Invasives Strike Force Citizen Science Program Tops 1,000 Miles of Trail Surveyed

Linda Rohleder, Trail Conference Director of Land Stewardship and Lower Hudson Partnership for Regional Invasive Species Management Coordinator
New York-New Jersey Trail Conference


Surveying plants to identify invasive species. Photo Credit: Jeremy Apgar

After only 5 years of service, the Trail Conference’s Invasives Strike Force volunteers have surveyed over 1,000 miles of trails in the region, creating the first-of-its-kind map of invasive plants along hiking paths from a broad landscape scale. When the program first started in 2011, the stated goal was to collect baseline data on all of the regional hiking trails with the intention of monitoring and halting the spread of invasive plants within our parks. Originally we targeted about 1,300 miles of trail in both New York and New Jersey, aiming to complete the entire slate within five to six years. We are currently on track and are very close to reaching our goal.

When we started the program, very little was known about the extent of invasive species in our parks. The surveys have turned up some interesting results. We've identified the top invaders in our parks: Japanese barberry, Japanese stiltgrass, multiflora rose, wineberry, and garlic mustard. In fact, the top two—Japanese barberry and Japanese stiltgrass—have been found in all of the parks surveyed so far.

We’ve also identified parks that have substantial areas with fairly low invasive plant levels, such as Abram Hewitt State Forest, the southern portion of Norvin Green State Forest in New Jersey, Schunemunk Mountain State Park and Storm King State Park in New York. We’ve also seen a pattern of more invasive species closer to human impacts, such as parking areas and buildings.

In addition, our advanced volunteers have been searching for newer invaders and have helped us establish the general ranges of Japanese angelica tree, black swallowwort, and other species just beginning to take hold in our region. This information allows us to plan targeted removal efforts to help restrict the spread of these invaders before they establish in new areas.

Our survey strategy assigns a manageable section of just two miles to each volunteer. Over the last five years, almost 300 volunteers have been involved in our surveys. In the process, they have collectively generated over 50,000 observations of invasive species–a substantial data set that will be useful in analyzing invasive species distribution and spread throughout the region.

Using the data collected by our volunteers, we are able to plan work days where we remove pockets of invaders to protect native habitats and also target new invaders to help keep them from establishing and becoming the next Japanese barberry. We’re also able to start predicting areas which are more likely to be invaded.

Our 2015 season has come to a close, but we’re already planning for next year. To participate in 2016, sign up for our mailing list by emailing Linda Rohleder, Director of Land Stewardship, at [email protected].

Has your park been surveyed?

Our volunteers have collected data at over 60 parks, many of which have had every trail completely surveyed. Find out which ones have been completed at