The Dynamic Changes In Fifteen Years Of Forest Resources For Liuwan Forest Farm In Guangxi

The researches are base on Forest Resource Planning Survey of Liu Wan forest farms in Guangxi from 2004 to 2013 and renewal survey in 2018.he current situation and dynamic changes of forest resources in fifteen-year forest farms were compared and analyzed by means of mathematical statistics and chart analysis,and their timber forests were evaluated.To explore the law of forest resource changes and management effect in forest farms.According to the actual production situation of the forest farm,the quantity and quality of timber forests were evaluated from five aspects: yield per unit area of timber forests,exploitable resources,age group area structure,accumulation structure and tree species structure.From the perspective of comprehensive benefits such as sustainable development of forest resources and sustainable development of forest farm economy,according to the current situation and the laws found,the paper puts forward the optimized management objectives,the optimized management direction in the later period and the management strategies.Themain research results are as follows:1.The existing land area of the forest farm is 15298.78 hm2,the management area of the forest farm is 12762 hm2,the storage of the living trees in the forest farm is 901619 m3,the forest stock keeps increasing.The increment of the forest stock in the fifteen-year period is 4735.58 m3,which shows an increasing trend as a whole.The forest coverage rate is 89.08%,the afforestation rate is 90.74%,and the overall growth rate is 13.53% and 4.14% in the fifteen-year period,respectively.2.Forest farms attach great importance to the development of timber forests,the total area of land increased in the fifteen-year periodand while the area of forest management decreased;the number of forested land increased,the occupied land decreased,the shrub land decreased;and the number of non-forested land increased.3.The primary management goal of timber forest in forest farm is short rotation eucalyptus plantation.The area of 15-year eucalyptus plantation decreased by 1147.8 hm2,showing a decreasing trend as a whole.However,the trend of eucalyptus denaturation is still obvious.The development and management of native and precious tree species are not paid enough attention,which leads to the unreasonable structure of existing tree species and age group.Eucalyptus accounts for 65.8% of timber forest area.4.Based on the timber forest quality index system,and using the comprehensive evaluation method to evaluate and analyze the timber forest quality in the past 15 years,the specific scoring results of each survey were32.69 points(2018)>25.02 points(2004)>24.82 points(2013)>21.08 points(2009).The timber forest quality in 2018 was rated as the best evaluation is good,but the other three calming results are secondary.5.The structure of timber forest needs to be further optimized.Reasonable adjustments should be made in the area of tree species,accumulative structure,age group area and accumulative structure,so as to make Eucalyptus:fir: pine: other broad = 5:2:2:1,adopt the concept of near-natural management,renew and cut after reaching normal forest,and strictly control the age of main cutting.Promote the maximum benefit of forest land and trees.6.The proportion of coniferous forests drinking other broad-leaved forests is small,and the proportion of mixed forests is small,which is not conducive to the formation and protection of forest diversity and species diversity.7.The structure of octagonal economic forest is not reasonable enough.Most of it is in the period of high yield.The octagonal economic pure forest is planted in large areas,the large-scale outbreak coefficient of octagonal anthracnose is increased,the pressure of pest control is to high,and the ability to resist risks is weakened.8.According to the analysis results of forest resources data and the existing management mode of Liuwan forest farm,it is suggested to adjust tree species structure,strengthen management,and put forward corresponding forest management planning and sustainable development direction.