秦岭地区华北落叶松人工林地土壤养分和酶活性变化  

Soil nutrients and enzyme activities in Larix principis-rupprechtii plantations in the Qinling Mountains,China

作　　者：赵海燕[1] 徐福利[1,2] 王渭玲[3] 王伟东[3] 陈钦程 赵亚芳[2] 马亚娟[3] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]中国科学院,水利部水土保持研究所,杨凌712100 [3]西北农林科技大学生命科学学院,杨凌712100

出　　处：《生态学报》2015年第4期1086-1094,共9页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划(973计划)2012CB416902资助

摘　　要：以秦岭地区不同林龄(5年生、10年生、20年生、30年生和40年生)华北落叶松人工林为研究对象,采用野外调查采样和室内分析相结合的方法,研究了不同林龄华北落叶松人工林地土壤剖面p H值、有机质养分和酶活性的变化。结果表明:土壤p H值随着林龄有降低趋势,随着土层深度的增加有升高趋势。土壤有机质和土壤速效氮、速效磷和速效钾在近熟龄期显著高于幼龄期。土壤中的磷酸酶、脲酶、蔗糖酶和过氧化氢酶活性随着林龄都呈"高—低—高"的趋势,幼龄期的土壤蔗糖酶活性显著高于近熟龄的,而磷酸酶、脲酶和过氧化氢酶活性是近熟龄期的显著高于中幼龄。土壤速效养分和酶活性都随着土层深度的增加有显著的降低。相关分析表明磷酸酶活性与有机质、速效氮、速效磷、速效钾和脲酶活性呈极显著的正相关性(P<0.01),脲酶与有机质、速效氮和速效钾呈极显著正相关。蔗糖酶与过氧化氢酶活性显著负相关(P<0.05),与p H值有一定的正相关性。秦岭地区华北落叶松人工林进入近熟林之后土壤肥力有一定的恢复,而在中幼龄阶段土壤养分比较缺乏,尤其是氮磷。Larix principis-rupprechtii was introduced in Shaanxi Province more than 50 years ago, and most of these trees were planted in the Qinling Mountains. In order to study the fertility of soil in different-aged Larix principis-rupprechtii plantations in this area, we chose young- （5 and 10 years old）, middle- （20 years old）, and near-mature- （30 and 40 years old） aged Larix principis-rupprechtii plantations in the Nantan Nursery Garden of Taibai and Huoditang of Ning-shan in Shannxi Province as the experimental sites, and established three 20 ×20-m plots in each age stand plantation in 2012. In each plot, soil samples were collected from three depths （0-20 cm, 20-40 cm, and 40-60 cm） at five randomly located points. Using these samples, we examined the soil chemical properties （pH, organic matter, available N, available P, and available K） and enzyme activities （phosphatase, urease, invertase, and catalase） in the different-aged plantations. Soil pH in the 0-20-cm layer decreased from 6.71 in the 10-year-old plantation to 5.72 in the 40-year-old plantation; however,with an increase in soil depth there was a slight increase in pH. Soil organic matter and available nutrients in near-mature plantations were significantly higher than those in the young plantations （P 〈 0.05 ）. The variation ranges of these soil properties in the 0-20cm layer were as follows： organic matter, 10.12-23.12 mg/kg; available N, 27.82-142.82 rag/ kg; available P, 1.91-2.53 mg/kg; and available K, 104.33-264.67 mg/kg. There were significant reductions in soil organic matter and available nutrients as the soil depth increased （ P 〈 0.05 ）. With an increase in plantation age, the activities of soil phosphatase, urease, invertase, and catalase showed a ＂high-low-high＂ tendency. In the 0--20cm soil layer, the variation ranges for these activities were as follows： phosphatase, 28.06-53.93 mg/100 g; urease, 0.31-0.65 mg/g; invertase, 6.04-68.42 mg/g; and catalase 1.39-4.61 ml. The activities of these four

关 键 词：秦岭地区 华北落叶松 速效养分 酶活性 

分 类 号：S714[农业科学—林学]