库布齐沙漠南缘风沙-植被相互作用及其景观效应

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 库布齐沙漠南缘风沙-植被相互作用及其景观效应 DOI: 10.5846/stxb202101270289 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41671002）；青海省重点研发与转化计划项目（2019-HZ-814-1） Interaction between aeolian processes and vegetation and its landscape effect in the southern fringe of Hobq Desert Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:干旱区尤其沙漠边缘地区的风沙与植被相互作用对塑造地表景观具有重要意义。选择库布齐沙漠南缘的油蒿灌丛地为研究区，开展了植被调查、风沙流观测和表层沉积物粒度采样测试，分析了顺风向植被盖度、风沙流结构与沉积物特征的沿程变化，探讨了风沙-植被相互作用及其对地表景观格局的影响。结果表明，风沙流与植被相互作用方式的改变使植物生长状况与地表蚀积模式发生变化，进而导致顺风向景观表现出明显的空间异质性。自上风向裸地过渡到均匀分布的新生油蒿和油蒿灌丛再至斑块状分布的灌丛沙堆，植被盖度与覆沙厚度先增大后减小，空气动力学粗糙度沿程不断增加且在过渡时其增幅最大，输沙率与沉积物粒度呈先减小后增大趋势，并在植被盖度与覆沙厚度最大处出现最小值。在沙漠边缘剥蚀高原上，起初适量风沙堆积促进油蒿定植与生长，均匀分布的油蒿灌丛进一步促进沙物质堆积，但当堆积厚度超过油蒿耐沙埋深度时发生退化，灌丛出现斑块状分布且风沙流在丘间地处侵蚀。据此，可理解为剥蚀高原风沙区景观异质性是风沙与植被相互协同与抑制作用的结果。 Abstract:The interaction between aeolian sand drift and vegetation in arid region, especially in the fringe of desert, is of great significance in shaping the surface landscape. To be specific, in the process of aeolian sediment transport, the fine particles provide nutrients and water for vegetation colonization and growth, and when plants grow to a certain extent, they affect the pattern of sand erosion and accumulation by covering surface, capturing sand materials and dispersing wind energy. The change of the pattern and the difference of vegetation growth make the landscape appear spatial heterogeneity. In order to explore the interaction between aeolian processes and vegetation and the resulting landscape heterogeneity, the Artemisia ordosica shrub land in the southern fringe of Hobq Desert, which was located in the arid and semi-arid transition zone, was selected as the study area, and then vegetation investigation, the field observation of air flow, sand transport rate and sampling of sediment grain size were carried out. Based on the work, we analyzed the changes of vegetation coverage, air flow structure and sediment grain size characteristics along the wind direction, and discussed the interaction between sand drift and vegetation and its impact on landscape pattern. The results show that the change of the interaction mode between aeolian processes and vegetation alters the pattern of plants growth and surface erosion and deposition, resulting in obviously spatial heterogeneity in the downwind landscape. From bare land to uniformly distributed newborn Artemisia ordosica and shrubs, and then to patch distributed nebkhas, the vegetation coverage and sand cover thickness firstly increase and then decrease, the aerodynamic roughness rises continuously along the process, and the growth is the largest during the transition, while the sand transport rate and sediment particle size show a trend of first descent and then ascent, and the minimum value appears at the maximum of vegetation coverage and sand cover thickness. On the denudate plateau of the desert fringe, an appropriate amount of sand accumulation promotes the colonization and growth of the Artemisia ordosica at first, and the uniformly distributed shrubs further boosts sand deposition. However, when the accumulation thickness exceeds the sand resistant burial depth of Artemisia ordosica, it degenerates. Then, the shrub appears patchy distribution and the sand flow erodes between the interdune. Therefore, it can be understood that the landscape heterogeneity in the sandy area of the denuded plateau is the result of the synergy and inhibition of aeolian processes and vegetation. 参考文献 相似文献 引证文献