桂西喀斯特过渡区马尾松人工林生物量特征OA

In order to investigate biomass accumulation and distribution rules of Pinus massoniana plantation in karst transition zone of western Guangxi,21-year-old P.massoniana plantation in Guangxi State-owned Yachang Forest Farm was selected as research object.Biomass of arbor layer,shrub layer,herb layer and litter layer were determined by standard tree stratified cutting method and total harvest method.Various organ bio-mass models of P.massoniana individual based on diameter at breast height(D)and tree height(H)were con-structed,and biomass characteristics of plantation were analyzed at scales of individual,diameter class and stand.Results showed that models taking D²H as independent variable fitted better for P.massoniana leaf,branch,stem,bark and whole biomass,while power function model taking D as independent variable fitted bet-ter for root biomass.Various organ biomass of P.massoniana individual followed order of stem>root>branch>leaf>bark,with whole biomass of 342.176 kg.Total biomass of arbor layer was 1 243.13 t/hm²,among which stem biomass accounted for 63.95%and root biomass accounted for 15.02%.Various organs and whole biomass showed trends of increase firstly and then decrease with increase of diameter class.Biomass of middle diameter class(>20-30 cm)accounted 66.66%for total biomass of arbor layer,among which>28-30 cm diameter class had the highest biomass.Understory vegetation biomass was relatively low(6.36 t/hm²),while litter layer bio-mass was relatively higher(5.69 t/hm²).P.massoniana plantation in karst transition zone of western Guangxi showed good adaptability to regional site conditions.It was recommended to cultivate target diameter class of>26-30 cm.