Harvard Forest >

Summer Research Project 2017

• Title: Group Project: Post-Harvest Carbon Dynamics, Forest Structure and Biodiversity
• Group Project Leader: Audrey Barker Plotkin
• Mentors: Audrey Barker Plotkin; J. William Munger; Timothy Whitby
• Collaborators: Audrey Barker Plotkin; J. William Munger
• Project Description:

  The concept of ‘sustainability’ can mean different things for different activities. Traditionally, forest management is considered sustainable if wood growth matches or exceeds wood harvested on a forested property. When ecosystem carbon balance is the metric, determining sustainability becomes more complicated. Because forest carbon has become an important component of policies to reduce greenhouse gas emissions or reduce atmospheric CO2, we need better quantitative understanding of carbon-balance consequences of forest management practices and biomass energy projects. In part as a bioenergy demonstration project, the Harvard Forest installed an efficient wood burning system in 2013 to heat more than 50,000 square feet of campus buildings, and be entirely supported by wood harvested from Harvard Forest land. Extensive data are collected on the boiler operation to quantify energy efficiency. More data are needed on the details of biomass harvest and net carbon balance as the forest regrows to fully evaluate how well this project meets its sustainability goals once carbon losses from harvesting and regrowth rates are considered. These results will help answer the critical question of what fraction of the regional energy requirement could be sustainably supplied with biomass and how much land area would have to be designated for harvest. This project will quantify the carbon budget of actual timber harvests under present-day conditions at Harvard Forest, using two focal field sites. We may establish additional study plots in forest stands currently being harvested to supply wood for the heating system.
  
  1. Forest Development after Plantation Removal
  The Harvard Forest harvested 32 hectares of mature plantation forests during 2008-2009 to restore a diversity of native tree species to these sites, and to add young forest to the research sites available. The plantations of primarily non-native conifers were established in old fields during the early years of the Harvard Forest, when forestry was a new science in the United States, and much emphasis was placed on plantation forestry. In contrast, current forest practices in Massachusetts emphasize working with natural processes and native species. The harvested blocks ranged in size from 1 – 15 hectares.
  
  A network of permanent plots in harvested and in unharvested control plantations was installed and sampled in 2007, prior to the harvest. In 2012, the plots were re-measured. Measurements include components of a carbon budget, including live and dead wood stocks, as well as measures of vascular plant species diversity. Collaborating scientists are conducting more rigorous studies of carbon stocks and fluxes in focal harvested stands. We will re-sample the 22 permanent plots this summer, 8-9 years post-harvest.
  
  2. Forest Carbon Changes after Partial Harvesting
  The Harvard Forest Environmental Measurements Site (HFEMS) tower provides the world's longest continuous record of net ecosystem CO2 exchange between the forest and atmosphere. In 2001, a partial harvest conducted at the outer edge of the HFEMS tower footprint removed about 25% of the aboveground biomass. Plots in the harvested and un-harvested portions of the footprint allowed an accounting of the short-term carbon consequences of harvest. Now, for the first time since 2007, we plan to re-measure live and dead wood stocks in the harvested area and compare the trajectory of forest re-growth to annual measurements of the unharvested plots.
  
  General Qualifications
  Valid drivers’ license to enable the students to drive a Harvard Forest vehicle
  Enthusiasm for being outdoors as majority of the summer will be spent conducting field work

• Readings:

  Manomet 2010 report https://www.manomet.org/sites/default/files/publications_and_tools/Manomet_Biomass_Report_Full_June2010.pdf
  
  Frances O’Donnell undergraduate Harvard U. thesis: http://harvardforest.fas.harvard.edu/sites/harvardforest.fas.harvard.edu/files/publications/pdfs/odonnell_thesis_2007.pdf
  
  Fahey et al. 2009: http://onlinelibrary.wiley.com/doi/10.1890/080169/full

• Research Category: Large Experiments and Permanent Plot Studies, Group Projects, Forest-Atmosphere Exchange, Conservation and Management