| Taiwania flousiana is the rare tree species,which focused on protecting in China.Its wood quality is good and grows fast.It is a very important extension species in hilly area.Therefore,studying on the growth and productivity of Taiwania flousiana can provide scientific data for the afforestation in karst landscape and promote the sustainable development of the forestry.This paper mainly studies the biomass and productivity of Taiwania flousiana Plantation.The results were as the followings:1.By the analysis of the growth process of the 37-year-old Taiwania flousiana in Xiangxi Autonomous Prefecture,the DBH,height and volume of the 37-year-old Taiwania flousiana both increase with age.The DBH height and volume of stand of Taiwania flousiana,which is3 7-year-old,came to 25.3cm,19.5m and 0.3959m3 respectively.The maximum DBH growth increment has appeared in the 15th year,which was 0.98cm.Themaximum average growth increment?0.88cm?has appeared in 20th year.The maximum height growth increment has appeared in the 10th year,the maximum average growth increment has appeared in 15th year.In 0?5th,Taiwania flousiana grew slowly in volume,after 5 years old it grew fast.The fast growing period of volume began at the 15 year and ended in 30 year.The current annual increment curve intersects the annual increment curve in 35 year.It means the quantitative mature age,the best age for final cutting,of the 37-year-old Taiwania flousiana plantation is 35.2.Five growth equations has been utilized to fit the DBH growth,height growth and volume growth of Taiwania flousiana.The results were as the followings:To DBH and volume,the best growth equation is Gompertz.While the suitable growth equation for tree height is Korf.These growth equation models have higher accuracy,so they can be used in predicting the growth of Taiwania Flousiana in karst landscape in Xiangxi Autonomous Prefecture.3.The average biomass per individual is 289.59 kg in 37-year-old Taiwania flousiana plantation.The aboveground biomass is 259.96 kg,accounting for 89.77%of individual total biomass.The underground biomass is 29.53 kg,accounting for 10.23%of individual total biomass.The order of biomass:trunk>branch>root>leaf>bark.4.The total biomass of 37-year-old Taiwania flousiana plantation in karst landscape in Xiangxi Autonomous Prefecture is 284.57t.hm-2.The tree layer biomass is 282.01 t.hm-2,accounting for 99.1%of total biomass.The litter layer biomass is 2.56 t.hm-2,accounting for 0.90%of total biomass.The tree layer biomass is composed of stem,branch,leaf,bark and root,respectively in total biomass of 62.15%?14.13%?7.17%?5.51%?10.14%.5.The productivity of 37-year-old Taiwania flousiana plantation in karst landscape in Xiangxi Autonomous Prefecture is 7.62t.hm-2.a-1.The above ground of tree layer productivity is 6.84t·hm-2·a-1,accounting for 89.77%of total productivity.While the underground of tree layer productivity is only 0.78t.hm-2.a-1,accounting for 10.23%of total productivity.The order of organ productivity:trunk>branch>root>leaf>bark.The level of trunk productivity accounted for a high proportion of the total productivity,in more than 60%.While the level of root and leaf productivity accounted for a low proportion of the total productivity.It shows that the 37-year-old Taiwania flousiana has matured.6.The BNR,BNI,FC,STR and CRR of 37-year-old Taiwania flousiana plantation in karst landscape in Xiangxi Autonomous Prefecture is 1.41,0.17,0.08,0.73,6.01 respectively.BNR and STR of 37-year-old Taiwania flousiana plantation is higher than 20-year-old Taiwania flousiana plantation while other indexes are not different. |
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