Grasslands are globally ubiquitous ecosystems that provide ecological goods and services including forage, biodiversity, and carbon (C) storage. Grassland carbon pools are documented as storing >30 % of carbon globally, and research suggests that there is potential to increase carbon storage via management practices at a rate of 0.5 Pg carbon y-1. In Alberta, Canada, the Alberta Livestock and Meat Agency is funding research to develop programs that will reward livestock producers for protecting carbon similar to those rewarding conservation tillage. To support this, we have quantified the total carbon profile of native grasslands (n=120 sites with paired long-term grazed and ungrazed treatments; 240 plant communities) in Alberta's Aspen Parkland, Foothills Fescue and Mixedgrass Prairie. We measured total carbon in above and belowground vegetation, litter, organic soil and mineral soil horizons to 30 cm depths. Recently we have extended this work to include carbon transformations by studying litter decomposition of predominant increaser and decreaser species at a subset (n= 33) of representative plant communities. These communities are paired with either presence/absence of grazing (n=24) or a three-way comparison among management intensive grazing, continuous grazing and absence of grazing (n= 9). In this study we will measure the decay rate of plant material, changes in litter chemistry and study the activity of microbial decomposers, the proximate drivers of carbon cycling, within litter and associated soil organic matter. The importance of this study is twofold as we will study microbial communities, a large component of the live carbon pool, and microbial function, the driver of carbon cycling, all in the context of grazing management. Ultimately we will link these projects to develop a dynamic framework that will inform policy to reward producers for protecting existing carbon and implementing grazing management strategies able to increase carbon in litter and soil pools.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.