农林复合系统作为一种土地综合利用体系,可以有效吸收和固定 CO_2、增加碳储量,在达到收获目的的同时,可有力减轻温室效应.农林复合系统对 CO_2的调控作用,使人们认识到农林复合系统较单一作物系统有着明显优势,因此,深入了解不同农林复合系统的碳汇功能及其影响因素,对全球碳循环研究及碳收支准确评估具有重要意义.本文综述了农林复合系统的概念与分类,探讨了农林复合系统不同组分的碳固存潜力及其影响因子,得出不同区域、不同类型农林复合系统内植被的固碳速率相差很大(0.59 ~ 11.08 t C·hm~(-2)·a~(-1)),其主要受到气候因子和农林复合系统自身特性(物种组成、林木密度和林龄)的影响.农林复合系统内土壤的固碳潜力受到系统内树木和非树木成分输入的生物量多少和质量、土壤质地、土壤结构的影响.不同地区的任何一个农林复合系统的碳储量多少主要依赖于复合系统中各组分的结构和功能.针对目前的研究现状,指出应重点加强农林复合系统优化结构的碳汇功能研究,以及加强农林复合系统碳储量的时空分布格局及其固碳机制的长期研究.
英文摘要:
As a land comprehensive utilization system,agroforestry system can absorb and fix CO_2effectively to increase carbon storage,and also reduces greenhouse effect convincingly while reaching the aim of harvest.The regulatory role in CO_2 makes humans realize that agroforestry systems have significant superiority compared with single cropping systems,therefore,understanding the carbon sinks of different components in an agroforestry system and its influencing factors play an important role in studying global carbon cycle and accurate evaluation of carbon budget.This paper reviewed the concept and classification of agroforestry system,and then the carbon sequestration potentials of different components in agroforestry systems and influencing factors.It was concluded that the carbon sequestration rate of plants from different agroforestry systems in different regions are highly variable,ranging from 0.59 to 11.08 t C·hm~(-2)· a~(-1),and it is mainly influenced by climatic factors and the characteristics of agroforestry systems (species composition,tree density and stand age).The soil C sequestration of any agroforestry system is influenced by the amount and quality of biomass input provided by tree and nontree components of the system and the soil properties such as soil texture and soil structure.Overall the amount of carbon storage in any agroforestry system depends on the structure and function of its each component.The future studies shouldfocus on the carbon sink functions of structurally optimized agroforestry systems,the temporal variation and spatial distribution pattern of carbon storage in agroforestry system and its carbon sequestration mechanism in a long time.