水保所知识产出(1956---)知识库

本文以安塞县纸坊沟流域典型黄土丘陵区坡耕地撂荒为研究对象，分别选
取坡耕地、撂荒 7 年、撂荒 12 年、撂荒 17 年、撂荒 22 年、撂荒 32 年六个年
限，分析植物生物量与多样性、土壤植物养分及其化学计量学特征、酶活性及
其化学计量学特征和温度敏感性，研究生态恢复过程中的植物-土壤-微生物学
间的相互关系，所得主主要结论如下：
1、撂荒演替中植物多样性经历了先增加后减少的变化过程，在撂荒 17 年
达到最大值；生物量不断积累，其中，生物量碳逐渐积累，但生物量氮、磷在
演替过程中先降低后升高。植物化学计量结果显示，植物在演替过程中表现出
氮磷含缺乏，并在撂荒 17 年表现最为严重。
2、撂荒过程中，土壤养分经历一个先降低后升高的过程，在撂荒 17 年前
后，土壤养分含量最低，土壤碳活性最强，此时土壤抗蚀性最差。受人类活动
向土壤中添加大量氮磷元素的影响，土壤氮磷元素在撂荒初期相对充足，撂荒
17 年以后，逐渐表现出磷缺乏。
3、撂荒演替过程中土壤水溶性有机物与热水溶性有机物表现出不同的变化
趋势，说明热水溶可提取有机物中的不溶性成分可以在一定条件下从一定程度
上替代水溶性有机物的生态功能，研究结果表明，热水溶性有机物中非水溶性
有机物多为碳水化合物，但不是氨基酸。
4、土壤酶在 20℃表现出较明显的活性变化，碳氮循环速率经历先降低后
升高过程，磷的循环速率相对稳定，通过对酶生态化学计量的分析，37℃的反
应体系下，经历 30 年生态恢复的氮磷相关循环的酶活性会稳定到一定比例，生
态系统物质循环过程中的催化剂并未达到稳态。
5、本文尝试构建了植物-土壤-酶的化学计量关系的模型，并通过结构方程
得以验证。
关键词：生态恢复 黄土丘陵区 撂荒 生态化学计量 地上地下相互关系

Plant-soil-microbiological characteristics in the process of ecological
restoration with different years of leaving uncultivated in typical hilly region of the
loess plateau is studied in this project, selecting abandoned farmland, 7 years, 12
years, 17 years, 22 years, 32 years, total six age limits. There are several analysis
indexes, which include plant biomass and diversity, soil plant nutrients,
characteristic of microbial diversity and enzyme activity. The main conclusions are
as follows:
1. Plant diversity increases initially and decreases afterwards in the succession
of land abandonment. Meanwhile, biomass and biomass carbon is accumulating,
biomass nitrogen and phosphorus decreases initially and increases afterwards. Plant
nitrogen and phosphorus contents are deficiency at this stage.
2. Soil nutrient decreases initially and increases afterwards in the medium of
succession of land abandonment. When nutrient content is in the minimum, and
corrosion resistance of soil is the worst accordingly, soil and water loss and soil
erosion need be paid special attention in this period.
3. Soil water soluble organic matter is different from hot water soluble organic
matter in the succession of land abandonment. Insoluble components of hot water
soluble organic matter replace ecological function of water soluble organic matter
under a certain degree and condition.
4 Based on the analysis of ecological stoichiometric enzyme, in the reaction
system of 37℃. After 30 years of ecological recovery of nitrogen and phosphorus
cycles, enzyme activity will be stable to a certain proportion. However, enzyme  activity of carbon cycle is still searched for the optimal solution. Catalyst of
ecosystem material circulation process does not reach steady state. In addition, to a
certain extent, stoichiometric features of enzymes can show resistance of ecosystem.
Key Words: Ecological restoration, Hilly region of the loess plateau, Leaving
uncultivated, Ecological stoichiometry, The relationship between
underground and on the ground