- Period: 2018-01-01
The Pine Popple DREAM research site is located within the Wild Rivers Legacy Forest in northeastern Wisconsin and is managed by the Wisconsin Department of Natural Resources. The 66 hectare/162 acre experimental site is characterized as a northern hardwood forest with silt loam soils and an overstory dominated by sugar maple (Acer saccharum). The stand was likely degraded by management legacies, white-tailed deer overbrowsing, and earthworms. These various legacies challenge sustainable management and, thus, offer an opportunity to test whether assisted migration may be a viable option to improve stand value and diversity.
The experiment is a partnership between the Michigan State University and has a core mission of testing a range of climate-smart silvicultural strategies for ten economically and ecologically important species in an assisted migration context. , , and
Projected Climate Changes and Analogs
The research site could experience mean annual temperature and precipitation increases as much as 6 – 11° F and 3” by end of century, respectively. We developed climate analog models of the research site to locate seed sources potentially adapted to these emerging climatic conditions. Climate analogs are locations that exist today that resemble the projected climate of another location – in this case our northern hardwood study site. Our models identified southern Wisconsin as a candidate location for mid-century seed collection and northern Indiana and northwestern Ohio for end-century collection of targeted species.
Our study site includes four replicate, 3.25 ha/8 acre blocks (Figure 1). Half of each block will be randomly assigned to either clearcut or uniform shelterwood. Additionally, half of each overstory cutting treatment will be fenced to exclude browsers and the other half left as an unfenced control. Further, an understory management (brushcut or control) will be randomly assigned within half of each fence and control portion. Treatment replication will be in four blocks.
Ten species will be planted in a fully factorial design. Our study species, from least to most shade-tolerant are: black walnut (Juglans nigra), tulip poplar (Liriodendron tulipifera), shagbark hickory (Carya ovata), white oak (Quercus alba), eastern white pine (Pinus strobus), American basswood (Tilia americana), white spruce (Picea glauca), northern white cedar (Thuja occidentalis), sugar maple (Acer saccharum), and eastern hemlock (Tsuga canadensis). Species were selected based on ecological (e.g., oak acorns for wildlife) and economic (e.g., timber; sugar maple syrup) importance and each study species will have three source populations representing current, mid-century, and end-of-century climatic analogues (Figure 1).
Figure 1. Map of the Pine Popple DREAM replicate. Black line represents overall stand boundary, and the red line represents the timber sale boundary. Blue, pink, and grey rectangles represent the shelterwood, clearcut, and uncut control areas. Inset illustrates the experimental design at the block level. Each block contains a full factorial design with planting locations for the three climate analogues (current, mid-century, and end of century climate) nested within browse fence and understory/overstory silvicultural treatments.