湘中丘陵区不同经营目标毛竹林年龄结构、生物量分配与碳贮量格局

经营模式对毛竹林生物量、碳贮量具有重要影响。研究了湘中丘陵区毛竹笋用林(Ⅰ)、笋材兼用林 (Ⅱ)和材用林(Ⅲ) 3种不同经营目标下的竹林年龄结构、生物量分配及碳贮量格局。结果表明：应减少1～2 a、增加5～6 a生竹的留养比例，控制达到1～2 a、3～4 a、5～6 a各占1/3左右的立竹年龄结构。不同层次生物量表现为乔木层＞凋落物层＞林下植被层，毛竹笋用林经营有利于增加乔木层生物量。乔木层生物量及所占比例分别为5183～5566 t/hm2、8895%～9293%，林下植被层生物量及所占比例分别为154～258 t/hm2、258%～443%，凋落物层生物量及所占比例分别为269～386 t/hm2、449%～662%。毛竹林总碳贮量排队顺序为Ⅱ（14263 t/hm2）＞Ⅰ（13389 t/hm2）＞Ⅲ（13004 t/hm2），笋材兼用林有利于提高竹林碳贮能力。不同层次碳贮量排列顺序总体均表现为土壤层＞乔木层＞凋落物层＞林下植被层。湘中丘陵区毛竹林生物量、碳贮量较低，应提高集约经营水平

AGE STRUCTURES,BIOMASS ALLOCATIONS AND CARBON STORAGE PATTERNS OF PHYLLOSTACHY EDULISFORESTS UNDER DIFFERENT MANAGING TARGETS IN THE HILLY REGION,CENTRAL HUNAN

It is of obvious effects for management patterns on the biomass and carbon storage of Phyllostachy edulis forests.Age structures,biomass allocations and carbon storage patterns were studied under different managing targets which included bamboo stands for shoot products(Ⅰ),for shoot and timber products(Ⅱ),and for timber products(Ⅲ) in the hilly region,central Hunan Province.The results showed that the proportions of retained bamboo of 1-2 a should be decreased and 5-6 a should be increased respectively,in order to control optimal age structures that the proportions of 1-2 a,3-4 a and 5-6 a were all one third.For biomass in different layers,it existed the regularity of tree layers >litter layers > vegetation layers under canopy and it was beneficial for Ⅰ managing to increase the biomass of tree layers.The biomass for tree layers,vegetation layers under canopy and litter layers were 51.83-55.66 t·hm-2,1.54-2.58 t·hm-2 and 2.69-3.86 t·hm-2,and their proportion were 88.95%-92.93%,2.58%-4.43% and 4.49%-6.62% respectively.For total carbon storages,it was in the order of Ⅱ(142.63 t·hm-2) >Ⅰ(133.89 t·hm-2) >Ⅲ(130.04 t·hm-2) which proved that Ⅱ managing was beneficial to increase carbon storage capacity.In different layers,carbon storages was in the order of soil layers > tree layers > litter layers > vegetation layers under canopy.It was urgent to enhance intensive management level to increase biomass and carbon storages of P.edulis forests in the hilly region,central Hunan.