Itasca State Park (ISP)

The 16-hectare Itasca ForestGEO Plot is located in Itasca State Park, northern Minnesota, USA. Situated at the temperate–boreal forest ecotone, the plot contains a mixture of fire-dependent conifers and mesic hardwood species. Relative to other plots in the ForestGEO network in eastern North America, Itasca supports a relatively high abundance of large, old conifer trees. Topographic variability within the plot is limited, although several small patches are seasonally flooded within the characteristic post-glacial “knob and kettle” landscape. The predominant soils are derived from glacial till and outwash, consisting of well-drained, deep, coarse-loamy to silty loams formed on moraines. The regional climate is continental, characterized by cold winters, warm and humid summers, and pronounced seasonal and diurnal temperature fluctuations. The mean annual temperature is –13.8 °C, with average annual precipitation of roughly 650 mm.

The Itasca plot consists of a main plot that is 15 hectares (380 meters x 400 meters) and an adjacent north plot that is 1 hectare (80 x 100 meters). In the main plot, sugar maple (Acer saccharum) is the most abundant species and occurs throughout the understory due to decades of fire suppression combined with warming annual temperatures. Large red pines (Pinus resinosa) and white pines (Pinus strobus) persist as canopy emergents, although almost no regeneration of either species is present in the understory. The dominant canopy is composed of multiple maple species (Acer rubrum and A. saccharum), oak (Quercus rubra and Q. macrocarpa), and aspen (Populus tremuloides and P. grandidentata), along with paper birch (Betula papryifera) and basswood (Tilia americana). In seasonally flooded locations, American elm (Ulmus americana) and green and black ash (Fraxinus pennsylvanica and F. nigra) become locally abundant. The understory includes dense patches of hazel (Corylus americana) along with more limited patches of mountain maple (Acer spicatum), ironwood (Ostrya virginiana), and muscle wood (Carpinus caroliniana). The north plot has a higher abundance of white pines from multiple age classes and a much lower presence of sugar maple in the understory. Common large mammals include black bear (Ursus americanus), white-tailed deer (Odocoileus virginianus), and porcupine (Erethizon dorsatum). Although the forest in the plot has not burned for at least 100 years due to long-standing fire suppression efforts, other human disturbance is minimal.