Effect of ecological restoration and climate change on ecosystems: a case study in the Three-Rivers Headwater Region, China

Jiang C. and Zhang L., 2016. Environmental Monitoring and Assessment

Original research (primary data)
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The Three-Rivers Headwater Region (TRHR) is the headwater of the Yangtze River Basin (YARB), Yellow River Basin (YRB), and Lancang River Basin (LRB); it is known as China’s ‘Water Tower’ owing to its important supply of freshwater. In order to assess ecosystem changes in the TRHR during 2000–2012, we systematically and comprehensively evaluated a combination of model simulation results and actual observational data. The results showed the following: (1) Ecosystem pattern was relatively stable during 2000–2010, with a slight decrease in farmland and desert areas, and a slight increase in grassland and wetland/water-body areas. (2) A warmer and wetter climate, and ecological engineering, caused the vegetation cover and productivity to significantly improve. (3) Precipitation was the main controlling factor for streamflow. A significant increase in precipitation during 2000–2012 resulted in an obvious increase in annual and seasonal streamflow. Glacier melting also contributed to the streamflow increase. (4) The total amount of soil conservation increased slightly from 2000 to 2012. The increase in precipitation caused rainfall erosivity to increase, which enhanced the intensity of soil erosion. The decrease in wind speed decreased wind erosion and the frequency of sandstorms. (5) The overall habitat quality in the TRHR was stable between 2000 and 2010, and the spatial pattern exhibited obvious heterogeneity. In some counties that included nature reserves, habitat quality was slightly higher in 2010 than in 2000, which reflected the effectiveness of the ecological restoration. Overall, the aforementioned ecosystem changes are the combined results of ecological restoration and climate change, and they are likely a local and temporary improvement, rather than a comprehensive and fundamental change. Therefore, more investments and efforts are needed to preserve natural ecosystems.

Case studies

Basic information

  • Case ID: INT-229-1
  • Intervention type: Mixed created/non-created habitats
  • Intervention description:

    in 2005, the state council promulgated and implemented the ‘Overall Planning of Eco-environment Protection and Construction in the TRHR’ project, commonly referred to as the ‘TRHR Project’….included 18 nature reserves, with a total area of 15.2 × 104 km2...The total project investment amounted to 1.2 billion USD, including expenses for returning pasture and farmland to forest, afforestation, and comprehensive treatment of soil degradation in black soil beach areas...The project named ‘Returning Pas- ture and Farmland to Forest’ accounted for the largest proportion of the expenditures from supplementary material, also show nature reserves protecting coniferous forests, grasslands, wetlands, and mountains

  • Landscape/sea scape ecosystem management: Yes
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Biomass cover loss  Positive Fractional Vegetation Cover (FVC) - obtained from remote sensing images, is a comprehensive quantitative indicator that describes the vegetation canopy density.
    Freshwater flooding  Unclear results water conservation: seasonal streamflow (spring and summer) reflected the ecosystem’s capacity to regulate streamflow in flood seasons.
    Reduced water availability  Unclear results Water conservation: annual streamflow reflected the water re- source level and water supply capacity of the ecosystem
    Soil erosion  Mixed results The amount of soil conservation was estimated by determining wind erosion and water erosion. We used the RUSLE and the RWEQ for estimations calculated soil conservation by using soil retention and sand fixation estimates, both in units of (t ha−1 year−1)
  • Approach implemented in the field: Yes
  • Specific location:

    The Three-Rivers Headwater Region (TRHR) is a nature reserve located in the hinterland of the Qinghai- Tibet Plateau … The TRHR includes 22 counties and cities, and it has a total area of 39.5 × 104 km2.

  • Country: China
  • Habitat/Biome type: Created forest | Created grassland | Temperate forests | Temperate grasslands | Montane/Alpine | Wetlands |
  • Issue specific term: Not applicable


  • Notes on intervention effectivness: compared the changes in outcome measures before, during and after implementation of the project mixed for soil erosion because while they report over the entire study area there was no significant decrease in soil conservation, in some of the project sites there was an increase, in others there was a decrease, also state that although at the end of the study there was a slight (non-significant increase) there was considerable variability in soil conservation throughout time. they are interested in not just the overall study area outcome but regional differences as well, as made clear from their hypothesis "" water conservation: (which reflects both floods and water availability) is coded as unclear because they only make statements about how climate has affected the outcome variables but not how the interventions affected it "The ecosystem changes in the TRHR are the combined results of the ecological restoration and climate change, and are likely local and temporary improvements, rather than compre- hensive and fundamental changes. "
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: Yes
  • Impacts on GHG: Positive
  • Assess outcomes of the intervention on natural ecosystems: Yes
  • Impacts for the ecosystem: Positive
  • Ecosystem measures: "The distribution of habitat quality is derived from the combination of the InVEST biodiversity model, landscape type sensitivity, and external threat intensity. The InVEST model assumes that good habitat quality is associated with high biodiversity. Habitat quality is the potential for the ecosystem to provide the necessary conditions for the survival and reproduction of the spe- cies." "Some counties that included nature reserves (e.g. Zhiduo, Guinan, and Maduo) had slightly higher quality habitat indexes in 2010 than in 2000, which reflected the effectiveness of ecological restoration " "The increase of the IJI and decline of the CONTAG suggested that the ecosystem patches in the TRHR became more equally adjacent to each other and less spatially aggregated." Interspersion and Juxtaposition Index (IJI), Contagion Index (CONTAG)
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: No
  • Experimental evalution done: Not applicable
  • Non-experimental evalution done: Empirical case study
  • Study is systematic: