Ecological Archives E096-070-A3

Richard P. Shefferson and Deborah A. Roach. 2012. The triple helix of Plantago lanceolata: Genetics and the environment interact to determine population dynamics. Ecology 93:793–802.

Appendix C. Exploration of fertility assumptions and their impacts on λ.

The high λ we observed in this study appeared to be strongly determined by high fertilities. We repeated all LTRE analyses described in the manuscript, first with all fertilities halved, and then with transitions from the seedling stage to adult size classes halved (but without fertilities halved). However, our LTRE results were neither particularly sensitive to these fertilities, nor to transitions from seedling to adult size classes. Re-analysis of the LTRE for cohort 1 but with fertilities halved produced the same patterns in influence of factors on λ via component demographic rates, although the magnitudes of the LTRE scores for fertilities were slightly muted in comparison (Fig. C1). A further re-analysis with transitions from seedling to adult size classes rather than fertilities halved produced identical results to those presented in Fig. 2 (Fig. C2).


FIG. C1. LTRE decomposition of summed contributions to Δλ by size class in cohort 1. This analysis is a repeat of the analysis shown in Fig. 2, but with all fertilities halved. Effects of sires on λ through fertility, progression, stasis, and retrogression transitions (a, b, c, and d, respectively). Effects of years on λ through fertility, progression, stasis, and retrogression transitions (e, f, g, and h, respectively). Year × sire effects on λ through fertility, progression, stasis, and retrogression transitions (i, j, k, and l, respectively), for sires 124 and 2. Effects for sire 124 are denoted with filled symbols and solid lines, while effects for sire 2 are denoted with open symbols and dashed lines. Years denoted with symbols as shown in (h). Bars denote standard errors.



FIG. C2. LTRE decomposition of summed contributions to Δλ by size class in cohort 1. This analysis is a repeat of the analysis shown in Fig. 2, but with all transition probabilities from the seedling stage to all adult size classes halved. Effects of sires on λ through fertility, progression, stasis, and retrogression transitions (a, b, c, and d, respectively). Effects of years on λ through fertility, progression, stasis, and retrogression transitions (e, f, g, and h, respectively). Year × sire effects on λ through fertility, progression, stasis, and retrogression transitions (i, j, k, and l, respectively), for sires 124 and 2. Effects for sire 124 are denoted with filled symbols and solid lines, while effects for sire 2 are denoted with open symbols and dashed lines. Years denoted with symbols as shown in (h). Bars denote standard errors.


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