A Preliminary Wetland Vegetation Classification for a portion of Colorado’s West Slope Final Report Submitted to: the Colorado Department of Natural Resources and the Environmental Protection Agency Prepared by: John Sanderson, Wetland Ecologist Steve Kettler, Ecologist The Colorado Natural Heritage Program 110 Natural Resources Building Colorado State University Fort Collins, CO 80523 Cover photo: In this subalpine lake at 3,200 m (10,400 ft.), a Rocky Mountain pondlily (Nuphar lutea ssp. polysepala) community with its striking yellow flowers grows in shallow water. Deep peat along the lake’s shore indicates that this site has remained relatively unchanged for thousands of years. A fewflower spikerush (Eleocharis quinqueflora) community occurs on the nutrient-poor waterlogged peat. i ACKNOWLEDGMENTS Financial support for this study was provided by a grant from the Environmental Protection Agency (EPA), Region VIII, through the Colorado Department of Natural Resources (DNR), with in-kind services provided by the Colorado Natural Heritage Program. We greatly appreciate the support and assistance of Doug Robotham and Kate Jones of the DNR. We would also like to thank Karen Hamilton, Sarah Fowler, John Peters, and Dale Vodenahl of the EPA for their help facilitating our funding. Ron Wright at the White River National Forest aided our effort by loaning us color infrared photos. Many people at the Colorado Natural Heritage Program contributed to the success of this project. Chris Pague helped design and write the original proposal and provided technical guidance. Gwen Kittel provided a model for this work with her ongoing riparian project. Amy Martin and Andy Kulmatiski helped collect data. The monumental task of plant specimen identification was aided by Julie Burt (especially with the genus Carex), Renée Rondeau, and Gwen Kittel (with the genus Salix). Miriam Colson Fritts assisted with several Carex specimens that proved beyond our local capabilities. William Weber and Tim Hogan at the University of Colorado Herbarium confirmed many specimens. i TABLE OF CONTENTS ACKNOWLEDGMENTS ............................................................................................................... i TABLE OF CONTENTS ................................................................................................................ ii LIST OF TABLES ...........................................................................................................................v LIST OF FIGURES ........................................................................................................................ vi SUMMARY .....................................................................................................................................1 INTRODUCTION............................................................................................................................2 Background ................................................................................................................................2 The Study Area ..........................................................................................................................4 METHODS ......................................................................................................................................7 Site Selection .............................................................................................................................7 Data Collection ..........................................................................................................................7 Data Analysis and Classification of Stands ...............................................................................9 The Colorado Natural Heritage Program and Determination of Natural Heritage Significance .........................................................................................................................10 RESULTS AND DISCUSSION ....................................................................................................12 PRELIMINARY KEY TO THE WETLAND PLANT ASSOCIATIONS OF THE STUDY AREA ..........................................................................................................18 IV.B.2.d. DECIDUOUS SEASONALLY FLOODED/SATURATED SHRUBLAND ................22 Betula glandulosa alliance .......................................................................................................22 Tentative Betula glandulosa (BEGL) plant association ....................................................22 Salix drummondiana alliance ...................................................................................................24 Salix drummondiana/Calamagrostis canadensis (SADR/CACA4) plant association ......24 Salix geyeriana alliance ...........................................................................................................26 Salix geyeriana/Calamagrostis canadensis (SAGE2/CACA4) plant association .............26 Salix monticola alliance ...........................................................................................................28 Salix monticola/Calamagrostis canadensis (SAMO2/CACA4) plant association ............28 Salix planifolia alliance............................................................................................................30 Salix planifolia/Caltha leptosepala (SAPL2/CALEL8) plant association ........................30 Salix planifolia/Carex aquatilis (SAPL2/CAAQA) plant association ...............................33 Salix wolfii alliance ..................................................................................................................35 Salix wolfii/Mesic forb (SAWO/Mesic forb) plant association .........................................35 ii VIII.A.2.e. SEMIPERMANENTLY FLOODED PERENNIAL TALL GRASS-LIKE (GRAMINOID) VEGETATION ...................................................................................................37 Scirpus tabernaemontani alliance ............................................................................................37 Scirpus tabernaemontani (SCTA80) plant association ......................................................37 VIII.B.2.d. SEASONALLY/TEMPORARILY FLOODED MEDIUM TALL GRASSLANDS ...39 Calamagrostis canadensis alliance ..........................................................................................39 Calamagrostis canadensis (CACA4) plant association .....................................................39 Calamagrostis canadensis–Mertensia ciliata (CACA4/MECI) plant association ............41 Deschampsia cespitosa alliance ...............................................................................................43 Deschampsia cespitosa–Caltha leptosepala (DECEC–CALEL8) plant association.........43 Unclassified Deschampsia cespitosa plant associations ..........................................................45 VIII.B.2.e. SEMIPERMANENTLY FLOODED MEDIUM TALL GRASSLAND .....................46 Carex utriculata alliance ..........................................................................................................46 Carex utriculata (CAUT) plant association .......................................................................46 Unclassified Carex utriculata stand .........................................................................................48 Carex vesicaria alliance ...........................................................................................................49 Carex vesicaria (CAVE6) plant association ......................................................................49 VIII.C.2.f. SEMIPERMANENTLY FLOODED SHORT GRASSLANDS ..................................51 Carex aquatilis alliance ...........................................................................................................51 Carex aquatilis (CAAQA) plant association .....................................................................51 Carex aquatilis–Carex utriculata (CAAQA–CAUT) plant association ............................53 Eleocharis palustris alliance ....................................................................................................55 Eleocharis palustris (ELPA3) plant association ................................................................55 VIII.C.2.g. SATURATED SHORT GRASSLANDS ....................................................................57 Carex saxatilis alliance ............................................................................................................57 Carex saxatilis (CASAS7) plant association .....................................................................57 Eleocharis quinqueflora alliance .............................................................................................59 Eleocharis quinqueflora (ELQU2) plant association .........................................................59 VIII.E.1.a. PERENNIAL LOW FORB VEGETATION ................................................................61 Caltha leptosepala alliance ......................................................................................................61 Caltha leptosepala (CALEL8) plant association ...............................................................61 Caltha leptosepala–Deschampsia cespitosa (CALEL8–DECEC) plant association.........63 Caltha leptosepala–Sedum rhodanthum (CALEL8–SERH) plant association ..................66 Unclassified Caltha leptosepala stand ...............................................................................67