Abstract:
simulation system for the succession of plant communities based on natural revegetation was developed to determine the duration and plant pattern of natural revegetation in mining subsidence area.The succession of plant communities in a subsidence area located in Meiyukou Mine,Datong City was simulated,and the spatial and temporal characteristics of plant succession,and key factors resulting in spatial heterogeneity of plant communities were analyzed.The results showed that the errors between simulated and actual plant patterns ranged from 0.04 to 0.59 according to normalized mean squared error (NMSE) in different landscape levels (10 m×10 m.20 m×20 m,50 m×50 m,80 m×80 m,100 m×100 m).Specifically the errors were between 0.06 and 0.59 in terms of shrub coverage,between 0.05-0.14 in terms of shrub coverage,and between 0.04 and 0.12 in terms of vegetation coverage.The results of 50 simulations with bare land as the initial vegetation condition showed it would take 10.46 years on average when the herb coverage reached between 35% and 55% and the shrub coverage reached 7% and 8% in the study area through natural revegetation.In terms of the dynamic of natural revegetation,the herb communities revegetated rapidly in the early stage of succession,while decreased and transformed into shrub communities with the developing shrub coverage.The shrub communities appeared firstly after 3-5 years of spontaneous succession,and the revegetating rate of shrub communities increased with the accumulation of soil nutrients.Only 2 out of 50 simulations of trees appeared after 10 years of natural revegetation.In terms of the distribution of vegetation pattern,the low-elevation gully area was rich in nutrients and water due to surface runoff,where shrub communities appeared firstly and spread.The shady area with a small slope was also easy to develop into a shrub community.In general,the developed simulation system in this study is able to accurately reflect the spatiotemporal dynamic of plant succession during natural revegetation,and simulate the pattern of plant communities after natural revegetation,which can serve as a tool for the selection of natural revegetation in coal mining subsidence areas.