Decreased ultraviolet radiation and decomposer biodiversity inhibit litter decomposition under continuous nitrogen inputs
Decreased ultraviolet radiation and decomposer biodiversity inhibit litter decomposition under continuous nitrogen inputs
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紫外线辐射和分解者生物多样性的减少抑制了连续氮输入下的凋落物分解
DOI：
10.1111/1365-2435.14015
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发表时间：
2022
影响因子：
5.2
通讯作者：
Yuanhe Yang
中科院分区：
文献类型：
--
作者：
Bin Wei;Dianye Zhang;Dan Kou;Guibiao Yang;Futing Liu;Yunfeng Peng;Yuanhe Yang
大气氮沉降改变了地球化学循环和生态系统功能。凋落物分解是陆地生态系统碳循环和养分循环的关键过程，对氮素输入十分敏感。然而，目前还不清楚紫外线（UV）辐射、土壤生物多样性（细菌、真菌和无脊椎动物）和传统驱动器（如凋落物化学和微生物活动）调节凋落物分解对连续N输入的响应。基于多级N添加实验平台，我们进行了一个为期2年的凋落物分解实验，以研究N诱导的生物和非生物因子变化在介导四种凋落物分解速率变化中的相对重要性结果表明，随着氮素浓度的增加，不同物种及其混合物的凋落物分解速率均呈下降趋势。随着N添加量的增加，分解速率减慢，这与N诱导的UV辐射和土壤细菌多样性的减少有关。另外的紫外辐射控制实验进一步证实了光降解对本研究地点植物凋落物分解的强烈影响。这些结果表明，N诱导的紫外辐射和土壤细菌多样性的下降抑制了凋落物分解，挑战传统观点，即凋落物化学和微生物活动的变化决定了凋落物分解对外部N输入的反应。这篇文章在《华尔街日报》博客上。
Atmospheric nitrogen (N) deposition has altered biogeochemical cycles and ecosystem functioning. As a key process involved in carbon and nutrient cycles in terrestrial ecosystems, litter decomposition is sensitive to external N inputs. However, it remains unclear how the interactions of ultraviolet (UV) radiation, soil biodiversity (bacteria, fungi and invertebrates) and conventional drivers (e.g. litter chemistry and microbial activities) regulate the responses of litter decomposition to continuous N inputs.Based on a multilevel N addition experimental platform, we conducted a 2‐year litter decomposition experiment to examine the relative importance of N‐induced changes in biotic and abiotic factors in mediating changes in the decomposition rates of four litter types (three representative species and their mixture) along an experimental N gradient in a Tibetan alpine steppe.Our results showed that litter decomposition rates exhibited a consistent decrease in response to N enrichment among all species and their mixture. The slowed decomposition rates with increasing N addition were associated with N‐induced reductions in UV radiation and soil bacterial diversity. An additional UV radiation manipulative experiment further confirmed that photodegradation had strong effects on plant litter decomposition at our study site.These results demonstrated that N‐induced declines in UV radiation and soil bacterial diversity inhibited litter decomposition, challenging the traditional view that changes in litter chemistry and microbial activities determine the responses of litter decomposition to external N inputs.Read the free Plain Language Summary for this article on the Journal blog.