红壤丘陵区不同林分类型土壤酶活性及养分特征

摘要

The soil enzyme activities,nutrient contents and their relationship were studied in different forest stands(i.e.Pinus massoniana,mixed forest of Pinus massoniana+Liquidambar formosana and natural secondary forest)in red soil hilly region.The results showed that the content of soil organic matter,total nitrogen,nitrate nitrogen,available phosphorus and available kalium in two soil layers(0~10 cm、10~20 cm)under the Pinus massoniana(PM)forest stand were significant lower than those under Pinus massoniana+Liquidambar formosana(PMLF)forest and natural secondary forest(NSF)stands(P<0.05).The content of ammonium nitrogen in two soil layers(0~10 cm、10~20 cm)under the PM forest stand was similar with the PMLF forest(P>0.05),but was significant lower than the NSF stands(P<0.05).With few exceptions,all soil enzyme activities under the PMLF and NSF stands were significant higher than under the PM stand(P<0.05).There was a significant correlation between soil enzyme and nutrient,except the correlation between hydrogen peroxidase and both ammonium nitrogen and available phosphorus.Comparing to the PM forest stand,the mixed forest of PMLF could obviously improve soil enzyme activities,nutrient contents and ecological environment in the stand.%以红壤丘陵区马尾松纯林（PM）、马尾松+枫香针阔混交林（PMLF）和天然次生林（NSF）为研究对象，通过“外调查和室内分析，研究了不同林分类型土壤酶活性和养分特征及其二者的相关性。结果表明：各土层（0~10 cm和10~20 cm）中，马尾松纯林有机质、全氮、硝态氮、速效磷和速效钾含量显著低于马尾松+枫香针阔混交林和天然次生林（P<0.05）；各土层马尾松纯林铵态氮含量显著低于天然次生林（P<0.05），与马尾松+枫香针阔混交林差异不显著（P>0.05）；天然次生林和马尾松+枫香针阔混交林林地各土层蔗糖酶、过氧化氢酶、脲酶和碱性磷酸酶活性在总体上显著高于马尾松纯林（P<0.05）；除过氧化氢酶与铵态氮和速效磷无显著相关性（P>0.05）外，土壤酶活性与养分间均呈现显著（P<0.05）或极显著（P<0.01）相关性。与马尾松纯林相比，马尾松+枫香针阔混交林可以明显改善林地内土壤酶活性和养分状况，改善林地生态环境。