Biodiversity patterns along environmental gradients

生物多样性模式通常沿着环境梯度进行研究，以阐明驱动物种组合的因素，并建立群落如何适应人为干扰的预测。然而，以物种多样性为中心的方法受到物种分类学相对缺乏关于观察模式的生态机制的事实的限制。将功能性状整合到生物多样性研究中可以提高我们理解和预测物种模式的能力，因为物种通过定义个体适应性的生物属性来响应生态过滤器。综合性状数据库的最新发展使得沿着广泛的环境梯度使用功能性状来理解生物模式成为可能。在这方面，代表群落功能特征的价值和范围的功能多样性已被证明与物种多样性呈非线性变化。我相信，首先沿着自然梯度研究物种和功能多样性之间的关系，然后观察这种关系在人为干扰下是如何改变的，可以极大地提高我们理解控制群落的因素和预测其长期命运的能力。在我目前的研究经费资助下，我利用湿地进行以下研究：1)沿着广泛的自然梯度研究物种和功能多样性之间的联系；2)评估不同环境下物种和功能多样性对人为干扰的响应；3)评估使用晚演替物种进行恢复如何有利于林下植物群落物种和功能多样性的恢复。我将使用一个庞大的植被数据库来研究泥炭地的纬度和矿物质营养（酸度）梯度。我将研究物种和功能多样性如何沿着这些自然梯度共同变化，并确定物种的特定功能群是否比其他物种的分布更窄。此外，我将研究人为干扰如何改变物种和功能多样性之间的关系，通过观察1)泥炭地的植被随时间的变化，在不同的人为发展水平的景观中，以及2)当洪水状态由水坝控制时，河岸森林的植被变化与维持自然状态时。最后，通过研究不同年龄（2 ~ 17年）河岸人工林与参考天然河岸林的植物演替，探讨恢复后河岸林林下植物的恢复能力。性状是环境驱动因素控制物种分布的载体。通过研究自然、受干扰和恢复环境中的物种和功能性状多样性，我的研究项目将提高我们理解沿环境梯度的群落模式的能力，并帮助我们预测生态系统对干扰的恢复能力。全球变化可能在所有尺度上改变环境过滤器，研究沿扩展纬度梯度的模式应该为在气候变化下预期的植被变化提供有价值的见解。此外，增加我们对群落如何应对干扰和恢复后恢复的了解是非常值得关注的，因为2011-2020年世界生物多样性战略计划将到2020年恢复15%的退化生态系统作为目标。

Biodiversity patterns are commonly studied along environmental gradients to elucidate factors driving species assemblages and build predictions on how communities will adapt under anthropogenic disturbances. However, approaches centered on species diversity are limited by the fact that species taxonomy is relatively information-poor regarding the ecological mechanisms underlying observed patterns. The integration of functional traits into biodiversity studies should increase our ability to understand and predict species patterns, simply because species respond to ecological filters through biological attributes that define individual fitness. Recent developments in comprehensive trait-databases have enabled the use of functional traits along extensive environmental gradients for understanding biological patterns. In that regard, functional diversity, representing the value and range of functional traits in a community, has been shown to vary non-linearly with species diversity. I believe that studying the relationship between species and functional diversity along natural gradients first, and then looking at how this relationship is modified under anthropogenic disturbances, could dramatically improve our capacity to understand factors governing communities and predict their fate in the long term. Under my current discovery grant, I use wetlands to 1) investigate the link between species and functional diversity along extensive natural gradients, 2) assess the response of both species and functional diversity to anthropogenic disturbances in different contexts, and 3) evaluate how restoration using late successional species favours the recovery of both species and functional diversity of understory plant communities. I will use a vast vegetation database to study the latitudinal and minerotrophic (acidity) gradients in peatlands. I will investigate how species and functional diversity co-vary along these natural gradients and identify whether particular functional groups of species have a narrower distribution than others. In addition, I will study how anthropogenic disturbances modify the relationship between species and functional diversity by looking at 1) vegetation change in peatlands over time, in landscapes with different levels of anthropogenic development, as well as 2) vegetation changes in riparian forests when flooding regime is controlled by dams versus when a natural regime is maintained. Finally, I will investigate the resilience of the riparian forest understory after restoration by studying plant succession in riparian plantations of different ages, from 2 to 17 years, compared to reference natural riparian forests. Traits are the vehicle on which environmental drivers act to control species distribution. By studying both species and functional trait diversity in natural, disturbed and restored environments, my research program will increase our capacity to understand community patterns along environmental gradients and help us predict the resilience of our ecosystems to disturbances. Global change may modify environmental filters at all scales, and studying patterns along extended latitudinal gradients should provide valuable insight into changes in vegetation that could be expected under shifting climate. In addition, increasing our knowledge of how communities respond to disturbances and recover after restoration is of great concern, as the world Strategic Plan for Biodiversity 2011-2020 sets as an objective the restoration of 15% of degraded ecosystems by 2020.