Report on the Impact of Land Use Change on Ecosystem Service Value in Karst Desertification Control Zones

Abstract

This study investigates the effects of ecological restoration and land-use change on ecosystem service functions in karst regions, focusing on three representative areas with varying levels of rocky desertification (RD). Key findings include:

1. Over 23 years, forest land and construction land increased continuously across all areas, while cultivated land and grassland decreased.
2. Total ecosystem service values (ESVs) varied significantly among areas, with hotspots linked to water body expansion and forest growth, and cold spots associated with construction land expansion, unused land development, and cultivated land enlargement.
3. Ecological restoration projects effectively controlled RD development, with land-use type exerting a stronger influence on ESV than RD severity.

This research supports systematic RD management and sustainable land-use strategies in karst regions, aligning with the United Nations Sustainable Development Goals (SDGs), particularly SDG 15 (Life on Land) and SDG 13 (Climate Action).

Introduction

Ecosystem services (ESs) are vital benefits provided by ecosystems to humans and other organisms, categorized into provisioning, regulating, cultural, and supporting services. The valuation of ecosystem service value (ESV) is crucial for sustainable development and policy-making, supporting SDG 15 (Life on Land) and SDG 11 (Sustainable Cities and Communities).

Land use and land cover (LULC) changes directly impact ecosystem structure and function, influencing ES supply and ESV. Understanding these impacts is essential for sustainable land management and ecological restoration, contributing to SDG 15 and SDG 12 (Responsible Consumption and Production).

Karst regions, covering 10-15% of continental land and supporting 25% of the global population, face significant ecological challenges due to rocky desertification (RD). China’s large-scale ecological restoration projects, such as the Grain for Green Project, have improved vegetation cover and carbon sequestration in these areas, advancing SDG 13 (Climate Action) and SDG 15.

Methods

Study Areas

• Salaxi: Potential–low RD level, located in Bijie city, Guizhou Province, with an area of 86.27 km² and annual precipitation of ~980 mm.
• Qingzhen: Low–moderate RD level, located near Qingzhen city, Guizhou Province, covering 60.21 km² with annual precipitation of ~1200 mm.
• Huajiang: Moderate–high RD level, located in the Beipan River canyon, Guizhou Province, covering 51.62 km² with annual precipitation of ~1100 mm.

Ecological restoration projects have been implemented since 2000-2011, significantly reducing RD in these areas.

Data Collection and Analysis

• Remote sensing images (30 m accuracy) from 2000 to 2023 were used for LULC and RD analysis.
• Land use was classified into six categories: arable land, forestland, grassland, water area, construction land, and unused land.
• ESV was calculated using an equivalent factor method adjusted for local biomass and economic data, supporting SDG 15 and SDG 13.
• Hotspot analysis identified spatial clusters of ESV changes.
• RD was classified into six levels to examine its effect on ESV.

Results

Land Use Change Analysis

Overall Trends

• Forestland and construction land increased in all study areas, while cultivated land and grassland decreased.
• Salaxi showed stable forestland with fluctuations; Qingzhen experienced rapid urbanization with increased construction land; Huajiang saw forestland growth and cultivated land reduction due to ecological projects.

Land Use Transfers

• Salaxi and Huajiang exhibited ecological restoration-driven land use changes, mainly converting cropland and grassland to forestland.
• Qingzhen showed urbanization-driven changes, with significant conversion of arable land to construction land.

Spatiotemporal Variability in Ecosystem Service Value (ESV)

Total ESV Changes

• Salaxi’s total ESV remained stable over time.
• Qingzhen’s total ESV decreased continuously, impacted by urban expansion.
• Huajiang’s total ESV increased, driven by forestland expansion.

ESV Component Changes

• Regulating services such as climate regulation, hydrological regulation, and soil retention dominated ESV contributions, reflecting SDG 13 and SDG 15 priorities.
• Provisioning services like food production showed mixed trends, with water supply services notably deficient, highlighting water scarcity challenges (SDG 6: Clean Water and Sanitation).

Spatial Distribution

• High ESV areas were concentrated in water bodies and forested mountainous regions.
• Low ESV areas corresponded to flat regions dominated by farmland and construction land.

Hotspot and Cold Spot Analysis of ESV Changes

• Hotspots were associated with forestland growth and water body expansion.
• Cold spots correlated with construction land expansion and vegetation degradation.

Rocky Desertification (RD) Evolution and Its Effect on ESV

• RD severity decreased across all study areas due to ecological restoration projects, supporting SDG 15.
• ESV per unit area did not consistently decrease with increasing RD severity; areas with higher RD showed greater ESV improvements due to restoration efforts.
• Human land use intensity influenced ESV more significantly than RD severity, emphasizing the need for sustainable land management.

