衡阳紫色土丘陵坡地不同植被恢复阶段土壤化学与微生物性质

摘要

以典型的衡阳紫色土丘陵坡地不同植被恢复阶段为研究对象，采用空间序列代替时间序列的方法，选用立地条件基本相似的草坡阶段（Grassplot, GT）、灌草阶段（Frutex and grassplot, FG）、灌丛阶段（Frutex, FX）和乔灌阶段（Arbor and Frutex, AF），通过调查取样和实验分析，对不同恢复阶段的土壤养分、土壤微生物数量、微生物生物量及其相关性进行研究。结果表明，（1）随着植被恢复进行，4个恢复阶段植被土壤有机碳、全氮、碱解氮、速效磷、速效钾、土壤微生物生物量碳和土壤微生物生物量氮含量的平均值显著增加（P<0.05），在每个恢复阶段他们随着土层深度的增加而显著减少（P<0.05）。（2）4个恢复阶段植被被土壤细菌数量平均值的大小顺序为：AF>FX>FG>GT，AF 细菌数量平均值显著高于其他3个恢复阶段（P<0.05）。真菌数量平均值的大小顺序为：FG>GT>FX>AF，AF真菌数量的平均值显著低于其他3个恢复阶段（P<0.05）。放线菌数量平均值的大小顺序为：GT>FX>FG>AF，AF放线菌数量的平均值显著低于其他3个恢复阶段（P<0.05）。在每个恢复阶段，细菌、真菌和放线菌数量均随着土层深度的增加而显著减少（P<0.05）。（3）细菌数量、土壤微生物生物量碳、土壤微生物生物量氮与土壤有机碳、全氮、碱解氮呈极显著正相关关系（P<0.01），真菌数量与土壤有机碳、全氮、碱解氮以及土壤微生物生物量碳、土壤微生物生物量氮与速效磷、速效钾呈显著正相关关系（P<0.05）。研究结果对于构建衡阳紫色土丘陵坡地植被恢复技术体系具有理论和实践意义。%By using the spatial series to replace time series, four typical sampling plots, grassplot (GT), frutex and grassplot (FG), frutex (FX), and arbor and frutex (AF), were selected to explore the relationships between soil nutrient and soil microbe. The four communities on sloping-land with purple soils were similar and typical, and denoted four different successive stages in Hengyang of Hunan Province, South-central China. The results showed that, (1) the average value of SOC (Soil organic carbon), TN (Total nitrogen), AN (Alkali-hydrolyzed nitrogen), AP (Available phosphorus), AK(Available potassium), SMBC (Soil microbial biomass carbon) and SMBN (Soil microbial biomass nitrogen) in four re-vegetation stages are significantly increased from GT to AF (P<0.05), and these contents are significantly decreased with the increase of soil layer depth in every re-vegetation stage (P<0.05). (2) The average number of bacteria in four re-vegetation stages are followed the order as AF>FX>FG>GT, and the average number of bacteria of AF are significantly higher than other three re-vegetation stages (P<0.05), fungi, FG>GT>FX>AF, and the average number of fungi of AF are significantly lower than other three re-vegetation stages (P<0.05), actiomycete, GT>FX>FG>AF, and the average number of actiomycete of AF are significantly lower than other three re-vegetation stages (P<0.05), the number of bacteria, fungi and actiomycete are significantly decreased with the increase of soil layer depth in every re-vegetation stage (P<0.05). (3) Correlation analysis show that there are very significant positive correlation between the number of bacteria, SMBC, SMBN and SOC, TN, AN (P<0.01), and significant positive correlation between the number of fungi and SOC, TN, AN (P<0.05), and significant positive correlation between SMBC, SMBN and AP, AK(P<0.05). These results would have a theoretical and practical significance for building re-vegetation technique system.