This story highlights a current research project at the Hubbard Brook Experimental Forest. To read more about research projects at HBEF, visit Current Research page. Check back regularly to learn about new research projects.
Climate Change Across Seasons Experiment (CCASE)
 

  Contact Info:
  Pamela H. Templer
Boston University
Department of Biology
5 Cummington Mall
Boston, MA 02215
Phone: 617-353-6978
email: ptempler@bu.edu

MEAN ANNUAL temperatures for the northeastern U.S. are projected to increase 3-5 °C by the year 2100, which could increase water and nutrient uptake and carbon storage by trees. However, the increase in temperature will lead to a smaller winter snowpack and increased frequency of soil freeze/thaw cycles, which may offset the positive effects of warming by damaging roots. The overall result could be reduced nutrient uptake and storage of carbon and further elevation of atmospheric CO2 concentrations. Understanding the mechanisms and controls underlying changes in nutrient uptake by trees is necessary for improving predictions of how ecosystems will respond as the climate changes. Whereas many studies have evaluated the impacts of climate change on forests within a single season, few have examined the impacts of climate change across seasons and how these impacts interact. These "across season" effects could be antagonistic or synergistic, which would not be apparent from examining one season alone.

The goals of this research are to determine the interactive effects of winter and growing season climate on water and nutrient uptake and carbon sequestration in northern hardwood forests. These goals are being accomplished with a new ecosystem warming experiment at Hubbard Brook.

  templer  
Figure 1 Experimental design for CCASE experiment in red maple (Acer rubrum) dominated forest. There are six plots total (each 11 x 14m). Two are warmed 5°C throughout the growing season. Two others are warmed 5°C in the growing season and have snow removed during winter to induce soil freeze/thaw cycles. Four kilometers (2.5 mi) of heating cable are buried in the soil to warm these four plots. Two additional plots serve as controls for our experiment.

 

We hypothesize that warmer soil temperatures will increase forest productivity, as well as rates of water, carbon, and nutrient uptake by trees and saplings. However, we expect that a reduced winter snowpack and increased soil freezing will offset these changes by damaging roots. Results from this study will help us understand the effects of climate change on rates of carbon sequestration and nutrient retention of these forests, as well as potential effects on water air and water quality.

  forest cover conduit  
  Experimental plots in red maple (Acer rubrum)
dominated forest
Conduit and junction boxes for warming cable  

  shed measuring  
  Rebecca Sanders-Demott and
Stephanie Juice.

  Dataloggers and soil temperature controls in shed.
   

Funding for the establishment of this experiment came from the Long Term Ecological Research Network and a National Science Foundation CAREER grant (DEB 1149929).

      Measuring soil frost in winter  

Date Prepared: June 2013