摘要
土壤呼吸是陆地生态系统碳循环的重要环节,也是影响全球气候变化的重要因素。研究土壤呼吸及其对环境因素的响应,对准确估计全球碳循环系统的收支平衡有重要意义。高寒区是陆地生态系统的重要组成部分,研究该区域环境因素对土壤呼吸的影响有助于深刻了解高寒区的土壤碳循环过程。本研究采用动态密闭气室红外CO2分析法,以青海高寒区的5种典型林分（华北落叶松林、云杉林、云杉-华北落叶松混交林、云杉-白桦混交林、白桦林）为对象,研究不同林分类型生长季土壤呼吸的变化规律及其与环境因子的关系。结果表明：5种林型土壤呼吸速率的大小为云杉林〉白桦林〉云杉-华北落叶松混交林〉华北落叶松林〉云杉-白桦混交林。土壤呼吸具有明显的季节变化,并在7月份达到最大值。云杉-华北落叶松混交林的土壤呼吸季节间变化幅度最大,华北落叶松林的变化幅度最小,最大土壤呼吸分别是最小土壤呼吸的17.36和1.83倍。华北落叶松林的土壤呼吸与土壤温度没有相关关系,与大气温度正相关（R2=0.75）且呈幂函数模型,与土壤水分含量负相关,其他4种林型的土壤呼吸与大气温度和土壤温度均呈现很好的正相关关系（R2=0.80~0.94）,且与大气温度和土壤温度均呈幂函数模型,与土壤水分含量不相关。土壤呼吸对凋落物量的增加产生正响应,且凋落物呼吸在混交林内所占的比重大于纯林。
Soil respiration,which has a great influence on global climate change,plays an important role in terrestrial ecosystem carbon cycle. Analysis of soil respiration and its response to global climate change is critical to assessment of ecosystem carbon budget. Alpine region is an important part of terrestrial ecosystem,thus the research of environmental factors influence on soil respiration in this region is contributive to understand the process of soil-carbon cycle. This paper used the method of infrared CO_2 determination in closed dynamic chamber system. Taking five kinds of typical forest stand（ L. principisrupprechtii plantation, Picea asperata plantation, mixed forest of Picea asperata and L. principisrupprechtii,mixed forest of Picea asperata and Betula platyphylla,natural forest of Betula platyphylla） in alpine region of Qinghai as the research object,the characteristics of seasonal variations of soil respiration in growing season and the relationship between soil respiration and environmental factors were studied.The results showed that the rank of soil respiration rate for five forest stands was Picea asperata forest Betula platyphylla forest mixed forest of Picea asperata and L. principis-rupprechtii L. principisrupprechtii forest mixed forest of Picea asperata and Betula platyphylla. Soil respiration of the five forest stands showed seasonal dynamic pattern consistently,which was peaking in July. The mixed Picea asperata and L. principis-rupprechtii forest had the maximum seasonal variation,while the L. principisrupprechtii forest had the minimum variation in soil respiration. The highest soil respiration was 17. 36 and1. 83 times of the lowest soil respiration respectively. The soil respiration of L. principis-rupprechtii forest had no relationship with soil temperature,a positive correlation with air temperature（ R2= 0. 75） and fitted a power function model,a negative correlation with soil moisture content. The soil respiration of the other four forest types had a positive correlation with the air temperature and soil temperature（ R2=0. 80 ~ 0. 94） and fitted a power function model,which is not related to the soil moisture content. Soil respiration increased with the increasing of litter biomass. The contribution of litter respiration in mixed forest was greater than the pure forest.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2016年第10期95-103,共9页
Journal of Beijing Forestry University
基金
林业生态科技工程(2015BAD07B030302)
中央高校基本科研业务费专项资金(2015ZCQ-SB-03)
关键词
高寒区
土壤呼吸
凋落物
土壤温度
大气温度
土壤水分
alpine region
soil respiration
litter
soil temperature
atmospheric temperature
soil moisture
作者简介
李思思。主要研究方向：水土保持。Email：lisisi824@163．com地址：100083北京市海淀区清华东路35号北京林业大学水土保持学院。
责任作者：贺康宁，教授，博士生导师。主要研究方向：水土保持。Email：hkn@bjfu．edu．cn
