Grantee Research Project Results
Impact of Winter Climate Change on Soil, Canopy and Ecosystem Carbon Exchange in a Northern Deciduous ForestEPA Grant Number: FP917362
Title: Impact of Winter Climate Change on Soil, Canopy and Ecosystem Carbon Exchange in a Northern Deciduous Forest
Investigators: Reinmann, Andrew B
Institution: Boston University
EPA Project Officer: Just, Theodore J.
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011)
Research Category: Fellowship - Global Change , Academic Fellowships
Northern forests typically have a continuous snowpack for much of the winter; however, winters with an inconsistent snowpack can have colder soils and a greater frequency and severity of soil frost. Climate models predict a reduction in snowpack depth and duration by the end of the 21st century in the northeastern United States, which may have important implications for ecosystem carbon fluxes. This research project will quantify the effects of a late-developing snow pack and increased soil frost on ecosystem carbon fluxes in a northern deciduous forest.Approach:
This snow pack manipulation experiment is being conducted in a mixed-deciduous forest at Harvard Forest located in central Massachusetts. During two treatment years, snow will be manually removed from three of six 13m x 13m plots for the first 5 weeks of winter to simulate late snow pack development and induce soil frost. Growing season canopy carbon exchange and sap flow will be measured in red oak (Quercus rubra) and red maple (Acer rubrum) trees in each plot. Heterotrophic, rhizospheric and total soil respiration and tree stem carbon dioxide efflux will be quantified in each plot throughout the year. By simultaneously measuring above- and belowground carbon dioxide fluxes, this study will be able to quantify the effects of a late-developing winter snow pack and increased soil frost on ecosystem carbon exchange. Phenology of leaf-out and root biomass production also will be measured to determine the importance of soil frost in the timing of these processes and to quantify their relationships with ecosystem carbon fluxes.Expected Results:
It is expected that snow removal will increase depth and duration of soil frost in winter and spring. This may result in reduced heterotrophic and rhizospheric soil respiration and canopy carbon dioxide uptake with a net effect of reducing ecosystem carbon exchange and the ability of mixed-deciduous forests to sequester carbon. It is possible that the expected decline in canopy carbon dioxide uptake will be smaller than the expected decline in heterotrophic soil respiration, which could result in either no change or an increase in forest carbon sequestration.
Potential to Further Environmental/Human Health Protection
Because forest ecosystems provide an important sink for anthropogenic carbon dioxide emissions, it is important to understand how changes in climate may affect the strength of this sink. By filling in the gaps in the understanding of the response of ecosystem carbon fluxes to changes in snow pack duration, the results from this study will improve the ability to predict how carbon sequestration will respond to future changes in winter climate. This will facilitate the development of meaningful carbon dioxide emissions goals and policies that are more effective at mitigating anthropogenic climate change.Supplemental Keywords:
climate change, soil frost, carbon dioxide, soil respiration, canopy carbon exchange, forest ecosystems