Study On The Structure And Ecological Function Of Typical Forest Stand In Mountainous Area Of Northern Hebei Province

With the deepening of forest ecosystem understanding and the emergence of more and more serious environmental problems,forest health has got more and more attention.International and domestic scholars have done a lot of exploration and research,but there are still many deficiencies,On the basis of exesting research,this paper studied the problems existing in the process of ecological protection forest and timber forest in northern Hebei province,and takes a large number of raw data research.Based on the structure-oriented and function-oriented principle,this paper focuses on the mixed forest of mountain birch and mountain birch in northern Hebei,Populus davidiana and Betula mixed forest,Pinus tabuliformis and Quercus mongolica Fisch mixed forest,Pure Larix gmelinii plantations and pure Pinus tabuliformis plantations,and provide reference for solving the sustainable development of ecological forest construction and forest production and operation in northern Hebei.The main research contents are as follows:(1)The distribution characteristics of species composition and tree height and DBH were studied systematically.The species composition,tree height structure and DBH structure of four typical stands in northern Hebei were obtained by means of sampling survey.Quantitative analysis was carried out using Weibull distribution function.The composition of DBH and tree height were analyzed.The results showed that the diameter distribution of all tree species in the plot was normal distribution,exhibiting inverted "J" shape distribution,bimodal or unimodal distribution,with obvious interval characteristics,tree height was mainly normal distribution,single or bimodal distribution the Lord.(2)Analyze and evaluated the spatial structure of the plot.On the basis of the composition and coordinates of the tree species,the Winkelmass program was used to analyze the spatial structure of the stands.The results showed that the dominant tree species were distributed evenly and the mixed degree and angle scale were basically reasonable.The spatial distribution of the pure forest is relatively reasonable,and most of the trees in the plot are randomly distributed,and the whole distribution pattern is evenly distributed.(3)Further study of species diversity and biomass allocation pattern through a large number of measured and investigated data.The results showed that the species diversity of plant community was closely related to the growth type,and the species diversity index herb layer>shrub layer>arbor layer;tree biomass allocation pattern showed tree trunk>tree root>leaf,shrub and herbaceous biomass allocation The pattern is shown as the underground part of the ground part.(4)A large number of soils were surveyed and the soil properties were studied comprehensively.The results showed that the soil physical,chemical and biological characteristics of different stands were different,soil particle size distribution and water content changed with the depth of soil layer.The change of Ph value in different soil layers was not obvious,Soil organic matter and soil nutrient increased with the depth of soil layer.Soil microbial content and soil enzyme activity decreased with the depth of soil layer,and the difference between soil layer and soil layer was lower than that of lower soil.(5)To carry out a large number of data research combined with theoretical research,to get the different characteristics of the forest stand characteristics.The results showed that the redistribution effect of canopy layer was obvious,and the average transmittance of different stands was Larch pure forest>Pinus tabulaeformis forest>Pinus tabulaeformis and Quercus mongolica mixed forest>Populus davidiana mixed forest,forest The average tree trunk flow rate of Pinus tabulaeformis mixed forest>Pinus tabulaeformis forest>Poplar mixed forest>Larch pure forest.The water holding capacity of litter in different forest types was different,and the interception effect of mixed forest of Populus dahurica was the most obvious,followed by Pinus tabulaeformis mixed forest,larch pure forest and Pinus tabulaeformis forest had the worst effect on precipitation.The infiltration capacity of Pinus tabulaeformis forest>Pinus tabulaeformis forest>Pinus tabulaeformis forest;infiltration time and infiltration rate were fitted by power function The best results.The chemical characteristics of different forest were different,and the effect of stand on elemental content was different.(6)Forest health management technology were analysed.The structured forest management technology takes the concept of "near nature" as the starting point,and takes the structure decision function as the starting point,maximizes the ecological benefit through the construction of the rich and reasonable structure,the proportionally coordinated forest ecosystem;the functionalized forest management As the goal,through the construction of the way to achieve business objectives,to achieve the objectives of the objectives of the stand,to achieve ecological,economic and social benefits of the coordinated development.