Value Realization of Grassland Ecosystem Products in the Karst Desertification Control Area: Spatial Variability, Drivers, and Decision-Making

Abstract

Transforming the ecological advantages of grassland ecosystems into economic benefits while ensuring their long-term health is an urgent but challenging question, particularly in karst areas characterized by significant spatial heterogeneity. This study selected three representative karst desertification control (KDC) areas within the South China Karst (SCK) as the research focus. Utilizing the quantified values of ecosystem products and their realization rates, we applied a random forest model to analyze the influencing factors. We found that: (1) The gross ecosystem products (GEP) of grassland per unit area increase with the severity of karst desertification. Conversely, the value realization rate decreases as the grade of karst desertification increases, contradicting the theoretical assumption that higher GEP correlates with a high value realization rate. (2) Water, soil, climate, and bare rock coupled with human activities (e.g., ecological engineering) affect the structure of the grassland GEP, which, in turn, affects the value realization rate of grassland ecosystem products in the KDC area. Based on our findings, we suggest that economic leapfrogging can be achieved through artificial grassland engineering in ecologically disadvantaged areas, challenging the conventional belief that a more fragile ecological environment results in poorer economic advantages. However, it is important to note that plant species diversity in artificial grassland in areas with severe karst desertification is low, and the trade-off and equity between ecology and economy must be carefully considered in future planning. Our findings can serve as a reference for subsequent phases of grassland ecosystem restoration for sustainability in ecologically fragile areas, particularly within the KDC regions.

Keywords: InVEST model; grassland; karst desertification control; random forest model; value realization of ecosystem products.

FIGURE 1

Research framework and technical approach. AA, Average altitude; AAP, Average annual precipitation; AAT, Average annual temperature; AG, Artificial grassland; AGR, Artificial grassland ratio; BIOD, Biodiversity; BRRG, Bare rocky ratio of grassland; CS, Carbon sequestration; DC, Distance to county; DTA, Distance to tourist attractions; GAR, Grassland area ratio; GC, Grazing capacity; GEP‐PUA, Gross ecosystem products per unit area; GPD, Grassland patch density; HFH, Hongfenghu; HJ, Huajiang; NG, Natural grassland; OP, Oxygen production; PCDIF, Per capita disposable income of farmers; PD, Population density; PMW, Proportion of migrant workers; PPLF, Proportion of pastoralists in the labor force; SLX, Salaxi; SR, Soil retention; VRR, Value realization rate; WR, Water retention.

FIGURE 2

Study area. (a) refers to the location of SCK in the world; (b–d) represent the location, DEM, and landform of Salaxi, Hongfenghu, and Huajiang study areas, respectively. Photo by Qi Wang.

FIGURE 3

Land use validation sites, grassland sampling points, and photo verification in the study area. (a–c) represent the Salaxi, Hongfenghu, and Huajiang study areas, respectively. Photo by Yongyao Li.

FIGURE 4

The physical quantity of grassland ecosystem products per unit area in the KDC area. Statistical significance level (p = 0.05) was evaluated using a one‐way analysis of variance with a one‐tailed test. AG, Artificial grassland; HFH, Hongfenghu; HJ, Huajiang; NG, Natural grassland; SLX, Salaxi..

FIGURE 5

The total value of each individual ecosystem product and its value per unit area. (a–f) represent the total value and unit area value of grazing capacity, water retention, soil retention, carbon sequestration and oxygen production, plant diversity, and landscape tourism across the three study areas, respectively. BIOD, Biodiversity; CSOP, Carbon sequestration and oxygen production; GC Grazing capacity; HFH, Hongfenghu; HJ, Huajiang; LT, Landscape and tourism; SLX, Salaxi; SR, Soil retention; WR, Water retention.

FIGURE 6

Distribution of grassland GEP and value realization rate in the KDC area. (a) represents the comparison of GEP, GEP per unit area, and value realization rates across the three study areas; (b) refers to the proportion of GEP structure in Salaxi; (c) describes the proportion of GEP structure in Hongfenghu; (d) illustrates the proportion of GEP structure in Huajiang. BIOD, Biodiversity; CSOP, Carbon sequestration and oxygen production; GC, Grazing capacity; GEP, Gross ecosystem products; HFH, Hongfenghu; HJ, Huajiang; LT, Landscape and tourism. SLX, Salaxi; SR, Soil retention; WR, Water retention.

FIGURE 7

Factors influencing the GEP per unit area and the value realization rate of grassland ecosystem products in the KDC area. (a–d) represent Salaxi, Hongfenghu, Huajiang, and three study areas combined, respectively. AA, Average altitude; AAP, Average annual precipitation; AAT, Average annual temperature; AGR, Artificial grassland ratio; BRRG, Bare rocky ratio of grassland; DC, Distance to county; DTA, Distance to tourist attractions; GAR, Grassland area ratio; GEP‐PUA, GEP per unit area; GEP‐PUA, Gross ecosystem products per unit area; GPD, Grassland patch density; HFH, Hongfenghu; HJ, Huajiang; PCDIF, Per capita disposable income of farmers; PD, Population density; PMW, Proportion of migrant workers; PPLF, Proportion of pastoralists in the labor force; SLX, Salaxi; VRR, Value realization rate; VRR, Value realization rate.

FIGURE 8

Relative importance of GEP‐PUA and VRR influences evaluated based on the random forest model. (a and b) represent the relative importance of GEP‐PUA and VRR influences, respectively. AA, Average altitude; AAP, Average annual precipitation; AAT, Average annual temperature; AGR, Artificial grassland ratio; BRRG, Bare rocky ratio of grassland; DC, Distance to county; DTA, Distance to tourist attractions; GAR, Grassland area ratio; GEP‐PUA, Gross ecosystem products per unit area; GPD, Grassland patch density; PCDIF, Per capita disposable income of farmers; PD, Population density; PMW, Proportion of migrant workers; PPLF, Proportion of pastoralists in the labor force; VRR, Value realization rate.