Harvard Forest Research

Hemlock Removal Experiment: Initial Responses

Principal Investigator: Aaron Ellison
Harvard Forest: Jan 01 2005 - Jan 01 2014:

Abstract:
The dynamics of hemlock forests in New England are changing rapidly with the invasion of the hemlock woolly adelgid (Adelges tsugae), an exotic insect pest that kills hemlock trees and is moving into central New England. Layered onto this regional-scale disturbance is the pre-emptive logging that many landowners are doing in anticipation of hemlock mortality. We have established a large-scale experiment to simulate the effects of hemlock removal from the forest ecosystem by adelgid and by logging. Our goals for Summer 2006 are to continue to monitor overstory tree response to girdling and assess immediate vegetation response after logging. We also will be continuing an effort to map all trees within the study plots. See below for specific sampling plans.

The logging of plots 2 & 4 was completed in April 2005.
The girdling manipulation of plots 1 & 5 took place in May-June 2005.

Permanent photographic points for long-term monitoring will be established by AME and ABP in May 2006.

Update 2007
1. Permanent photographic points for plot panoramas were established in May 2006. These photos are taken annually in August (next scheduled for August 2007).
2. Canopy photos are taken annually in April and September (next scheduled for April 18, 2007)
3. Mapping of all trees in plots is complete; only some field checking and data QA/QC remains to be done.

Update 2008
1. Plot panorama points to be better marked (rebar/pvc)
2. Canopy photos will shift from film to digital in 2008 with purchase of Nikon D-3 camera

Update 2009
1. Plot panorama points still to be better marked (rebar/pvc) (not done in 2008; needs to be done in 2009).
2. In July 2008, soil temperature probes were changed from one probe at 10cm depth to two probes, one in organic and one in mineral soil layer.

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