Ecological dynamics
This site is a dry to dry-mesic conifer dominated woodland. Soils are sandy or loamy and have a low available water capacity. This site was historically was influenced by drought and reoccurring fire events. Numerous successional communities may occur on this site. Immediately following a disturbance event, the early successional community consists of red pine, white pine, balsam fir and quaking aspen. As the community matures in the absence of major disturbances, the canopy becomes co-dominated by red pine, jack pine, spruce, and oak. The rotation of all fires combined is estimated to be approximately 100 years, understory fire occurrence may have been more often pre-colonization and depending on fire regime (MN DNR, 2005).
Jack pine (Pinus banksiana) occurs over a broad range of glacially scoured bedrock and outwash sand plains, with cover ranging from sparse to dense, depending on habitat features. On sand plain habitats, the combination of physiognomy, floristics, and disturbance factors can be used to further distinguish the denser forests with blueberries
(Vaccinium spp.) and feathermoss (Pleurozium schreberi) from more open stands, maintained by a 25 to 50 year fire rotation, where oaks (Quercus spp.), little bluestem (Schizachyrium scoparium), and other prairie forbs may be common. Herbivores respond positively to the understory plants after fire has cycled through the stands. This provides ideal browsing to moose and deer (Faber-Langendoen 2001). Young woodlands recovering from fire, are dominated by jack pine mixed with quaking aspen and paper birch. Followed by a transition period marked by a gradual decline in jack pine and quaking aspen. Red pine and paper birch are most abundant during this transition period. Spruce, balsam fir, and white pine invade and increase in abundance. At 95+ years mature woodlands form characterized by mixed canopies dominated by spruce with some paper birch, balsam fir, white pine, and old jack pine. Black spruce is the spruce species most associated with this community, but white spruce is also present (MN DNR 2005, MN DNR 2022).
State 1
Reference State
This is a dry to dry-mesic conifer-hardwood woodland composed of jack pine, red pine, black spruce, white pine, paper birch, quaking aspen, and oak. The site occurs on sandy outwash plains, lake plains, and moraines. Historically, the site was influenced by fire events at a rotations of approximately 100+ years. Young woodlands (0-55 years) recovering from fire, are dominated by jack pine mixed with quaking aspen and paper birch. Followed by a transition period (55-75) marked by a gradual decline in jack pine and quaking aspen. Red pine and paper birch are most abundant during this transition period. Spruce, balsam fir, and white pine invade and increase in abundance. At 75+ years mature woodlands then form characterized by mixed canopies dominated by spruce with some paper birch, balsam fir, white pine, and old jack pine. Subsequently old growth woodlands occur at 100+ years and understory fires may cycle through as many tree species use this natural fire cycle to maintain dominance on this ecological site. Black spruce is the spruce species most associated with this community, but white spruce is also present (MN DNR 2005).
Community 1.1
Mature-Old Dry Pine Community
This community is characterized by a lack of severe disturbance for 75 years or more. This community is dominated by a mixture of white spruce, red pine, and very old jack pine. Scattered old white pines are also present, with many white pine seedlings in the understory. The understory composition will be influenced by the presence or lack of ground fires. The important understory species included Canada mayflower (Maianthemum canadense), bunchberry (Cornus canadensis), twinflower (Linnaea borealis), and large-leaved aster (Aster macrophyllus). Mosses and lichens are important on sites with shallow soils over bedrock. The most frequent shrub species are juneberries (Amelanchier spp.), lowbush blueberry (Vaccinium angustifolium), and bush honeysuckle (Diervilla lonicera). Jack pine, red pine, white pine, and paper birch seedlings and saplings are common post-burn. White pine, white spruce, and balsam fir seedlings and saplings will be present on sites absence of fire. A sub canopy is rarely present in this community. (MN DNR, 2005)
Community 1.2
Early Successional Dry Pine Community
This young woodland community is 0-55 years of age. Immediately after a large fire event, this site is usually dominated by red pine, jack pine, and paper birch seedlings. As the stand progressively ages (35-55 years), red pine and paper birch will become dominant. The important understory species included Canada mayflower (Maianthemum canadense), bunchberry (Cornus canadensis), twinflower (Linnaea borealis), and large-leaved aster (Aster macrophyllus). Mosses and lichens are important on sites with shallow soils over bedrock. The most frequent shrub species are juneberries (Amelanchier spp.), lowbush blueberry (Vaccinium angustifolium), and bush honeysuckle (Diervilla lonicera). (MN DNR, 2005) Most trees on this site are naturally suited to be either fire-resistant or regenerate easily after a fire (MN DNR 2022).
