Lake Chelan State Park

Rare Plant and Vegetation Survey of Lake Chelan State Park Pacific Biodiversity Institute 2 Rare Plant and Vegetation Survey of the Lake Chelan State Park George Wooten [email protected] and Peter H. Morrison [email protected] December 2008 Pacific Biodiversity Institute P.O. Box 298 Winthrop, Washington 98862 509-996-2490 Recommended Citation Wooten G. and P.H. Morrison, 2008. Rare Plant and Vegetation Survey of the Lake Chelan State Park. Pacific Biodiversity Institute, Winthrop, Washington. 44 p. Acknowledgements Juliet Rhodes, Diana Hackenburg, Hans Smith and Alexis Monetta assisted with fieldwork and entered the data we collected into databases. Juliet Rhodes checked the data for errors and edited this report. The photographs in this report were taken during this project. Project Funding This project was funded by the Washington State Parks and Recreation Commission. 3 Executive Summary Pacific Biodiversity Institute (PBI) conducted a rare plant and vegetation survey of Lake Chelan State Park for the Washington State Parks and Recreation Commission (WSPRC). Lake Chelan State Park covers about 147 acres. The park lies within the glacial trough of Lake Chelan Valley, about ten miles above its lower, southernmost end. Lake Chelan is the second-deepest lake in the United States. The park is situated just below a saddle to Navarre Coulee that served as the outlet for glacial ice and water during the Pleistocene glaciation. A total of 14 polygons covered by 5 plant associations and 2 general land cover types were mapped and visited in Lake Chelan State Park. Existing plant communities were characterized within each polygon. Natural forest types were predominantly dominated by either ponderosa pine or Douglas-fir. No rare plants listed by the State of Washington were found in Lake Chelan State Park. We found two Class B noxious weeds and four Class C noxious weeds. The most widespread noxious weed in the park is diffuse knapweed (Centaurea diffusa). This plant favors disturbed roadsides. About 25 % of Lake Chelan State Park is developed. The ecological condition of non-developed plant communities in the park was ranked primarily in good condition. However the rankings do not convey the detrimental effects of fire suppression that is occurring here. Even in stands that are nearly free of invasive species, fire suppression has created dense understories of shrubs that are competing with the native pines for available nutrients. Due to fire suppression, many of the upland areas have become heavily stocked with woody species that now pose a fire hazard. We recommend undertaking a program of thinning and controlled burning to try and save these stands. 4 Table of Contents Introduction.................................................................................................................................6 Survey Conditions and Survey Routes.....................................................................................6 Vegetation Communities............................................................................................................7 Methods......................................................................................................................................................7 Historical Vegetation .................................................................................................................................8 Results........................................................................................................................................................9 Vegetation Community Mapping.......................................................................................................... 9 Vegetation Community and Land Cover Types.................................................................................. 12 Rare Plant Surveys...................................................................................................................17 Methods....................................................................................................................................................17 Results......................................................................................................................................................17 Vascular Plant List for the 2008 Project Area ........................................................................18 Discussion and Recommendations ........................................................................................21 Noxious Weeds ........................................................................................................................................21 Ecological Condition................................................................................................................................21 Restoration Opportunities ........................................................................................................................23 GIS Products Produced ...........................................................................................................24 References ................................................................................................................................25 Appendix A – Vegetation Survey Codes and Instructions....................................................26 Appendix B – Ecological Condition Ranking System ...........................................................28 Appendix C – Definitions of Vegetation Community Conservation Status .........................30 Appendix D – Vegetation Survey Data....................................................................................31 5 Introduction Lake Chelan State Park is located in Chelan County along Lake Chelan, a 60-mile long glacial valley with its terminus about a mile away from the Columbia River. The park is bordered on three sides by privately owned parcels. Lake Chelan is a rapidly growing recreational destination used by tourists throughout the country. Lake Chelan State Park has a stream running through it and several wetlands and small springs that appear to be derived from agricultural runoff. The climate is moderated by the lake, and this in turn offers a less harsh growing environment compared to areas with similar soils and climate elsewhere in the county. The vegetation is predominantly ponderosa pine forest or bitterbrush-dominated shrub-steppe. Some of the pines are up to four feet in diameter. Both of these plant groups have become densely overstocked with vegetation due to fire suppression. Survey Conditions and Survey Routes Lake Chelan State Park was initially visited on May 13, 2008. A second visit was conducted on August 10. The survey routes are shown in Figure 1. Access to the easternmost portion of Lake Chelan State Park is blocked by a steep cliff above the lake. Access is possible only by crossing private land or by scrambling up the cliff talus. This polygon was only visited once. 6 Figure 1. Field survey schedule and routes. Vegetation Communities Methods Pre-field reviews of literature, GIS data, and remote sensing data were conducted early in the season. Maps, GIS data, and remotely sensed data were assembled together into an ArcMap GIS project covering the project area. Topographic maps and digital elevation models (DEMs) were also assembled. Using the gathered spatial data resources, discrete vegetation polygons meant to represent specific plant communities or mosaics of plant communities were manually delineated by staff ecologists as polygon features in an ESRI shapefile format. The park was then visited twice during the field season to assure observation of both early and late- blooming plant species. The first visit was primarily a reconnaissance of the project area, meant to create a basic plant list for the park and to conduct initial rare plant surveys for early bloomers. Later visits focused on collecting field data for the vegetation polygon map and adding more species to the plant list during different times of the season. Before the field season was complete, all vegetation polygons that could be accessed safely were visited and field data was collected. 7 Plant community data was recorded on a form initially developed by the WSPRC (Appendix A). Recorded data included a wide variety of information about the vegetation composition, environmental characteristics, disturbance history and other notes for each polygon. Each polygon was rated for its overall ecological condition. Vegetation community and land cover classifications were assigned using information and keys from standard literature sources cited in the Reference section of this document. During field visits survey personnel had printed and digital maps available that included high-resolution aerial imagery. Digital maps were accessed in the field using ArcPad software (ESRI 2007) running on pocket PC, GPS enabled devices. Use of ArcPad allowed all survey routes to be mapped on a GPS recorder in real time, and allowed for viewing and editing data directly from field locations, resulting in field-verified attributes for the vegetation polygons. Once gathered, the field data was edited and entered into a Microsoft Access database and linked to the vegetation polygon geodatabase. Further refinements and editing of the vegetation data stored in the personal geodatabase was made based on information collected in the field with ArcPad. Historical Vegetation The natural vegetation at Lake Chelan State Park is currently undergoing a rapid change.

Load more