极端干旱区紫外辐射对凋落物分解速率及化学组分变化的影响OA北大核心CSTPCD

Litters are exposed to intense sunlight for an extended period due to limited precipitation and prolonged sunshine duration in extremely arid regions.The influence of solar radiation on litter mass loss is predominant in extremely arid ecosystems.The litterbag method was employed to investigate litter decomposition of three dominant plant species under natural light exposure and shading from ultraviolet radiation in Cele Oasis desert area,the southern edge of the Taklamakan Desert.The results showed that decomposition rate of all the three types of litter was significantly higher under natural light than under UV shading.The mass remaining rate of litter at the end of decomposition under UV shading was 79.97％,77.79％,and 82.55％higher than that under natural light for Kare-linia caspica,Alhagi sparsifolia,and Populus euphratica,respectively.The Pearson correlation coefficients between organic matter loss rate and mass loss rate under natural light were 0.975,0.982,and 0.991 for Karelinia caspica,Alhagi sparsifolia,and Populus euphratica respectively,and 0.786,0.906,and 0.800 correspondingly under UV shading,with a stronger association under natural light compared to UV shading.Additionally,UV shading signifi-cantly mitigated the loss of soluble salt,C,and N as well as altered the C:N ratio in all three types of litter.Find-ings from this study contribute to enhance our understanding of the decomposition mechanism of litter in extremely arid regions,providing a fundamental basis for future investigations on litter decomposition in arid ecosystems.