摘要
采用熏蒸-提取法、Biolog微平板培养法,研究了定西典型人工乔木林、人工灌木林、农田、撂荒地、天然草地等植被类型下0~20cm土层土壤微生物生物量和土壤微生物群落代谢多样性,并通过通径分析的方法解释了土壤微生物与土壤养分的关系,从土壤微生物的角度对当地典型植被类型做出了评价.结果表明:相对于耕作而言,退耕还林(草)对恢复土壤微生物资源具有积极意义;研究区垄坡荒地、撂荒地和油松林的土壤微生物生物量碳较高,其次为柠条林、苜蓿地、侧柏-山杏和道沿荒地,以小麦和马铃薯农田较低;研究区垄坡荒地、撂荒地、油松林、柠条林和苜蓿地的土壤微生物生物量氮较高,小麦和马铃薯农田较低;具有根瘤固氮菌的植被(柠条和苜蓿)的土壤微生物生物量氮占全氮的比例最高;农田由于长期生物量损耗且补充不足,其土壤微生物的储量和活性均很低,而通过种植人工乔木林、灌木林或弃耕撂荒,土壤微生物数量和活性能恢复到天然草地的水平,且效果随恢复年限的增加而更显著;柠条灌木林通过20a的恢复,其地下微生物数量与50a林龄的油松林相近,其微生物活性和土壤养分利用效率甚至超过了油松林.综合考虑不同立地条件下植被的土壤微生物特性,认为豆科灌木(如柠条)是恢复植被的较好选择.
By using fumigation-extract (FE) method and Biolog Ecoplate,this paper investigated the microbial biomass and diversity in 0-20 cm soil layer under five vegetation types,including artificial woodland,shrubland,cropland,abandoned farmland,and natural grassland,in Dingxi of Gansu Province.In the meanwhile,the relationships between soil microbes and soil nutrients were studied by path analysis,and the five typical vegetation types were evaluated from the aspect of soil microbes.Relative to cropland,"grain for green" project played a key role in improving soil microbial resources.Microbial biomass carbon was the highest in ridge grassland,abandoned farmland,and pine woodland,followed by in Caragana korshinskii land,Medicago sativa land,restored land,and roadside land,and in wheat field and potato field.Microbial biomass nitrogen was the highest in ridge land,abandoned farmland,Pinus tabulaeformis woodland,Caragana korshinskii land,and Medicago sativa land,followed by in restored land and roadside land,and in wheat field and potato field.Caragana korshinskii land and Medicago sativa land,due to the existence of N-fixing rhizobium,had the highest ratio of soil microbial biomass nitrogen to soil total nitrogen.Owing to the continual biomass loss and rare feedback,cropland had the lowest quantity and activity of soil microbes.Through planting trees,shrubs and grasses or through fallowing,soil microbial biomass and activity were recovered,and the effect was increased with time.In 20-year old Caragana korshinskii land,the quantity and activity of soil microbes were similar to those in 50-year old Pinus tabulaeformis woodland,and the microbial community catabolic activity and soil nutrient use efficiency were higher.Considering the features of soil microbes under test vegetation types,Caragana korshinskii would be a good choice for local vegetation restoration.
出处
《应用生态学报》
CAS
CSCD
北大核心
2010年第1期165-173,共9页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(40801041
40621061)
国家"十一五"科技支撑计划项目(2006BAC01A06)资助
关键词
植被类型
微生物生物量
微生物熵
微生物群落代谢活性
微生物群落代谢多样性
通径分析
vegetation type
microbial biomass
microbial quotient
microbial community catabolic activity
microbial community catabolic diversity
path analysis