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摘要: 紫外线-B（UV-B）辐射增强将对陆地生态系统凋落物的分解和养分循环产生直接和间接的多重影响。直接影响表现在将增加对凋落物木质素的光降解作用从而促进凋落物的分解，改变分解者包括土壤动物和微生物的种类组成、数量、活性和移殖，从而抑制凋落物的分解。间接影响表现为改变植物生长期间叶、茎等器官化学成分如纤维素、类黄酮、多酚和丹宁等的含量，并进而影响分解过程中分解者的种类和动态。UV-B辐射对凋落物分解的作用最终将影响到生态系统的营养循环和碳储量。由于试验材料和试验方法不一致，已有研究结果之间差异较大，可比性较差。在今后的研究中，应重点从凋落物的基质质量变化和分解者的组成及活性等方面加强UV-B辐射对凋落物分解影响机制的研究。参65Abstract: Elevated solar ultraviolet-B （UV-B） radiation has been a hot issue in regards to global environmental change as UV-Bs could directly or indirectly affect litter decomposition and nutrient cycling in terrestrial ecosystems. As a consequence of accelerated photochemical breakdown of lignin，solar UV-B radiation could increase the litter decomposition rate；it could also decrease decomposition by directly altering species composition，quantity，activity，and colonization of decomposers （including animals and soil microbes） exposed to solar radiation. Indirect effects of UV-B radiation on litter chemical composition have included both reductions and increases in the concentrations of cellulose，flavonoids，and tannins during growth. This has subsequently affected community composition and competitive ability of decomposers thereby either decreasing or accelerating litter decomposition rates in soils. Through its influence on litter decomposition，UV-B radiation could further affect nutrient cycling and carbon storage of the ecosystem. Effects of UV-B radiation （both direct and indirect） on litter decomposition have been species-specific making previous studies difficult to compare due to differences in litter type，ecosystems，and experimental approaches simulating ozone depletion. Thus，further research on how UV-B radiation influences litter decomposition，which focuses mainly on changes in litter quality and composition as well as decomposer activity，is necessary.［Ch，65 ref.］
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链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2010.01.022
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