Bark traits and life-history strategies of tropical dry- and moist forest trees
Bark traits and life-history strategies of tropical dry- and moist forest trees
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DOI：
10.1111/1365-2435.12158
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发表时间：
2014-02
影响因子：
5.2
通讯作者：
L. Poorter;Adam Mcneil;V. Hurtado;H. Prins;F. Putz
中科院分区：
文献类型：
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作者：
L. Poorter;Adam Mcneil;V. Hurtado;H. Prins;F. Putz
摘要1.树皮对树木至关重要，因为它可以保护树干免受火灾和其他危害，还因为它对同化物运输，水分关系和修复的重要性。我们评估的树皮厚度的大小依赖的变化，从潮湿的森林和50个树种，从干燥的森林在玻利维亚和树皮厚度的其他树皮特性，物种的生活史策略和木材性能。2. 71%的树种树皮厚度与茎粗的异速生长系数显著小于1（平均0.74，范围0.38 ~ 120），说明树皮厚度随茎粗的增加而绝对增加，但茎粗越大，对树皮厚度的投入越少。3.我们假设，为了应对更频繁的火灾，干燥的森林物种应该有更厚的树皮树木。与此预测相反，干旱和干旱森林树种的异速生长树皮系数和树皮厚度相似。4.在这两种森林类型中，大约50%的物种从未发育出足够厚的树皮，以避免火灾对其维管形成层的损害。因此，最近火灾频率和范围的增加可能对这些森林的组成产生巨大影响。5.在每一个森林中，共存的物种表现出不同的树皮投资策略，和树皮厚度的树木40厘米干直径的变化高达15倍，物种（从17到257毫米不等）。6.在这两个森林中，树苗树皮厚度与该物种的成年身高（最大高度）呈正相关，这可能是因为长寿物种的树木在其生命周期中更有可能经历火灾，而对于那些典型的小或短命的物种，它可能不会回报大量投资于树皮，他们可能会遵循一种重新发芽的策略。幼树树皮厚度与树种的耐荫性无关。7.树皮和木材性状密切相关，显示出一方面具有坚韧组织（树皮和木材密度高）的物种与另一方面具有含水组织（树皮和木材含水量高）和厚树皮的物种之间的权衡。8.不同的树皮投资策略的物种共存于潮湿和干燥的热带森林研究。树皮和木材履行许多功能，所观察到的权衡可能反映了不同的植物策略，以应对火灾，避免和修复茎损伤，避免和抵抗干旱胁迫，机械稳定性。
Summary 1. Bark is crucial to trees because it protects their stems against fire and other hazards and because of its importance for assimilate transport, water relationships and repair. We evaluate size-dependent changes in bark thickness for 50 woody species from a moist forest and 50 species from a dry forest in Bolivia and relate bark thickness to their other bark characteristics, species life-history strategies and wood properties. 2. For 71% of the evaluated species, the allometric coefficient describing the relationship between bark thickness and stem diameter was significantly <1 (average 074; range 038–120), indicating that species attain an absolute increase in bark thickness with increasing stem diameter but invest relatively less in bark thickness at larger diameters. 3. We hypothesized that in response to more frequent fires, dry-forest species should have thicker barked trees. Contrary to this prediction, dry- and moist-forest tree species were similar in allometric bark coefficients and bark thickness. 4. In both forest types, about 50% of the species never developed bark thick enough to avoid fire damage to their vascular cambia. Recent increases in fire frequency and extent may therefore have potentially large effects on the composition of these forests. 5. Within each forest, coexisting species displayed a diversity of bark investment strategies, and bark thickness of trees 40 cm stem diameter varied up to 15-fold across species (ranging from 1 7t o 257 mm). 6. In both forests, sapling bark thickness was positively related to adult stature (maximum height) of the species, possibly because trees of long-lived species are more likely to experience fire during their life span, whereas for species that are characteristically small or short-lived, it may not pay off to invest heavily in bark and they may follow a resprouter strategy instead. Sapling bark thickness was not related to species’ shade tolerance. 7. Bark and wood traits were closely associated, showing a trade-off between species with tough tissues (high densities of bark and wood) on the one hand vs. species with watery tissues (high water contents of bark and wood) and thick bark on the other hand. 8. Species with different bark investment strategies coexist in both the moist and the dry tropical forest studied. Bark and wood fulfil many functions, and the observed trade-offs may reflect different plant strategies to deal with fire, avoidance and repair of stem damage, avoidance and resistance of drought stress, and mechanical stability.