Biomass, Litter, and Soil Respiration Along a Precipitation Gradient in Southern Great Plains, USA
Biomass, Litter, and Soil Respiration Along a Precipitation Gradient in Southern Great Plains, USA
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DOI：
10.1007/s10021-009-9296-7
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发表时间：
2009-11
期刊：
影响因子：
3.7
通讯作者：
Xuhui Zhou;M. Talley;Yiqi Luo
中科院分区：
文献类型：
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作者：
Xuhui Zhou;M. Talley;Yiqi Luo
了解生态系统碳（C）过程如何对降水变化作出反应，对于评估气候变化对陆地生态系统的影响至关重要。在这项研究中，我们研究了地上部和根系生物量的变化，立木和地表凋落物，土壤呼吸，土壤碳含量沿着自然降水梯度从430至1200毫米，美国南部大平原。结果表明，地上部生物量和土壤呼吸随年平均降水量（MAP）的增加呈线性增加，而根系生物量和土壤C含量沿降水梯度沿着保持相对恒定。因此，根冠比与MAP呈线性下降。然而，模式的站立，表面，和总凋落物质量遵循二次关系与MAP沿着梯度，可能导致凋落物生产和分解之间的平衡。这些线性/二次方程描述的生态系统C过程与降水的变化可能是有用的模型开发，参数化，并在景观和区域尺度验证，以提高预测的C动态响应气候变化的草原。我们的研究结果表明，降水是一个重要的驱动力，在塑造生态系统功能，反映在植被生产，凋落物质量，在草地生态系统的土壤呼吸。
Knowledge of how ecosystem carbon (C) processes respond to variations in precipitation is crucial for assessing impacts of climate change on terrestrial ecosystems. In this study, we examined variations of shoot and root biomass, standing and surface litter, soil respiration, and soil C content along a natural precipitation gradient from 430 to 1200 mm in the southern Great Plains, USA. Our results show that shoot biomass and soil respiration increased linearly with mean annual precipitation (MAP), whereas root biomass and soil C content remained relatively constant along the precipitation gradient. Consequently, the root/shoot ratio linearly decreased with MAP. However, patterns of standing, surface, and total litter mass followed quadratic relationships with MAP along the gradient, likely resulting from counterbalance between litter production and decomposition. Those linear/quadratic equations describing variations of ecosystem C processes with precipitation could be useful for model development, parameterization, and validation at landscape and regional scales to improve predictions of C dynamics in grasslands in response to climate change. Our results indicated that precipitation is an important driver in shaping ecosystem functioning as reflected in vegetation production, litter mass, and soil respiration in grassland ecosystems.