I I I A Preliminary Classification I of the I Riparian Vegetation I of the I Yampa and I San Miguel/Dolores River Basins I I A Final Report Submitted to i the Colorado Department of Health I and the Environmental Protection Agency I by I Gwen M. Kittel and Nancy D. Lederer I The Nature Conservancy's Colorado Program 1244 Pine St., Boulder, CO 80302 I February 26, 1993 I I I I I I I TABLE OF CONTENTS I SUMMARY ............................................... 1 I INTR.ODUCTION . .. 2 STUDY AREA .........••.•.........•...•.................. 3 Yampa River Basin . .. 3 I San Miguel/Dolores River Basin . .. 6 METHODS . .. 6 I Representative site selection .........................•....... 6 Collection of vegetation and environmental data ............ 8 Data analysis and storage . 9 I Classification ........................................ 10 Determination of Ecologically-significant sites .................... 13 I RESULTS ....0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •• 16 YAMPA RIVER BASIN RESULTS I Key to Yampa River Basin Riparian Plant Associations . .. 24 Yampa River Basin Riparian Plant Association Descriptions . .. 28 Evergreen Forests ...................................... 28 I Picea engelmannii-Abies lasiocarpalAlnus incana spp. tenuifolia ..... 28 Picea engelmannii-Abies lasiocarpalLonicera involucrata . .. 29 Picea pungenslAlnus incana spp. tenuifolia . .. 29 I Mixed Deciduous-Evergreen Forests ............................ 30 Populus angustifolia-Picea pungenslAlnus incana spp. tenuifolia-Comus sericea ..................................... 30 I Deciduous Forests ....................................... 31 Populus angustifolia-Acer negundolComus sericea .............. 32 Populus angustifolialAlnus incana spp. tenuifolia ................ 32 I Populus angustifolialAmelanchier alnifolia . 33 Populus angustifolialComus sericea . .. 34 I Populus angustifolialSalix exigua . .. 35 Populus deltoides ssp. wislizeniilRhus trilobata ................. 35 Tall-Willow Shrublands . .. 36 I Salix boothiilmesic forb ............................... 37 I 111 I I Salix boothiilCarex rostrata . • • . 37 I Salix drummondiana/Calamagrostis canadensis ................ 38 t.J~coal· IX exlguu/J• ··~!.m eslC . gramm. o·d!l. • • • • • • • • • • • • • • • • • • • • • • • . • • 39 Salix geyeriQ1Ul/Carex rostrata ....•.......•............. 39 I Salix lasimuJra var. caudatalmesic graminoid .................. 40 Salix monticola/Carex aquatilis .•...........••......•..... 40 !..ow-Willow Shrublan.ds . .. 41 I Salix planifoiia var. monica/Carex aquatilis .................. 41 Salix woljiilmesic forb ............................... 42 Non-Willow Shrublands • . • . • . • . • . .. 43 I Alnus incana spp. tenuifolia-Comus sericea ................... 43 Alnus incana spp. tenuifolia-Salix geyeriana . .. 43 Alnus incana spp. tenuifolialmesic forb . .. 44 I Rhw tnlobata .................................... 44 Shepherdia {Jrgentea-Leymus cinereus . .. 45 Herbaceous Plant Associations . .. 46 I Care%' aq'Ualilis • . • . .. 46 Carex rostrata .................................... 47 I Carex -nebraJcemis ..............................._.. 48 Distichlis spicllta . .. 48 Eleocharis palustris . .. 49 I Iva axillaris . .. 49 Juncus balticus . .. 50 Muhlenbergia asperij'olia . .. 50 I Scirpus americanus ................................. 51 Sci'rp'US maritim'US ................................... 51 Miscellaneous Plant Associations ............................. 52 i SAN MIGUEUDOLORES RIVER BASIN RESULTS Key to the San MigueVDolores River Basin Riparian Plant Associations .... 54 I San MigueVDolores River Basin Plant Association Descriptions ......... 58 Evergreen Forests ...................................... 58 Picea engelmannii-Abies lasiocarpa/Alnus incana spp. tenuifolia ..... 58 I Picea engelmannii-Abies lasiocarpa/mesic forbs . 59 Picea pungensJAlnus incana spp. tenuifolia ................... 60 Picea pungensJComus sericea . • . 60 I Mixed Deciduous-Evergreen Forests ........................... 61 Populus angustifolia-Picea pungens/Alnus incana spp. tenuifolia-Comus sericea ..................................... 61 I Picea pungens-Populus angustifolia/Alnus incana spp. tenuifolia- wniClra inVOl'ucTata . 62 Deciduous Forests ....................................... 63 I Acer negundolBetula occidentalis .•.....••...•....•........ 64 Populus angusti/olia/Comus sericea • . • . 64 I iv I I I I Populus angustifolia/Rhus trilobata .......................• 65 Populus deltoides ssp. wislizenii/Rhus trilobata ................. 66 Tall-Willow Shrublan.ds . 67 I Salix drummondianalmesic forb ........................... 67 Salix exigua/mesic graminoid . 68 Salix monticola-Salix geyeriana/mesic forb . .. 69 I ww-Willow Shrublan.ds . .. 