】The purpose of this study was to explore the change trend and characteristics of soil nutrient content and enzyme activity in Cupressus funebris plantation forest with different densities.【Method】Taking 35-55 year old Cupressus funebris plantation forest as the research object,the changes of soil nutrient content and enzyme activity in 0-40 cm soil layer of different stand densities(4160,992 and 452 plants/hm^(2),respectively)of C.funebris plantation forest were researched.【Result】The soil nutrient content and enzyme activity of C.funebris plantation forest decreased with the increase of soil depth,showing obvious surface aggregation.With the decrease of stand density,soil nutrient content first decreased and then increased.The contents of soil total nitrogen,total phosphorus,total potassium,alkaline hydrolysis nitrogen and available potassium were the highest at the stand density of 452 plants/hm^(2).The activities of phosphatase and sucrase increased as a whole,and the activities were the highest at the stand density of 452 plants/hm^(2).The results of correlation analysis showed that the sucrose enzyme and phosphatase were closely related to soil nutrient indexes.【Conclusion】The suitable stand density is more beneficial to soil nutrient accumulation of C.funebris plantations,thereby improving soil fertility effectively.