 | Shefferson, R.P., B. K. Sandercock, J. Proper, and S. R. Beissinger. 2001. | |
| Estimating dormancy and survival of a rare herbacious perennial using mark- recapture models. Ecology 82: 145-156 |
Abstract Mark-recapture statistics have rarely been applied to plants, yet they can be
useful for estimating plant demographic traits where individuals may be missed or
unobservable. We applied mark-recapture statistics based on an information theory
approach to estimate annual probabilities of dormancy in a five-year study of a
threatened, perennial plant, the small yellow lady’s slipper orchid (Cypripedium
calceolus ssp. parviflorum (Salisb.) Fernald). The aboveground states of 548 genets in
eight patches were monitored over five years. Apparent survival probabilities (phi),
corrected for dormancy, were calculated. The best-fit model suggested that apparent
survival was constant throughout the study for all patches, while dormancy varied
additively with time among patches. The mean probability of dormancy was 0.320 ±0.
024, with a mean maximum overestimation of 0.067 as calculated using an estimate of
the probability of detection. Dormancy typically lasted for no longer than two consecutive
years, although dormancy as long as four years was observed. Dormancy displayed a
strong covariate relationship with spring frost days, although effects of precipitation and
mean spring temperature were almost equally strong. Mean apparent survival
probabilities were high in each patch (phi = 0.878), but dormancy probabilities varied
considerably among patches (d = 0.188 - 0.672). Conventional resprouting probabilities
underestimated apparent survival by a mean difference of 0.288 (range: 0.150 - 0.589).
This novel application of mark-recapture statistics to plant demography allowed robust
survival estimates that accounted for uncertainty due to an unobservable, dormant life
stage.
Article copyright notice: © 2001 by the Ecological Society of America
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Copyright 2009 Richard P. Shefferson. All rights reserved.
Shefferson et al. 2001
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