Effect of land cover and hydro‐meteorological controls on soil water DOC concentrations in a high‐elevation tropical environment
Effect of land cover and hydro‐meteorological controls on soil water DOC concentrations in a high‐elevation tropical environment
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DOI：
10.1002/hyp.13224
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发表时间：
2018-07
影响因子：
3.2
通讯作者：
Juan Pesántez;G. Mosquera;P. Crespo;L. Breuer;D. Windhorst
中科院分区：
文献类型：
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作者：
Juan Pesántez;G. Mosquera;P. Crespo;L. Breuer;D. Windhorst
Páramo土壤储存了大量的有机碳。然而，气候变化和土地覆盖和利用的变化(LC/LU)的影响可能会导致这一高海拔热带生态系统的碳储存能力下降。因此，迫切需要更好地了解影响Páramo土壤碳储存和输出的因素。为了填补这一认识空白，我们在厄瓜多尔南部的奎努阿斯生态水文观测站调查了四种LC/LU类型(草丛、天然林、松林和牧场)土壤水中溶解有机碳(DOC)含量的差异及其控制因素。从2014年10月至2017年1月，在土壤有机层和矿物层内对土壤水分DOC浓度、气象变量、土壤水分含量和来自不同深度和坡位的温度进行了每周测量。这些数据被用来生成回归树和随机森林统计模型，以识别控制土壤水分DOC浓度的因素。从高到低，天然林的DOC浓度最高，其次是牧场、草坪草和松林。对于所有LC/LU类型，DOC浓度随着土壤水分的降低而增加。结果还表明，LC/LU是土壤水分DOC浓度的最重要预测因子，其次是采样深度和土壤水分。有趣的是，在监测期间，大气变量以及之前的蒸散量和降水条件对DOC浓度的影响很小。我们的发现提供了独特的信息，有助于改善帕拉莫和其他以泥炭为主的生态系统的土壤和水资源管理。
Páramo soils store high amounts of organic carbon. However, the effects of climate change and changes in land cover and use (LC/LU) in this high‐elevation tropical ecosystem may cause a decrease in their carbon storage capacity. Therefore, better understanding of the factors influencing the Páramo soils' carbon storage and export is urgently needed. To fill this knowledge gap, we investigated the differences in dissolved organic carbon (DOC) content in the soil water of four LC/LU types (tussock grass, natural forest, pine plantations, and pasture) and the factors controlling its variability in the Quinuas Ecohydrological Observatory in south Ecuador. Weekly measurements of soil water DOC concentrations, meteorological variables, soil water content, and temperature from various depths and slope positions were monitored within the soils' organic and mineral horizons between October 2014 and January 2017. These data were used to generate regression trees and random forest statistical models to identify the factors controlling soil water DOC concentrations. From high to low concentrations, natural forest depict the highest DOC concentrations followed by pasture, tussock grass, and pine forest. For all LC/LU types, DOC concentrations increase with decreasing soil moisture. Our results also show that LC/LU is the most important predictor of soil water DOC concentrations, followed by sampling depth and soil moisture. Interestingly, atmospheric variables and antecedent evapotranspiration and precipitation conditions show only little influence on DOC concentrations during the monitoring period. Our findings provide unique information that can help improve the management of soil and water resources in the Páramo and other peat dominated ecosystems elsewhere.