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用顶盖埋管法 (Close- Top Tube Incubations)就西双版纳 3种热带森林 (热带季节雨林、片断热带雨林、橡胶林 )研究了土壤铵态氮 (NH4- N )和硝态氮 (NO3- N)以及土壤氮素矿化速率的季节动态情况。结果表明 :西双版纳3种不同林型土壤 NH4- N、NO3- N和氮素矿化速率均具有明显的季节性变化。 NH4- N以干热季 (4月末 )最高 (平均为 2 6 .92 mg· kg- 1 )和干季 (2月末 )最低 (平均为 12 .0 1mg· kg- 1 ) ;NO3- N则以雨季中期 (7月中旬 )最高 (平均为8.9m g· kg- 1 )和干季 (2月末 )最低 (平均为 4.0 4m g· kg- 1 ) ;矿化速率则以干热季 ((2月末～ 4月末 )最高 (平均为 0 .496 m g· kg- 1 · d- 1 ) ,以雨季 (7月中旬～ 11月初 )最低 (平均为 0 .0 0 37m g· kg- 1 · d- 1 )。就不同林型而言 ,季节雨林年均氮矿化速率 (0 .319m g· kg- 1 · d- 1 ) >片断热带雨林 (0 .2 5 m g· kg- 1 · d- 1 ) >橡胶林 (0 .0 74mg·kg- 1 · d- 1 )。
Soil samples were collected from three tropical forests (tropical seasonal rainforest, tropical rainforest and rubber plantations) in Xishuangbanna, China by using Close-Top Tube Incubations. The effects of soil NH4-N and NO3- ) And the seasonal dynamics of soil nitrogen mineralization rate. The results showed that NH4- N, NO3- N and N mineralization rates of three forest types in Xishuangbanna all had obvious seasonal changes. NH4-N was the highest (average 26.692 mg · kg-1) in the dry-hot season (at the end of April) and lowest (average 12.01 mg · kg-1) in the dry season (at the end of February) The highest in the middle of the rainy season (mid-July) (average 8.9 mg · kg -1) and the lowest (4.0 4 m g · kg -1) in the dry season (late February) (0.496 mg · kg-1 · d-1 on average), and the lowest in the rainy season (mid-July to early November) (mean 0. 0 37 m g · kg -1 · d -1) 1). For different forest types, the average annual rate of nitrogen mineralization in the seasonal rainforest (0. 319m g · kg -1 · d -1)> fragmented tropical rainforest (0.52 · mg -1 · d -1 )> Rubberwood (0. 0 74mg · kg-1 · d-1).