70 Salix brachycarpa/mesic forb ..••.•..................... 70 Salix planifolia var. monica/Caltha leptosepala ................ 71 I Salix woljii/Carex aquatilis ............................ 71 Non-Willow Shrublan.ds . 72 Forestiera pubescens-Salix exigualPhragmites australis ........... 72 I Rhus trilobata ..................................... 72 Herbaceous Plant Associations . .. 73 Carex. aquatilis . .. 74 I Carex rostrata .................................... 74 Eleocharis pal'UStris . .. 75 Sporobolus airoides ................................ 76 I Misce1lan.eous Plan.t Associations .............................. 76 I LITERATURE CITED . .. 108 APPENDICES I Appendix 1. Proposed Ecologically-Significant Riparian Areas. 1-1 i Appendix 2A. Yampa River Basin Plant Species (scientific and common names). 2A-l Appendix 2B. San Miguel/Dolores River Basin Plant Species (scientific and common I nam.es). .. 2B-l Appendix 3. Yampa River Basin plot locations on 7.5" topographic maps..... 3-1 I Appendix 4. San Miguel/Dolores River Basin plot locations on 7.5 11 topographic maps. ......................................4-1 I Appendix 5. Blank field forms and instructions . ~ ................... 5-1 Appendix 6. Color photographs of selected Yampa River Basin Riparian Plant I Associations. .. 6-1 Appendix 7. Color photographs of selected San Miguel/Dolores River Basin I Riparian Plan.t Associations.. 7-1 I Appendix 8. Memorandum of Understanding (MOU). ................ 8-1 I v I I TABLES I Table 1. Cross-reference of UNESCO and Cowardin Classification Classes used to classify riparian plant associations ......................... 11 I Table 2. Definition of Natural Heritage State Rarity Ranks . .. 15 I Table 3. Riparian Plant Associations of the Yampa River Basin. 20 Table 4. Riparian Plant Associations of the San Miguel/Dolores River Basin ..... 22 I Table 5 . Yampa Basin Coniferous Forest plant association constancy and average percent cover values. ................................. 78 I Table 6. Yampa Basin Mixed Deciduous-Evergreen Forest plant association constancy and average percent cover values. 80 I Table 7. Yampa Basin Deciduous Forest plant association constancy and average percent cover values. ................................. 81 I Table 8. Yampa Basin Tall-Stature Willow Shrubland plant association constancy and average percent cover values. ......................... 86 I Table 9 . Yampa Basin Low-Stature Willow Shrubland plant association I constancy and average percent cover values. 90 Table 10. Yampa Basin Non-Willow Shrubland plant association constancy and Ii average percent cover values. 92 Table 11. Yampa Basin Herbaceous plant association constancy and average I percent cover values. ................................. 94 Table 12. San Miguel/Dolores Basin Evergreen Forest plant association constancy I and average percent cover values. ......................... 97 Table 13. San Miguel/Dolores Basin Mixed Deciduous-Evergreen Forest plant I association constancy and average percent cover values. 99 Table 14. San Miguel/Dolores Basin Deciduous Forest plant association constancy I and average percent cover values. ........................ 101 I I Vl I I I I Tables, continued. Table 15. San Miguel/Dolores Basin Tall-Stature Willow Shrubland plant I association constancy and average percent cover values. .. 103 Table 16. San Miguel/Dolores Basin Low-Stature Willow Shrubland plant I association constancy and average percent cover values. .. 105 Table 17. San Miguel/Dolores Basin Non-Willow Shrubland plant association I constancy and average percent cover values. .. 106 Table 18. San Miguel/Dolores Basin Herbaceous plant association constancy and I average percent cover values. .. 107 I FIGURES I Figure 1. Upper Colorado River Basin in Colorado . .. 4 I Figure 2. Yampa River Basin Map and Plot Locations . .. 5 I Figure 3. San Miguel/Dolores River Basin Map and Plot Locations . .. 7 Figure 4. Yampa River Basin Cluster Analysis Dendrogram ............... 17 I Figure 5. San Miguel/Dolores River Basin Cluster Analysis Dendrogram ....... 18 I I I I I I I vii I I I I I I I I I I I i I I I I I I I I I I I I SUMMARY In this final report, we present results from two years of field surveys of the Yampa and San Miguel/Dolores River Basins. We have classified riparian plant associations found I along intact, relatively undisturbed reaches of perennial rivers and streams and placed them in the context of the UNESCO Physiognomic-Ecological Classification of Plant Formations of the Earth (Mueller-Dombois and Ellenberg 1974), and the Classification of Wetland and I Deepwater Habitats of the United States (Cowardin et al. 1979). This classification is preliminary, subject to peer review, field testing, and revision. This report