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Comparative Study
. 2014 Mar 20;9(3):e92177.
doi: 10.1371/journal.pone.0092177. eCollection 2014.

Spatial and temporal dynamics of fucoid populations (Ascophyllum nodosum and Fucus serratus): a comparison between central and range edge populations

Rita M Araújo  1 , Ester A Serrão  2 , Isabel Sousa-Pinto  3 , Per Åberg  4
Affiliations
Comparative Study

Spatial and temporal dynamics of fucoid populations (Ascophyllum nodosum and Fucus serratus): a comparison between central and range edge populations

Rita M Araújo et al. PLoS One. .

Abstract

Persistence of populations at range edges relies on local population dynamics and fitness, in the case of geographically isolated populations of species with low dispersal potential. Focusing on spatial variations in demography helps to predict the long-term capability for persistence of populations across the geographical range of species' distribution. The demography of two ecological and phylogenetically close macroalgal species with different life history characteristics was investigated by using stochastic, stage-based matrix models. Populations of Ascophyllum nodosum and Fucus serratus were sampled for up to 4 years at central locations in France and at their southern range limits in Portugal. The stochastic population growth rate (λ(s)) of A. nodosum was lower and more variable in central than in southern sites whilst for F. serratus this trend was reversed with λ(s) much lower and more variable in southern than in central populations. Individuals were larger in central than in southern populations for both species, which was reflected in the lower transition probabilities of individuals to larger size classes and higher probability of shrinkage in the southern populations. In both central and southern populations elasticity analysis (proportional sensitivity) of population growth rate showed that fertility elements had a small contribution to λ(s) that was more sensitive to changes in matrix transitions corresponding to survival. The highest elasticities were found for loop transitions in A. nodosum and for growth to larger size classes in F. serratus. Sensitivity analysis showed high selective pressure on individual growth for both species at both locations. The results of this study highlight the deterministic role of species-specific life-history traits in population demography across the geographical range of species. Additionally, this study demonstrates that individuals' life-transitions differ in vulnerability to environmental variability and shows the importance of vegetative compared to reproductive stages for the long-term persistence of populations.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Life cycle graph for A. nodosum and F. serratus showing the different stage classes and all possible transitions.
Individuals in a size class (2–6) that survive can grow (G), shrink (S) or stay in the same size class (L). Class 1 includes new recruits that, if survive, enter class 2. Individuals in class 3–6 are reproductive.
Figure 2
Figure 2. Mean (±SD), minimum (*) and maximum (#) stochastic growth rates (λs) for southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 3
Figure 3. Stable distribution of the mean matrix for southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 4
Figure 4. Reproductive values for each stage class of southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 5
Figure 5. Elasticity of the population growth rate to changes in matrix elements summed over different regions (growth, loop, shrinkage and fertility) for southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 6
Figure 6. Elasticity of the population growth rate to changes in the survival transitions for each stage class in southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 7
Figure 7. Sensitivity of the population growth rate to changes in matrix elements expressed as relative contributions and summed over different regions (growth, loop, shrinkage and fertility) in southern (Portugal) and central (France) A. nodosum and F. serratus populations.
Figure 8
Figure 8. Sensitivity of the population growth rate to changes in the survival transitions for each stage class in southern (Portugal) and central (France) A. nodosum and F. serratus populations.
See this image and copyright information in PMC

References

    1. Gaston KJ (2009) Geographic range limits: achieving synthesis. Proc R Soc B 276: 1395–1406. - PMC - PubMed
    1. Bridle JR, Vines TH (2007) Limits to evolution at range margins: when and why does adaptation fail? Trends Ecol Evol 22: 140–147. - PubMed
    1. Sexton JP, Patrick JM, Angert AL, Rice KJ (2009) Evolution and ecology of species range limits. Ann Rev Ecol Evol Syst 40: 415–436.
    1. Case TJ, Taper ML (2000) Interspecific competition, environmental gradients, gene flow, and the coevolution of species’ borders. Am Nat 155: 583–605. - PubMed
    1. Holt RD, Keitt TH (2005) Species’ borders: a unifying theme in ecology. Oikos 108: 3–6.

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