[Turbulence micro-meteorological characteristics over the plantation canopy.]

Area of Science:

• Environmental Science
• Meteorology
• Forest Ecology

Background:

• Understanding micro-meteorological characteristics of forest ecosystems is crucial for studying energy balance and material exchange.
• Forest canopy structure influences atmospheric interactions and turbulence dynamics.

Purpose of the Study:

• To analyze turbulence characteristics, intensity, normalized standard variance, and bulk transfer coefficient over a forest plantation canopy.
• To deepen the understanding of micro-meteorological features and their impact on energy and material exchange.

Main Methods:

• Utilized an eddy-covariance system for monitoring during leaf germination and leaf forming periods in 2015.
• Analyzed turbulence spectrum, intensity, normalized standard variance of wind speed, and bulk transfer coefficient.

Main Results:

• Turbulence spectrum showed a peak in the low-frequency zone, with dissipation following the -5/3 law.
• Turbulence intensity was significantly influenced by canopy structure, with specific wind speed thresholds in spring and summer.
• Normalized standard variance in the horizontal direction surpassed the vertical, adhering to the 1/3 power similarity law.
• Bulk transfer coefficient decreased with increasing stability, showing significant differences between unstable and stable conditions.

Conclusions:

• Forest canopy structure directly influences wind speed turbulence in all directions.
• This influence alters the diffusion patterns of materials and energy within the canopy.
• Findings provide a scientific basis for further research on forest ecosystem energy balance and material exchange.