摘要
冻融使土壤经历一系列物理、化学和生物变化过程,冻融作用对土壤的影响主要表现为:改变土壤结构、含水量分布和水热运动,影响微生物活性和以微生物为媒介的有机质矿化作用,改变土壤元素的生物地球化学循环过程,从而对土壤生态系统结构和功能产生影响。冻融作用对土壤理化性质的作用主要受冻融速率、温度、冻融交替次数和土壤含水量、pH值、有机质、土壤质地状况等因素的影响。通过冻融作用改善土壤结构,提高土壤微生物活性和养分的有效性,有利于耕作和促进植物生长,但也可通过含水量的重新分布和径流淋失而导致土壤养分损失。
Temperature is an important natural factor affecting soil physical and chemical characteristics and determines the eco - system conditions. The impacts of temperature include the action of water and thermal of soil to the eco - system, in which the action of freezing and thawing is one of the important temperature factors which can cause the changes of soil physical, chemical and biological characteristics. The performance aspects of freezing and thawing to the soil are in changing the soil aggregate stability, redistributing the water content and the movement of water and thermal of soil. Furthermore freezing and thawing affects microbial activity and mineralization of the organic matter and increases or decreases the biogcochemical cycling of soil element and compounds. The intensities of freezing and thawing are affected by the rates, temperature and alternate times of freezing and thawing, as well as by the soil characteristics including the water content, soil pH, organic matter content and soil texture conditions etc. The freezing and thawing of soil can increase the availability of soil organic matter through improving soil structure and up - grading microbial activity, which is beneficial to cultivation and plant growing but can cause the runoff of soil nutrient.
出处
《地理与地理信息科学》
CSCD
北大核心
2007年第2期91-96,共6页
Geography and Geo-Information Science
基金
国家重点基础研究发展计划973项目(2004CB418507)
国家自然科学基金项目(90211003)
关键词
土壤
冻融作用
理化效应
soil
freezing and thawing
physical and chemical effect
