Acid Peatland

Description

Moss cover is very indicative for this site, driving the successional dynamics and species diversity. Sphagnum sp. absorb dissolved mineral cations, and release organic acids, which lowers the pH of stagnant surface water below 5.0 (MN DNR 2003). Sphagnum tends to form carpets of hummocks, which creates an acidic environment cut off from groundwater and on-site ponding. In recently developed bogs, on sites mostly in the western range of the MLRA where soils are less continuously saturated, on sites where water table fluctuations are less variable, or on inclusions of sites where there are upwellings of groundwater, isolated minerotrophic species (i.e. creeping sedge or bluejoint) may be present. Other ground cover includes fine-leaved graminoids, and minimal presence of forbs. Occasionally, seedlings of deciduous tree species associated with adjacent sites (i.e. red maple or paper birch) may become established on Sphagnum hummocks but typically do not survive to become saplings or trees (MN DNR 2003).

The overstory usually consists of scattered, stunted (<30ft [10m] tall) black spruce or tamarack (<50% cover) where Sphagum hummocks provide relief from surface flooding (MN DNR Forestry). Most vascular plants associated with Acid Peatlands have a strong association with mycorrhizal fungi, depending on them to obtain minerals and nutrients in this depauperate and harsh environment (MN DNR 2003). These fungi are more diverse on this ecological site than on other sites throughout the region.

Dominant plant species

1. black spruce (Picea mariana), tree

2. tamarack (Larix laricina), tree

3. bog birch (Betula pumila), shrub

4. speckled alder (Alnus incana ssp. rugosa), shrub

5. bog Labrador tea (Ledum groenlandicum), shrub

6. threeseeded sedge (Carex trisperma var. trisperma), grass

7. threeleaf false lily of the valley (Maianthemum trifolium), grass

8. sphagnum (Sphagnum), grass

Submodel

Description

This state describes the removal of tamarack and black spruce through logging. The natural plant community has been severely disturbed and the site has been impacted by heavy equipment. Compositional changes in canopy cover and soil/water disturbances impact all layers of the plant community. Best management practices can help reduce site damage and the implementation of post-logging timber stand improvement practices can enhance tree regeneration.

Dominant plant species

1. bog birch (Betula pumila), shrub

2. sedge (Carex), grass

3. cottongrass (Eriophorum), grass

4. sphagnum (Sphagnum), grass

Submodel

Description

In this state, invasive species such as Typha sp. or reed canary grass (Phalaris arundinacea) are present. Water ponding for a longer than normal duration results in canopy mortality of tamarack and spruce trees and opening of the understory to light. Alder and willow shrubs often remain on edge zones. Site disturbance such as logging often allows for the introduction of non-native vegetation on these sites.

Dominant plant species

1. hybrid cattail (Typha ×glauca), grass

2. reed canarygrass (Phalaris arundinacea), grass

3. sedge (Carex), grass

Submodel

Description

This state is characterized by sphagnum-dominated acidic peatlands with variable microtopography that includes hummocks, deep hollows, and areas of sphagnum "carpets". This state will exhibit variability in plant community composition due to these variations in microtopography.

Dominant plant species

1. leatherleaf (Chamaedaphne calyculata), shrub

2. bog laurel (Kalmia polifolia), shrub

3. bog Labrador tea (Ledum groenlandicum), shrub

4. sedge (Carex), grass

5. sphagnum (Sphagnum), grass

Submodel