长沙城市绿地森林与草地土壤呼吸及温度敏感性变化特征
Soil respiration and temperature sensitivity characteristics of forest and grassland in urban green space in Changsha City
李淼 1邓正苗 2谢永宏 2李有志 3王涛 2汪丽燕 2李峰 2张贤铭4
作者信息
- 1. 湖南农业大学,湖南长沙 410128;中国科学院亚热带农业生态研究所,湖南长沙 410125
- 2. 中国科学院亚热带农业生态研究所,湖南长沙 410125
- 3. 湖南农业大学,湖南长沙 410128
- 4. 远大芯建数字科技有限公司,湖南长沙 410138
- 折叠
摘要
城市绿地在减缓城市碳排放和温室效应中发挥着巨大作用.土壤呼吸是城市绿地碳循环的重要环节,决定着生态系统碳汇功能的强弱.以湖南省长沙市远大城园区内森林和草地生态系统为研究对象,于2021年11月-2022年12月对土壤呼吸速率及土壤环境进行监测,并结合2022年发生的极端干旱事件,分析城市绿地森林与草地生态系统土壤呼吸特征及其对极端干旱的响应.结果表明:森林和草地生态系统土壤呼吸速率总体呈现出夏秋季(231.98、239.33 mg·m-2·h-1)＞冬春季(179.28、91.15 mg·m-2·h-1)(以 C计);极端干旱下土壤呼吸变化显著,在森林生态系统中更加明显;年尺度下,森林和草地生态系统土壤碳排放量分别为681.55、564.66 g·m-2·a-1(以C计);森林和草地生态系统土壤呼吸温度敏感性系数(Q10值)的范围分别为0.81～1.06、1.19～1.80,草地生态系统对温度变化的响应更敏感,在极端干旱气候条件下可能会导致更多的土壤碳流失.研究结果可以为城市绿地建设和城市"碳中和"目标的实现提供科学依据.
Abstract
Urban green spaces play a significant role in mitigating urban carbon emissions and the greenhouse effects.Soil respiration is a crucial aspect of the carbon cycle in urban green spaces,determining the effectiveness of the ecosystem's carbon sequestration function.Taking the forest and grassland ecosystems in Broad Town in Changsha City,Hunan Province as the research objects,the soil respiration rates and soil environmental conditions were monitored from November 2021 to December 2022.Combined with the extreme drought event in 2022,the soil respiration characteristics of forests and grassland ecosystems were analyzed,as well as their responses to extreme drought.The results showed that the soil respiration rates of forest and grassland ecosystems in summer and autumn(231.98 and 239.33 mg·m-2·h-1,respectively)were higher than those in winter and spring(179.28 and 91.15 mg·m-2·h-1,respectively)(calculated as C).Soil respiration changed significantly under extreme drought,and was more pronounced in forest ecosystems.At an annual scale,the soil carbon emissions of forest and grassland ecosystems were 681.55 and 564.66 g·m-2·a-1(calculated as C),respectively.The temperature sensitivity coefficient(Q10 values)of soil respiration in forest and grassland ecosystems ranged from 0.81 to 1.06 and from 1.19 to 1.80,respectively.The grassland ecosystem was more sensitive to temperature changes,which might lead to more soil carbon loss under extreme drought conditions.The research can provide a scientific basis for urban green space development and the realization of urban"carbon neutrality".
关键词
城市绿地/土壤呼吸/温度敏感性/极端干旱/长沙市Key words
urban green spaces/soil respiration/temperature sensitivity/extreme drought/Changsha City引用本文复制引用
基金项目
长沙市杰出创新青年培养计划(kq2305035)
出版年
2024
NETL
NSTL
万方数据