From plant traits to vegetation structure/Des traits des végétaux à la structure de la végétation

从植物性状到植被结构/Des Traits des Végétaux à la Structure de la Végétation

• 批准号: RGPIN-2014-05989
• 负责人: Shipley, JohnWilliam(Bill)
• 金额: $ 3.64万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632084
• 关键词: plant; traits; vegetation; structure; Des

I view community assembly as a selection process occurring at the level of individuals belonging to different species, based on the adaptive fit of functional traits to prevailing environmental filters. This general framework, continued in this proposal, has been pursued using a combination of comparative experiments under controlled conditions, manipulative field experiments, observational studies along environmental gradients and mathematical modelling. The general goal of my research program is to answer the following general questions: Given a regional species pool (a list of plant species that are found in a region), a knowledge of the values of key functional traits of these species, and the environmental conditions found in a local community within this region, which species from the species pool will be found at this site? Which of these species will be dominant, subdominant or rare? How will the answers to the first two questions change if we were to change the position of this local community along important environmental gradients? How does the multivariate distribution of trait values within a community affect important ecosystem properties like primary productivity, nutrient cycling and litter decomposition?I recently (2010) published the general theoretical model of my understanding of trait-based community assembly (“From plant traits to vegetation structure: Chance and selection in the assembly of ecological communities”, Cambridge U Press). In this next 5-year proposal my students and I will be testing and expanding this understanding based on five specific research projects. A current PhD student (Jessy Loranger) will use a unique set of 11 long-term field experiments throughout France, involving community composition, plant traits and environmental gradients, to test my general model (“CATS: Community Assembly by Trait Selection”). A second PhD student (Michaël Belluau) will conduct a series of controlled experiments involving 40 contrasted herbaceous dicots, field observations, and multivariate modelling to better link multiple correlated patterns in leaf economic traits and plant hydraulic architecture to precisely measured levels of water stress. This is currently a relatively poorly studied stress in herbaceous species. A third PhD student (Yuanzhi Li) will be exploring a little-recognized implication of trait-based community assembly that is linked to the classical notion of limiting similarity: if communities are assembled while requiring a certain minimum amount of overlap in multivariate trait-space, then the total area of trait-space occupied by communities must expand as species richness increases. Yuanzhi will test these ideas using an existing long-term replicated experiment involving 24 1X1X1 m3 field mesocosms that initially received the same seed mixture but that differ in levels of soil fertility as well as the intensity and frequency of disturbance. The last two projects involve students yet to be recruited. One MSc student will conduct field and mesocosm experiments by manipulating soil water availability in order to test whether the trait syndromes related to water stress of actual and created plant communities, identified by Michaël Belluau (PhD student) change as predicted. A second MSc student will measure ecosystem responses (primary productivity, nutrient loss and litter decomposition) in the longterm mesocosm experiment and relate these responses to differences in community weighted trait values and their variance.These research projects will contribute to the longterm goal of predicting plant community structure and functioning from generalizable plant traits.

我认为，社区大会作为一个选择过程中发生的个人属于不同的物种，基于适应性的功能特征，以现行的环境过滤器的水平。本提案继续采用这一总体框架，并结合了在受控条件下进行的比较实验、人工实地实验、沿沿着环境梯度进行的观测研究和数学建模。我的研究计划的总体目标是回答以下一般性问题：给定一个区域物种库（在一个区域中发现的植物物种列表），这些物种的关键功能性状的价值的知识，以及在该区域内的当地社区中发现的环境条件，将在该网站上发现物种库中的哪些物种？这些物种中哪一个是优势种、次优势种或稀有种？如果我们沿着重要的环境梯度沿着改变这个当地社区的位置，前两个问题的答案会有什么变化？群落内性状值的多元分布如何影响重要的生态系统特性，如初级生产力、养分循环和凋落物分解？我最近（2010年）发表了我对基于特征的社区组装的理解的一般理论模型（“从植物特征到植被结构：生态社区组装中的机会和选择”，剑桥U出版社）。在接下来的五年计划中，我和我的学生将根据五个具体的研究项目来测试和扩展这种理解。一个目前的博士生（marty Loranger）将使用一套独特的11个长期的实地实验在法国各地，涉及社区组成，植物性状和环境梯度，以测试我的一般模型（“猫：社区大会性状选择”）。第二个博士生（Michaël Belluau）将进行一系列对照实验，涉及40个对比的草本双子叶植物，实地观察和多变量建模，以更好地将叶经济性状和植物水力结构的多种相关模式与精确测量的水分胁迫水平联系起来。这是目前在草本植物中研究相对较少的胁迫。第三个博士生（Yuanzhi Li）将探索基于特征的社区组装的一个鲜为人知的含义，它与限制相似性的经典概念有关：如果社区组装时需要在多变量特征空间中有一定的最小重叠量，那么社区占据的特征空间的总面积必须随着物种丰富度的增加而扩大。元智将使用现有的长期重复实验来测试这些想法，该实验涉及24个1X1X1 m3的田间中生态系统，这些中生态系统最初接受相同的种子混合物，但土壤肥力水平以及干扰的强度和频率不同。最后两个项目涉及尚未招募的学生。一名硕士生将通过操纵土壤水分供应进行田间和围隔实验，以测试与实际和创建的植物群落的水分胁迫相关的性状综合征是否如Michaël Belluau（博士生）所预测的那样变化。第二个硕士学生将测量生态系统的反应（初级生产力，养分损失和凋落物分解）在长期的围隔实验，并将这些反应与社区加权性状值及其方差的差异。这些研究项目将有助于预测植物群落结构和功能的长期目标从概括的植物性状。