The regional variation of aboveground live biomass in old-growth Amazonian forests
The regional variation of aboveground live biomass in old-growth Amazonian forests
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DOI：
10.1111/j.1365-2486.2006.01120.x
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发表时间：
2006-07-01
影响因子：
11.6
通讯作者：
Vinceti, Barbara
中科院分区：
文献类型：
--
作者：
Malhi, Yadvinder;Wood, Daniel;Vinceti, Barbara
热带森林的生物量在全球碳循环中发挥着重要作用，既作为碳的动态储存库，又作为森林砍伐地区大气中二氧化碳的来源。然而，人们对热带森林生物量的绝对大小和环境决定因素仍然知之甚少。在这里，我们基于 227 个森林地块的数据（其中许多以前未发表过），对整个南美洲古老低地热带森林的底面积和地上活生物量进行了新的综合和插值。森林生物量根据两个不相关的因素进行分析：断面积和平均木材密度。断面积受当地景观因素影响较大，但在潮湿的热带森林区域尺度上相对不变，而在干燥的林区外围则显着下降。平均木材密度与森林动态呈负相关，亚马逊西部动态森林的平均木材密度较低，亚马逊东部生长缓慢的森林较高。这两个因素的结合导致亚马逊流域中部和圭亚那中等季节性、生长缓慢的森林生物量最高（高达 350 毫克干重 ha(-1)），而在西部、南部和东部边缘则下降至 200-250 毫克干重 ha(-1)。总体而言，考虑到藤本植物和小树，我们估计完整的亚马逊雨林（2000 年面积为 5.76 x 10(6) km(2)）的地上总生物量为 93 +/- 23 Pg C。包括死亡生物量和地下生物量将使该值分别增加约 10% 和 21%，但这些附加项的空间变化仍需要量化。
The biomass of tropical forests plays an important role in the global carbon cycle, both as a dynamic reservoir of carbon, and as a source of carbon dioxide to the atmosphere in areas undergoing deforestation. However, the absolute magnitude and environmental determinants of tropical forest biomass are still poorly understood. Here, we present a new synthesis and interpolation of the basal area and aboveground live biomass of old-growth lowland tropical forests across South America, based on data from 227 forest plots, many previously unpublished. Forest biomass was analyzed in terms of two uncorrelated factors: basal area and mean wood density. Basal area is strongly affected by local landscape factors, but is relatively invariant at regional scale in moist tropical forests, and declines significantly at the dry periphery of the forest zone. Mean wood density is inversely correlated with forest dynamics, being lower in the dynamic forests of western Amazonia and high in the slow-growing forests of eastern Amazonia. The combination of these two factors results in biomass being highest in the moderately seasonal, slow growing forests of central Amazonia and the Guyanas (up to 350 Mg dry weight ha(-1)) and declining to 200-250 Mg dry weight ha(-1) at the western, southern and eastern margins. Overall, we estimate the total aboveground live biomass of intact Amazonian rainforests (area 5.76 x 10(6) km(2) in 2000) to be 93 +/- 23 Pg C, taking into account lianas and small trees. Including dead biomass and belowground biomass would increase this value by approximately 10% and 21%, respectively, but the spatial variation of these additional terms still needs to be quantified.