干旱区山水林田湖草沙冰一体化保护与系统治理 ——基于土地退化平衡视角

Integrated protection and restoration for full-array ecosystems in dryland:A perspective of land degradation neutrality

目标明晰、统筹兼顾、干预适度是山水林田湖草沙冰一体化保护与系统治理的客观要求。基于土地退化平衡(LDN)视角,构建涵盖双重对象、双重法则、双重原则、指标体系、价值取向的理论框架,并以天山北坡城市群为例,揭示土地退化与改善的类型及程度,评判LDN实现与否。结论如下:(1)像元尺度改善区面积略多于退化区,并以轻微改善或轻度退化为主;重度退化同未利用地、城镇用地、矿业用地转入及水域、冰川、林地转出密切相关,而耕地、草地发生退化或改善与自身质量变化关系更为紧密。(2)区域尺度由于维持生态系统服务功能的地域空间未达标,整体上未实现LDN;大多数行政单元或格网都遭遇双重对象的同时否定。(3)从规范价值取向、偏向功能主义、促进人地协调视角出发,践行LDN要全局底线性思维和局部适度性治理相协调、要素差别化治理和系统一体化保护相统一,继而协同多元目标以实现人与自然和谐共生。研究可为干旱区山水林田湖草沙冰一体化保护与系统治理提供科学依据和决策参考。

How to seek solutions with clear objectives,appropriate interventions,and integrated approaches is especially critical to integrated protection and systematic governance(IPSG)of full-array ecosystems(FAE).Thus,the concept of land degradation neutrality(LDN)was introduced into the practice of IPSG in FAE,whereby a theoretical framework encompassing dual objects,dual laws,dual principles,indicator systems,and value orientations was constructed.Then,in the case of urban agglomeration of north slope of the Tianshan Mountains,the type identification and degree measurement of degraded and improved land was completed at the pixel scale,while the gap to LDN was quantified at both administrative units and grid scales.The results showed that:(1)At the pixel scale,the area of improved land was marginally higher than that of degraded land in 2005-2020,which was mainly mildly improved or degraded.Severe degradation was often associated with the transfer-in of unutilized land,urban land,and mining land,along with the transfer-out of water bodies,glaciers,and forests.However,cultivated land and grassland could affect degradation or improvement no matter whether the transfer occurred or not.(2)At the regional scale,the target of LDN was not achieved in the study area,owing to the denial of land resources maintaining ecosystem services and functions.Similarly,the vast majority of administrative units or grids encountered the simultaneous negation of the dual objects,while achieving LDN is only rare.(3)Drawing upon normative value orientations,functionalist tendencies,and human-land coordination,we propose that emphasis should be placed on coordinating the bottom-line thinking with moderate governance,unifying the differential treatment of elements with system-wide integrated protection,and subsequently synergizing multiple objectives to achieve harmonious coexistence between humans and nature.In conclusion,the LDN target encompasses characteristics of openness,inclusivity,and prudence,so this study could provide scientific foundations and decision-making references for the IPSG of FAE in dryland.