An ecological perspective on terrestrial biogeosciences

加拿大人面临的一大挑战是预测全球环境变化和/或替代土地管理做法如何影响陆地生态系统的功能及其提供的各种服务。关注对碳和营养循环的生物控制是应对这一挑战的一种有希望的方法。为此，可以应用几个科学学科，每个学科都为一个特定的现象提供不同的见解和解释模型。我自己的学术训练很好地扎根于生物地理学(即农业土壤科学理学学士；森林养分循环博士；森林土壤管理博士后)。但自从16年前搬到舍布鲁克以来，我已经融入了一群基础生态学家，他们向我灌输了对碳和养分循环的互补观点。因此，我和我的学生们培养了一种关于陆地生态系统的双重视角，使我们能够同时解决机械问题和理论问题。作为生物地质学家，我们研究的过程和机制是驱动陆地营养循环的直接因素。作为生态学家，我们提出并依赖理论框架来理解这些相同现象的进化含义，以及推测、概括和做出大胆的预测。简而言之，作为生物地质学家，我们经常问某些现象是如何发生的；作为生态学家，我们经常问它们为什么会发生。DG的这一建议是基于这样一种信念，即通过放弃对陆地生物地理科学的生态观点，可以实现大量的知识和技术。在这个框架内，我和我的学生将探索四个研究主题：(I)根引发效应(RPE)对土壤有机质(SOM)分解的影响；(Ii)全球环境变化对北方森林生物固氮(BNF)的影响；(Iii)植物-丛枝菌根(AM)群落结构的原因和后果；以及(Iv)近红外光谱(NIRS)绘制大型草食动物景观营养质量的地图。这一跨学科研究计划将有助于提供关于群落组装以及碳和养分循环的生物控制的重要基础知识，将提高我们预测全球环境变化和土地管理影响的能力，并开发一种新的工具来监测食草动物的食物景观。

One of the great challenges facing Canadians is predicting how global environmental changes and/or alternative land management practices affect the functioning of terrestrial ecosystems and the myriad of services that they provide. Focusing on the biotic controls over carbon and nutrient cycling is a promising way to tackle this challenge. Several scientific disciplines may be applied to this end, each offering different insights and explanatory models for a given phenomenon. My own academic training is well-ensconced in the biogeosciences (i.e. BSc in agricultural soil science; PhD in forest nutrient cycling; Postdoc in forest soil management). But since moving to Sherbrooke 16 y ago, I have integrated a group of fundamental ecologists who have instilled into me a complementary outlook on carbon and nutrient cycling. My students and I thus foster a dual perspective on terrestrial ecosystems that allows us to address both mechanistic and theoretical questions. As biogeoscientists, we study processes and mechanisms that are the proximate factors driving terrestrial nutrient cycles. As ecologists, we advance and rely upon theoretical frameworks to understand the evolutionary implications of these same phenomena, as well as to speculate, generalize and make bold predictions. Simply put, as biogeoscientists we often ask “how” do certain phenomena occur; as ecologists, we often ask “why” do they occur. This DG proposal is predicated on the belief that substantial knowledge and technologies can be achieved by shedding an ecological perspective on terrestrial biogeosciences. Within this structure, my students and I will explore 4 research themes: (i) root-priming effects (RPE) on soil organic matter (SOM) decomposition, (ii) the effects of global environmental changes on biological N fixation (BNF) in boreal forests, (iii) causes and consequences of plant–arbuscular mycorrhizal (AM) community structure, and (iv) near infrared spectroscopy (NIRS) to map the nutritional quality of landscapes for large herbivores. This transdisciplinary research program will contribute important and fundamental knowledge on community assembly and the biotic controls over carbon and nutrient cycling, will increase our ability to predict the impacts of global environmental changes and land management, and develop a new tool for monitoring the food landscape for herbivores.