Plant Association Classification for Northern Alaska Keith Boggs, Tina V. Boucher, and Monica L. McTeague July 31, 2018 Contents Acknowledgements ......................................................................................................................... 1 Introduction ..................................................................................................................................... 2 Methods........................................................................................................................................... 2 Field Work .................................................................................................................................. 2 Data Analysis .............................................................................................................................. 3 Plant Associations of Conservation Concern .................................................................................. 6 Key to Plant Associations ............................................................................................................... 7 Alder Plant Associations ............................................................................................................... 14 Alnus viridis ssp. fruticosa/Betula nana/Carex lugens Plant Association ................................ 14 Alnus viridis ssp. fruticosa/Vaccinium uliginosum Plant Association ...................................... 16 Alnus viridis ssp. fruticosa/Arctagrostis latifolia Plant Association (provisional) ................... 18 Alnus viridis ssp. fruticosa/Ribes triste Plant Association (provisional) .................................. 19 Low–Tall Willow Plant Associations ........................................................................................... 20 Salix alaxensis Plant Association.............................................................................................. 20 Salix alaxensis/Dryas octopetala Plant Association ................................................................. 22 Salix arbusculoides Plant Association ...................................................................................... 24 Salix glauca Plant Association.................................................................................................. 25 Salix glauca-Vaccinium uliginosum Plant Association ............................................................ 27 Salix niphoclada/Salix reticulata Plant Association ................................................................. 29 Salix pulchra-Carex aquatilis Plant Association ...................................................................... 31 Salix pulchra/Hylocomium splendens Plant Association .......................................................... 33 Salix pulchra-Eriophorum angustifolium Plant Association .................................................... 35 Salix richardsonii/Arctous rubra-Salix reticulata Plant Association (provisional) ................. 37 Salix richardsonii/Carex membranacea Plant Association (provisional) ................................ 39 Salix richardsonii/Eriophorum angustifolium Plant Association ............................................. 40 Birch Ericaceous Low Shrub Plant Associations.......................................................................... 42 Betula nana/Cladina rangiferina Plant Association ................................................................. 42 Betula nana/Rhododendron tomentosum Plant Association ..................................................... 43 Rhododendron tomentosum/Vaccinium vitis-idaea Plant Association ..................................... 45 Vaccinium uliginosum/Dryas octopetala Plant Association ..................................................... 47 Tussock Tundra Plant Associations .............................................................................................. 49 Carex lugens/Salix reticulata Plant Association....................................................................... 49 Eriophorum vaginatum/Rhododendron tomentosum Plant Association ................................... 51 Tussock Shrub Tundra Plant Associations ................................................................................... 53 Betula nana-Carex lugens Plant Association ........................................................................... 53 Betula nana-Eriophorum vaginatum Plant Association ........................................................... 55 Salix pulchra-Eriophorum vaginatum Plant Association ......................................................... 57 Mesic Sedge/Dwarf Shrub Tundra Plant Associations ................................................................. 59 Carex aquatilis/Vaccinium vitis-idaea Plant Association......................................................... 59 Carex lugens/Dryas octopetala Plant Association ................................................................... 61 Carex lugens/Vaccinium vitis-idaea Plant Association (provisional) ...................................... 63 Equisetum arvense/Salix reticulata Plant Association ............................................................. 65 Dwarf Shrub-Dryas Plant Associations ........................................................................................ 67 Dryas integrifolia-Salix reticulata (Floodplain) Plant Association .......................................... 67 Dryas integrifolia (Upland) Plant Association ......................................................................... 69 Dryas octopetala-Cassiope tetragona Plant Association ......................................................... 71 Dryas octopetala-Salix phlebophylla Plant Association........................................................... 73 Dwarf Shrub-Other Plant Associations ......................................................................................... 75 Arctous rubra-Carex aquatilis Plant Association ..................................................................... 75 Cassiope tetragona-Vaccinium uliginosum Plant Association ................................................. 77 Salix arctica-Salix polaris Plant Association ........................................................................... 79 Salix phlebophylla-Carex lugens Plant Association ................................................................. 81 Salix rotundifolia Plant Association ......................................................................................... 83 Freshwater Marsh Arctophila fulva Plant Association ................................................................. 85 Arctophila fulva Plant Association ........................................................................................... 85 Freshwater Marsh Carex aquatilis Plant Association ................................................................... 87 Carex aquatilis Plant Association ............................................................................................. 87 Wet Sedge Plant Associations ...................................................................................................... 89 Carex aquatilis-Eriophorum angustifolium Plant Association ................................................. 89 Carex aquatilis-Eriophorum spp./Sphagnum spp. Plant Association ....................................... 91 Carex rotundata-Eriophorum angustifolium Plant Association ............................................... 93 Carex saxatilis-Eriophorum angustifolium Plant Association ................................................. 95 Eriophorum angustifolium-Carex spp. Plant Association ........................................................ 97 Eriophorum chamissonis-Eriophorum angustifolium Plant Association ................................. 99 Trichophorum cespitosum-Carex rotundata Plant Association .............................................. 100 Mesic Herbaceous Plant Associations ........................................................................................ 101 Carex microchaeta-Scorpidium spp. Plant Association ......................................................... 101 Equisetum variegatum-Equisetum arvense Plant Association ................................................ 102 Poa arctica-Calamagrostis stricta spp. inexpansa Plant Association .................................... 104 Rubus chamaemorus-Polytrichum spp. Plant Association (provisional) ................................ 106 Coastal Marsh Plant Associations ............................................................................................... 107 Carex glareosa Plant Association ........................................................................................... 107 Carex subspathacea Plant Association ................................................................................... 109 Carex subspathacea-Salix ovalifolia Plant Association ......................................................... 111 Dupontia fisheri Plant Association ......................................................................................... 114 Puccinellia phryganodes Plant Association............................................................................ 116 Marine Beach/Beach Meadow Plant Associations ..................................................................... 118 Honckenya peploides Plant Association ................................................................................. 118 Leymus mollis Plant Association ...........................................................................................