植物生态学报 ›› 2024, Vol. 48 ›› Issue (预发表): 0-0.DOI: 10.17521/cjpe.2023.0300  cstr: 32100.14.cjpe.2023.0300

所属专题: 全球变化与生态系统 生态系统碳水能量通量 碳储量

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基于LUCC1986–2022年松花江流域陆地生态系统碳储量动态监测

张智洋,赵颖慧,甄贞   

  1. 东北林业大学
  • 收稿日期:2023-10-20 修回日期:2024-04-04 出版日期:2024-08-20 发布日期:2024-05-24
  • 通讯作者: 甄贞

Dynamic monitoring of carbon storage of the terrestrial ecosystem in Songhua River Basin from 1986 to 2022 based on land use and land cover change

Zhiyang Zhang,Yinghui Zhao,Zhen Zhen   

  1. Northeast Forestry University
  • Received:2023-10-20 Revised:2024-04-04 Online:2024-08-20 Published:2024-05-24
  • Contact: Zhen Zhen

摘要: 松花江流域是东北地区经济可持续发展的重要载体,涵盖了许多重要的生态保护区和水源涵养区,流域内土地利用类型复杂,使整个流域生态系统呈现多元化。流域尺度的土地利用/土地覆盖变化动态监测和陆地生态系统碳储量估测,可以为优化土地利用、提高陆地生态系统碳储量、为实现“双碳”目标提供建议。本研究基于1986-2022年Landsat 5 TM和Landsat 8 OLI影像,应用随机森林获取松花江流域1986-2022年10期高精度的土地利用分布图,并结合Integrated Valuation of Ecosystem Services and Trade-offs模型、Mann-Kendall检验和Theil-Sen Median趋势分析,对松花江流域36年间土地利用类型和生态系统碳储量变化进行动态监测。结果发现,流域内各土地利用类型面积由大到小依次为耕地>有林地>草地>未利用地>水域>建设用地>疏林地>灌木林地,耕地、有林地和草地为研究区主要土地利用类型。1986-2022年间耕地面积增加11462.68 km2,有林地面积减少18567.21 km2。建设用地为研究区变化最快地类,变化率为5.3%,面积增加3505.82 km2。疏林地变化率为4.7%,仅次于建设用地,但由于其面积变化较小,对流域影响不大。未利用地变化速率为4.5%,其面积增加了5385.43 km2。流域内陆地生态系统碳储量空间分布存在明显的空间异质性,碳储量高值区分布在大、小兴安岭和长白山脉;中值区分布在兴安盟、松嫩平原和三江平原;低值区分布在大庆和白城。36年间该流域内陆地生态系统碳储量整体呈现减少趋势,减少区域主要分布在碳储量高值区,碳储量增加区域则是零星分布。1994年、2002年和2018年松花江流域生态系统碳储量出现三次恢复,且均与有林地面积变化有关。在保障已有林地面积不再减少的基础上,增加有林地面积,持续开展林业工程,可以有效阻止碳储量下降,恢复研究区生态系统碳储量。

关键词: 土地利用与土地覆盖变化, InVEST模型, 碳储量, 松花江流域

Abstract: Songhua River basin, encompassing numerous vital ecological protection areas and water conservation zones, is crucial in facilitating sustainable economic development in Northeast China. The basin exhibits a complex array of land use types, resulting in a diverse ecosystem. The dynamic monitoring of watershed-scale land use/land cover changes (LULCC) and carbon stocks estimation of the terrestrial ecosystem can provide suggestions for optimizing land utilization, enhancing terrestrial ecosystem carbon storage, and achieving the objective of "dual carbon". Based on the Landsat 5 TM and Landsat 8 OLI images from 1986 to 2022, this study employed random forest to obtain ten land use/land cover maps of the Songhua River Basin with high accuracy and conducted dy-namic monitoring of LULCC and its ecosystem carbon storage using an Integrated Valuation of Ecosystem Ser-vices and Trade-offs model, Mann-Kendall tests and Theil-Sen Median trend analysis. Results showed that farm-land has the largest area in the basin, followed by forest land, grasslands, unused lands, water, construction land, sparse forest land, and shrub land. Among them, farmland, forest, and grassland are the dominant land use types in the study area. During 1986-2022 period, the farmland expanded 11462.68 km2 while forest land decreased 18567.21 km2; the construction land experienced the largest change rate of 5.3% with an increased area of 3505.82 km2; the change rate of the sparse forest is 4.7%, ranking the second after construction land, but having minimal impact on the overall basin due to limited area changes. The change rate of unused land was 4.5%, with an increased area of 5385.43 km2. There was evident spatial heterogeneity in the distribution of the terrestrial ecosystem carbon stocks within the Songhua basin, with high carbon stocks predominantly found in the Dax-ingan and Xiaoxingan as well as the Changbai Mountains. The median carbon stock values were observed in Hinggan League, Songnen Plain, and Sanjiang Plain. In contrast, the areas with low carbon values were observed in Daqing and Baicheng. Over the 36 years, there was an overall decline in carbon storage within the basin, pri-marily concentrated in the regions initially characterized by high carbon stock values. However, the area with increased carbon stock is scatterly located in the basin. Notably, three recovery instances of ecosystem carbon stock occurred in 1994, 2002, and 2018 within the Songhua River Basin, all related to the changes in forest land. Based on ensuring no reduction of current forest land, it is recommended to expand forestland and continue im-plementing forestry projects to effectively prevent further depletion of terrestrial ecosystem carbon storage in the Songhua River basin.

Key words: land use/land cover change, InVEST model, carbon storage, Songhua River Basin