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Cornell University

New York State Hemlock Initiative

Keeping the legacy alive

MyHemlock

Your Trees, Your Data

Hemlock woolly adelgid (HWA) poses a big threat to native hemlock trees throughout New York, and HWA surveying can help limit the damage by informing management decisions and contributing to research efforts. Landowners are especially critical players in managing invasive forest pests since, according to the DEC, 76% of New York’s forested lands are privately owned. While the MyHemlock program was developed with landowners in mind, anyone interested in hemlock conservation efforts is welcome to participate.

MyHemlock volunteers choose one site—their own property or woodlot, or a favorite local conservation area—and survey a group of trees on that site twice per year. Surveys help the NYSHI team better understand the behavior and spread of HWA in New York and help local landowners and managers time and prioritize HWA management efforts.

What to expect as a MyHemlock team member:

MyHemlock participants will choose one site to survey and return to that site to survey hemlock trees once in the late fall and early winter season (late November through early December) and again in the late spring season (late May through early June). These two annual surveys will contribute data on changing tree health and HWA winter mortality patterns, as well as where and how quickly HWA is spreading in New York. Surveying the same site over time will help us better understand HWA population dynamics over time and learn more about what is happening in hemlock forests locally and regionally.

Sign up to be a part of MyHemlock:

For Hard Copies of Program Materials:

Conducting Your Survey

First, you’ll choose a stand of hemlock at your study site to survey. A stand is a group of trees, and the stand you choose can include as few or as many trees as you like.  Once you have chosen your site, you will register it in the MyHemlock program so that you don’t need to input location and stand information each time you input data.The registration form includes site location and site description data that will help us learn more about the forest conditions in your area. While our team keeps survey location information on file, we will never share information about your property without your consent.

During the two surveying times in the year, you’ll check the stand for HWA and assess overall tree health, then input that data into the MyHemlock survey form. Our form is available online, or as a hard copy that you may scan and email or mail to us.

MyHemlock site registration forms for new volunteers:

HWA survey forms for current MyHemlock program volunteers:

MyHemlock Survey Data

We look for three critical pieces of data to understand more about HWA in New York’s forests:

Overall tree health
Tree health indices include any sightings of a thinning canopy and whether or not there are dead branches present in a stand.

HWA Presence or Absence
Surveys help us know whether or not an infestation is present in a stand.

Severity of HWA infestation
We also look for data concerning the overall density of HWA in a stand, or whether you see many or few woolly masses on tree twigs.

Report HWA Findings

To tell us about hemlock woolly adelgid findings in your area, click here