Causes of plant functional trait variability under environmental change and consequences for biogeochemical processes

将森林变为农田对地球的生物和非生物系统造成了前所未有的破坏。最大的影响是全球氮(N)和碳(C)循环的普遍变化。随着森林被农田所取代，支撑植物在生态系统中如何发挥功能的性状多样性正在急剧减少或改变，破坏了C和n的循环。这些功能性状是植物的生化、生理和形态特征，既控制着植物对环境条件的反应，也控制着植物对生态系统过程的影响。对性状变异的程度和原因的研究——比如这里提出的项目——将提供对地球生态系统过程如何以及为什么发生了变化、正在发生变化以及预计会发生变化的更深入的理解。我的长期研究目标是了解植物性状的变化如何影响管理和自然生态系统中的生物地球化学循环。这可以通过一个整合三个研究主题的项目来实现，重点是：(1)树木和森林生态系统过程的功能特征；(2)作物功能性状与农业生态系统过程；(3)土地利用变化对植物功能性状多样性的影响。这一动态计划依赖于现场、实验室和开放获取数据研究的强大组合，跨越一系列陆地生态系统，并使用多种尖端科学技术、仪器和数据库。为了达到我的短期目标，这项研究将通过揭示对树木和主要粮食作物性状变异的程度和原因的更丰富的理解，然后应用这种理解来解释和预测正在进行和未来的生态系统过程，从而显著推进全球变化科学。这项研究将对从事全球变化生物学、森林与农业生态学、植物生态生理学和生物地球化学交叉研究的科学家产生重大影响。通过为世界上许多最常见的作物和树木提供高质量的性状数据，以及性状-生态系统功能关系的分析，该研究也将对应用生态系统生物地球化学建模、粮食安全预测和政策以及土地利用规划和管理具有重要意义。我预计这个项目将培养7名研究生水平的科学家，他们将领导10多篇论文和科学报告。这个项目将大大加强我们对以下方面的理解：(1)如何利用加拿大的森林来缓解气候变化的战略，而且还有助于(2)对加拿大农业用地的生产和可持续性进行长期预测，以及(3)对加拿大生态系统中植物多样性和生态系统过程在未来可能发生的变化进行预测。至关重要的是，这些贡献将带来切实的政策效益，包括加拿大如何切实履行其2016年《巴黎协定》关于减缓气候变化的承诺。

Objectives Turning forests into agricultural lands has caused unprecedented disruptions to Earth's living and non-living systems. The greatest impacts are pervasive changes to global nitrogen (N) and carbon (C) cycles. As forests are replaced by croplands, the diversity of traits that underpin how plants function within ecosystems are being drastically reduced or altered, disrupting the cycling of C and N. These functional traits are the biochemical, physiological, and morphological characteristics of plants that govern both plant responses to environmental conditions, and plant impacts on ecosystem processes. Research on the extent and causes of trait variability-such as the program proposed here-would provide a deeper understanding of how and why Earth's ecosystem processes have changed, are changing, and are predicted to change. My long-term research aim is to understand how variation in plant traits influences biogeochemical cycles in managed and natural ecosystems. This achievable through a program that integrates three research themes focused on (1) functional traits in trees and forest ecosystem processes; (2) functional traits in crops and agroecosystem processes; and (3) global shifts in plant functional trait diversity through land-use change. This dynamic program relies on a powerful combination of field, lab, and open access data research, spans a range of terrestrial ecosystems, and uses multiple cutting-edge scientific techniques, instrumentation, and databases. Impact In reaching my short-term goals, this research will significantly advance global change science by revealing a richer understanding of the extent and causes of trait variation in trees and staple food crops, and then applying this understanding to explain and predict ongoing and future ecosystem processes. This research will most affect scientists working at the intersection of global change biology, forest and agroecology, plant ecophysiology, and biogeochemistry. By providing high-quality trait data for many of the world's most common crops and trees, and analyses on trait-ecosystem function relationships, this research will also be important for applied ecosystem biogeochemical modelling, food security forecasting and policy, and land--use planning and management. Expected Outcomes I anticipate this program to train 7 graduate-level scientists, who will lead over 10 papers and scientific presentations. This program will substantially strengthen not only our understanding of (1) how Canada's forests may be used in strategies to mitigate climate change, but also for making (2) long-term predictions of the production and sustainability of Canada's agricultural lands, and (3) projections of how plant diversity and ecosystem processes in Canada's ecosystems are likely to change in the future. Crucially, these contributions will have tangible policy benefits, including how Canada could viably meet its 2016 Paris Agreement commitments to mitigating climate change.