Discussion

The implementation of comprehensive rocky desertification control (RDC) and soil-water conservation ecological restoration projects (ERPs) since 2000-2011 has improved vegetation cover, reduced RD, and enhanced ecosystem services in karst regions. These efforts contribute directly to achieving several Sustainable Development Goals:

• SDG 15 (Life on Land): By restoring degraded lands and controlling desertification, biodiversity and ecosystem functions are preserved and enhanced.
• SDG 13 (Climate Action): Increased forestland and vegetation cover improve carbon sequestration, mitigating climate change impacts.
• SDG 6 (Clean Water and Sanitation): Water body expansion and hydrological regulation services support improved water resources, although water supply remains a challenge.
• SDG 11 (Sustainable Cities and Communities): Managing urban expansion and construction land growth is critical to balancing development and ecosystem protection.

Land use changes, particularly the expansion of forestland and water bodies, positively influence ESV, while construction land expansion leads to ESV decline. The study highlights the importance of integrating land use planning with ecological restoration to maximize ecosystem service benefits.

Despite improvements, challenges remain due to ongoing human-environment conflicts and potential RD expansion. Continuous monitoring, adaptive management, and policy integration of ESV assessments are essential for sustainable development in karst regions.

Conclusions

1. Forestland areas increased while cultivated land decreased across all study areas from 2000 to 2023, with construction land expanding notably in urbanizing regions.
2. Total ESV remained stable in potential–low RD areas, decreased in low–moderate RD areas due to urbanization, and increased in moderate–high RD areas due to ecological restoration.
3. Karst soil and water conservation projects effectively reduced RD severity, increasing no RD and potential RD areas, supporting ecological sustainability.
4. ESV per unit area did not decline with RD severity; higher RD areas showed greater ESV improvements, indicating restoration efforts’ effectiveness.

These findings emphasize the need to incorporate ecosystem service valuation into land use policies and restoration strategies to achieve sustainable development goals, particularly SDG 15 and SDG 13, in fragile karst desertification control zones globally.

1. Relevant Sustainable Development Goals (SDGs) Addressed in the Article

1. SDG 15: Life on Land
   • The article focuses on ecological restoration, land-use change, and combating rocky desertification in karst regions, which directly relates to the sustainable management of terrestrial ecosystems.
   • It discusses forestland expansion, soil and water conservation, and biodiversity maintenance, all core aspects of SDG 15.
2. SDG 13: Climate Action
   • The study highlights the role of ecological restoration projects in carbon sequestration and climate regulation services, contributing to climate change mitigation.
3. SDG 6: Clean Water and Sanitation
   • Water body expansion and hydrological regulation are discussed as key ecosystem services, linking to sustainable water management.
   • Water supply challenges and improvements through restoration projects are addressed.
4. SDG 11: Sustainable Cities and Communities
   • Urbanization impacts and construction land expansion are analyzed, highlighting the balance between development and ecosystem services.
5. SDG 1: No Poverty
   • The article mentions that ecological restoration projects help impoverished and ecologically fragile areas escape poverty traps, linking ecosystem services to socioeconomic development.

2. Specific Targets Under the Identified SDGs

1. SDG 15: Life on Land
   • Target 15.3: By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought, and floods, and strive to achieve a land degradation-neutral world.
   • Target 15.1: Ensure the conservation, restoration, and sustainable use of terrestrial and inland freshwater ecosystems and their services.
   • Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity.
2. SDG 13: Climate Action
   • Target 13.2: Integrate climate change measures into national policies, strategies, and planning.
3. SDG 6: Clean Water and Sanitation
   • Target 6.6: Protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers, and lakes.
4. SDG 11: Sustainable Cities and Communities
   • Target 11.3: Enhance inclusive and sustainable urbanization and capacity for participatory, integrated, and sustainable human settlement planning and management.
5. SDG 1: No Poverty
   • Target 1.4: Ensure that all men and women, particularly the poor and vulnerable, have equal rights to economic resources, as well as access to basic services.

3. Indicators Mentioned or Implied to Measure Progress Towards the Targets

1. Land Use and Land Cover Change (LULC)
   • Changes in areas of forestland, cultivated land, grassland, water bodies, construction land, and unused land over time (2000–2023) are used to assess ecosystem restoration and degradation.
   • Land use dynamic degree and land use transfer matrix quantify the rate and direction of land use changes.
2. Ecosystem Service Value (ESV)
   • Total and per unit area ESV calculated using equivalent factor and economic valuation methods to quantify ecosystem services’ contributions.
   • ESV hotspots and cold spots identified through spatial hotspot analysis (Getis-Ord Gi* statistics) to detect spatial clustering of ecosystem service changes.
3. Rocky Desertification (RD) Levels
   • Classification of RD severity into nonkarst, non-RD, potential RD, low RD, moderate RD, and high RD levels to monitor desertification status.
   • Area changes in RD categories over time as indicators of desertification control effectiveness.
4. Normalized Difference Vegetation Index (NDVI)
   • Implied as an important factor influencing ESV, used to assess vegetation cover and ecosystem health.
5. Socioeconomic Indicators
   • Grain yield, market prices, and economic values related to agricultural production used to adjust ESV coefficients.
   • Indicators of poverty alleviation through ecological restoration projects mentioned qualitatively.

4. Table of SDGs, Targets, and Indicators

Source: nature.com