Native Freshwater Wetland Plant Associations of Northwestern Oregon
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NATIVE FRESHWATER WETLAND PLANT ASSOCIATIONS OF NORTHWESTERN OREGON John A. Christy Oregon Natural Heritage Information Center Oregon State University 2004 Photographs (by author): Cover: Polytrichum commune Association Following page: Sagittaria latifolia Association NATIVE FRESHWATER WETLAND PLANT ASSOCIATIONS OF NORTHWESTERN OREGON John A. Christy Oregon Natural Heritage Information Center Oregon State University 2004 THE AUTHOR John Christy is a wetlands ecologist with the Oregon Natural Heritage Information Center. His specialties are wetland community ecology, bryophytes, and historical ecology. He received a B.S. in General Science from the University of Oregon and an M.S. in Botany from the University of British Columbia. ACKNOWLEDGEMENTS AND DISCLAIMER Production of this guide would not have been possible without funding from the USDA Forest Service (Cindy McCain), the Oregon Watershed Enhancement Board (Ken Bierly and the OWEB Board), and the Environmental Protection Agency (Yvonne Vallette). Cindy McCain also provided critical expertise, mountains of archived plot data, and infinite patience. The report summarizes datasets from numerous wetland studies: Three Sisters Wilderness (Fred Hall, 1966- 1969); Mt. Jefferson Wilderness (Leonard Volland, 1976-1984); coastal and Cascade peatlands (John Christy 1978-2002); Willamette National Forest (Leighton Ho and Warren Pavlat, 1984; Cindy McCain, Jennifer Lippert, Warren Pavlat, Evelyn Everett, L. Rankin, Kim McMahan, Marie Palumbo, Saxton, 1991); Mt. Hood National Forest (Nancy Diaz, Mark Boyll, Gordon Whitehead, Tom High, Fred Small, Jennifer Guard, Paul Bakke, Paula Brooks, 1989-1990); lower Columbia River (John Christy and Judy Putera, 1992); Oregon Dunes National Recreation Area (John Christy, Jimmy Kagan, Tim Rettmann, 1993); Willamette Valley (Jonathan Titus, 1994-1996); Mt. Hood, Siuslaw, and Willamette National Forests, and Eugene and Salem BLM Districts (Michael Murray, Rachel Schwindt, Nick Otting, Danna Lytgen, 1999; David Alley and Peter Stocking, 2001). These earlier projects were funded by USFS, BLM, EPA, and The Nature Conservancy. Elaine Stewart of Metro kindly provided most of the data for the Carex aperta association, collected in 2003. Some of the text is adapted from earlier material that I wrote for Kunze (1994), Guard (1995), and Christy et al. (1998), as well as various internal reports cited elsewhere in this guide. The map on page 5 was obtained from the Color Landform Atlas of the United States (http://fermi.jhuapl.edu/ states), compiled by Ray Sterner. Construction of a vegetation classification for the northwestern Oregon area was challenging because of the variation among the different datasets, sampled by so many different observers in so many different localities over the last 38 years. It is often difficult to visualize and describe plant associations without seeing them firsthand in the field. In these cases, photographs and qualitative descriptions are extremely useful when available, but difficulties still remain in interpreting someone else's data and concepts. A further complication is the tendency for tidy concepts of local or regional plant associations to lose their resolution at a larger geographic scale. What fits a neat package on a district or National Forest scale may become increasingly difficult to interpret as species composition, elevation, and even hydrology change within an expanded study area and extended latitude. As interpreter of these data, I assume all responsibility for any distortions, omissions, and improbable leaps of faith. TABLE OF CONTENTS SUMMARY .....................................................................................................................................................4 PREVIOUS WORK..........................................................................................................................................4 SCOPE, LOCATION, AND ENVIRONMENT.......................................................................................................4 MAJOR WETLAND TYPES..............................................................................................................................7 DISTURBANCE PROCESSES .........................................................................................................................8 EXOTIC PLANTS ...........................................................................................................................................10 METHODS....................................................................................................................................................10 RESULTS .....................................................................................................................................................12 KEY TO NATIVE FRESHWATER WETLAND PLANT ASSOCIATIONS OF NORTHWESTERN OREGON .............13 I. FOREST AND WOODLAND ASSOCIATIONS ..............................................................................................21 Alnus rubra / Athyrium filix-femina - Lysichiton americanus Association ........................................................21 Alnus rubra / Carex obnupta - Lysichiton americanus Association..................................................................22 Fraxinus latifolia / Carex aquatilis var. aquatilis Association...........................................................................23 Fraxinus latifolia / Carex deweyana - Urtica dioica ssp. gracilis Association ...................................................24 Fraxinus latifolia / Carex obnupta Association ..............................................................................................25 Fraxinus latifolia / Spiraea douglasii Association ..........................................................................................26 Fraxinus latifolia / Symphoricarpos albus Association...................................................................................27 Picea sitchensis / Carex obnupta - Lysichiton americanus Association ..........................................................28 Picea sitchensis / Cornus sericea / Lysichiton americanus Association..........................................................29 Pinus contorta var. contorta / Carex obnupta Association..............................................................................31 Populus balsamifera ssp. trichocarpa / Cornus sericea / Impatiens capensis Association...............................32 Populus tremuloides / Carex obnupta Association ........................................................................................33 Thuja plicata / Lysichiton americanus Association........................................................................................34 Tsuga heterophylla / Ledum glandulosum / Carex obnupta - Lysichiton americanus Association .......................35 II. SHRUBLAND ASSOCIATIONS ..................................................................................................................36 Alnus incana / Lysichiton americanus Association........................................................................................36 Alnus viridis ssp. sinuata / Lysichiton americanus Association ......................................................................37 Alnus viridis ssp. sinuata / Scirpus microcarpus Association.........................................................................38 Betula nana / Carex aquatilis var. dives Association......................................................................................39 Cornus sericea / Lysichiton americanus Association.....................................................................................40 Kalmia microphylla / Carex aquatilis var. dives Association............................................................................41 Ledum glandulosum - Gaultheria shallon / Carex obnupta Association............................................................42 Ledum glandulosum / Carex obnupta / Sphagnum Association ......................................................................43 Ledum glandulosum / Darlingtonia californica/ Sphagnum Association ...........................................................45 Ledum glandulosum - Myrica gale Association .............................................................................................47 Ledum glandulosum / Sanguisorba officinalis Association.............................................................................48 Malus fusca / Carex obnupta Association ....................................................................................................49 Myrica gale / Carex aquatilis var. dives Association.......................................................................................50 Salix commutata Association .....................................................................................................................51 Salix geyeriana complex.............................................................................................................................52 Salix hookeriana - (Salix sitchensis) Association..........................................................................................53 Salix hookeriana - Malus fusca / Carex obnupta - Lysichiton americanus Association......................................54 Salix lucida ssp. lasiandra / Urtica dioica ssp. gracilis Association ................................................................55 Salix lucida ssp. lasiandra / Salix sitchensis