An ecological perspective on terrestrial biogeosciences

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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. **