摘要
对川南天然常绿阔叶林及其人工更新成檫木林、柳杉林和水杉林后土壤不同形态碳素含量、碳库管理指数、养分含量和酶活性进行研究,并探讨了土壤不同形态碳素及碳库管理指数与土壤肥力之间的关系。结果表明:各季节土壤有机碳、水溶性有机碳、微生物量碳、活性有机碳、稳定态碳、碱解氮、有效磷和速效钾含量及蔗糖酶、磷酸酶和过氧化氢酶活性均为天然常绿阔叶林>檫木林>水杉林>柳杉林,土壤碳库管理指数也为天然常绿阔叶林>檫木林>水杉林>柳杉林,且土壤不同形态碳素含量和碳库管理指数与土壤养分含量及酶活性之间存在显著的相关关系。这说明了天然常绿阔叶林人工更新后土壤不同形态碳素含量、碳库管理指数和土壤肥力下降,且各人工林下降程度不同,而且土壤不同形态碳素含量和碳库管理指数的变化能够较好地表征土壤肥力的变化。研究结果为保护天然常绿阔叶林、选择适宜的更新树种和天然常绿阔叶林人工更新后林地土壤的科学管理提供依据,也为退耕还林中树种的选择提供参考。
Soil organic matter （SOM） is a stable and long-lasting carbon source and contains nearly all nutrients for plant growth, therefore is a meaningful index for evaluating soil fertility. The quantity and quality of soil organic carbon influence soil potential productivity and reflect the spatial distribution and succession of plant community. However, the measurement of total SOM is not sensitive enough to detect short and medium term changes, and thus techniques that measure meaningful fractions of SOM should be used. The carbon management index （CMI） calculated from changes in labile and total carbon fractions relative to a reference soil was show to be a useful technique for describing soil fertility. An investigation was carried out to study the changes of soil carbon fractions and CMI, and their relationships with fertility under natural evergreen broad-leaved forest and its artificial regeneration forests of Sassafras tzumu, Cryptomeria fortunei and Metasequoia glyptostroboides in southern Sichuan Province. Soil samples were collected from each forest to determine soil carbon fractions, available nutrients, enzyme activity and CMI. Regression analysis was used to determine the relationship between soil carbon fractions, CMI and fertility. The results showed that the contents of soil organic carbon, water-soluble carbon, microbial biomass carbon, labile carbon, non-labile carbon, hydrolysis-N, available-P and available-K, the activity of invertase, phosphatase and catalase, and CMI were ranked with different seasons and followed the order： natural evergreen broad-leaved forest 〉 Sassafras tzurnu plantation 〉 Metasequoia glyptostroboides plantation 〉 Cryptorneria fortunei plantation. The soil carbon fractions and CMI were positively and significantly （ P 〈 0.05 ） correlated with available nutrients and enzyme activity. Artificial regeneration of natural evergreen broad-leaved forest would result in decrease in all soil carbon fractions, CMI and fertility, but the size of change varies with regenerated forest types. The results indicate that soil carbon fractions and CMI could be used to evaluate the soil fertility for natural evergreen broad-leaved forest and its artificial regeneration forests, which will lay a solid foundation for protecting natural evergreen broad-leaved forest, tree selection for its artificial regeneration, and soil management, moreover, tree selection during the process of converting farmland to forestland.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第6期2536-2545,共10页
Acta Ecologica Sinica
基金
国家“十五”科技攻关资助项目(2001BA510B02-03,2001BA606A-06)
四川省重点学科建设资助项目(SZD2004)~~
关键词
天然常绿阔叶林
人工更新
土壤碳库
碳库管理指数
土壤肥力
natural evergreen broad-leaved forest
artificial regeneration
soil carbon pool
CMI
soil fertility
作者简介
龚伟（1980-）男，四川崇州人，博士，主要从事林业生态工程和土壤生态研究；E-mail：gongwei@sicau．edu．cn
胡庭兴：通讯作者 E-mail：hutx001@yahoo．com．cn
