pl This document is made available electronically by the Minnesota Legislative Reference Library as part of an ongoing digital archiving project. http://www.leg.state.mn.us/lrl/lrl.asp (Funding for document digitization was provided, in part, by a grant from the Minnesota Historical & Cultural Heritage Program.) 340 .M665x r I I r ! \1 1 1 Phase II ~· Peat Program :F'orestrJ/ #-:- Plant Com:nuni ties Report .:, Vegetation Types, Species and Areas of Concern and Forest Resources Utilization of Northern Minnesota' s Peatlands / / Prepared for the Minnesota Department of Natural Resources; by Vilis Kunnis ·- ·· L, Henry L. ··Hansen John J. Olson Allan R. ~.ho ! f I' L! College of Forestry University of Mirmesota May, 1978 TABLE OF CONTENTS Page INTRODUCTION. 1 PHYSIOGNOMIC CLASSIFICATION OF PEAT.LANDS. 2 Bog. 3 Fen. 3 Swamp. 4 WETLAND VEGETATIONAL PROCESSES. 7 Hydrarch Succession. 7 Paludification . 11 VEGETATION TYPES. 14 Treeless Bog 17 Wooded Bog . 18 Treeless Fen . 19 Wooded Fen • 20 String Fen and Bog • 22 Swamp Shrubs 24 Swamp Hardwoods. 25 Swamp Conifers 27 White-cedar forest. 27 Tamarack forest 28 Black spruce alder forest 29 Black spruce feather rross forest. 30 Black spruce sphagnum forest. 31 UNIQUE PLANT SPECIES AND AREAS. 33 Species categories 33 S:pecies of Special Concern 35 Areas of Special Concern 53 FOREST RESOURCES OF MINNFSOI'A'S PEATLANDS 58 Area and I.ocation. 58 Use Patterns . 58 Peatland Forest Types. 61 Uses, Values, and Harvest. 65 P~icing Practices. 71 SUMMARY 73 REffiMMENDATIONS 78 A SELECTED BIBLIOGRAPHY . 80 LIST OF TABLES 1. Groundwater Characteristics of Bog, Fen, and Swamp. 5 2.' Indicator Species of Bog, Fen, and Swamp. • . • . • . • • 6 3,. Hydrarch Succession of Plant Cormrunities as Described by Three Authors. • • • • • • • . • • • • • 9 4. Peatland Plant Species of Special Concern 36 5. Optimum Levels of Habitat Factors for Selected Peatland Species . • , . • • • • • . • • . • . • . 50 6. Plant Species and Habitats Associated with Peatland Species of Special Concern. • • . • • . • . • . 51 7. Areas of Special Concern in Northern Minnesota Peatlands. 56 8. Total Land Area and Peatland Acreage in Selected Minnesota Counties. • . • . • .••.•. 59 9. Peatland Uses in Selected Minnesota Counties. • 60 10. Total Acreage, Forest Land and Comnercial Forest Land in Selected Minnesota Counties. • . • • . • . • . 62 11. Similar Units in the "Forest Type" and "Vegetation Type" Classification Systems. • . • • • . • . • 63 12. Cornm2rcial Peatland Forest Acreage by Forest Type in Selected Minnesota Counties . • . • • • • • • • • 63 13. Changes in Corrmercial Forest Acreages in Carlton, Koochiching, and St. I.Duis Counties, 1962 to 1977 • • G4 14. Pulp .Mills in Minnesota . • • . ~ . ~ . ' . 67 -r 15. Summary of State Timber Sales by Species and Product for Fiscal 1976--Koochiching County . • • . • . , 70 - 16. Stumpage and r:e~ivered Prices for Selected Species and Prcx:lucts . • . • . • . • . LIST OF FIGURES 1. Edaphic Relationships of I.Dwland Vegetation Types in Northern Minnesota. • . • . • . • . • . 15 2. Locations of Peatland Vegetation Studies in Northern Minnesota . • . 16 3. Reported I.Dcations of Species of Special Concern . 52 4. Locations of Scientific and Natural Areas, Critical Areas, and National Natural Landrna.tks •..•.....•.. 55 Introduction This report summarizes the results of studies conducted pursuant to a research contract by the College of Forestry, University of Minnesota, with the Minnesota Department of Natural Resources entitled J?hase II - P~at Program Forestry - Plant Corrmunities. Objectives of this study as prescribed were as follows: 1. Survey and assessment of previous studies on peatland vegetation types and plant corrmunity associations. 2. Identification and verification of potential resources conflicts associated with peat development; i.e. natural areas, forest products and unique plants. 3. Recommendation of future investigations and info:r:mation acquisition for further refinerrent of guidelines for peat develo:pnent. The project fonna.t involved an assessment and evaluation of published literature and other infonna.tion sources relevant to northern Minnesota's peat, vegetation and potential resource conflicts associated with possible peatland developnent. The study area considered. was primarily, but not exclusively, Foseau, Beltrami, lake of the Wood.s, Koochiching, Itasca, Aitkin, Carlton, and St. IDuis counties. Principal emphasis in the study includes plant corrmunities and their relationship to environmental conditions and processes; individual plant specie·s and areas of special concern; and the peatland forest resource and its current industrial utilization. 