Shefferson et al. 2003

		Shefferson, R.P., J. Proper, S.R. Beissinger, and E.L. Simms. 2003. Life
		history trade-offs in a rare orchid: the costs of flowering, dormancy, and sprouting. Ecology 84:1199-1206

Abstract We tested for life history trade-offs among dormancy, sprouting, and
flowering in a seven-year study of a threatened, perennial plant, the small yellow lady’
s slipper orchid (Cypripedium calceolus ssp. parviflorum (Salisb.) Fernald). The
aboveground states of 629 genets were monitored over seven years in a wet
meadow in northeastern Illinois, USA. With mark-recapture statistics, survival,
resighting, and stage transitions were calculated among three stage classes of
individuals: dormant, vegetative, and flowering. The best-fit and most parsimonious
models suggested that (1) survival was constant among years, but varied by stage;
(2) dormant individuals suffered significantly higher mortality and were more likely to
become dormant in future years than sprouting or flowering individuals; (3) flowering
individuals had significantly higher survival and were more likely to flower in the
future than sprouting and dormant individuals; and (4) sprouting individuals had a
significantly higher stage transition to dormancy from the vegetative state than to any
other state. Thus, our results identified costs of dormancy and sprouting to survival
and future reproduction, but no costs of reproduction either to survival or future
flowering effort. Dormancy seems unlikely to be adaptive except perhaps as a bet-
hedging strategy under catastrophic conditions. Applying mark-recapture models to
test predictions from life history theory provided a robust means to explore
hypothetical trade-offs that may not have been observed in a conventional analysis
and allowed dormancy to be estimated robustly without biasing survival estimation.

Article copyright notice: © 2003 by the Ecological Society of America

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Shefferson et al. 2003