土地利用变化的碳排放机理及效应研究综述
Summarization of the Effects of Land Use Changes on Carbon Emission

就影响陆地生态系统碳储量的主要生态机制(CO2施肥效应、氮沉降增加、污染、全球气候变化、土地利用变化和土地管理),阐述了土地利用变化对陆地生态系统结构和功能产生的影响,以及对系统造成的碳储量变化.主要从土地利用变化和土地管理两方面对土地利用碳排放效应进行论述:森林砍伐后变为农田和草地,使生态系统中植被和土壤碳贮量大大降低；农田和草地弃耕恢复为森林,以及农田保护性管理措施的利用,能够使大气中的碳在植被和土壤中得到汇集；森林恢复过程中植被可以大量汇集大气中的碳,而由于农田耕种历史不同以及土壤空间异质性,导致土壤碳汇集速率差异极大；保护性农田管理措施(诸如免耕、合理的种植制度、化肥的施用等)可以影响土壤理化特性、作物根系生长以及残茬数量和质量、土壤微生物数量和活性,维持和提高土壤碳含量水平.土地利用碳排放核算主要从陆地生态系统的植被碳和土壤碳入手,综述了目前国内外的研究进展.
Bases on the impact of a major ecological mechanisms of the terrestrial ecosystem carbon stocks(CO2 fertilization effect,increased nitrogen deposition,pollution,global climate change,land use change and land management),the impact of land use change on terrestrial ecosystem structure and function was described,as well as changes of system carbon stocks.This article discusses the effect of land use carbon emissions from land-use change and land management,deforestation into farmland and grassland greatly reduces ecosystem vegetation and soil carbon storage.Farmland and grassland abandonment revert to forest,and the use of farmland protective management measures,can make the atmosphere in the vegetation and soil carbon get together.The forest vegetation recovery progress can collect a lot of pooled atmospheric carbon, however, because of farmland farming history and different soil spatial heterogeneity,which lead to soil carbon collection rate vary enormously.Protective farmland management measures(such as zero tillage,reasonable cropping system,fertilizer application,etc.)can affect the soil physical and chemical properties,crop root growth and residue quantity and quality,soil microbial quantity and activity,maintain and improve soil carbon content level.Land use carbon emissions accounting mainly from vegetation and soil carbon of terrestrial ecosystem carbon,reviewes the research progress at home and abroad