The effect of landform variation on vegetation patterning and related sediment dynamics
The effect of landform variation on vegetation patterning and related sediment dynamics
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DOI：
10.1002/esp.4377
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发表时间：
2018-08-01
影响因子：
3.3
通讯作者：
Saco, Patricia M.
中科院分区：
文献类型：
--
作者：
Baartman, Jantiene E. M.;Temme, Arnaud J. A. M.;Saco, Patricia M.
半干旱生态系统在空间上往往是自组织的，典型的植被带格局是植物覆盖率高，散布着裸露的土壤区域，也称为"虎斑"。在建模研究中，最常见的是使用平直的平面斜坡来分析植被格局。坡度的影响已被广泛研究，一些研究探讨了微地形和山坡方向的影响。然而，在更大的集水范围内，景观的整体形式可能会影响植被格局，这些更复杂的景观比直坡更普遍。因此，我们的目标是确定地形变化对植被格局和沉积动力学的影响。我们将两个完善的模型联系起来，模拟（a）植物生长、死亡和植被扩散，以及（B）侵蚀和沉积动力学。该模型进行了测试，在一个平直的平面山坡，然后应用到（i）一组简单的合成地形与不同的曲率和（ii）三个更复杂的，现实世界的景观不同的形态。结果表明，带状植被格局的所有合成地形，总是垂直于坡度。有趣的是，我们还发现，乐队的运动-一个有争议的现象-似乎是依赖于曲率。模拟冲积扇的斜坡上和沿着切割和起伏景观的山谷斜坡上的植被带。在所有景观中，当地的山谷发展了一个完整的植被覆盖引起的水浓度，这是与世界各地的观测结果一致。最后，带状植被模式被发现，以减少侵蚀显着相比，其他植被配置。(c)2018作者地球表面过程和地貌由约翰威利父子有限公司出版。
Semi-arid ecosystems are often spatially self-organized in typical patterns of vegetation bands with high plant cover interspersed with bare soil areas, also known as tiger bush'. In modelling studies, most often, straight planar slopes were used to analyse vegetation patterning. The effect of slope steepness has been investigated widely, and some studies investigated the effects of microtopography and hillslope orientation. However, at the larger catchment scale, the overall form of the landscape may affect vegetation patterning and these more complex landscapes are much more prevalent than straight slopes. Hence, our objective was to determine the effect of landform variation on vegetation patterning and sediment dynamics. We linked two well-established models that simulate (a) plant growth, death and dispersal of vegetation, and (b) erosion and sedimentation dynamics. The model was tested on a straight planar hillslope and then applied to (i) a set of simple synthetic topographies with varying curvature and (ii) three more complex, real-world landscapes of distinct morphology. Results show banded vegetation patterning on all synthetic topographies, always perpendicular to the slope gradient. Interestingly, we also found that movement of bands - a debated phenomenon - seems to be dependent on curvature. Vegetation banding was simulated on the slopes of the alluvial fan and along the valley slopes of the dissected and rolling landscapes. In all landscapes, local valleys developed a full vegetation cover induced by water concentration, which is consistent with observations worldwide. Finally, banded vegetation patterns were found to reduce erosion significantly as compared to other vegetation configurations. (c) 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.