Du Ningning, Li Wenrao, Qiu Liping, Zhang Yanjiang, Wei Xiaorong, Zhang Xingchang
College of Natural Resources and Environment Northwest A&F University Yangling China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Yangling China.
Ecol Evol. 2020 Mar 12;10(7):3367-3382. doi: 10.1002/ece3.6129. eCollection 2020 Apr.
Mass loss and nutrient release during litter decomposition drive biogeochemical cycling in terrestrial ecosystems. However, the relationship between the litter decomposition process and the decomposition stage, precipitation, and litter quality has rarely been addressed, precluding our understanding of how litter decomposition regulates nutrient cycling in various ecosystems and their responses to climate change. In this study, we measured mass loss as well as carbon and nutrient releases during the decomposition of 16 types of leaf litter under three precipitation treatments over 12 months in a common garden experiment (i.e., using standardized soil and climatic conditions). Sixteen types of leaves were divided into three functional groups (evergreen, deciduous, and herbaceous). The objectives were to understand the effects of decomposition stages and precipitation regimes on litter decomposition and to examine the relationship between this effect and chemical properties. The mass loss and release of nitrogen and potassium were significantly higher in the 6- to 12-month stage of decomposition (high temperature and humidity) than in the 0- to 6-month stage. Phosphorus was relatively enriched in evergreen leaves after 6 months of decomposition. The rates of mass loss and nutrient release were significantly greater in herbaceous than in deciduous and evergreen leaves. Increasing precipitation from 400 to 800 mm accelerated mass loss and potassium release but decreased phosphorus release in the 0- to 6-month stage of decomposition. These results highlighted the contribution to and complexity of litter chemical properties in litter decomposition.
凋落物分解过程中的质量损失和养分释放驱动着陆地生态系统中的生物地球化学循环。然而，凋落物分解过程与分解阶段、降水和凋落物质量之间的关系鲜有研究，这妨碍了我们理解凋落物分解如何调节各种生态系统中的养分循环及其对气候变化的响应。在本研究中，我们在一个共同园圃实验（即使用标准化土壤和气候条件）中，测量了16种叶片凋落物在三种降水处理下12个月分解过程中的质量损失以及碳和养分释放。16种叶片被分为三个功能组（常绿、落叶和草本）。目的是了解分解阶段和降水格局对凋落物分解的影响，并研究这种影响与化学性质之间的关系。分解6至12个月阶段（高温高湿）的质量损失以及氮和钾的释放显著高于0至6个月阶段。分解6个月后，磷在常绿叶片中相对富集。草本叶片的质量损失和养分释放速率显著高于落叶和常绿叶片。在分解的0至6个月阶段，降水量从400毫米增加到800毫米会加速质量损失和钾的释放，但会减少磷的释放。这些结果突出了凋落物化学性质在凋落物分解中的作用和复杂性。
