Short Effects Of Management Measures On Tree Growth And Carbon Density Of Different Low-function Or Damage Stands

Reasonable forest management measures can improve the growth environment of tree,optimize the stand structure,promote the growth and development of forest,improve the productivity of forestland and quality of forest.Taking the low-function or damage stands of Cunninghamia lanceolate,Pinus massoniana,Pinus elliotii,Sassafras tsumu and Alniphyllum fortune as the research object in the Xinyu and Jian city of Jiangxi Province,divided into eight types based on the different degree of low-function or damage of tree species or same species,and accorded to the stand characteristics and other factors of each types,appropriate management measures were formulated,the mainly included replanting,thinning and replanting,control coppice shoot and replanting,reforestation.Through4-year continuous investigation of the each types plots and determination of the samples,the short effects of management measure on tree growth and carbon density of stand were analyzed in order to provide references for quality improvement of low-function or damage stands.The main results and conclusions were as follows:(1)The effects of management measures on the DBH(diameter at breast height)and volume of individual tree of different low-function or damage stands were inconsistent.After the replanting measures were adopted in the damage?Pinus elliotii palntations,the damage Alniphyllum fortune forest,the damage Cunninghamia lanceolata and Sassafras tsumu plantations,the DBH and volume growth of individual tree were increased during the 4 years,the DBH growth of individual tree were increased by 50.00%,37.50%,17.65%and 4.54%respectively compared with control,and the volume growth of individual tree were increased by 36.58%,12.80%,6.62%and 3.05%respectively compared with control.After the thinning and replanting measures were adopted in the low-function?and low-function?Pinus massoniana plantations,the DBH and volume growth of individual tree of low-function?Pinus massoniana plantations were increased during the 4 years,increased by 77.78%and 109.68%respectively compared with control.The DBH and volume growth of low-function?Pinus massoniana plantations were decreased by 20.00%and 29.54%respectively compared with control.After the control coppice shoot and replanting measures were adopted in the low-function Cunninghamia lanceolata plantations,the DBH and volume growth of individual tree were increased by 30.43%and20.49%respectively compared with control during the 4 years.After the reforestation measures were adopted in the damage?Pinus elliotii palntations,the DBH and volume growth of individual tree were decreased during the 4 years,decreased by 13.64%and24.59%respectively compared with control.By paired samples T test showed that there were significant differences in treatment and control plots of the damage?and damage?Pinus elliotii palntations,the low-function?and low-function?Pinus massoniana plantations,the low-function Cunninghamia lanceolata plantations and damage Alniphyllum fortune forest(P<0.05),while there were no significant differences in the damage Cunninghamia lanceolata and Sassafras tsumu plantations(P>0.05).(2)The effects of replanting measures on the carbon density of totals and different layers of four types in the damage?Pinus elliotii palntations,the damage Alniphyllum fortune forest,the damage Cunninghamia lanceolata and Sassafras tsumu plantations were inconsistent.They were no significant differences on the carbon density of arbor layers(P>0.05).The carbon density of litter layers expressed as the high significant increased for damage?Pinus elliotii palntations,damage Sassafras tsumu plantations and damage Alniphyllum fortune forest(P<0.01),the significant increased for damage Cunninghamia lanceolata palntations(P<0.05).The carbon density of understory vegetation layers expressed as the significant increased for damage Sassafras tsumu plantations(P<0.05),the high significant decreased for damage Cunninghamia lanceolata palntations and damage?Pinus elliotii palntations(P<0.01),it has no significant impact for damage Alniphyllum fortune forest(P>0.05).The increment of the carbon density of soil layers of control were greater than treatment plots,and except the damage Alniphyllum fortune forest to showed significant differences(P<0.05),the other three types were no significant differences(P>0.05).The 4 year growth of total carbon density of stands except the damage?Pinus elliotii palntations was increased by 0.27 t/hm~2 compared with control,the damage Alniphyllum fortune forest,the damage Cunninghamia lanceolata and Sassafras tsumu plantations were decreased by 4.66 t/hm~2,0.42 t/hm~2 and 3.16 t/hm~2 respectively compared with control,and the damage Alniphyllum fortune forest to showed significant decreased(P<0.05),the other three types were no significant differences(P>0.05).(3)The effects of thinning and replanting measures on the carbon density of totals and different layers in low-function?and low-function?Pinus massoniana plantations performed as follows:they were slowed down the increment of carbon density of arbor layers,the carbon density of understory vegetation and litter layers in low-function?Pinus massoniana plantations expressed as the high significant decreased(P<0.01)and significant increased(P<0.05)respectively,while it has no significant impact on the carbon density of understory vegetation and litter layers in low-function?Pinus massoniana plantations(P>0.05).The increment of the carbon density of soil layers of control were greater than treatment plots,the carbon density of soil layer on low-function?Pinus massoniana plantations to showed significant differences(P<0.05),but it has no significant differences on low-function?Pinus massoniana plantations(P>0.05).The 4year growth of total carbon density of stands were significant lowered compared with control(P<0.05),and the increment of low-function?and low-function?Pinus massoniana plantations were decreased by 4.91 t/hm~2 and 0.88 t/hm~2 respectively compared with control.(4)The control coppice shoot and replanting measures has significant impact on increased of carbon density of arbor and litter layers in low-function Cunninghamia lanceolata plantations(P<0.05),but it has significant decreased on the carbon density of understory vegetation layer(P<0.05),while it has no significant impact on the carbon density of soil layer(P>0.05).The 4 year growth of total carbon density of stand was decreased by 3.92 t/hm~2 compared with control,but there were no significant differences(P>0.05).(5)After the reforestation measures were adopted in the damage?Pinus elliotii palntations,the carbon density of litter layer to showed significant increased(P<0.05),the carbon density of understory vegetation and soil layers were significant decreased(P<0.05),while it has no significant impact on the carbon density of arbor layer(P>0.05).The 4 year growth of total carbon density of stand was decreased by 8.54 t/hm~2 compared with control,and there were significant differences(P<0.05).