生态学报2017，Vol.37Issue(20)：6847-6854,8.DOI:10.5846/stxb201607311571
黄土丘陵区植被类型与土壤微生物区系及生物量的关系
Relationship among vegetation types and soil microbial biomass in the Loess Hilly region of China
摘要
Abstract
To remedy adverse impacts on ecological environments,vegetation restoration has been completed on the Loess Hilly region of China,thus yielding changes in vegetation types,and secondary forests and exotic vegetation have reclaimed most of this area.Vegetation type plays an important role in soil quality,and similar land-use types usually possess similar soil properties and,most likely,similar microbial communities.To assess the effects of vegetation type on soil development,we measured the basic physicochemical properties,microbial biomass carbon (MBC) and nitrogen (MBN),and the number of bacteria and fungi of soils from areas with five different vegetation types,including a secondary natural oak forest,a non-typical natural forest of oriental arborvitae,a natural shrub land,a planted forest of black locust,and a plot of unforested bare land.We found that (1) soil properties improved with the presence of vegetation,compared with the abandoned bare land,and that there were differences in the physicochemical properties of soil from the different land-use types.Soils from the bare land and black locust forest yielded higher pH values than the natural forests,and the overall trend of soil quality was:natural forest ＞ plantation ＞ bare land.This indicated that vegetation coverage,especially natural types,has a beneficial effect on soil nutrient conditions and soil pH.(2) Similar to the trend of the other soil parameters,both MBC and MBN were highest in the oak forest and shrub land and lowest in the bare land and black locust forest.These two indices (MBC and MBN) were also strongly correlated with specific soil properties (soil organic carbon,r2=0.725,total nitrogen,r2=0.736,and phosphorus,r2=0.775;P ＜ 0.001),suggesting that vegetation type and soil properties influence microbial biomass.Thus,microbial biomass can be used to assess soil trophic status and which lower in oligotrophic soils on the Loess Plateau of China.In our study area,the soil was alkaline (pH 8.18-8.48),and the MBC/MBN ratio was ～6,indicating that actinomycetes were dominant,possibly facilitated by the alkaline soil conditions.(3) Bare land harbored the lowest abundance of bacteria,and the abundance of fungi in the black locust was lower than that of the oak forest.The abundance of bacteria exhibited a strong relationship with specific soil properties and was positively correlated with C/N ratio (r2=0.754,P ＜ 0.001),soil organic carbon (r2=0.636,P ＜ 0.05),total nitrogen (r2=0.611,P ＜ 0.05),and phosphorus (r2=0.775,P ＜ 0.05),and negatively correlated with pH (r2=0.761,P ＜ 0.001).In contrast,the abundance of fungi was only correlated with soil pH,thus confirming previous reports that bacteria and fungi respond to different environmental factors.This discrepancy may result from the different functions of bacteria and fungi.Fungi are primarily responsible for the decomposition of recalcitrant soil organic matter in forest soils.Thus,the overall trend of soil characteristic was:natural forest ＞ plantation ＞ bare land,indicating that the recovery of soil quality differed among plots with different vegetation types,and both soil microorganisms and soil microbial biomass,to a certain extent,can be used as an important index of soil fertility.关键词
植被类型/土壤细菌/土壤真菌/土壤微生物生物量碳/土壤微生物生物量氮Key words
vegetation type/soil bacteria/soil fungi/soil properties/the Loess Hilly region引用本文复制引用
田琴,牛春梅,谷口武士,山中典和,时伟宇,杜盛..黄土丘陵区植被类型与土壤微生物区系及生物量的关系[J].生态学报,2017,37(20):6847-6854,8.基金项目
国家自然科学基金(41411140035,41171419) （41411140035,41171419）
