Abstract:

To reveal the effect of different land use types on soil cellulase activity （SCA） and soil fertility factors， and clarify the relationship between soil chemical factors and SCA. In Hailun City， Heilongjiang Province， the soils from dry land and forest land were as the research object， and path analysis method was used to clarify the positive and negative effects of soil chemical factors on SCA. The results showed that the contents of organic carbon， total nitrogen， total phosphorus， water content and SCA of forest land were significantly higher than those of dry land， while the pH of dry land was significantly higher than that of forest land. The correlation analysis showed that there was significant negative correlations between SCA and organic carbon， total nitrogen in dry land， and there was extremely significantly positive correlation between SCA and organic carbon， water content， and significant positive correlation between SCA and TN in forest land. Path analysis showed that pH， total nitrogen and water content were important factors that had significant and direct effects on SCA in dry land， while organic carbon and total nitrogen had indirect negative effects on SCA. Organic carbon and total nitrogen were the main controlling factors of SCA in forest land. The soil fertility factors and SCA were obviously difference between dry land and forest land. The nutrient level and SCA of dry land soil were lower than those of forest land， which indicated that there was long-term and intensive human use of dry land in this region， leading to the degradation of the nutrient status of dry land and the reduction of water content.

Key words: soil cellulase activity, dry land, forest land, soil fertility factors

摘要：

为揭示不同土地利用类型对土壤纤维素酶活性（soil cellulase activity，SCA）和土壤肥力因子的影响，阐明土壤肥力因子与SCA之间的关系及影响，在黑龙江省海伦市，选择土地利用类型为旱地和有林地的土壤为研究对象，运用通径分析方法，阐明土壤肥力因子对SCA的正负效应。结果表明，有林地土壤的有机碳、全氮、全磷、含水率、SCA极显著高于旱地；旱地土壤的pH极显著高于有林地。相关性分析表明，旱地土壤SCA与有机碳、全氮含量呈显著负相关；有林地土壤SCA与有机碳含量和土壤含水率呈极显著正相关性，与全氮含量呈显著正相关。通径分析表明，土壤pH、全氮和含水率是直接显著影响旱地土壤SCA的重要因子， 有机碳和全氮对SCA产生间接负效应；有机碳、全氮是决定有林地土壤SCA的主控因子。土壤肥力因子与SCA在旱地与有林地间存在极显著差异，旱地土壤肥力水平与SCA劣于有林地，说明该区域旱地存在长期高强度人为利用，导致旱地的养分状况发生退化，水分减少。

关键词: 土壤纤维素酶活性, 旱地, 有林地, 土壤肥力因子