黄土丘陵区不同土壤-微生物-植物系统生态化学计量特征对肥力梯度的响应

发布时间：2018-01-27 22:41

本文关键词： 土壤微生物植物系统优势群落化学计量学肥力水平黄土丘陵区　出处：《西北农林科技大学学报(自然科学版)》2017年10期 　论文类型：期刊论文

【摘要】：【目的】研究施肥对土壤-微生物-植物系统化学计量学特征的影响,探究土壤-微生物-植被系统的"内稳性",为黄土高原植被恢复提供科学依据。【方法】基于长期试验(2004年开始),在2种植被恢复系统(自然恢复系统和人工恢复系统)中,设置3种肥力水平(无肥,不施肥;低肥,施用45 000kg/hm2有机肥;高肥,施用105 000kg/hm2有机肥),2015年9月采集2种植被恢复系统中不同处理的土样以及灌木优势种叶片(自然恢复系统中为沙棘,人工恢复系统中为柠条),分析不同土壤肥力水平下2种土壤-微生物-植物系统碳、氮、磷化学计量比值特征及其相关关系。【结果】在2种植被恢复系统中,随着肥力水平的升高,土壤有机碳、微生物量碳、微生物量磷含量均明显提高;土壤、微生物量及植物叶片C/N总体增加,微生物及植物叶片N/P明显减小。相对于无肥处理,高肥处理下沙棘和柠条群落土壤C/N、C/P、N/P的变化幅度分别为40%,49%,7%和12%,27%,13%;微生物量C/N、C/P、N/P的变化幅度分别为80%,14%,50%和36%,9%,34%;叶片C/N、C/P、N/P的变化幅度分别为10%,23%,14%和40%,9%,31%。相对于自然植被恢复系统,在人工恢复系统中土壤养分与优势灌木叶片化学计量比的相关关系更强。【结论】在坡地侵蚀环境下施肥,可一定程度上提高了土壤肥力水平,改变土壤-微生物-植物系统生态化学计量特征,进而可能改变土壤-微生物-植物系统的物质循环,影响土壤质量演变和植被演替进程。在植被恢复过程中,人工植被恢复系统比自然植被恢复系统能更快建立土壤-叶片养分互馈关联。
[Abstract]:[objective] to study the effect of fertilization on the characteristics of soil-microorganism plant system chemometrics, and to explore the "internal stability" of soil-microbial vegetation system. [methods] on the basis of long-term experiment (2004), the vegetation restoration system (natural restoration system and artificial restoration system) was established in two planting systems (natural restoration system and artificial restoration system). Set up three fertility levels (no fertilizer, no fertilizer; Low fertilizer, 45 000 kg / hm 2 organic fertilizer; High fertilizer, 105,000 kg / hm ~ 2 organic fertilizer was applied, in September 2015, two soil samples were collected from different treatments of restoration system and shrub dominant species leaf (seabuckthorn in natural recovery system). Caragana korshinskii was used in artificial restoration system. Two kinds of soil-microorganism plant system carbon and nitrogen were analyzed under different soil fertility levels. [results] the soil organic carbon, microbial biomass carbon and microbial biomass phosphorus content increased with the increase of fertility level in the restoration system. Soil, microbial biomass and plant leaf C / N increased, and microbial and plant leaf N / P decreased significantly. Compared with no fertilizer treatment, the soil C / N / P of Hippophae rhamnoides and Caragana korshinskii community was increased under high fertilizer treatment. The changes of N / P were 40% and 27%, respectively, and 12%, 27% and 13%, respectively. The variation of microbial biomass C / N / P / P was 80%, 14% and 36%, respectively. The changes of C / N / P / P in leaves were 102314% and 40%, respectively, compared with the natural vegetation restoration system. The correlation between soil nutrients and the stoichiometric ratio of dominant shrub leaves was stronger in artificial restoration system. [conclusion] fertilization in slope erosion environment can improve soil fertility to some extent. It is possible to change the material cycle of the soil-microbial plant system by changing the eco-stoichiometric characteristics of the soil-microorganism plant system, thus affecting the evolution of soil quality and the process of vegetation succession. The artificial vegetation restoration system can establish the soil-leaf nutrient mutual feed correlation faster than the natural vegetation restoration system.
【作者单位】：西北农林科技大学林学院;中国科学院水利部水土保持研究所;
【基金】：国家科技基础性工作专项“黄土高原主要生态系统资源分布与生源要素”(2014FY210100)
【分类号】：S158.3
【正文快照】： 生态化学计量学是一种用来估计特定元素的相对数量关系是如何影响生态系统中营养元素循环的思路,能够在元素水平上统一生物系统基本化学元素(碳、氮、磷)循环及生态系统能量平衡[1]。元素间化学计量关系是生态系统功能的核心,是联结食物网及其生物地球化学过程的内在纽带[2]。

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