摘要
【目的】通过增温对比试验观测天然次生林演替序列森林内不同层次植物根系呼吸速率生长季的变化,揭示森林演替和模拟增温及其交互作用对根系呼吸速率的影响,为森林更新过程中土壤碳循环对气候变暖响应机制的研究提供数据支持。【方法】以关帝山4种天然次生林(杨桦林、油松林、华北落叶松林和白杄林)为对象,采用野外定点对比试验,以林下地面搭建温室模拟林地增温和用去根试验结合差减法区分根系呼吸组分。于2016—2019年利用Li-6400便携式分析仪观测根系呼吸速率。【结果】增温提高了4种林型细根生物量和根系总呼吸(土壤自养呼吸)的生长季碳通量;增温显著提高了灌木层和草本层根系呼吸速率,提高幅度分别为8.37%~15.26%和10.88%~14.00%,降低了根系呼吸速率的温度敏感性(Q_(10))。但增温没有改变根系呼吸的生长季单极值变化特征。各林分细根生物量和根系呼吸速率均随演替进程而降低,而根系呼吸速率Q_(10)的值则升高。【结论】灌木和草本层根系呼吸速率对增温和演替及其交互作用的响应程度显著,而乔木层根系呼吸速率对增温和增温与演替的交互作用响应程度不显著。随林地温度升高,森林根系呼吸速率升高而温度敏感性却降低,说明森林根系呼吸速率对温度升高的响应较为复杂。
【Objective】In order to reveal the effects of forest succession and simulated warming on forest plant and soil autotrophic respiration rates and their coupling effects,we measured soil and plant root autotrophic respiration rates from the warming.The root respiration rates of different plant layers during the growing season were measured to analyze their responses to warming,intending to provide more data for the research on the response mechanism of forest soil carbon cycle to climate warming in the process of forest succession.【Method】Four natural secondary forest types from Guandi Mountains were selected for the study,including poplar-birch broad-leaved deciduous forest,Pinus tabulaeformis conifer and broad-leaved mixed forest and Larix principis rupprechtii forest and Picea meyeri forest.Field fixed-point comparison test was used to simulate forest warming by building greenhouses on the forest floor.Root removal method was used to distinguish root respiration from the total soil respiration.We used Li-6400 portable CO 2 analyzer to measure the root respiration rates from 2016 to 2019 during the growing seasons.【Results】The results showed that the warming increased the fine root biomass and carbon flux of total root respiration in the four forest types.Warming and its interaction with forest types significantly increased the root respiration rates of shrubs and herbs by 8.37%~15.26%and 10.88%~14.00%,respectively.As temperature increases the sensitivity of root respiration(Q_(10))decreased.However,warming did not change the patterns of root respiration during each growing season.The fine root biomass and root respiration rates decreased with progress of forest succession while the temperature sensitivity of root respiration(Q_(10))increased.【Conclusion】Warming and its interaction with forest types did not significantly affect tree-root respiration rates.In contrast,root respiration rates of shrubs and herbs were significantly affected by warming,forest types and their interaction.With the increase of forest land temperature,forest root respiration rate increased,but its temperature sensitivity decreased,which indicated that the response of forest root respiration rate to temperature increase was complex.
作者
赵世魁
郭晋平
张芸香
Zhao Shikui;Guo Jinping;Zhang Yunxiang(College of Forestry,Shanxi Agriculture University ,Taigu 030801;Jinzhong College of Information, Taigu 030801)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2023年第2期10-21,共12页
Scientia Silvae Sinicae
基金
山西省国际合作项目(2015081001)。
关键词
演替
林地增温
天然次生林
根系呼吸
暖温带
succession
woodland warming
natural secondary forest
root respiration rate
warm-temperate zone
