Dynamic prediction of forest litter load based on litter decomposition rate

Objective Forest fallen leaves play a crucial role in the occurrence and development of Forest Fires as ignition and flammable materials. This article takes the Betula platyphylla forest in Daxing'an Mountains as an example to construct a mathematical model from the perspective of forest leaf litter generation and decomposition, predict the future dynamics of forest leaf litter load, and provide a theoretical basis for forest fire prevention scientific research.

Method The forest floor litter is regarded as the accumulation of residual amounts from the decomposition of litter over the years. Using the Olson single-exponential decomposition equation, a set of litter decomposition equations is constructed. Mathematical methods such as series summation, substitution, and stepwise search are applied to simplify the equations, and the litter decomposition rate coefficient and decomposition turnover period are solved. Subsequently, the litter decomposition rate coefficient and decomposition turnover period are used to derive a litter load prediction model. Model variable data are obtained through the establishment of Survey Sample Site to verify the operability and accuracy of the prediction model.

Result A forest litter load prediction model based on litter decomposition rate was established, which predicted the litter load in the survey plots for the next two years. The relative error between the predicted and measured litter loads ranged from 0.05 to 0.26, with an average error of 0.14. Overall, the model's predicted values were relatively consistent with the measured values.

Conclusion Through model prediction, it is revealed that the litter load in the Daxing'anling forest region exhibits a periodic fluctuation pattern over time. Forest stands with a fast decomposition rate have a shorter variation cycle, maintaining a relatively stable litter load; while forest stands with a slow decomposition rate have a longer variation cycle, with the litter load undergoing continuous changes over a longer period of time.