Relationship between soils and Amazon forest biomass: A landscape-scale study
Relationship between soils and Amazon forest biomass: A landscape-scale study
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DOI：
10.1016/s0378-1127(98)00494-0
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发表时间：
1999-06-14
影响因子：
3.7
通讯作者：
Gascon, C
中科院分区：
文献类型：
--
作者：
Laurance, WF;Fearnside, PM;Gascon, C
对亚马逊流域中部 1000 km(2) 景观中 65 l ha 地块的活树（包括棕榈树）的地上干生物量进行了估计。研究区域位于亚马逊地区广泛分布的风化严重、营养贫乏的土壤上。通过测量每个地块中所有大于或等于 10 厘米的树木的胸径 (DBH)，然后使用异速生长方程和小树的校正因子来估计树木总生物量，得出生物量值。从每个地块的土壤表面样本（0-20厘米）收集土壤质地、有机碳、可用水容量、pH、常量和微量养分以及微量元素的详细信息，同时使用测斜仪测量坡度。生物量估计值相差两倍以上，从 231 吨 ha(-1) 到 492 吨 ha(-1)，平均值为 356 +/- 47 吨 ha(-1)。简单相关性与严格 (p < 0.006) Bonferroni 校正表明，生物量与土壤中的总氮、总交换碱、K+、Mg2+、粘土和有机碳呈正相关，与 Zn+、铝饱和度和沙子呈负相关。排序分析揭示了研究区域的一个主要和几个次要土壤梯度，主要梯度区分具有不同比例粘土的地点（粘土具有较高浓度的总氮、有机碳、大多数阳离子，以及较低的铝饱和度和较少的沙子）。多元回归分析表明，主要的粘土养分梯度是唯一显着的预测因子，该模型解释了生物量总变化的 32.3%。分析结果表明，土壤肥力参数可以解释亚马逊陆地森林地上生物量变化的三分之一或更多。我们认为，由于森林转变为牧场往往会减少土壤中的氮、粘土、有机碳和养分含量，因此在以前被砍伐的土地上再生的森林的生物量可能低于原始森林，特别是在土壤肥力较低的地区。 (C) 1999 Elsevier Science B.V. 保留所有权利。
Above-ground dry biomass of living trees including palms was estimated in 65 l ha plots spanning a 1000 km(2) landscape in central Amazonia. The study area was located on heavily weathered, nutrient-poor soils that are widespread in the Amazon region. Biomass values were derived by measuring the diameter-at-breast-height (DBH) of all greater than or equal to 10 cm trees in each plot, then using an allometric equation and correction factor for small trees to estimate total tree biomass. Detailed information on soil texture, organic carbon, available water capacity, pH, macro- and micro-nutrients, and trace elements was collected from soil surface samples (0-20 cm) in each plot, while slope was measured with a clinometer. Biomass estimates varied more than two-fold, from 231 to 492 metric tons ha(-1), with a mean of 356 +/- 47 tons ha(-1). Simple correlations with stringent (p < 0.006) Bonferroni corrections suggested that biomass was positively associated with total N, total exchangeable bases, K+, Mg2+, clay, and organic C in soils, and negatively associated with Zn+, aluminum saturation, and sand. An ordination analysis revealed one major and several minor soil gradients in the study area, with the main gradient discriminating sites with varying proportions of clay (with clayey soils having higher concentrations of total N, organic C, most cations, and lower aluminum saturation and less sand). A multiple regression analysis revealed that the major clay-nutrient gradient was the only significant predictor, with the model explaining 32.3% of the total variation in biomass. Results of the analysis suggest that soil-fertility parameters can account for a third or more of the variation in above-ground biomass in Amazonian terra-firme forests. We suggest that, because the conversion of forest to pasture tends to reduce the nitrogen, clay, organic carbon, and nutrient contents of soils, forests that regenerate on formerly cleared lands may have lower biomass than the original forest, especially in areas with low soil fertility. (C) 1999 Elsevier Science B.V. All rights reserved.