摘要
以三峡库区汝溪河流域的马尾松纯林和马尾松+青冈混交林为研究对象,比较两种林分0～20,20～40和40～60cm土层土壤氮库及相关酶活性特征,包括土壤全氮、铵态氮、硝态氮、微生物氮、蛋白酶、过氧化氢酶、脲酶和蔗糖酶.结果表明:马尾松+青冈混交林和马尾松纯林各土层全氮含量无显著差异;马尾松+青冈混交林林地各土层铵态氮含量分别为47.21,47.69和43.83 mg/kg,显著高于马尾松纯林,分别增加了13.7%,24.8%和31.5%;与马尾松纯林相比,马尾松+青冈混交林林地20～40,40～60cm土层的硝态氮含量提高了2.2%和3.2%,0～20,20～40cm土层的微生物氮含量提高了77.4%和60.4%.马尾松+青冈混交林林地各土层蛋白酶、过氧化氢酶、脲酶、蔗糖酶活性均显著高于马尾松纯林.因此,与马尾松纯林相比,马尾松+青冈混交林显著提高林地内土壤酶的活性,改善土壤氮循环与供应状况.
Taking the Pinus rnassoniana pure forest and the Cyclobalanopsis glauca Oerst and Pinus massoniana mixed forest of the Ruxi River Basin in the Three Gorges Reservoir Region as test objects, an investigation was made of soil NH＋4-N, NO3-N, SMBN and total nitrogen, and protease, catalase, urease and invertase activities of the 0-20 cm, 20-40 cm and 40-60 cm soil layers, so as to understand the difference between the two forest types. Total nitrogen of the three layers showed no significant differences between the two stands. Soil NH＋4-N of the mixed forest in the 0-20 cm, 20-40 cm and 40-60 cm soil layers was 47.21, 47.69 and 43.83 mg/kg, significantly higher than in the pure forest by 13.7%, 24.8% and al. 5%, respective ly. Compared with the pure forest, the mixed forest increased soil NOa-N by 2.2% and 3.2%in the 20- 40 cm and 40-60 cm soil layers and SMBN by 77.4% and 60.4% in the 0-20 cm and 20-40 cm soil lay ers, respectively. Enzyme activities of protease, eatalase, urease and invertase of the three layers were sig nificantly higher in the mixed forest than in the pure forest. In conclusion, the ability to supply nitrogen to plants and to improve nitrogen cycle and enzyme activities was higher in the C. glauca Oerst and P. mas- soniana mixed forest than in the P. massoniana pure forest.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第11期88-94,共7页
Journal of Southwest University(Natural Science Edition)
基金
三峡库区流域生态修复关键技术与示范研究(201004039)
三峡库区常绿阔叶林重要建群种-栲树
小叶栲近自然经营关键技术及在库区生态屏障建设的示范研究(CSTC
2010AB1110)
提升林地生产力复合经营技术研究(CSTC
2009AB1115)
三峡库区森林生态保护与恢复重庆市市级重点实验室(CSTC
2007CA1001)
关键词
林分
马尾松纯林
马尾松+青冈混交林
酶活性
氮库
stand Pinus massoniana pure forest Cyclobalanopsis glauca Oerst and P. massoniana mixedforest enzyme activity nitrogen pool
