Hemlock Removal Experiment - Seed Bank

• Investigators: Aaron Ellison, Kelley Sullivan
• Contact: Aaron Ellison
• Start date: 2004-06-01
• End date: 2005-08-31
• Location: Simes Tract (Harvard Forest)
• Latitude: +42.47
• Longitude: -72.22
• Elevation: 200 to 240 meters
• Taxa: Cyperaceae, Juncaceae, Poaceae, Acer spp., Betula spp., Tsuga canadensis
• Keywords: Betula, hemlock, hemlock woolly adelgid, regeneration, seed bank, Tsuga
• Release date: 2005
• EML version: knb-lter-hfr.105.2
• Revisions:
• Abstract:

  The impending loss of hemlock trees due to hemlock woolly adelgid (Adelges tsugae) infestation prompted the need to identify the colonizers in the seed bank. The distribution of seeds buried in the soil in six hemlock and two hardwood stands at the Simes Tract at the Harvard Forest in Petersham, MA was determined using the direct germination method. In hardwood and hemlock seed banks, birch was the most abundant species, dominating the top 8 cm of the soil seed bank. Carex spp. and Rubus spp. were less common in the upper 8 cm of the seed bank. Graminoids were more abundant in hardwood seed banks with sedges normally distributed in the seed bank with a peak occurrence at 8 - 12 cm depth. Rubus spp., Bidens spp., and Apocynum spp. were evenly distributed across depths in hardwood stands but were normally distributed in the hemlock seed banks with peak occurrences at 10 - 12 cm depths. Large-seeded species were transient in the seed bank and except for birch, small-seeded species were buried deeper in the seed bank.

• Methods:

  At five randomly-located points in each of the 8 experimental plots in the Simes Tract, we censused all vascular plant species present in a 1-m2 plot centered on each point. We collected a single 60 x 60 cm x 20 cm deep soil cores at each point. Soil cores were sliced into 2-cm increments, and placed in the greenhouse at full light. Seed bank composition was assessed using the direct germination method. Species identification was confirmed by Jerry Jenkins, Glenn Motzkin, and Elizabeth Farnsworth. Nomenclature follows Gleason and Cronquist, Manual of vascular plants of northeastern United States and adjacent Canada, 1991.

• Use:

  This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

• Related datasets: HF035 HF051 HF106