The Spatiotemporal Dynamics And Management Countermeasures Of Forest Structure In Hubei Province

Forest plays an important role in coping with global climate change,maintaining ecological balance and improving ecological environment,and its role is closely related to forest structure.At present,my country’s forest area is increasing continuously,and forest quality has been greatly improved.But there are still problems such as unreasonable structural composition,low stand health and low multiple benefits,which are not conducive to the sustainable development strategy of forestry.With the introduction of precision forestry,how to establish and maintain the best structure of forest has become the focus of forest management research.Based on the second-class survey data of forest resources in Hubei Province,this study analyzes the dynamic changes of forest resources structure in Hubei Province and 17 municipal administrative regions from 1999 to 2009 and 2009 to 2019 from the time and space scales.At the same time,this study uses analytic hierarchy process,coefficient of variation method and comprehensive index method to evaluate the forest structure of each small class in Hubei Province,and puts forward the management countermeasures of forest structure in different regions according to the structure evaluation grade,in order to provide reference for the optimization of forest management scheme and the sustainable development of forestry.The main results are as follows:(1)In 1999,Hubei Province began the pilot work of returning farmland to forests.At the same time,combined with the implementation of natural forest protection project,green man Jing Chu project,characteristic economic forest industry poverty alleviation and other projects,the forest area in the province will increase to 9851700 hectares in2019,including 7861700(79.80%)hectares of forest land.This shows that the forest resources have been effectively managed and protected,and the forest land area has increased rapidly.From 1999 to 2019,the forest standing stock in Hubei Province increased from 191210100 cubic meters to 539321700 cubic meters.In 2019,the area of five forest species in Hubei Province totaled 9176600 hectares,with an area ratio of29:2:53:4:11.From 1999 to 2009,a large number of newly increased woodlands have been transformed into public welfare forests in combination with the changes of woodland area.The forest structure has been improved and adjusted to a certain extent.From 2009 to 2019,the area of protective forests has decreased and the area of timber forests has increased.In the future,while building the ecological security pattern of forestry,the green development of forestry industry will be improved.(2)A good forest structure is conducive to the sustainable management of trees.From 1999 to 2009 and from 2009 to 2019,the natural forest area in Hubei Province increased first and then decreased,and the artificial forest area continued to increase.In1999,2009 and 2019,the forest resources are mainly middle-aged and young forests,and the age group structure belongs to the growth type.During this period,the transition from young forests to middle-aged forests and from middle-aged forests to near mature forests is obvious.The forests in various regions have been reasonably managed and managed,but the area of middle-aged and young forests still accounts for a large proportion,so appropriate tending measures should be taken to speed up the growth of trees.From 1999 to 2019,the area of coniferous forest in Hubei Province decreased by 699000 hectares,broad-leaved forest area increased by 2331300 hectares,the area of coniferous and broad-leaved mixed forest increased by 817900 hectares,indicating that the management of forest resources was in place during the study period.At the same time,the existence of natural disasters and pests led to the death of Masson pine trees,and the coniferous forests in various municipal administrative regions gradually changed to coniferous and broad-leaved mixed forests and broad-leaved forests.From 2009 to 2019,the forests in all municipal administrative regions were dominated by complete structure,and the area of the whole province increased by 3150100 hectares,the forest area with relatively complete structure increased by 1266200 hectares in 15 municipal administrative regions,and the forest area with simple structure in each region is relatively small,the forest structure has been adjusted to a certain extent.As the Masson pine forest is threatened by diseases and pests,and pure forests such as Chinese fir and Masson pine are degraded,combined with the implementation of the strategy of sustainable forest management,pure forests are gradually developing into mixed forests.By 2019,the pure forest area in Hubei Province has been reduced by 3852000 hectares,the area of mixed forest increased by 4373900 hectares.At the same time,during the investigation period,with the implementation of forestry measures such as tending and cutting,replanting and transformation,the forest has been well closed,and the forest canopy density has gradually changed from low,low and high levels to higher levels.In the future,it is necessary to further optimize the forest structure reasonably according to the implementation of forestry policies.(3)The weights of forest structure evaluation obtained by analytic hierarchy process and coefficient of variation method are quite different.The comprehensive weights of the two methods can better balance the subjective and objective bias in the evaluation process.In the index weights of forest structure evaluation,the weight values of stand community structure and tree species mixing ratio are greater than 0.16,indicating that these two indicators are the key indicators of forest structure evaluation.The research shows that the key points of optimizing forest structure and improving stand stability are to improve community structure,improve stand mixing degree,promote the transformation from plantation to natural forest,and improve the distribution proportion of stand age.(4)The areas with medium or lower forest structure comprehensive evaluation grade are mainly distributed in the north of Shiyan City,the middle and east of Hubei Province,and the small class area of lower and lower grades is 689000 hectares,which needs some structural optimization in the future.The structure of forest resources in western mountainous areas and Suizhou city is excellent,especially in Shennongjia forest region,with large forest coverage and stable structure.Generally speaking,the forest structure in Hubei Province is in good condition in the western mountainous areas,while the forest structure in the central and eastern areas is poor.(5)According to the forest structure index and comprehensive evaluation grade of each region in Hubei Province,and with reference to the relevant technical regulations for forest management,From the aspects of near naturalization transformation of artificial forest,improvement of community integrity,optimization of age structure,broadleaf transformation of coniferous forest,mixed transformation of pure forest and optimization of canopy density,the corresponding management countermeasures are put forward for areas with poor structure.