Potential Natural Vegetation Group (PNVG): Rapid Assessment Reference Condition Model

This system is typified by dense to open, low to medium-tall forests of needle-leaf evergreen and deciduous trees on shallow organic and deep peatland soils. They occur primarily as discontinuous pockets or stringers within fire-prone upland vegetation communities which are primarily pine communities. In Minnesota and the eastern UP they may occur in very extensive delineations occupying several hundred acres. The canopy may be sparse and/or stunted, especially in very acid (pH < 5.5) peatlands. Low hummocks and water-filled depressions may be present, especially around the edges. These edges tend to be poor fens in an open, acidic peatland and a rich fen in the closed canopy peatland. Forested rich peatlands (pH> 5.5) occur in closed wet depressions, especially in small watersheds or catchment areas, and drains and toe slopes adjacent to streams. Acid peatlands occur in large, flat, poorly drained landscapes, especially peatlands on glacial lake plains, often forming adjacent to fen water tracks or in stagnant areas between heads of peatland streams and drains. Soils are very poorly drained, saturated throughout the growing season in normal years, and may be deep organic peat (acid and rich peatlands) or less than 12 ” of organic peat over primarily sandy soils (mineral soil bog). Vegetation Description The canopy is dominated by combinations of black spruce, tamarack, white cedar, and jackpine with white pine occurring on drier hummocks- particularly in mineral soil bogs. Broadleaf tree species may also b