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土壤是陆地生态系统的重要组成部分,是地球最大的碳库之一。土壤呼吸是陆地生态系统向大气释放CO2的主要途径之一,其微小的变化将导致大气CO2浓度的较大波动。菌根是土壤真菌与植物根系形成的共生体,存在于绝大多数植物(90%)的根系和生境中。菌根共有7种类型,其中,在自然界中以丛枝菌根和外生菌根为主。众多研究表明,菌根对土壤呼吸有着至关重要的影响,是预测土壤CO2释放速率必须考虑,但却是难以估算的因素。文章总结了有关菌根(包括丛枝菌根和外生菌根)对土壤呼吸影响的研究进展,对目前所得到的研究结果进行了分析,表明菌根真菌侵染植物根系形成菌根后,能提高土壤呼吸的速率,其可能的途径有3条:(1)增强了根系的呼吸,(2)菌根真菌自身呼吸的组分,(3)根外菌丝促进了非根际区土体的呼吸。但是,菌根侵染对根系呼吸敏感性(Q10)影响的研究,大多数则表现为不显著。同时,菌根对土壤呼吸的影响受到各种因素的制约。通过对不同温度下菌根真菌呼吸速率的分析,表明菌根真菌对温度的升高具有适应性。从目前已发表的报道来看,目前关于菌根对土壤呼吸影响的研究还非常少,但可喜的是,近年来,越来越多的研究已经意识到了菌根在土壤呼吸中的重要作用。准确评估菌根在土壤呼吸中的贡献,将有助于预测未来在气候变化下,土壤CO2的排放量。
Soil is an important part of terrestrial ecosystems and one of the largest carbon pools on the planet. Soil respiration is one of the main ways for terrestrial ecosystems to release CO2 to the atmosphere. Slight changes will lead to large fluctuations in atmospheric CO2 concentration. Mycorrhizal is a symbiont formed by soil fungi and plant roots and exists in the roots and habitats of most plants (90%). There are 7 types of mycorrhiza, among them, arbuscular mycorrhizae and ectomycorrhizae in nature. Numerous studies show that mycorrhizas have a vital impact on soil respiration. Predicting the rate of soil CO2 release must be considered, but it is a difficult factor to estimate. The paper summarizes the research progress on the influence of mycorrhizae (including arbuscular mycorrhiza and ectomycorrhiza) on soil respiration, and analyzes the results obtained so far. It indicates that after the mycorrhizal fungi invade the plant root, There are three possible ways to increase the rate of soil respiration: (1) enhanced root respiration, (2) components of mycorrhizal fungi that breathe themselves, and (3) extracellular mycelium promote non-rhizosphere soil Body breathing. However, most of the studies on the effects of mycorrhizal infection on root respiration susceptibility (Q10) did not show significant effects. At the same time, mycorrhizal effect on soil respiration is restricted by various factors. Through the analysis of mycorrhizal fungi respiration rate at different temperatures, mycorrhizal fungi showed the adaptability to the increase of temperature. According to the published reports, there are very few studies on the influence of mycorrhiza on soil respiration. However, it is gratifying that more and more researches have realized the important role of mycorrhizal in soil respiration in recent years. Accurate assessment of the mycorrhizal contribution to soil respiration will help predict the future soil CO2 emissions under climate change.