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Harvard Forest REU Symposium Abstract 2014
- Title: Nitrogen availability impacts productivity and carbon storage at three recently cleared sites at Harvard Forest
- Author: Alayna M Johnson (University of Minnesota - Morris)
- Abstract:
Assessing the productivity of a forest ecosystem is crucial for understanding the total amount of carbon being stored as biomass within a forest, and therefore what role a forest has in broader discussions of climate change. However, site-specific variables should be considered, such as the effect of nutrient availability on productivity. Since the productivity of temperate and boreal forests is often limited by nitrogen availability, examining this factor is important for more accurately understanding the carbon balance of forests. To test the hypothesis that greater nitrogen availability correlates with greater productivity across recently cleared sites at Harvard Forest, bulk organic and mineral soil samples were collected and analyzed for total carbon and nitrogen percentage. Productivity at each site was determined through woody biomass vegetation surveys and allometry. Preliminary data also suggests that there is an inverse exponential trend between above-ground sapling biomass and mean C:N ratios, suggesting that sites with low C:N ratios correlate with increases in productivity. Greater productivity at these sites may suggest that larger amounts of carbon are being stored in the biomass of regenerating forests that are less restricted by nitrogen availability. Thus, the role of nutrient-limitation is shown to be an important factor for accurate analysis of the overall carbon storage in similar regenerating New England forests.
- Research Category: Forest-Atmosphere Exchange; Soil Carbon and Nitrogen Dynamics
