衡阳紫色土丘陵坡地退化植被和恢复植被土壤微生物生物量的研究

摘要

土壤微生物量常被作为植物所需营养元素的转化因子和资源库，是表明土壤发育状况和生化强度的一项主要指标。为了研究衡阳紫色土丘陵坡地退化植被与恢复植被的土壤微生物生物量特征。以退化植物群落（狗尾草群落）（Ass. Setaria viridis）和恢复植群落(枫香+苦楝-剌槐+牡荆-野菊花+夏枯草群落）（ Ass. Liquidamdar formosana+Melia azedarach-Robinia pseudoacacia+Vitex negundo var. cannabifoloa-Chrysanthemum indicum+Prunella vulgaris）作为研究对象，通过调查取样和实验分析相结合的方法，分析2种植物群落的0~10、10~20、20~30、30~40和40~50 cm土层的土壤微生物生物量的变化特征。结果表明：（1）随着土层深度增加，土壤微生物生物量、土壤细菌和丝状微生物生物量均显著降低，其大小顺序为：0~10 cm土层>10~20 cm土层>20~30 cm土层>30~40 cm土层>40~50 cm土层（P<0.05）；（2）恢复植被各土层中的土壤微生物生物量均显著高于退化植被（P<0.05）；（3）土壤微生物生物量与土壤含水量、土壤容重、土壤有机质和土壤微生物生物量存在显著或极显著的相关关系（P<0.05或P<0.01）。研究表明：恢复植被有利于土壤微生物生物量的提高和土壤质量的改善。%Soil microbial biomass was not only usually looked as transforming factors and pool of resource of nutritional elements needed by plants, but also a main index of development status and biochemical capacity of soils. In order to study the properties of soil microbial biomass in degenerated vegetation and recovered vegetation on sloping-land with purple soils in Hengyang of Hunan Province, China. Taking degenerated plant community (Ass. Setaria viridis) and recovered plant community (Ass. Liquidamdar formosana+Melia azedarach-Robinia pseudoacacia+Vitex negundo var. cannabifoloa-Chrysanthemum indicum+Prunella vulgaris) in the region as test objects, soil samples from depths of 0~10 cm, 10~20 cm, 20~30 cm, 30~40 cm and 40~50 cm were collected to study the properties of soil microbial biomass through the combination of sample investigation and experimental analysis. The results showed that:(1) With the increase of soil depth, the total soil microbial biomass, bacteria and filamentous microbial biomass were followed the order as 0~10 cm soil layer>10~20 cm soil layer>20~30 cm soil layer>30~40 cm soil layer>40~50 cm soil layer(P<0.05); (2) The soil microbial biomass in recovered vegetation was significantly higher than that in degenerated vegetation(P<0.05);(3) The soil microbial biomass was significantly and very significantly correlated with SWC (Soil water content), SBD (Soil bulk density), SOM (Soil organic matter) and SMB (Soil microbial biomass) (P<0.05 or P<0.01). All the results indicated that recovered vegetation was beneficial to the increase of soil microbial biomass and improvement of soil quality.