University of Notre Dame Environmental Research Center NEON / UNDE

UNDE is a terrestrial NEON sampling site located at the University of Notre Dame Environmental Research Center (UNDERC), found between Northern Wisconsin and Michigan’s Upper Peninsula on the southwestern edge of Ottawa National Forest. NEON samples 29.39 km² (7262 acres) of area within UNDERC. This NEON site is very distinct from NEON's other terrestrial sites in this area, Treehaven and Steigerwaldt, because of its minimal forest management. The landscape at the site features primarily second-growth mixed forest dominated by red and sugar maple, aspen, and birch. It also contains 30 different lakes, including the NEON aquatic site at Crampton lake. UNDE is located within the Great Lakes Domain (D05), which includes northern Ohio, Michigan, northern Wisconsin, and parts of Indiana and Illinois. D05 hosts four other NEON field sites: two aquatic and two terrestrial, located in Wisconsin and Michigan. [1] [2]

The climate of northern Wisconsin is characterized by bitterly cold winters and generally cool summers with brief times of excessive heat. Precipitation varies from year to year, with the majority of precipitation usually falling during the warmer part of the year. Snowfall also varies from year to year, however, the very northern portion of the state can see heavy snowfall due to lake effect events along the southern shore of Lake Superior. The area can also be subject to severe winter storms and thunderstorms. NEON’s UNDE field site is typically cool for most of the year with an average yearly temperature of 4.3°C (40°F). The average precipitation per year in this area is 802 mm (31.6 in.). [6] [13] [14]

The soils at UNDERC are primarily spodosols within the subgroup Argic Fragiaquods. The particle size control sections show that this site’s texture is dominantly sandy with small proportions of coarse-loamy, sandy or sandy-skeletal, coarse-silty, and coarse-loamy over sandy or sandy-skeletal. [5]

UNDE and the surrounding area are covered in open water areas from lakes, ponds, vernal ponds, and wetlands. The numerous open water areas are thought to be the result of ice block depressions formed by glacial activity in the area. [4] [5]

The dominant vegetation type at this NEON site is primarily second-growth Northern mesic forest. The dominant species of the area are red and sugar maple (Acer rubrum and saccharum), aspen (Populus tremuloides and P. grandidentata), and paper birch (Betula papyrifera). The evergreen forests are typically made up of balsam fir (Abies balsamea) but may include hemlock (Tsuga canadensis). Around this site you can also find wet areas that are home to cedar (Thuja accidentalis) and black spruce (Picea mariana). Some areas within the site are poorly drained, which can lead to open, acidic sphagnum bogs that contain tamarack (Larix laricina) and black spruce. [1]

UNDERC East is located right on the border of Wisconsin and Michigan beside Ottawa National Forest. The proximity to the national forest provides a great abundance of wildlife habitat. This area is home to many species such as the bald eagle (Haliaeetus leucocephalus), fox (Vulpes), and grey wolf (Canis lupus). NEON’s target species are typically small mammals such as the southern red-backed vole (Myodes gapperi), North American deermouse (Peromyscus maniculatus), and the woodland jumping mouse (Napaeozapus insignis). [3] [10]

The main portion UNDERC East was donated to the University of Notre Dame in the 1930s by Martin J. Gillen. This area was marked by clearcutting from 1880 until the 1960s. Starting in the 1940s, there was an increase in frequency of clearcutting, which peaked in the 1950s. Since that time, the amount of cutting has decreased until the most recent logging operation in 1968; since then, there has been no large-scale cutting in UNDERC East. In the past, the most desirable wood to be harvested from this area was eastern white pine (Pinus strobus). This preference led to the clearing of large stands of trees just to reach the white pines. [7]

This site is currently maintained by the University of Notre Dame Environmental Research Center (UNDERC). A long history of clearcutting until the 1960s has resulted in a landscape dominated by a mixture of successional forest regrowth, with large portions of secondary growth. Since the last clearcutting, the forest has been minimally managed in order to maintain access for recreational, education and research goals. Much of the management of this area is to support the extensive aquatic systems on the land. They are focused on providing a unique research opportunity for systems, such as their aquatic ecosystem, that have a very limited amount of disturbance from the public. [1] [8]

UNDE had its initial sampling readiness review for terrestrial sampling in May 2014 but did not get cleared for TOS and TIS sampling until December 2014. The plot establishment took place in May 2015. TIS phase 3 was begun in February 2017.