Grant: Alliance Grants

Healthy forests start with healthy soils. Soils host the greatest level of biodiversity found on Earth and provide many other benefits to forest ecosystems including water purification, nutrient cycling and the support of productive forests. Soils also contain by far the largest carbon stocks in terrestrial ecosystems. About 28,800 million tonnes of carbon are sequestered in mineral soils of Canadian forests alone, corresponding to 10% of stocks found in forest soils globally. Even small variations in these extremely large stocks can have a profound impact not only on the carbon balance of Canadian forests, but also on the global carbon cycle. Yet, despite their importance, there is still great uncertainty about the mechanisms controlling soil carbon persistence. Our research project aims to address this major knowledge gap by quantifying soil carbon formation and persistence across the major forested ecozones of Canada. We have established a nationwide network of experimental sites to compare key soil types under different tree species representative of Canadian managed forests. We will measure the decadal sensitivity of soil carbon to environmental shifts including global change, harvesting and fire. We will clarify linkages between carbon persistence and soil biodiversity. Overall, this research project will establish the foundational scientific knowledge required to improve current predictions of soil carbon response to environmental shifts in Canadian forests. This will, in turn, inform management adaptation strategies tailor-made for sustaining Canadian forests and their soils. Lastly, outcomes of our proposed research will allow for a meaningful inclusion of forest soil carbon in Canadian climate policies, including global commitments under the United Nations Framework Convention on Climate Change.