Height-diameter allometry of tropical forest trees
Height-diameter allometry of tropical forest trees
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DOI：
10.5194/bg-8-1081-2011
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发表时间：
2011-01-01
期刊：
影响因子：
4.9
通讯作者：
Lloyd, J.
中科院分区：
文献类型：
--
作者：
Feldpausch, T. R.;Banin, L.;Lloyd, J.
热带树高直径（H：D）的关系可能会因森林类型和区域而异，如果忽略这些差异，对地上生物量的大规模估计会有偏差。因此，我们开发了一个新的全球热带森林数据库，包括39955并发H和D测量，包括283个网站在22个热带国家。利用这个数据库，我们的目标是：1。以确定H：D关系是否因地理区域和森林类型（从湿林到干林，包括森林和稀树草原重叠的紧张地带）而不同。确定H：D关系是否受气候和/或森林结构特征（例如林分断面积A）的调节.开发H：D异速生长方程并评估偏差，以减少未来热带森林生物量从局部到全球估计的误差。年降水变异系数（P-V）、旱季长度（S-D）和年平均气温（T-A）成为泛热带和区域尺度H：D关系变化的关键驱动因素。植被结构也起到了一定的作用，在高A森林中的树木，平均来说，在任何给定的D。在考虑到环境和森林结构的影响之后，可以确定两个主要的区域集团。平均而言，亚洲、非洲和圭亚那地盾的森林都具有相似的H：D关系，但亚马逊盆地和热带澳大利亚的大部分森林中的树木在任何给定的D处通常都比其他地方的树木短。区域环境结构模型采用最低的赤池信息标准和最低的偏差估计所有地块的林分水平H，中位数在真实值的-2.7至0.9%之间。该模型未考虑的H：D关系中的一些地块间变异性可归因于土壤物理条件的变化。在其他条件相同的情况下，在没有土壤物理限制的情况下，树木往往更细长，特别是在较小的D。泛热带和大陆一级的模型提供了不太强大的估计H，特别是当调制H：D异速生长的气候和林分结构的作用没有同时考虑。
Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were:1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap).2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A).3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass.Annual precipitation coefficient of variation (P-V), dry season length (S-D), and mean annual air temperature (T-A) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere.The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within a median -2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account.