Carbohydrate allocation to storage as a basis of interspecific variation in sapling survivorship and growth
Carbohydrate allocation to storage as a basis of interspecific variation in sapling survivorship and growth
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DOI：
10.2307/3546590
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发表时间：
1997-11-01
期刊：
影响因子：
3.4
通讯作者：
Kobe, RK
中科院分区：
文献类型：
--
作者：
Kobe, RK
在初秋取样了四种不同树种幼苗根系的总非结构碳水化合物（TNC），这四种树种的光依赖性生长和生存能力（“耐荫性”）不同。两种落叶树种（糖槭和美洲黄曲柳）的TNC浓度高于常绿树种（加拿大Tsuga和strobus Pinus），可能是因为秋季为春季重新落叶积累了储备。在落叶和针叶林对的单独比较中，糖蜜和加拿大柽柳在弱光下的TNC浓度和存活率分别高于美洲柽柳和strobus。在强光条件下，甜葡萄和美洲葡萄的TNC水平无显著差异，两种植物的存活率均为0.98%。碳水化合物分配的分析模型表明，贮藏分配的变化会影响存活和生长，并且在弱光条件下贮藏的机会成本较低。模型和经验数据与观察到的物种间生长决定论与遮荫耐受性之间的相关以及高光生长率与弱光存活率之间的负相关一致。分配储存可能是一种有效的耐阴策略，因为它在弱光下相对便宜，并提供了对压力的缓冲。
Total nonstructural carbohydrates (TNC) of roots were sampled in early autumn from saplings of four species that differ in light-dependent growth and survivorship (''shade tolerance''). The two deciduous species (Acer saccharum and Fraxinus americana) had higher TNC concentrations than the evergreens (Tsuga canadensis and Pinus strobus), presumably because of autumn build-up of reserves for spring refoliation. In separate comparisons of deciduous and coniferous pairs, A. saccharum and T. canadensis had higher low-light TNC concentrations and survivorship than F. americana and P. strobus, respectively. In high light, TNC levels were not significantly different between A. saccharum and F. americana and both species had > 98% survivorship. An analytical model of carbohydrate allocation demonstrates that variation in storage allocation can influence survivorship and growth and that the opportunity cost of storage is lower under low light. The model and empirical data are consistent with an observed correlation among species between growth determinancy and shade tolerance and a negative correlation between high-light growth rates and low-light survivorship. Allocation to storage may be an effective strategy of shade tolerance because it is relatively inexpensive under low light and provides a buffer against stresses.