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  

Impacts of ultraviolet radiation on litter decomposition rate and alterations in chemical constituents in an extremely arid region

作　　者：李美琪 李成道 李向义[1,2,3] 王鹏 LI Meiqi;LI Chengdao;LI Xiangyi;WANG Peng(Xinjiang Key Laboratory of Desert Plant Root Ecology and Vegetation Restoration,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi,83001,China;National Field Scienti-fic Observation and Experimental Station of Celle Desert Grassland Ecosystem,Celle 848300,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院新疆生态与地理研究所,新疆荒漠植物根系生态与植被修复重点实验室,乌鲁木齐830011 [2]中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,乌鲁木齐830011 [3]新疆策勒荒漠草地生态系统国家野外科学观测实验站,新疆策勒848300 [4]中国科学院大学,北京100049

出　　处：《生态学杂志》2024年第11期3300-3308,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41877420,41571057和41807335);博士后创新人才支持计划项目(BX201700279)资助。

摘　　要：极端干旱区降水稀少,日照时间长,凋落物长期暴露在强光下,质量损失主要受太阳辐射的影响。为探究紫外辐射对凋落物分解的影响,采用分解袋法研究自然光照和紫外辐射遮蔽2种条件下塔克拉玛干沙漠南缘-策勒绿洲边缘荒漠地区3种优势植物凋落叶的分解。结果表明:自然光照下3种凋落物分解速率明显快于UV遮蔽处理,分解末期UV遮蔽下凋落物质量残留率比自然光照高79.97%、77.79%和82.55%;自然光照下花花柴、骆驼刺和胡杨凋落物有机物损失率与质量损失率的Pearson相关系数分别为0.975、0.982和0.991,UV遮蔽下分别为0.786、0.906和0.800,自然光照下相关性优于UV遮蔽;UV遮蔽显著减少3种凋落物的可溶性盐、C、N损失和C∶N。研究结果有助于深入了解极端干旱区凋落物的分解机制,为今后对干旱生态系统凋落物分解的研究奠定基础。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.

关 键 词：凋落物分解 极端干旱区 光降解 养分释放 

分 类 号：Q948[生物学—植物学]