Projection of Abies balsamea distribution under conditions of climate change: incorporation of species plasticity to environmental change

气候变化条件下冷杉分布的预测：物种可塑性与环境变化的结合

• 批准号: RGPIN-2015-05709
• 负责人: Bourque, Charles
• 金额: $ 1.53万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=646040
• 关键词: Projection; Abies; balsamea; distribution; under

Having intially been used strictly for silvicultural purposes, provenance tests are now being viewed as well-suited to study intra-specific variation in adaptation of trees to changes in climate. Studies which assess tree performance under changing climatic conditions, when conducted under controlled conditions are, however, limited by spatial and temporal restrictions. These limitations make long term provenance plots established in North America useful in providing data that may give reliable information on species performance outside their natural range.***An important physiological process in plant productivity is photosynthesis, the rate of which can be influenced by provenance variation. Photosynthetic response of plant species to variations in environment can be assessed at both the small, leaf-level, and large, ecosystem-level, scales. An eddy covariance tower in the Acadian Research Forest, southcentral New Brunswick (NB), will provide the data needed to characterise photosynthesis at the large, ecosystem scale. Species photosynthetic response at the ecosystem scale is determined by mathematically decomposing tower-based measurements of net CO2 exchange (or the negative of net ecosystem productivity, -NEP) into its component fluxes of gross ecosystem production, associated with light interception and assimilation, and respiration with simple NEP models and numerical optimisation. Information generated by the leaf- and ecosystem-level data collection can then be used to specify the parameters of the same models as a function of leaf-level information. This would allow the use of the models to provide an ecosystem-level characterisation of species response for forests lacking tower data, as is the case for 12 provenances currently growing at the North Star Provenance Test in northwest NB. The seeds for the provenances come from source areas within the present-day range of balsam fir, a commercially- and ecologically-important tree species in Canada. Ecosystem-level species-response functions formulated from the work will help re-define balsam fir distribution projections for a significant part of Atlantic Canada. Current species distribution models use "crisp" thresholds that are derived from assessments of range characteristics related to climate. This work will add a new level of realism (i.e., species plasticity) in balsam fir distribution projections for Atlantic Canada.******

起源测试最初严格用于造林目的，现在被认为非常适合研究树木适应气候变化的种内变异。然而，在受控条件下评估树木在变化的气候条件下的性能的研究受到空间和时间的限制。这些限制使得在北美建立的长期种源地块有助于提供数据，这些数据可以提供有关其自然范围之外的物种表现的可靠信息。***植物生产力的一个重要生理过程是光合作用，其速率可能受到种源变化的影响。植物物种对环境变化的光合作用反应可以在小叶级和大生态系统级尺度上进行评估。新不伦瑞克省中南部阿卡迪亚研究森林的涡流协方差塔将提供在大型生态系统规模上表征光合作用所需的数据。生态系统尺度上的物种光合作用反应是通过将基于塔的净二氧化碳交换（或净生态系统生产力的负值，-NEP）测量值数学分解为其总生态系统生产的组成通量来确定的，与光拦截和同化以及简单的 NEP 模型和数值优化的呼吸相关。然后，可以使用叶级和生态系统级数据收集生成的信息将相同模型的参数指定为叶级信息的函数。这将允许使用这些模型为缺乏塔数据的森林提供物种反应的生态系统水平特征，就像目前在新布伦茨西北的北极星种源测试中生长的 12 个种源的情况一样。种源的种子来自当今香脂冷杉范围内的源区，香脂冷杉是加拿大的一种具有商业和生态重要性的树种。这项工作制定的生态系统级物种响应函数将有助于重新定义加拿大大西洋大部分地区的香脂冷杉分布预测。当前的物种分布模型使用“清晰”阈值，该阈值源自对与气候相关的范围特征的评估。这项工作将为加拿大大西洋地区的香脂冷杉分布预测增加一个新的现实水平（即物种可塑性）。******