Variation characteristics of soil particle composition and multifractal analysis of natural recovery forestland after damage under the disturbance of flood induced disasters

  Objective  Fractal dimension of soil particle composition can reflect soil particle distribution in detail. To accurately reveal the changing rules of forest soil particle during recovery process under the disturbance of disasters induced by flood, it is crucial to study the fractal dimensions in different damage stages of the forests.

  Method  Using the research method of substituting space with time, we chose three kinds of forest including secondary broadleaved forest, Chinese fir forest, and Moso bamboo forest in different damage states (undamaged, just damaged, recovered for 7 years after damage) as research sites. We collected soil samples of different soil layers and analyzed particle size, then the multifractal parameters were calculated based on fractal theory.

  Result  (1) Disaster interference had a significant impact on the distribution of soil particle in forestland. (2) After disaster interference, different recovery stages and different depth of soil affected all three kinds of woodlands, and the response of different woodlands to interference was different. (3) Through comprehensive analysis of particle size composition and multifractal parameters of three kinds of forestland under different restoration states, it can be seen that the soil texture of damaged forestland was worse than undamaged forestland. The variation trend of soil particle composition in different depth was different under varied damage conditions.

  Conclusion  In this study, the effects of flood induced disasters on secondary broadleaved forests, Chinese fir forests and Moso bamboo forest were clarified from the perspective of soil particle composition changes.