A new scientific framework of dryland ecological quality assessment based on 1OAO principle

Abstract

Human disturbance and climate change can easily lead to the shift of dryland ecological quality. However, how to comprehensively assess the shift of dryland ecological quality remains challenging. The ecological quality of specific dryland ecosystem in Northern China is less investigated following the launch of long-term large-scale national ecological restoration projects. This study established a dryland ecological quality assessment framework by the “One-out, all-out (1OAO)” principle. The ecological quality dynamics of Otindag sandy land in Northern China was evaluated by choosing 16 years (2000–2015) ecological quality as a baseline and comparing it to the report period (2005–2020). Three indicators, normalized difference vegetation index (NDVI), soil organic carbon (SOC) and dust sandstorm (DSS) was used to represent vegetation, soil and atmosphere quality, respectively. Our results showed that the vegetation quality kept stable in most areas, improved area of vegetation quality accounted for 30% of Otindag sandy land. The soil quality improved and degraded area accounted for 10% and 83%, respectively. The atmosphere quality increased in 98% area of Otindag sandy land. Overall, the ecological quality of Otindag sandy land improved in one fifth but degraded in four fifth following the launch of the national ecology restoration projects. Both degradation area is persistent since 2000 and no recent degradation found compared baseline to report period. The improvement was mainly in the southeastern part and the degradation was in western part of Otindag sandy land. This study provides practical basis for the scientific evaluation of dryland ecological quality dynamics and will facilitate the regional ecosystem management.