Spatial Ecological Characteristics And Functions Of Main Forest Types In Mountainous Regions Of Beijing

In recent years,a large range of afforestation had implemented every year in China,but the spatial structure and characteristics of forest types was not very clear,which affected the function of forest types.In this context,the research analyzed the adaptablility,dominance,development potential,growth status and ecological benefit of the main forest types in mountainous area of Beijing,by using data processing method such as multiple linear regression,GIS and Markov chain,based on data of investigation of forest resources,data from forest ecology research station and forest samples in Beijing mountain,aimed at improving the quality of forest,exerting multi-function of forest ecology system and providing scientific instruction for forest operation in Beijing mountainous regions.The results showed as:(1)The spatial distribution of forest types was different.Distribution by ages:Platycladus orientalis,Larix principis-rupprechtii Mayr,Quercus acutissima and Populus davidiana were mainly distributed in middle and young ages.Pinus tabulaeformis was mainly distributed in near mature,middle and young ages.Betula platyphylla Suk was mainly distributed in near mature and middle ages.Robinia pseudoacacia was mainly distributed in mature and young ages.Distribution by altitudes:Platycladus orientalis,Pinus tabulaeformis,Robinia pseudoacacia and Populus davidiana were found mostly at an altitude of below 1000m,Larix principis-rupprechtii Mayr was found mostly at an altitude of 501-1500m,Betula platyphylla Suk was found mostly at an altitude of 1001-2000m,Quercus acutissima was found mostly at an altitude of 501-1000m.Distribution by site levels:Platycladus orientalis and Robinia pseudoacacia were widely located in level ?and ?.Pinus tabulaeformis and Quercus acutissima were widely located in level ?.Larix principis-rupprechtii Mayr,Betula platyphylla Suk and Populus davidiana were widely located in level ? and ?.(2)There was a significant linear relationship between the average growth rate of different ages and site factors,the basic model is Y=aX1+bX2+cX3+dX4+eX5+fX6.Growth factors of forest types reflect significantly different site factors,the same growth factor at different ages also refect different site factors.(3)The development potential of forest types was different in different ages and site factors.Platycladus orientalis was high potential at altitude of below 500m,Pinus tabulaeformis was high potential at altitude of below 1000m,Larix principis-rupprechtii Mayr and Betula platyphylla Suk was high potential at altitude of 1001-1500m,Quercus acutissima was high potential at altitude of 501-1000m,Robinia pseudoacacia was high potential at altitude of below 500m,Populus davidiana was high potential at altitude of 501-1000m.Platycladus orientalis and Robinia pseudoacacia was high dominance at sunny and semi-sunny slope,Pinus tabulaeformis,Larix principis-rupprechtii Mayr and Quercus acutissima was high dominance at shade and semi-shade slope.Platycladus orientalis and Robinia pseudoacacia was high dominance at soil thickness of 11-30cm,Pinus tabulaeformis and Larix principis-rupprechtii Mayr was high dominance at soil thickness of 21-30cm,Robinia pseudoacacia was high dominance at soil thickness of 21-40cm.(4)The change trend diameter at breast height,tree height,number of forest types was consistent.diameter at breast height,tree height,number,stand volume growth and biomass of forest types at different site factors had an obvious dissimilarity.Logarithmic curve equation fitting was well.(5)The ecological function of forest types in each unit areas was different.The quality of Populus davidiana in each unit areas was higher than other forest types in soil conservation,carbon fixation and oxygen release.The quality of Quercus acutissima in each unit areas was higher than other forest types in water conservation and biological diversity conservation.The quality of Betula platyphylla Suk in each unit areas was higher than other forest types in atmospheric purifictation.(6)The change trend of each ecological function of forest types were basically the same under different unfluence factors.Logarithmic curve equation fitting was well.the influencing degree of biomass,density and ages was different.Biomass made a big difference on water conservation,soil conservation,fixing carbon and releasing oxyge,nutrients accumulation,atmospheric purifictation and biological diversity conservation.Density had an effect on water conservation,atmospheric purifictation and biological diversity conservation.Ages had a big impact on soil conservation,fixing carbon and releasing oxyge and nutrients accumulation.