WETLAND CONSERVATION STRATEGY FOR THE WEISER RIVER BASIN, IDAHO Prepared by Edward Bottum Idaho Conservation Data Center March 2005 Idaho Department of Fish and Game Natural Resource Policy Bureau 600 South Walnut, P.O. Box 25 Boise, ID 83707 Report prepared with funding from the United States Environmental Protection Agency through Section 104(b) (3) of the Clean Water Act Grant No. CD 970007-01-2 TABLE OF CONTENTS SUMMARY.....................................................................................................................................1 ACKNOWLEDGMENTS ...............................................................................................................2 INTRODUCTION ...........................................................................................................................3 SURVEY AREA..............................................................................................................................4 METHODS ......................................................................................................................................5 FIELD METHODS....................................................................................................................5 Reference Areas and Sample Sites ......................................................................................5 Field Data Collection ...........................................................................................................5 OFFICE METHODS .................................................................................................................6 National Wetlands Inventory ...............................................................................................6 Wetland Plant Associations .................................................................................................6 Site and Community Databases ...........................................................................................7 Site Ranking.........................................................................................................................8 RESULTS ........................................................................................................................................9 WETLAND CONDITION.........................................................................................................9 Wetland Losses ....................................................................................................................9 Functional Shifts ................................................................................................................10 WETLAND DIVERSITY........................................................................................................11 Wetland Plant Associations ...............................................................................................11 RARE FLORA.........................................................................................................................13 Rare Animals .....................................................................................................................13 CONSERVATION PRIORITIES FOR WETLANDS ............................................................13 Class I Sites........................................................................................................................14 Class II Sites ......................................................................................................................14 Reference Sites...................................................................................................................14 Habitat Sites.......................................................................................................................15 Other Sites and Priorities for Conservation .......................................................................15 How This Information Can Be Used .................................................................................15 How To Request Additional Information ..........................................................................16 LITERATURE CITED ..................................................................................................................16 APPENDICES ...............................................................................................................................27 i TABLE OF CONTENTS (Continued) APPENDIX A................................................................................................................................28 IDAHO CONSERVATION DATA CENTER SITE AND COMMUNITY REPORTING FORMS.........................................................................28 APPENDIX B ................................................................................................................................35 GUIDELINES FOR ASSIGNING SPECIES AND PLANT ASSOCIATION ELEMENT RANKS.......................................................................35 APPENDIX C ................................................................................................................................37 SITE SUMMARIES FOR WETLANDS IN THE WEISER RIVER BASIN.........................37 APPENDIX D................................................................................................................................70 KEY TO WETLAND AND RIPARIAN PLANT ASSOCIATIONS IN THE WEISER RIVER BASIN................................................................................................70 APPENDIX E ................................................................................................................................81 CHARACTERIZATION ABSTRACTS FOR HIGH RANKING PLANT ASSOCIATIONS IN THE SURVEY AREA ........................................81 APPENDIX F...............................................................................................................................121 TAXONOMY, RANGE, STATUS, AND MANAGEMENT OF RARE WETLAND AND RIPARIAN PLANT SPECIES IN THE WEISER RIVER BASIN.............................121 APPENDIX G..............................................................................................................................133 ANIMAL SPECIES OF SPECIAL CONCERN IN THE WEISER RIVER BASIN............133 LIST OF FIGURES Figure 1. Location of wetland sites in the Weiser River basin. Site numbers correspond to those used in Table 7. ..............................................................................................19 LIST OF TABLES Table 1. Accessing wetlands-related data housed at Idaho Department of Fish and Game. .....20 Table 2. Definition of wetland and deepwater habitat systems (Cowardin et al. 1979)............20 Table 3. Definitions and indicators of criteria for allocating wetland sites into management categories................................................................................................21 Table 4. Wetland and riparian plant associations in the Weiser River basin arranged by Cowardin system, class, and subclass..........................................................................22 ii TABLE OF CONTENTS (Continued) Table 5. Plant species of special concern in the survey area, conservation rank, and Idaho Native Plant Society (INPS) category. ..............................................................24 Table 6. Wetland associated animal species of special concern in the survey area...................25 Table 7. Wetland sites in Weiser River basin. Management categories are defined in the text................................................................................................................................26 iii SUMMARY The Idaho Conservation Data Center has received wetland protection grant funding from the Environmental Protection Agency under the authority of Section 104 (b)(3) of the Clean Water Act to enhance existing wetland information systems. The goal is to identify the following: 1) Where are the wetlands? 2) What is the condition and management status of wetlands? 3) What kind of wetlands are they? This information can then be applied to state biodiversity, conservation, and water quality enhancement projects on a watershed basis. The current project builds on previous inventories in the state to create a consistent source of wetland information. Previous project areas included Idaho Panhandle watersheds, the Henrys Fork Basin, the Big Wood and Snake Rivers, southeastern Idaho watersheds, east-central basins, the west-central mountain valleys of Idaho, and the high valleys of the Salmon River. This document summarizes our findings in the Weiser River basin of western Idaho. We used the United States Fish and Wildlife Service (USFWS) National Wetlands Inventory (NWI) to gain a broad perspective on the extent and types of wetlands in the survey area. Land ownership and management layers were overlaid on the NWI to determine ownership and the protected status of wetlands. Plant associations occurring in the survey area were placed into the hierarchical NWI classification and provide information relative to on-the-ground resource management. Assessment of the quality and condition of plant associations and the occurrence of rare plant and animal species allowed us to categorize ten wetland sites based on conservation intent. Five wetlands occur in a relatively natural condition and full protection is the priority. The biological significance of the surveyed wetland sites, abstracts for rare plant communities, and summaries of animal