TITLE: PREDICTING CRITICAL HABITATS OF FRAXINUS NIGRA (BLACK ASH) ACROSS THE
GEOGRAPHICAL RANGE IN MAINE AND NORTHERN NEW YORK:
AN APPROACH TO PRIORITIZING A REGION’S RESPONSE TO ENVIRONMENTAL STRESSORS
ABSTRACT: Fraxinus nigra (black ash) is a species of ash tree that is most commonly found in moist
lowland sites and is typically thought of as a wetland species. While there is not a large population of
black ash throughout the eastern United States, this species nonetheless serves an important socioeconomic and ecological role. Native American tribes have used black ash for centuries to weave
baskets, which have become a key component in the tribes’ histories, cultures, and economies. Black
ash also fills a particular ecological niche in that it is one of only a few species that can colonize wetland
sites. Based on this important niche that F. nigra fills and the socio-economic role that this species plays
for Native American tribes, it is essential to identify and map critical habitats where black ash grows so
that the species may be better monitored and protected from environmental stressors. Such
information is necessary in prioritizing responses to a potential introduction of the emerald ash borer
(Agrilus planipennis). These critical habitats will be defined as sites where F. nigra can regenerate
successfully; where there is a wide (greater than 2mm) increment of annual growth at DBH; and where
there is little to no decline in annual growth levels over time. By identifying the characteristics that
qualify a black ash site as productive, healthy, and containing trees suitable for basket-making (i.e.,
increments greater than 2mm for 20 consecutive years), a comprehensive GIS map will be created
detailing and predicting the locations of critical habitat that can be used by other researchers and land
owners aiming to monitor and protect F. nigra.
OBJECTIVE:
To develop a GIS map that indicates the probable location of sites in Maine and
northern New York which are deemed critical habitat for Fraxinus nigra.
GOAL:
Produce a GIS map that can be used by local land owners, basket-tree harvesters, tribes,
foresters, and researchers to prioritize areas with black ash for protection against the
impending emerald ash borer invasion and other environmental stressors.
RATIONALE BEHIND OBJECTIVE:
In the United States and Canada, there are currently three species of ash that are predominantly
being impacted by the invasion of the emerald ash borer (EAB); green ash (Fraxinus pennsylvanica),
white ash (Fraxinus americana), and black ash (Fraxinus nigra). Black ash is also susceptible to drought
and fluctuating water tables. While the invasive emerald ash borer and potential damage from droughts
and fluctuating water tables threaten all ash trees in North America, it has been found that black ash is
of particular importance both ecologically and socio-economically (Benedict, L., 2010; Benedict, M.,
2001; Benedict and Frelich, 2008; Livingston, 2010; Palik, 2011) and thus requires further attention and
protection if it is to subsist as a key species in the Northeastern United States.