鄂尔多斯高原弃耕农田恢复过程中土壤物理性质和生物结皮的变化

发布时间：2018-06-26 05:15

本文选题：灌丛化 + 弃耕农田　；参考：《应用生态学报》2017年03期

【摘要】：在鄂尔多斯高原软梁、硬梁弃耕农田上选取一系列不同时限的弃耕农田,研究弃耕演替过程中地表凋落物、生物结皮,以及不同土层土壤容重、机械组成、含水量的动态变化.结果表明:软梁弃耕农田表层(0~10 cm)物理环境随弃耕年限增加明显改善,土壤黏粒含量、地表凋落物随弃耕年限增加明显增加,土壤容重明显降低,土壤含水率略微升高;中层(10~30cm)土壤物理环境随弃耕年限增加稍显恶化,土壤黏粒含量升高,土壤含水量略微降低;深层(30~50 cm)土壤物理性质变异较大.硬梁弃耕农田土壤表面凋落物盖度、生物结皮盖度、生物结皮厚度随弃耕年限增加而增加,表层(0~10 cm)土壤容重、黏粒含量、含水量随弃耕年限变化总体变化不显著,深层(10~40 cm)土壤物理性质变异较大.地表凋落物和土壤黏粒物质的累积导致软梁弃耕农田土壤水分浅层化,可能是20年内浅根性多年生草本植物群落取代半灌木油蒿群落的关键因素.硬梁弃耕农田在演替过程中未见油蒿入侵,可能与较高的浅层含水量和生物结皮发育有关.
[Abstract]:A series of abandoned farmland with different time limits were selected from soft beam and hard beam field in Ordos Plateau to study the dynamic changes of litter, biological crust, soil bulk density, mechanical composition and water content in different soil layers during the succession of abandoned tillage. The results showed that the physical environment of the surface layer (0 ~ 10 cm) of soft beam abandoned farmland improved obviously with the increase of abandoned years, the content of soil clay and litter increased obviously, the bulk density of soil decreased obviously, and the soil moisture content increased slightly. The soil physical environment of middle layer (10~30cm) deteriorated slightly with the increase of abandoned tillage, the content of soil clay increased, the soil moisture content decreased slightly, and the physical properties of the deep layer (30 ~ 50 cm) varied greatly. The soil litter coverage and biological crust thickness increased with the increase of abandoned years, but the bulk density, clay content and water content of the surface layer (0 ~ 10 cm) did not change significantly with the years of abandoned tillage. The physical properties of the deep soil (10 ~ 40 cm) varied greatly. The accumulation of surface litter and soil clay resulted in the shallow layer of soil water in the abandoned farmland, which may be the key factor to replace the subshrub Artemisia subshrubs community by the shallow perennial herbaceous community within 20 years. There was no invasion of Artemisia annua in the succession of hard Liang abandoned farmland, which may be related to the higher water content in shallow layer and the development of biological crust.
【作者单位】：中国科学院植物研究所北方资源重点实验室;中国科学院大学;
【基金】：国家自然科学基金项目(41330749,41401105)资助~~
【分类号】：S152;S154

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