Plant Communities of Hartley Park

Abstract

This project builds on and updates an ecological survey of Hartley Park in Duluth, Minnesota that was conducted in 2003 by consulting ecologist Ethan Perry to evaluate the potential to nominate the park to the Duluth Natural Areas Program (DNAP). In 2003 DNAP was a new program to provide legal protection to city-owned or private lands of ecological or geological significance. DNAP guidelines explain that land in Duluth can be eligible for this protection by meeting criteria in at least one of five categories. The 2003 ecological survey gathered information necessary to determine if parts of Hartley Park qualify for the Native Plant Communities category of DNAP criteria. Although Hartley Park was not designated under DNAP after the 2003 survey, the City of Duluth and Hartley Park managers recently wanted to update the maps and submit a DNAP nomination package in fall of 2019. The City of Duluth contracted with ecologists and geographic information system (GIS) staff at the University of Minnesota Duluth, Natural Resources Research Institute (NRRI) to update the maps. This technical report describes the methods and results of surveys conducted in summer 2019 to update the Plant Community maps of Hartley Park. The project area for this map includes Hartley Park (660 acres) and 38 acres of adjacent open land that the park wants to evaluate for acquisition. The total area mapped in 2019 was 698 acres, with a wide variety of types of vegetation. To evaluate the quality of these vegetation types, the entire park was divided into patches or polygons of different plant community types, most of which were visited by ecologists, some more intensively than others. Access to some polygons was difficult due to steep topography and many trees blown down in a July 2016 wind storm. For these more remote or difficult-access polygons, air photo imagery was interpreted, and additional low-altitude air photos were acquired by NRRI staff using unmanned aerial vehicles (UAVs). For native plant communities, the polygons were classified using the system developed by the MN DNR Biological Survey Program, described in the 2003 publication Field Guide to the Native Plant Communities of Minnesota, The Laurentian Mixed Forest Province. Since the names of the DNR communities are often long and not always descriptive of local vegetation, we have provided alternative cover names specific to Hartley (Table 1). Vegetation types not considered native plant communities (including conifer plantations, parking lots, ball fields, and areas dominated by non-native species) were divided into general land cover categories; these land cover types as a group are called “Cultural and other communities” similar to NOAA classifications of “Cultural” cover types so modified by human activities that they are not considered “natural” or native plant communities. The cultural cover types had a total of 168 acres. This report focuses primarily on the 530 acres of native plant communities in the project area.