Community 1.3
Mid Successional Dry Pine Community
The mid successional woodland stage (55-75 years of age) is the transitional period approaching a mature woodland with multiple canopy species including red pine, white pine, and paper birch. Overstory canopy starts to become the most prevalent and sub canopy starts to recede. The important understory species included Canada mayflower (Maianthemum canadense), bunchberry (Cornus canadensis), twinflower (Linnaea borealis), and large-leaved aster (Aster macrophyllus). Mosses and lichens are important on sites with shallow soils over bedrock. The most frequent shrub species are juneberries (Amelanchier spp.), lowbush blueberry (Vaccinium angustifolium), and bush honeysuckle (Diervilla lonicera). (MN DNR, 2005)
Pathway 1.1A
Community 1.1 to 1.2
A severe disturbance, such as a catastrophic fire, will transition the reference community to an early successional community.
Pathway 1.2A
Community 1.2 to 1.3
Time and natural plant community growth will transition the site to community 1.3.
Pathway 1.3A
Community 1.3 to 1.1
Time and natural plant community succession will transition the community to a mature woodland.
Pathway 1.3B
Community 1.3 to 1.2
A severe disturbance, such as a major fire event, will transition the community back to an earlier successional stage.
State 2
Disturbed State
Removal of canopy species for timber harvest creates an open canopy and a highly disturbed understory. Shrubs often dominate after canopy removal. A very dense shrub layer can impede tree regeneration. Heavy machinery are a common seed source for non-native species. Human and recreational activities can also lead to seed sources of non-native species being established (MN DNR 2005). This site offers a few options for crop trees, with six species having a fair, good, or excellent suitability. Jack pine, white pine, red pine, and northern pin oak are all ranked as excellent choices as crop trees by virtue of their frequent occurrence and moderately high cover (MN DNR 2022).
Community 2.1
Logged community
With the canopy removed, the initial post-logging community will be dominated by shrubs. A dense shrub layer can impeded tree regeneration, so management inputs may be necessary to enhance stand regeneration. This site offers a few options for crop trees replanting post logging, with six species having a fair, good, or excellent suitability. Jack pine, white pine, red pine, and northern pin oak are all ranked as excellent choices as crop trees by virtue of their frequent occurrence and moderately high cover (MN DNR 2022).
Community 2.2
Invaded Community
This community is identified by the presence of non-native plant species. Heavy machinery and soil disturbance provide an opportunity for invasives to become established. The invasive species on site will depend on the seed source. Some invasive species that may be present on site are leafy spurge (Euphorbia esula), purple loosestrife (Lythrum salicaria L.), and buckthorn (Rhamnus cathartica). If stands are to be silviculturally manipulated to favor one species over another, mean cover-when-present is the more important element of the index, with the higher covers more likely to result in higher stocking following treatment. Low frequency and high mean cover-when-present is the hallmark of trees with greater potential for the site than is commonly observed. The loss of seed trees due to historic over-exploitation, lower frequency of a historic disturbance like fire, the arrival of new diseases/pests or changes in their virulence, and species’ range expansions due to climate change could all explain this pattern (MN DNR 2022).
Pathway 2.1A
Community 2.1 to 2.2
Invasive species are introduced to the site and become established. This may be due to encroaching from machinery movement and some recreational human drive activities. The loss of seed trees due to historic over-exploitation, lower frequency of a historic disturbance like fire, the arrival of new diseases/pests or changes in their virulence, and species’ range expansions due to climate change (MN DNR 2022).
Transition T1A
State 1 to 2
This transition represents the removal of canopy species and/or severe understory disturbance from fires prescribed or natural.
Restoration pathway R2A
State 2 to 1
Careful restoration and management of the site may transition the Logged State back to Reference State depending on invasive species seed bank accumulation. This restoration pathway will be cost prohibitive and difficult to scale if invasive species have become established in the seed bank.
