Ecological dynamic model of grassland and its practical verification

Area of Science:

• Ecological Dynamics
• Biophysical Modeling
• Meteorology
• Grassland Ecology

Background:

• Grassland ecosystems face threats from climate variability and land use.
• Understanding the complex interactions between vegetation, soil, and climate is essential for effective grassland management.
• Existing models may not fully capture the nuanced biophysical processes governing grassland dynamics.

Purpose of the Study:

• To develop a novel ecological dynamic model for grasslands.
• To simulate the interactions between living grass biomass, wilted grass biomass, and soil wetness.
• To investigate the impact of precipitation and grazing on grassland stability and desertification.

Main Methods:

• Developed a mathematical ecological dynamic model based on physico-biophysical principles.
• Incorporated three interactive variables: living grass biomass, wilted grass biomass, and soil wetness.
• Utilized inverse parameterization with climatological and ecological data, including sensitivity studies for parameter estimation.

Main Results:

• Identified a minimum annual precipitation threshold (approx. 300 mm) for grassland maintenance.
• Established a significant positive correlation between annual precipitation and living grass biomass.
• Demonstrated that overgrazing is a direct driver of desertification.

Conclusions:

• The developed model accurately reflects real-world grassland dynamics.
• Accumulated wilted grass provides a crucial shading effect, reducing soil temperature and evaporation, thus aiding grassland persistence.
• The model provides valuable insights for sustainable grassland management and combating desertification.