Adventitious root production and plastic resource allocation to biomass determine burial tolerance in woody plants from central Canadian coastal dunes
Adventitious root production and plastic resource allocation to biomass determine burial tolerance in woody plants from central Canadian coastal dunes
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DOI：
10.1093/aob/mcl196
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发表时间：
2006-11-01
期刊：
影响因子：
4.2
通讯作者：
Maun, M. Anwar
中科院分区：
文献类型：
--
作者：
Dech, Jeffery P.;Maun, M. Anwar
背景与目的埋藏是海岸沙丘植物反复承受的压力。木本植物被埋在开阔的海岸沙丘和活跃喷涌后的森林地区；然而，人们对这些物种的埋藏反应和适应特征知之甚少。本研究的目的是：(a)确定加拿大中部沿海沙丘原产于的7种木本植物的生长和形态对埋砂的响应；(b)确定这些物种中决定埋藏耐受性的特征。方法采用野外试验的方法，测定不同种属对掩埋的反应。苗木分别以其高度的0%、10%、25%、50%和75%进行掩埋处理。通过对总生物量、高度、不定根产量以及地上部、根和不定根生物量分配比例对埋藏率的回归，评价了埋藏响应。重点结果油松和青云杉缺乏埋藏耐受性。在对埋藏梯度的响应中，这些物种的总生物量表现出强烈的线性下降，不定根产量最小，在中等水平（25- 50%的埋藏）达到峰值，并且在茎和根的分配上没有变化。耐受性树种弗吉尼亚杜松（Juniperus virginana）、西柏（Thuja occidentalis）和马里亚云杉（Picea mariana）对埋藏表现出二次响应，在埋藏50%以下生物量变化不大，但在75%以下生物量大幅下降。这些物种产生丰富的不定根，可达埋藏的50%，但在埋藏水平范围内不改变分配模式。白杨和白柳受埋藏刺激。随着埋深的增加，这些物种的生物量呈线性增加，在整个梯度上产生了大量的不定根，并且在高埋深条件下，它们的分配明显转向垂直枝生长和不定根的产生，而牺牲了原有的根。结论不定根的产生和塑料资源对生物量的分配是加拿大中部沿海沙丘木本植物的适应性特征，为评估世界各地沿海沙丘木本植物的埋藏耐受性提供了依据。
Background and Aims Burial is a recurrent stress imposed upon plants of coastal dunes. Woody plants are buried on open coastal dunes and in forested areas behind active blowouts; however, little is known about the burial responses and adaptive traits of these species. The objectives of this study were: (a) to determine the growth and morphological responses to burial in sand of seven woody plant species native to central Canadian coastal dunes; and (b) to identify traits that determine burial tolerance in these species.Methods Field experiments were conducted to determine the responses of each species to burial. Saplings were exposed to burial treatments of 0, 10, 25, 50 and 75 % of their height. Burial responses were evaluated based on regressions of total biomass, height, adventitious root production and percentage allocation to shoot, root and adventitious root biomass on percentage burial.Key Results Pinus strobus and Picea glauca lacked burial tolerance. In response to the burial gradient, these species showed a strong linear decline in total biomass, minimal adventitious root production that peaked at moderate levels (25-50 % burial) and no change in allocation to shoots vs. roots. The tolerant species Juniperus virginiana, Thuja occidentalis and Picea mariana showed a quadratic response to burial, with little change in biomass up to 50 % burial, but a large decline at 75 %. These species produced abundant adventitious roots up to 50 % burial, but did not alter allocation patterns over the range of burial levels. Populus balsamifera and Salix cordata were stimulated by burial. These species showed linear increases in biomass with increasing burial, produced copious adventitious roots across the gradient and showed a clear shift in allocation to vertical shoot growth and adventitious root production at the expense of the original roots under high burial conditions.Conclusions Adventitious root production and plastic resource allocation to biomass are adaptive traits of coastal dune woody plants in central Canada, and provide a basis for assessing burial tolerance in woody plants on coastal dunes throughout the world.