期刊
FRONTIERS IN FORESTS AND GLOBAL CHANGE
卷 1, 期 -, 页码 -出版社
FRONTIERS MEDIA SA
DOI: 10.3389/ffgc.2018.00011
关键词
Acer saccharum; canopy; experimental warming; leaf traits; photosynthesis; Tilia americana; thermal acclimation
资金
- National Institute of Food and Agriculture U.S. Department of Agriculture McIntireStennis Cooperative Forestry Research Program [1001534]
- Department of Energy [DE-SC-0011806]
- DeVlieg Foundation Fellowship
- Ecosystem Science Center at Michigan Technological University
Northern hardwood forests are experiencing higher temperatures and more extreme heat waves, potentially altering plant physiological processes. We implemented in-situ leaf-level warming along a vertical gradient within a mature forest canopy to investigate photosynthetic acclimation potential of two northern hardwood species, Acer saccharum and Tilia americana. After 7 days of +3 degrees C warming, photosynthetic acclimation was assessed by measuring differences between heated and control photosynthetic rates (A(opt)) at leaf optimum temperatures (T-opt). We also measured the effects of warming and height on maximum rates of Rubisco carboxylation, stomatal conductance, transpiration, and leaf traits: leaf area, leaf mass per area, leaf nitrogen, and leaf water content. We found no evidence of photosynthetic acclimation for either species, but rather A(opt) declined with warming overall. We found slight shifts in LMA and N-area, leaf traits associated with photosynthetic capacity, after 1 week of experimental warming. T. americana LMA and N-area was lower in the upper canopy heated leaves than in the control leaves, contributing a shift in N-area height distribution in the heated leaves. T. americana showed evidence of greater resiliency to warming, with greater thermoregulation, physiological plasticity, and evapotranspiration. As expected, A(opt) of A. saccharum increased with height, but A(opt) of T. americana was highest in the sub canopy, possibly due to constraints on leaf water balance and photosynthetic capacity in the upper canopy. Thus, models relying on canopy height or light environment may incorrectly estimate vertical variation of photosynthetic capacity. If these species are not able to acclimate to warmer temperatures, we could see alteration of plant carbon balance of these two key northern hardwood species.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据