Spatial and temporal effects of drought on Chinese vegetation under different coverage levels

Area of Science:

• Ecology
• Environmental Science
• Climate Change Research

Background:

• Land surface vegetation dynamics are significantly influenced by drought events.
• Understanding vegetation's response to drought is crucial for enhancing biome stability.
• Drought impacts vary across different ecosystems and geographical regions.

Purpose of the Study:

• To investigate the relationship between vegetation activity and drought using Normalized Difference Vegetation Index (NDVI) and Palmer Drought Severity Index (PDSI).
• To analyze vegetation responses to drought across diverse ecological types and drought severities from 1982 to 2015.
• To identify regions and ecosystem types most vulnerable to drought under current and future climate scenarios.

Main Methods:

• Utilized Normalized Difference Vegetation Index (NDVI) data to assess vegetation activity.
• Employed Palmer Drought Severity Index (PDSI) to quantify drought severity.
• Correlated monthly NDVI and PDSI data across various timescales (1-36 months) to determine drought impact.
• Analyzed vegetation responses across different drought regions and ecological community types.

Main Results:

• The highest correlation between NDVI and PDSI indicated the degree of drought impact on vegetation.
• Northern grassland, cropland, and desert ecosystems exhibited strong drought impacts.
• Homogenous vegetation types, particularly grasslands on the Inner Mongolia Plateau, were most susceptible to long-term drought.
• Grasslands experienced the strongest drought impact during summer, a high-frequency drought season.

Conclusions:

• Vegetation responses to drought are diverse, depending on drought characteristics and climatic conditions.
• Future warming trends may increase the frequency and severity of high-temperature droughts, threatening plateau grasslands, arid plains, and rain-fed croplands.
• Moist forests showed resilience to normal drought conditions.
• Future research should prioritize vegetation activity in northern and southwestern China due to high drought sensitivity.