集约经营毛竹林土壤酶活性对模拟氮沉降的初期响应

Effect of Simulated Nitrogen Deposition on Soil Enzyme Activities in Phyllostachys heterocycla cv. pubescens Stand

采用典型样方法,在浙江省临安市设立毛竹（Phyllostachys heterocycla cv.pubescens）林分条件和环境状况较一致的代表性样方12个,研究了集约经营毛竹林蔗糖酶、纤维素酶、脲酶和过氧化氢酶4种土壤酶活性对不同水平的模拟氮沉降（低氮30 kg N·hm-2·a-1、中氮60 kg N·hm-2·a-1、高氮90 kg N·hm-2·a-1和对照）的初期响应。结果表明：模拟的氮沉降显著降低了集约经营毛竹林0~20 cm土壤蔗糖酶、纤维素酶、脲酶和过氧化氢酶的活性,显著抑制了〉20-40 cm土壤蔗糖酶的活性,对纤维素酶和过氧化氢酶的活性影响不显著。

Twelve selective sample quadrats were established at Phyllostachys heterocycla cv. pubescens stands in Lin＇an, Zhejiang province, with similar stand condition and environment. Experiments were conducted of simulated nitrogen deposition with three treatments of 30 kg N/ha·a-1, 60 kg N/ha·a-1, 90 kg N/ha·a-1, and no treatment（control） on soil enzyme activities. The short-term responses of soil enzymes, including invertase, cellulase, urease and catalase were detected. The results showed that simulated N deposition decreased significantly the activities of the four tested enzymes at layer of 0-20 cm, as well as invertase activities at 20-40 cm, but had no significant effect on activities of cellulase and catalase at 20-40 cm.