Erosion regulation as a function of human disturbances to vegetation cover: a conceptual model
Erosion regulation as a function of human disturbances to vegetation cover: a conceptual model
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DOI：
10.1007/s10980-013-9956-z
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发表时间：
2014-02
影响因子：
5.2
通讯作者：
V. Vanacker;N. Bellin;A. Molina;P. Kubik
中科院分区：
文献类型：
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作者：
V. Vanacker;N. Bellin;A. Molina;P. Kubik
人类活动引起的土地覆被变化正在对山区生态系统提供的生态服务产生重要影响，关于人类活动对土壤侵蚀和沉积物产生影响的案例研究数量迅速增加。在本文中，我们提出了一个概念模型，可以评估人类干扰后侵蚀调节的总体变化。该模型的基本思想是，土壤侵蚀机制是独立的人类的影响，但侵蚀率的频率-幅度分布的变化作为对人类干扰的响应。前干扰（或自然）侵蚀速率来自于在现场produced 10 Be在河流沉积物中的浓度，而后干扰（或现代）侵蚀速率来自于小流域的沉积速率。在其简单性，该模型使用植被覆盖变化作为人类干扰的代理。侵蚀调节模型在这里应用于两个山区不同的植被动态，气候和地质环境：南厄瓜多尔，和西班牙贝蒂奇科迪勒拉。自然侵蚀基准对于评估人类引起的侵蚀率变化是必要的。虽然西班牙Betic Cordillera通常被描述为退化景观，但现代全流域侵蚀和长期剥蚀率之间没有显著差异。相反的情况是正确的南厄瓜多尔，自然侵蚀的份额在总的现代侵蚀率是最小的干扰网站。当汇集来自这两个地区的干扰前和干扰后的侵蚀数据时，数据表明，人类加速侵蚀与植被干扰有关。经验回归模型预测人类加速侵蚀，在这里定义为干扰后干扰前（或自然基准）的侵蚀速率的比率，作为植被干扰的指数函数。这表明，对人类加速侵蚀的敏感性将取决于生态系统，并与人类影响造成的潜在植被覆盖干扰有关。因此，可以预期，在植被良好的生态系统中，人为干扰和未受干扰或恢复的地点之间的植被覆盖可能存在很大差异，侵蚀调节的潜力较大。
Human-induced land cover changes are causing important effects on the ecological services rendered by mountain ecosystems, and the number of case-studies of the impact of humans on soil erosion and sediment yield has mounted rapidly. In this paper, we present a conceptual model that allows evaluating overall changes in erosion regulation after human disturbances. The basic idea behind this model is that soil erosion mechanisms are independent of human impact, but that the frequency–magnitude distributions of erosion rates change as a response to human disturbances. Pre-disturbance (or natural) erosion rates are derived from in situ produced10Be concentrations in river sediment, while post-disturbance (or modern) erosion rates are derived from sedimentation rates in small catchments. In its simplicity, the model uses vegetation cover change as a proxy of human disturbance. The erosion regulation model is here applied in two mountainous regions with different vegetation dynamics, climatic and geological settings: the Austro Ecuatoriano, and the Spanish Betic Cordillera. Natural erosion benchmarks are necessary to assess human-induced changes in erosion rates. While the Spanish Betic Cordillera is commonly characterized as a degraded landscape, there is no significant difference between modern catchment-wide erosion and long-term denudation rates. The opposite is true for the Austro Ecuatoriano where the share of natural erosion in the total modern erosion rate is minimal for most disturbed sites. When pooling pre- and post-disturbance erosion data from both regions, the data suggest that the human acceleration of erosion is related to vegetation disturbances. The empirical regression model predicts human acceleration of erosion, here defined as the ratio of post-disturbance to pre-disturbance (or natural benchmark) erosion rate, as an exponential function of vegetation disturbance. This suggests that the sensitivity to human-accelerated erosion would be ecosystem dependent, and related to the potential vegetation cover disturbances as a result of human impact. It may therefore be expected that the potential for erosion regulation is larger in well-vegetated ecosystem where strong differences may exist in vegetation cover between human disturbed and undisturbed or restored sites.