Allocation to defense or growth in dipterocarp forest seedlings in Borneo
Allocation to defense or growth in dipterocarp forest seedlings in Borneo
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DOI：
10.1007/s00442-004-1566-7
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发表时间：
2004-06
期刊：
影响因子：
2.7
通讯作者：
H. Kurokawa;Y. Kitahashi;T. Koike;J. Lai;T. Nakashizuka
中科院分区：
文献类型：
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作者：
H. Kurokawa;Y. Kitahashi;T. Koike;J. Lai;T. Nakashizuka
我们量化了植物次生代谢物（特别是浓缩单宁和木质素）的净产量分配，以评估婆罗洲三种热带森林冠层物种对资源可用性假设-à-vis防御机制的投资。我们特别关注婆罗洲铁木（Eusideroxylon zwageri，樟科），它似乎采用了极端的防御策略。这种木材非常耐用，具有很高的比重，生长速度非常慢。将婆罗洲铁木的防御分配与该森林群落优势科双龙科的两个新兴种进行了比较。在2个光照水平× 2个养分水平4个控制条件下，对幼苗进行了遮荫试验，结果表明：茨瓦格里亚的产量远低于其他两个物种，而且它将更多的净产量分配给叶片和根，而不是茎。浓缩单宁和木质素在该树种的叶和茎中含量非常高，分别约为20%和30%。总的来说,E。zwageri将其净产量的最多约35%分配给防御性物质(例如：<？A3B2显示$132#?>e。浓缩单宁+木质素)。相比之下，两种双翅果将其净产量的20-25%分配给防御物质。浓缩的单宁酸。zwagerii有助于延长叶子的寿命，而茎中的木质素提高了木材的耐久性。因此,althoughE。茨瓦格里生长非常缓慢，分配防御性物质似乎是在黑暗条件下生存的有利策略。
We quantified the allocation of net production to plant secondary metabolites (especially condensed tannins and lignins) to evaluate the investment into defense mechanisms of three tropical forest canopy species in Borneo vis-à-vis the resource availability hypothesis. In particular, we focused on Borneo ironwood (Eusideroxylon zwageri, Lauraceae), which seemed to employ an extreme defensive strategy. The wood of this species is extremely durable and has a high specific gravity with a very slow growth rate. The allocation to defense by Borneo ironwood was compared to two emergent species of Dipterocarpaceae, the dominant family in this forest community. We conducted shade-house experiments on seedlings under four controlled conditions (two light levels × two nutrient levels) and showed that the growth rate ofE. zwageriwas much lower than those of the other two species, and it allocated more of its net production to leaves and roots than to stems. The concentrations of condensed tannins and lignins were very high in the leaves and stems of this species, at about 20 and 30%, respectively. In total,E. zwageriallocated a maximum of about 35% of its net production to defensive substances (i.<?A3B2 show $132#?>e., condensed tannins + lignins). In contrast, the two dipterocarp species allocated about 20–25% of their net production to defensive substances. The condensed tannins inE. zwagerihelp to prolong the lifespan of the leaves, and the lignins in the stems enhance the durability of the wood. Thus, althoughE. zwagerigrows very slowly, the allocation to defensive substances seems to be an advantageous strategy for survival under dark conditions.