【摘要】 近年来人类活动的干扰导致许多连续的自然森林破碎为斑块化的森林片断(如村落旁保留的"风水林"),研究森林斑块的面积与森林生物量的关系对改善森林的碳汇作用具有十分重要的意义。本文在位于广州市东部的风水林中分别选取立地条件、森林植被类型和结构、林龄、森林生长发育阶段等因素相同但面积不同的大斑块(15-25 hm~2)、中斑块(5-8 hm~2)和小斑块(0.5-2 hm~2)各5个,采用样方调查和遥感估算相结合的方法,研究风水林地上生物量与斑块面积的关系,以及风水林斑块从林缘到林内地上生物量的梯度变化。结果显示:(1)平均生物量呈现出大斑块(199.33 t/hm~2)>中斑块(181.59 t/hm~2)>小斑块(147.51 t/hm~2)的趋势,大、中、小斑块的地上生物量之间存在显著性差异(P <0.01),斑块面积对地上生物量的影响比较显著;(2)样地调查结果和遥感数据都显示,边缘效应对风水林斑块地上生物量的影响比较明显:大斑块生物量从林缘到林内呈现斑块中心(290.24 t/hm~2)>斑块中心到林缘的中间位置(226.63 t/hm~2),>板块边缘(129.16 t/hm~2)的趋势;(3)大斑块中高大树木的比例较大,这是大斑块的生物量大于中、小斑块的主要原因。本研究的结果表明,保护和建设较大的森林斑块,有助于提高森林的碳汇作用。更多还原

【Abstract】 Human activities led to many continuous natural forests fragmented into such as Fengshui forests around villages,how their forest carbon sinks are related to forests’ patch sizes and vegetation biomasses demands academic research.In a case study of a Fengshui forest in eastern Guangzhou suburbs,five large patches for each of three patches with area sizes of 15-25 hm~2,5-8 hm~2 and 0.5-2 hm~2,respectively,were selected based on site conditions,vegetation type,forest structure,stand age and growth stage.Then,the above-ground biomass and gradient variation from the edge to center for the Fengshui forest were investigated to figure out the relationship between patch size and above-ground biomass by using combined quadrat survey and remote sensing estimation.The results are as follows:(1) the average above-ground biomass obviously varies from large to small patches(P<0.01),and generally shows an increase trend with the forest size with a biomass of 199.33 t/hm~2 for large patches,181.59 t/hm~2 for medium,and 147.51 t/hm~2 for small patches.(2) In large patches,the above-ground biomass increases from 290.24 t/hm~2,226.63 t/hm~2 to 129.16 t/hm~2 from center to edge,showing that the edge effect has a great impact on ground biomass in the Fengshui forest patches.(3) There is the largest proportion of tall and thick trees in large patches,which probably results in a larger biomass in large patches than in medium and small patches.So the improvement of forest carbon sink needs the protection and construction of large forest patches.更多还原