A Recovery Strategy for Tall Bugbane (Cimicifuga Elata) in Canada
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A Recovery Strategy for Tall Bugbane (Cimicifuga elata) in Canada. Prepared by Brian Klinkenberg and Rose Klinkenberg for The Tall Bugbane Recovery Team and the BC Ministry of Water, Land and Air Protection March 31, 2003 EXECUTIVE SUMMARY Cimicifuga elata is a rare herbaceous species in the Ranunculaceae that is endemic to the Pacific Northwest of North America, where it is presently known from Oregon, Washington and British Columbia. In Canada it is known only from the Chilliwack River Valley drainage in British Columbia. Throughout its range, it occurs in small numbers in scattered populations in mature or old-growth mixed forests dominated by red cedar-hemlock forest with associated big-leaf maple. It occurs predominantly on north-facing slopes, where it occupies mesic to wet mesic sites near creeks or seeps, sometimes in close proximity to Mountain Beaver. The biological factors that limit the prevalence of this species include its occurrence in Canada at the northern tip of its range (climatic factors), its natural rarity in the landscape throughout that range, its occurrence in small, isolated populations, the lack of genetic exchange between populations, pollinator dependence, herbivory, and limited dispersal mechanisms. Anthropogenic factors that influence its abundance in the landscape include fire suppression and forest management activities. In assessing the potential strategies for recovery for this species, we have considered the various ecological principles and issues that may apply, such as metapopulation dynamics, conservation genetics, the ecology of rarity, influences of herbivory and the effects of pollinator limitation. We have also considered the historical occurrence of the species, and the factors that have influenced its current distribution. Using ancillary datasets, we have also produced a map showing potential habitat for Cimicifuga elata. The first and most critical component of species at risk recovery in the short term is habitat protection. Biologists and ecologists in general recognize that habitat protection is the key to species protection. Within this framework, specific steps required for recovery of Cimicifuga elata include but are not limited to: ? protection of known sites from logging operations and protection of populations from the indirect effects of logging through the use of buffers. This will be achieved in part by the implementation of the currently recommended provincial Wildlife Habitat Areas as defined in the Identified Wildlife Management Strategy, with boundaries delineated on the ground; ? intensive targeted search for the species throughout the known and predicted areas of occurrence in the Chilliwack area; ? establishment of monitoring plots and assessment of the population dynamics for our northern populations of the species. This includes assessment of population size and change over time, seed production and recruitment, critical habitat, pollinator role and more precise site/habitat information, including site-specific limiting factors. Collection of this information will be aimed at establishing population trends, viability and recruitment. If the above measures do not result in, at the minimum, maintenance of our known populations, and monitoring reveals serious on-going decline (greater than 25% change in one year), then other options should be reviewed. ii Critical components for recovery and persistence in the long term will be outreach to the forestry community in order to develop an understanding of the ecological requirements and importance of this species, and the development of a species-specific strategy for logging operations. Within the critical range for this species, the ability of forestry/logging crews to identify the plants, and thus work around them during extraction work, would be beneficial. This could be achieved by the production of an endangered species handbook/document for field identification. While tall bugbane can initially be confused with other species of Cimicifuga, this can be easily resolved with short, targeted training. iii Table of Contents EXECUTIVE SUMMARY........................................................................................................................................................................ii Table of Contents.......................................................................................................................................................................................iv List of Figures............................................................................................................................................................................................vi List of Tables .............................................................................................................................................................................................vi Disclaimer .................................................................................................................................................................................................vii Acknowledgements ..................................................................................................................................................................................vii GOAL ..........................................................................................................................................................................................................1 INTRODUCTION ......................................................................................................................................................................................2 PART I: BACKGROUND.........................................................................................................................................................................3 SPECIES INFORMATION..................................................................................................................................................................3 Taxonomy Update ...........................................................................................................................................................................3 Species Description .........................................................................................................................................................................3 Global Range ...................................................................................................................................................................................4 Canadian and BC Range .................................................................................................................................................................8 Percent of Global Distribution in Canada ......................................................................................................................................8 Discussion ........................................................................................................................................................................................8 HABITAT and ECOLOGY..................................................................................................................................................................8 Introduction......................................................................................................................................................................................8 Habitat ..............................................................................................................................................................................................9 Soil Type and Substrate.................................................................................................................................................................11 Slope and Aspect ...........................................................................................................................................................................11 Elevation ........................................................................................................................................................................................12 Associated Species ........................................................................................................................................................................12 Fire Association .............................................................................................................................................................................13 Overlapping Species of Concern ..................................................................................................................................................14 Distribution Bias............................................................................................................................................................................15 SPECIES BIOLOGY..........................................................................................................................................................................15 Life-span ........................................................................................................................................................................................15 Dormancy.......................................................................................................................................................................................15