2 PHYSICGNOMIC CLASSIFICJ\TION OF PEAT.LANDS The developnent of diverse vegetation types in diff~ent areas of a peatland is related to the flow, level, and chemistry of groundwater. Levels of nutrient ions, oxygen content, and pH of the water supply are key factors (Heinselroan, 1963b; 1970). Water chemistry tends to Var'f along a gradient. Highest concentrations of nutrients are along peatland margins near mineral soil. The concentration decreases towards .central rog areas with thick peat accumulations (central raised bogs).. Abrupt changes in groundwater chemistry tend to be reflected by markedly different vegetation types on the surface .. A gradual gradient results in gradual changes in vegetation types. The effect of these vari­ ables is that certain plant communities are clearly identifiable, while others can only be divided somewhat arbitrarily along a vegetation continuum. Water chemistry can be related to source. Groundwater flowing into a peatland from adjacent areas of mineral soil (m.inerotrophic) has a different makeup than peatland waters which have originated from direct rainfall and have not flOW'ed through mineral soil (orobrotrophic) • The degree of ombrotrophy or minerotrophy of peatland waters correlates well with the vegetation of the area (Sjors, 1959; Heinselman, 1963b; 1970) • Peatlands can be divided into three main physisiognomic classes: l:ogs, fens, and swamps. A fourth class, marsh, by definition does not accumulate , significant amounts of peat (Jeglum et al., 1974). The classes are defined by plant cover, water chemistry, and peat type. 3 Bogs are peat-covered or filled areas with a high water table and a surface carpet of rrosses, chiefly sphagnum. The surface is often raised; or if it is flat or level with the surrounding wetlands, it is virtually isolated from mineral soil waters. Precipitation is the major source of .water and nurtients for the l:og surface. Surface bog waters and peat are u5ually strongly acid and extremely deficient in mineral nutrients. Sphagnum species are responsible for the acidic reaction. Oxygen saturation is low. Upper peats are usually mainly sphagnum remains, are acidic, and undecomposed (Jeglum et al., 1974). Sedges may be present on l:ogs. If a tree layer is present, it consists mainly of black spruce (Picea mariana) or tamarack (Larix Zarcinia) . Ericaceous species typify the l:og shrub layer. Comron shrub species are leatherleaf (Chamaedaphne caZycuZata), bog rosemary (And:r1omeda glaucophyZZa) , bog laurel (KaZmia polifoZia) , and cranberries (Vacciniwn spp.). Fen Fens are peatlands with surface layers of poorly to rroderately de­ composed sedge peat. Basal peats are often well decomposed. Sedges are the· dominant vegetation, often in association with grasses and reeds. SP.hagnum is sul:ordinate or absent. A low to medium height shrub layer may be present. Trees are usually restricted to raised strings or islands , (Heinselman, 1970) . The water and peat in fens are less acidic than those of l:xJgs. Typically, slow drainage occurs through seepage down low gradient 4 slopes (Jeglum et al., 1974). As a result of the slow drainage oxygen saturation is low and the mineral nutrient supply is restrictive. Swamp Swarnps are defined as wooded wetlands where standing or gently flowing surface water persists for long pericx:ls. While rrost swa:rrps are dominated by trees some are dominated by shrub thickets. The substrate is usually waterlogged. The water is circurmeutral to mildly acidic with little or no deficiency in oxygen or mineral nutrients. The substrate is a mixture of mineral and organic sediment or peat (Jeglum et al., 1974). Swa:rrps are typically the rrost minerotrophic peatland type. They are also floristically richer than either b::>gs or fens and ma.y be prcx:luctive forests. The groundwater characteristics of lx>gs, fens, and swamps are canpared in Table 1. Indicator species for each of the water conditions described in Table 1 are listed in Table 2. 5 Table 1. Groundwater Characteristics of Bog, Fen, and Swamp. Bog: (ornbrotrophic) pH range: 3.1 - 4.2 ' ca cnntent: 0. 8 - 2. 7 ppm ca + Mg content: 1.0 - 3.0 ppm "corrected conductivity" : :::: 0 Fen or Poor Swamp: (weak rninerotrophic) pH range: 4.3 5.8 ca content: 3 - 10 ppm ca + ~ content: 5 - 13 ppm ·"corrected oonductivity": 20 - 75 µ.Mhos Swamp: (minerotrophic) pH range: 5.8 - 7.0 Ca content: 10 - 25 ppm ca + ~ content: 13 - 30 ppm "corrected conductivity": 75 - 120 µMhos Source: Heinselnlan, 1970. 6 Table 2. Indicator Species of Bog, Fen, and Swarrp Waters. Species of Bog Areas (ornbrotrophic) Picea mariana ' Kalmia polifolia Chamaedaphne calycuZata Eriophorum spp. PZezaiozium schreberi Sphagnwn fuscwn Species of ":poor swamp" or Fen Areas (weak minerotrophic) Larix laricina Betula pwniZa Andromeda gZaucophyZla Menyanthes trifoliata Iris versico for UtricuZaria spp.