中文摘要：

不同用地类型的土壤氮、磷收支平衡决定了氮、磷在土壤的富集，进一步影响氮、磷的流失强度，分析该过程有助于揭示不同用地类型对区域的环境效应．以位于太湖上游低山丘陵地区的天目湖流域为研究区，采用农户调查问卷、土壤和植被生物量实验分析、文献调研和氮、磷表观平衡模型的方法，选择研究区的茶园、水田、马尾松林和竹林四种典型用地类型，系统分析了氮、磷的输入要素，包括肥料输入、大气沉降、秸秆返田／枯枝落叶、生物固氮、人畜排泄物返田，以及输出要素，包括植物生长吸收、氨挥发、反硝化，并比较不同用地类型氮、磷收支特征．在此基础上进一步与土壤表层氮、磷含量比较，揭示太湖流域上游丘陵山区主要用地类型的水环境效应．研究结果显示：土壤氮、磷盈余量大小顺序为茶园〉水田〉马尾松林〉竹林，分别是648．6、248．9、115．5、53．6kgN／（hm^2·a）和319．9、29．7、1．2和-3．4kgP／（hm^2·a）；氮、磷利用效率以竹林最高，茶园的氮、磷利用效率均最低，仅为15．0％和3．1％；土壤氮盈余量与表层氮含量未能呈现出一致的关系，土壤磷盈余量与表层磷含量比较类似，并由此得出竹林比马尾松林更有利于水环境保护，而茶园对水环境的不利影响超过水田

英文摘要：

The enrichment of nitrogen and phosphorus in soil depends on the soil nitrogen and phosphorus budget of different land use types, which can also influence the strength of nitrogen and phosphorus loss. Understanding this process can help us to know its regional environment effect of different land use types. The study area is Lake Tianmu Basin, located in the hilly area of Lake Taihu upper-river basin. We calculated the soil nitrogen and phosphorus budget of different land use types by questionnaire, exper- imental analysis of soil and biomass, literature investigation and soil apparent balance model, and chose four land use types, inclu- ding tea garden, paddy fields, masson pine and bamboo forest. We made a systematic analysis of the import and export elements of nitrogen and phosphorus. The import elements included fertilizer, atmospheric deposition, the straw returned to field or dry bran- ches and leaves, biological nitrogen fixation and manure. The export elements included plant absorption, ammonia volatilization and denitrifying. The above analysis can reveal the water environmental effect of mainly land use types in hilly area of Lake Taihu upper-river basin by comparing with the soil nitrogen and phosphorus content. Results show that the order of soil nitrogen and phos- phorus surplus are tea garden, paddy field, masson pine and bamboo forest, with the values of 648.6, 248.9, 115.5, 53.6 kgN/（ ha · a） and 319.9, 29.7, 1.2, -3.4 kgP/（ha ·a）, respectively. The nitrogen and phosphorus utilization efficiency of bamboo forest is the highest, while tea garden is the lowest one, only 15.0% and 3.1%. The soil nitrogen surplus and nitrogen content failed to present a consistent relationship although the soil phosphorus surplus and phosphorus content is similar. This shows that the bamboo forest is more advantageous to the water environmental protection than masson pine, and the tea garden is worse to the water environmental protection than paddy fields.