Assessment of ecosystem quality changes based on optimizing key indicators in Nanwenghe National Nature Reserve, Heilongjiang, China

Ying Yong Sheng Tai Xue Bao. 2023 Nov;34(11):3064-3072. doi: 10.13287/j.1001-9332.202311.022.

Abstract

Net primary productivity (NPP) is an indicator to reflect the production capacity of terrestrial ecosystems, as well as a key indicator for ecological quality. NPP at large scale is difficult to be measured. At present, most of the assessment of ecosystem quality uses NPP products with low resolution, which cannot capture the detailed characteristics of the ecosystem and is not conducive to the assessment of ecosystem quality at small-scale. The establishment of a rapid and efficient assessment method for small-scale ecosystem quality will greatly promote the protection and restoration of ecosystems in China. We focused on the calculation method of ecosystem quality assessment and NPP, and optimized the calculation process of the NPP, and obtained NPP by remote sensing without ground observation data. We established a regression model for remote sensing inversion of leaf area index, and estimated the vegetation coverage by using dimidiate pixel model, developed a set of methods for rapid assessment of ecosystem quality by remote sensing. Taking Nanwenghe National Nature Reserve as an example, we evaluated the change of ecosystem quality from 2001 to 2022. The results showed that from 2001 to 2022, the ecosystem qua-lity of the reserve was good as a whole, and that the area with good and excellent quality accounted for more than 85% in 2022. High vegetation coverage was the backbone of the sustainable good ecosystem quality of the reserve. From 2001 to 2022, ecosystem quality of the reserve showed a trend of first decreasing and then increasing, with the lowest point of ecosystem quality in 2013. This method had achieved good results in the evaluation of ecosystem quality in Nanwenghe National Nature Reserve. The index optimization method proposed in this study could facilitate the rapid and accurate assessment of ecosystem quality in small-scale regions, and thus provides technical reference for the precise improvement of ecosystem quality.

净初级生产力(NPP)是反映陆地生态系统生产能力的指标,也是衡量生态质量的关键指标。NPP难以进行大面积实测,目前大多数评估生态系统质量使用的是分辨率较低的NPP产品,低分辨率NPP不能够捕捉到生态系统的细节特征,不利于小尺度区域生态系统质量评估。建立快速、高效的小尺度区域生态系统质量评估方法将有力推进我国生态系统保护和修复。本研究针对生态系统质量评估和NPP的计算方法,优化了NPP的计算流程,使得NPP作为评估指标时不需要地面观测数据即可通过遥感反演得到,并建立回归模型遥感反演叶面积指数,采用像元二分法估算植被覆盖度,形成一套遥感快速评估生态系统质量的方法,并以南瓮河国家级自然保护区为例,评估其2001—2022年生态系统质量变化。结果表明: 2001—2022年间,保护区生态系统质量整体良好,2022年质量等级良、优面积占比达85%以上;高植被覆盖度是保护区生态系统质量持续良好的中坚力量;2001—2022年,保护区生态系统质量呈先降低后升高的趋势,2013年为生态系统质量最低点。本研究构建方法在评估南瓮河国家级自然保护区生态系统质量上取得了良好效果。本研究提出的指标优化方法可助力小尺度区域生态系统质量快速、精准评估,可为生态系统质量的精准提升提供技术参考。.

Keywords: change assessment; ecosystem quality; index optimization.; net primary productivity (NPP).

MeSH terms

  • China
  • Climate Change
  • Ecosystem*
  • Models, Theoretical*
  • Remote Sensing Technology