| This paper is conducted in Taojiang moso bamboo yield cultivation demonstration base which is loacated in Taojiang county,Hunan province,and based on moso bamboo(Phyllostachys heterocycla (Carr.) Mitford cv.Pubescens) as the research object.Through using 5 different rejuvenation measures including plowing+ fertilization,straw and chaff mulch,straw mulch,bamboo leaf mulch and semi-desert treatment to transform low yield moso bamboo forests,and then investigating and recording stand density,crown density, age,diameter at breast heigt and height of moso bamboo forests after the transformation. Select average moso bamboo of different age and rejuvenation,and then analyse these average moso bamboo in order to gaining wet weight and dry weight of different organs of these average bamboo, and then according to the correlation between biomass of moso bamboo organs and diameter at breast height and bamboo height selecting reasonable biomass regression models,and then we can establish regression equation between moso bamboo organs and average diameter at breast height and average height,so we can estimate tree layer biomass of moso bamboo.According to the relationship between biomass and carbon storage of moso bamboo,we can estimate carbon storage of tree layer,combined with carbon storage of litter layer, soil carbon storage, draw the bamboo forest ecosystem carbon storage. The results showed that:(1) the influence of different rejuvenation measures on the stand density of moso bamboo.Through using different rejuvenation measures to transform low yield moso bamboo forests, study group reduce 30%-50%on stand density than that in control group(semi-desert treatment),the minimum stand density is the straw and chaff mulch for 2958 plants · hm-2, and the maximum stand density is semi-desert treatment for 6433 plants · hm-2, which is much larger than reasonable density of moso bamboo culture for 3500～4000 plants · hm-2, and the other 3 rejuvenation measures like plowing+fertilization, straw mulch and bamboo leaves mulch,their stand density lie between 3125 plants · hm-2 and 4200 plants · hm-2,which lies among a reasonable density interval. Taking rejuvenation measures can significantly reduce stand density of moso bamboo to improve the status of bamboo, which makes the forest structure more reasonable.(2) the influence of different rejuvenation measures on the average diameter at breast height and average height of moso bamboo.Through different rejuvenation measures, the average diameter at breast height of moso bamboo after the transformation for the performance of straw and chaff mulch> straw mulch> bamboo leaf mulch> plowing+fertilization> semi-desert treatment, and compared with the control group by semi-desert treatment, the average diameter at breast height of experimental groups increased by 20%-37%.In aspect of the average height of moso bamboo, straw mulch> straw and chaff mulch> bamboo leaf mulch> plowing+fertilization> semi-desert treatment, and the average height of experimental groups increased by 25.4%～46.9% than these in the control group, and the largest increase is straw mulch, which increased by 4.4m than semi-desert treatment, so it can be known that rejuvenation measures like the mulching and fertilization etc. can promote growth of moso bamboo in diameter at breast height and height, moreover, and mulching treatment has more obvious effect on diameter at breast height and height of bamboo bamboo than fertilizer treatment.(3) the influence of different rejuvenation measures on biomass of moso bamboo.According to the correlation between biomass of moso bamboo organs and diameter at breast height and height, ultimately select the power function W=c*DaHb as biomass regression model of moso bamboo,and then establish regression equation between bamboo organs and diameter at breast height, bamboo height. The regression equation of bamboo culm biomass is M= 0.03SD0.881H1.406,and the regression equation of bamboo branch biomass is M=0.0834 D0.685 H0.777,and the regression equation of bamboo leaf biomass is M=0.0547 D0.152 H0.84,and the regression equation of belowground biomass (including Zhu Dou, rhizome, bamboo root and so on)is M=0.0957 D-0.274 H1.867,and coefficient of determinations r2 of these equations are really high, P<0.01,therefore it can be used to estimate the local moso bamboo biomass.Comparedwith bamboo biomass of different rejuvenation measures,plowing+ fertilization>semi-desert treatment>straw mulch>bamboo leaf mulch> straw and chaff mulch, and biomass respectively is 78.651 · hm-2,74.64t · hm-2,73.79t·hm-2, 72.71·hm-2 and 70.1t· hm-2.(4) different rejuvenation measures have significant effects on soil carbon storage and carbon storage of ecosystem of moso bamboo.By comparison the average soil carbon storage of different treatment plots,straw and chaff mulch> straw mulch> bamboo leaf mulch> plowing+ fertilization> semi-desert treatment, and the average soil carbon storage is 166.36 t·hm-2,155.46t·hm-2,141.19t·hm-2,116.89t·hm-2,113.43 t·hm-2 in sequence. the straw and chaff mulch is higher 52.93 t · hm-2 than semi-desert treatment, which increase close to nearly half soil carbon storage of semi-desert treatment for 46.6%, and it can show that through different rejuvenation measures to transform low yield moso bamboo forests can significantly improve the forest site conditions,and increase the bamboo forest carbon sequestration benefits.On the account of moso bamboo ecosystem’s carbon storage, straw and chaff mulch> straw mulch> bamboo leaf mulch> plowing+fertilization> semi-desert treatment, and the average soil carbon storage is 201.71t·hm-2,192.37t·hm-2,177.85 t · hm-2,156.54t·hm-2,151.07t·hm-2 in sequence, it is obvious that taking different rejuvenation measures has different influence on low yield moso bamboo forest’s transformation, and mulching treatment is better than fertilization treatments on the carbon storage,and straw and chaff mulch works best in moso bamboo carbon sequestration among 5 kinds of rejuvenation measures; but there are less significant influences on experimental groups in increasing diameter at breast height and height of moso bamboo, but which were better than the control group. |
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