科研之友
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摘要
Goldenseal, Hydrastis canadensis L. (Ranunculaceae), is a perennial woodland herb of eastern North America harvested for the medicinal properties of its rhizome. Although listed in Appendix II of the Convention on Trade in Endangered Species, little is known of its population dynamics in the core of its historical range. We investigated the demography of wild populations at three forest interior sites in Ohio, including both sexual and asexual reproduction, in order to model population dynamics in the core of its historical range. We recognized six life history stages, and parameterized stage-structured (Lefkovich) transition matrices for each population. Marked individuals were monitored and field experiments were conducted to characterize and quantify seed dormancy, seedling establishment, and vegetative reproduction. We found seedling recruitment to be more common than suggested by previous studies, but less common than vegetative reproduction, and less important to projected population growth. The finite rate of increase, lambda, was greater than 1 for each population based on transition matrices for 1998-1999, but much less than 1 for two populations (and a parts per thousand 1 for the third) based on 1999-2000 matrices. This reduction in lambda appears due to lower survival and growth of established (non-seedling) plants, which may have been due to drought in spring 1999. In both year-to-year transitions, fertile plants typically regressed to the large sterile stage. This research provides a basis for exploring the effects of different harvest strategies on the population dynamics of H. canadensis, enabling assessment of sustainability.
- 出版日期2010-10
