文献类型： 外文期刊

作者： Yang, Sen ¹ ; Jia, Zhou ³ ; Chang, Pengfei ¹ ; Wu, Yuntao ¹ ; Huang, Junsheng ¹ ; Wang, Jing ⁶ ; Deng, Meifeng ¹ ; Su, Jiao ¹ ; Hong, Songbai ⁷ ; He, Yue ⁸ ; Zhu, Juntao ⁹ ; Zhang, Pujin ¹⁰ ; Wang, Yang ¹ ; Guo, Xiaowei ¹¹ ; Zhang, Zhenhua ¹¹ ; Zhang, Yangjian ⁹ ; Hu, Shuijin ¹³ ; He, Jinsheng ² ; Piao, Shilong ⁸ ; Liu, Lingli ¹ ;

作者机构： 1.Chinese Acad Sci, State Key Lab Forage Breeding By Design & Utilizat, Key Lab Vegetat & Environm Change, Inst Bot, Beijing, Peoples R China

2.Peking Univ, Inst Ecol, Coll Urban & Environm Sci, Beijing, Peoples R China

3.Hebei Acad Agr & Forestry Sci, Inst Agr Resources & Environm, Shijiazhuang, Peoples R China

4.China Natl Bot Garden, Beijing, Peoples R China

5.Univ Chinese Acad Sci, Beijing, Peoples R China

6.Hebei Univ, Coll Life Sci, Baoding, Peoples R China

7.Peking Univ, Sch Urban Planning & Design, Shenzhen Grad Sch, Shenzhen, Peoples R China

8.Peking Univ, Inst Carbon Neutral, Sino French Inst Earth Syst Sci, Coll Urban & Environm Sci, Beijing, Peoples R China

9.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing, Peoples R China

10.Inner Mongolia Univ, Sch Ecol & Environm, Inner Mongolia Key Lab Grassland Ecol, Hohhot, Peoples R China

11.Chinese Acad Sci, Northwest Inst Plateau Biol, Key Lab Adaptat & Evolut Plateau Biota, Xining, Peoples R China

12.Chinese Acad Sci, Northwest Inst Plateau Biol, Qinghai Prov Key Lab Restorat Ecol Cold Area, Xining, Peoples R China

13.North Carolina State Univ, Dept Entomol & Plant Pathol, Raleigh, NC USA

14.Lanzhou Univ, Coll Pastoral Agr Sci & Technol, State Key Lab Herbage Improvement & Grassland Agro, Lanzhou, Peoples R China

15.Chinese Acad Sci, Inst Tibetan Plateau Res, State Key Lab Tibetan Plateau Earth Syst Resources, Beijing, Peoples R China

关键词： climate gradient; desert steppe; dryland ecosystem; lignin/N ratio; litter decomposition; photodegradation; ultraviolet radiationalpine steppe

期刊名称：GLOBAL CHANGE BIOLOGY （ 影响因子：12.0； 五年影响因子：14.0 ）

ISSN： 1354-1013

年卷期： 2025 年 31 卷 8 期

页码：

收录情况： SCI

摘要： Litter decomposition is a critical biogeochemical process for carbon and nutrient cycling in terrestrial ecosystems. Ultraviolet (UV) radiation has been recognized to accelerate litter-derived C release in arid and semi-arid ecosystems; yet its spatial controls on determining the regional pattern of litter decomposition are poorly explored. Moreover, the limited understanding of how UV radiation interacts with traditional decomposition drivers, such as climate and litter quality, significantly restricts our ability to accurately quantify the contribution of UV-driven photodegradation to large-scale carbon turnover. In this study, we established a coordinated, distributed UV-manipulation network, spanning 3500-km and covering four grassland ecosystem types, to assess the impact of UV radiation on litter decomposition across gradients of aridity, UV dose, and litter lignin/N ratio. With a modified modeling approach, we further quantified the contribution of UV radiation to litter layer decomposition across temperate grasslands in China. After more than three years in the field, we found that UV attenuation reduced litter mass loss across climatic gradients. The UV-induced facilitation effect primarily occurs in the latter stages of decomposition. The strength of photochemical degradation increased with higher cumulative UV dose, amplified by environmental aridity and litter lignin/N ratio. Across Chinese temperate grasslands, UV exposure shortens mean residence time (MRT) of litter layer by 0.40 years, representing a 16.85% reduction. Hotspots, where UV reduces MRT by over a year, are primarily located in arid and high-altitude grasslands. The sensitivity analysis indicates that the vulnerability of grassland litter decomposition to UV fluctuations intensifies as environmental aridity increases. These findings reveal the pervasiveness of UV-driven litter photodegradation across diverse grasslands and provide a comprehensive framework to improve the predictability of litter-originated C turnover in dryland ecosystems, enabling more constrained projections of terrestrial carbon-climate feedbacks in the context of global UV fluctuations and aridification.