凋落物和积雪覆盖对低温季节西南亚高山森林表层土壤脲酶动态的影响  

Impacts of Litter and Snow Cover on Topsoil Urease Activity Dynamics of Subalpine Forest in Southwestern China in the Cold Season

作　　者：马丽红[1] 黄雪菊[2] 秦纪洪[3] 孙辉[1] 李沙[1] 

机构地区：[1]四川大学环境科学与工程系,成都610065 [2]四川省环境科学保护研究院,成都610041 [3]成都大学城乡建设学院环境工程系,成都610106

出　　处：《水土保持研究》2013年第2期60-65,共6页Research of Soil and Water Conservation

基　　金：国家自然科学基金(40871124;41271094);成都市科技局项目(10YTYB130SF-023);成都大学校基金(2010XJZ13)

摘　　要：土壤脲酶(URE)活性易受到温度、地表覆盖(凋落物和积雪覆盖)、土壤水热动态等的影响,是常用的表征土壤中有机态氮转化与矿化状况的生物活性的指标之一。为探索凋落物和积雪覆盖对低温季节川西亚高山森林土壤脲酶活性的影响,以低温季节亚高山针叶林均质化土壤为研究对象,采用4种不同覆盖处理(裸露地表、凋落物覆盖、积雪覆盖、凋落物和积雪同时覆盖)进行原位培养,对各处理在低温季节(11月至翌年5月)表层(0—10cm)和下层(10—20cm)土壤进行采样并分析其脲酶活性动态。结果表明:(1)川西亚高山森林土壤脲酶活性在低温季节仍相对较高;整体呈现出先增高,随后急剧降低,到低温末期达到峰值的变化趋势。(2)整个低温季节凋落物和积雪对URE活性的影响均达到极显著水平,凋落物和积雪两因素之间存在显著的交互作用。凋落物和积雪覆盖动态格局深刻影响着亚高山森林的生态过程,亚高山森林高海拔土壤脲酶活性可以作为低温季节高海拔生态系统环境变化的一个短期响应特征。Urease activity is often used as one of biochemical indices to assess soil organic nitrogen transforma- tion and mineralization because of its vulnerability and sensitivity to soil temperature, surface cover, mois- ture dynamics. In order to determine impacts of litter and snow cover on topsoil urease activity dynamics of subalpine forest in southwestern China in the cold season, based on homogenized soil columns incubated in si- tu under four treatments （i. e. , bare soil without snowcover, bare soil with snowcover, litter without snow- cover, and litter with snowcover）, soil of 0--10 cm and 10--20 cm layers of the four treatments were sam pied in October, December, January, February, March and May, respectively, and their urease activities were analyzed. The results showed that： （1） urease activities were relatively higher in subalpine forest soil during the cold season from November to May, and it increased gradually in the initial period, then reduced sharply, and reached to the summit by the end of the cold season; （2） soil urease activities were impacted significantly by litter and snow cover in 0 10 cm and 10--20 cm layers during the cold season, and interac tion of snow cover and litter cover on URE activity were significant. Soil urease activity could be used as one of soil biochemical indicators of short-term response to environment changes in subalpine cold ecosystems.

关 键 词：亚高山森林 低温季节 土壤脲酶活性 覆盖 低温生态系统 

分 类 号：S714.3[农业科学—林学] S154.2