Written By Kris Brown.
Posted on June 24th, 2021.
Cornell Cooperative Extension developed a method called Assessing Vegetation Impacts from Deer (AVID) that anyone can use to assess deer browsing impacts in their area. Annual measurements of seedling heights are the basis for quantifying the impact of deer browse. Over time, this data can help to inform management decisions to reduce deer browsing impacts so that desirable tree species may grow.
New York State has a forest regeneration problem. That is, white-tailed deer are often so abundant that palatable tree seedlings like maple, ash, and oak have a tough time growing to maturity. When timber harvesting or natural disturbance events remove canopy trees, these spaces are occupied by vegetation that deer prefer not to eat. This allows species like hay-scented fern and American beech to dominate the understory and future forest conditions.
Cornell Cooperative Extension (CCE) developed a method called Assessing Vegetation Impacts from Deer (AVID) that anyone can use to assess deer browsing impacts in their area. Annual measurements of seedling heights are the basis for quantifying the impact of deer browse. Over time, this data can help to inform management decisions to reduce deer browsing impacts so that desirable tree species may grow.
Tracey Testo of CCE Columbia and Greene Counties has taught volunteer, landowner, and professional groups how to set up and monitor AVID plots. She is also leading an effort to establish AVID plots at several Model Forests in the NYC Watershed. In late-May 2021, Dr. René Germain (SUNY ESF), John Hannum (4-H Team Leader, CCE Delaware Co.), and I helped Tracey establish four AVID plots at Lennox Model Forest in Delhi, NY.
The AVID plots will be used as demonstration sites for campers attending 4-H Camp Shankitunk, located across the road from Lennox. As such, we wanted the plots to be relatively close to the trailhead. Another consideration was that we wanted the plots to be in the same stand of trees, which is a management unit defined by a forest management plan. We spent 10-15 minutes scanning the forest floor and found (in order of abundance) white ash, red maple, sugar maple, and red oak seedlings. Note that AVID does require some tree identification skills, but you don’t need to be an expert.
Each plot should contain at least 5-6 tree seedlings of a target species, ranging from about six inches to four feet tall. We decided to make white ash our target species as it was most abundant, but we also measured other tree species that happened to be in the plots. As you might have guessed, plots are not selected randomly, but to maximize the number of individuals from a target species.
To start, we marked the center of each plot with a hunter orange stake and a GPS point:
Tracey looped piece of twine around the plot center and cut it at length of six feet, equal to the plot radius. We used a compass to flag out the cardinal directions. This divided the circular plot into four quadrants (NE, SE, SW, and NW):
Tracey and René flagging out the plot area.
For each tree seedling, we recorded the species, tag number, quadrant, and height (inches). In subsequent years, we will need to measure only tree height. Note that annual re-measurements should occur within a week of the establishment date, in this case May 21.
Numbered seedling tags were secured around the base of each seedling within the plots.
René attaching a seedling tag.
Tracey measuring seedling height.
René measuring seedling height.
In the end, this is what the plots looked like:
Plot Number 4, complete with an orange center stake, red pin flags marking the cardinal directions, and 28 tagged seedlings.
And here is what our datasheets looked like:
After reviewing the AVID user guide and spending an afternoon setting up plots with Tracey, I feel confident I could install these plots in my own woodlot. Also, I look forward to helping to re-measure these seedlings during the third week of May 2022. What a beautiful time of year for field work. To learn more about AVID, check out: https://aviddeer.com/