Tradeoffs between soil conservation and soil‐water retention: The role of vegetation pattern and density
Tradeoffs between soil conservation and soil‐water retention: The role of vegetation pattern and density
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DOI：
10.1002/ldr.4123
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发表时间：
2021-10
影响因子：
4.7
通讯作者：
Wei Wei-Wei;Daili Pan;Feng Jing
中科院分区：
文献类型：
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作者：
Wei Wei-Wei;Daili Pan;Feng Jing
平衡侵蚀控制和水资源保护服务是水资源有限条件下密集植被重建的主要目标。通过田间试验，研究了黄土高原旱地不同植被类型和密度对土壤保水性能的影响。设计并实施了五种植被模式（上坡覆盖、下坡覆盖、高低均匀覆盖、无覆盖），三种草密度水平（220 g m−2、110 g m−2和0）。一个新的指标EEW（侵蚀减少和水消耗之间的交换），作为任何额外的消耗土壤水分，以改善每一个单位的土壤保持的成本，被用来代表在一个完整的干-湿-干土壤水分转换周期的权衡。EEW越高，SC和SWR之间的权衡越差。这说明，较高的植被密度可以促进SC，但不一定抑制EEW。CLP目前的典型草密度约为220 g m−2，在优化SC-SWR权衡方面是多余的。集中和集中的植被分布主要在下坡，EEW为11.6 mm m2 kg−1，并被确认为有利的植被格局。模拟的CLP典型密度和空间格局（约220 g m−2且均匀分布）的EEW为20.5 mm m2 kg−1，通过将密度降低至约110 g m−2和下坡集中植被再分布，EEW减少了43.4%。在干-湿-干循环的长期干旱条件下，与半覆盖和裸土样地相比，全覆盖样地的土壤水分下降更急剧，这是由于较高的植物密度导致更多的蒸散和垂直水分损失。本研究证实，种植密度和植被格局可以操纵SC-SWR权衡，因此，它是可能的，优化它通过调整植被的强度和结构在实践中。
Balancing erosion control and the water conservation service is the primary goal of intensive revegetation in water‐limited conditions. In this study, a field experiment was conducted in the dryland Chinese Loess Plateau (CLP), to investigate the role of vegetation pattern and density in their tradeoff between soil conservation (SC) and soil water retention (SWR). Five vegetation patterns (up‐slope covered, downslope covered, low and high uniformly covered, no coverage) with three levels of grass density (220 g m−2, 110 g m−2, and 0) were designed and implemented. A novel indicator EEW (the exchange between erosion reduction and water consumption), as the cost of any extra depletion of soil water to improve each unit of soil conservation, was used to represent the tradeoff during a complete dry‐wet‐dry soil water convert cycle. The higher EEW, the poorer tradeoff between SC and SWR. It was illustrated that higher vegetation density could promote SC but not inevitably suppress EEW. The present typical grass density in CLP, round 220 g m−2, was redundant in optimizing the SC‐SWR tradeoff. A concentrated and centralized vegetation distribution mainly in the downslope obtained an EEW at 11.6 mm m2 kg−1 and was confirmed as a favoured vegetation pattern. The simulated typical density and spatial pattern in CLP (about 220 g m−2 and uniformly distribution) had EEW at 20.5 mm m2 kg−1, by reducing the density to about 110 g m−2 and a downslope centralized vegetation redistribution, the EEW was reduced by 43.4%. Under long‐term drought conditions at dry‐wet‐dry cycles, soil water decreased more sharply in the Full‐covered plots, due to more evapotranspiration and vertical water loss caused by higher plant density, compared with half‐covered and bare soil plots. The present study confirmed that planted density and vegetation pattern can manipulate SC‐SWR tradeoff and it was thus possible to optimize it by adjusting revegetation's intensity and structures in practice.