Study On Accurate Spatial Distribution Of Suitability And The Highest Canopy Closure Of Main Artificial Coniferous Forests In Hubei Province

Coniferous forests in Hubei province account for up to 55% of the total forest area,and their reasonable forest management plays an important role in improving the ecological functions.In the past afforestation,due to the inadequate analysis of the spatial distribution of meteorological elements,some plots failed to achieve a tree fit;besides,as the sparse or lack of understory vegetation in pure coniferous forests,most people think it is allelopathy effect.The study found that due to the excessive canopy closure,the conifer deciduous formed a thick deciduous layer,and its mechanical action prevented the shrub grass seeds from falling to the ground to take root and germinate,which in turn caused the sparse vegetation under the forest and heavy soil erosion.Therefore,this paper combines the principles of plant ecology and spatial information technology,which takes the main artificial coniferous forests in Hubei Province as the research object,and uses Multiple linear regression kriging model(MLRK)interpolation to obtain 20 geographic elements of 30 m resolution spatial distribution data,and combines 422 plot data,Using the combination of geographic restriction factor elimination method and the maximum entropy model(Max Ent)to comprehensively analyze the spatially accurate and suitable distribution units of the main coniferous tree species,and to explore the understory vegetation coverage of coniferous forests in different geographical areas to achieve the highest canopy closure under the conditions of effectively preventing soil erosion.It aims to provide production guidance for the improvement of forest ecological functions.Research indicates:(1)The growth suitability of Pinus massoniana in Hubei Province is greatly affected by altitude,accumulated temperature,annual average temperature difference between day and night,rainfall deviation,slope and rainfall in the wettest season.It is suitable to grow at the geographical environment areas with an altitude of 100?1500m,accumulated temperature of 2800?5600?,annual average temperature difference between day and night of 7.75?10.3°C,the wettest season rainfall of 360?710mm,and a slope of less than 40°;which is mainly distributed in the northeast,middle and east middle and low mountains and hilly areas,suitable areas occupy 70.63% of the province's area.With the spatial changes of different geographical environments,the highest canopy closure of pinus massoniana was 0.65 ? 0.71 when the understory vegetation could be restored to prevent soil erosion effectively.(2)The growth suitability of Cunninghamia lanceolata in Hubei Province is greatly affected by the annual rainfall,rainfall deviation,altitude,humidity,slope and annual average temperature.The humidity and annual rainfall conditions in the province are suitable for the growth of Cunninghamia lanceolata,and it is suitable for growth at the geographical environment areas with a rainfall deviations below 70 mm,elevations less than 2100 m,annual average temperature greater than 13.2°C,and slopes less than 40°;which is mainly distributed in parts of the southeast,northeast and west,suitable areas account for 65.09% of the province's area.With the spatial changes of different geographical environments,the highest canopy closure of Cunninghamia lanceolata was 0.65 ? 0.76 when the understory vegetation could be restored to prevent soil erosion effectively.(3)The growth suitability of Cupressus funebris in Hubei Province is greatly affected by altitude,humidity,accumulated temperature,the lowest temperature of the coldest month,rainfall deviation and annual average temperature.It is suitable to grow at the geographical environment areas with an altitude of 100?1000m,humidity conditions below 81%,accumulated temperature of 2500?5500?,and the lowest temperature of the coldest month greater than-14.5?;which is mainly distributed in the northwest,midwest and southeast regions,suitable areas occupy 44.49% of the province's area.With the spatial changes of different geographical environments,the highest canopy closure of Cupressus funebris was 0.58?0.65 when the understory vegetation could be restored to prevent soil erosion effectively.