西北干旱区绿洲–荒漠过渡带生态演变机理与可持续管理研究

Research on the Ecological Evolution Mechanisms and Sustainable Management of Oasis-Desert Ecotones in Arid Northwest China

摘要: 绿洲–荒漠过渡带是西北干旱区生态安全格局中的关键屏障，其位于灌溉绿洲或河岸林外缘与连续荒漠背景之间，沿地下水埋深、土壤水分、植被覆盖度和风沙活动呈显著梯度变化的生态交错带，可通过高分辨率遥感解译、NDVI/植被覆盖度梯度、地下水埋深监测与样带调查共同识别。本文围绕西北干旱区绿洲-荒漠过渡带生态演变机理与可持续管理展开综述，重点分析水文过程、植被演变、人类活动和生态系统服务价值变化之间的相互关系。研究表明，地下水位是调控过渡带天然植被健康状态的重要因子；灌溉方式改变可能通过减少深层渗漏和侧向补给、降低地下水可及性、改变土壤水盐格局等路径影响天然植被，但现有证据多来自遥感趋势、地下水观测和案例研究，因果强度仍需长期定位观测、稳定同位素和通量观测进一步验证。胡杨、柽柳和梭梭等典型荒漠植物通过差异化水分利用策略和空间分布格局适应干旱环境，但仍受到水分竞争、养分限制及二者耦合作用的制约。同时，农业扩张和土地利用转型导致生态系统服务价值下降，尤其影响水文调节、碳储量和防风固沙功能。未来应从流域尺度优化水资源配置，维持合理地下水位，实施差异化生态治理，加强人工林抚育，并推动政府、农户和社会多主体协同管理，以提升绿洲–荒漠过渡带生态稳定性和可持续发展能力。

Abstract: The oasis-desert ecotone is a critical ecological barrier in the arid regions of Northwest China, and it is operationally defined as the transitional belt between the outer margin of irrigated oases or riparian forests and the continuous desert matrix, where groundwater depth, soil moisture, vegetation cover and aeolian activity change along clear gradients. This belt can be identified by combining high-resolution remote-sensing interpretation, NDVI or fractional vegetation-cover gradients, groundwater-depth monitoring and field transects. This review focuses on the ecological evolution mechanisms and sustainable management of oasis-desert ecotones in arid Northwest China, with emphasis on the interactions among hydrological processes, vegetation dynamics, human activities and changes in ecosystem service values. The review indicates that groundwater depth is an important factor regulating the health of natural vegetation in the ecotone. Changes in irrigation practices may affect natural vegetation by reducing deep percolation and lateral recharge, lowering groundwater accessibility and reshaping soil water-salt conditions; however, most available evidence is based on remote-sensing trends, groundwater observations and case studies, so the strength of causality should be evaluated cautiously and further tested with long-term monitoring, stable isotopes and flux observations. Typical desert plants, such as Populus euphratica, Tamarix and Haloxylon ammodendron, adapt to drought through differentiated water-use strategies and spatial distribution patterns, but remain constrained by water competition, nutrient limitation and water-nutrient coupling. Meanwhile, agricultural expansion and land-use transformation have reduced ecosystem service values, especially hydrological regulation, carbon storage and windbreak functions. Future management should optimize water allocation at the watershed scale, maintain appropriate groundwater levels, implement differentiated ecological restoration, improve artificial forest tending and promote coordinated governance among governments, farmers and society to enhance ecological stability and sustainable development in oasis-desert ecotones.