PHENOTYPIC DIFFERENTIATION AT SOUTHERN LIMIT BORDERS: THE CASE STUDY OF TWO FUCOID MACROALGAL SPECIES WITH DIFFERENT LIFE-HISTORY TRAITS

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Rita Araujo (Author) Other; Ester A Serrao (Author) Other; Isabel Sousa Pinto (Author) FCUP; Per Aberg (Author) Other

Journal

Title: Journal of Phycology

Vol. 47

Pages: 451-462

ISSN: 0022-3646

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 30 Citations

Scopus - 33 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-002-R51

DOI: 10.1111/j.1529-8817.2011.00986.x

Abstract (EN): Marginal populations are often geographically isolated, smaller, and more fragmented than central populations and may frequently have to face suboptimal local environmental conditions. Persistence of these populations frequently involves the development of adaptive traits at phenotypic and genetic levels. We compared population structure and demographic variables in two fucoid macroalgal species contrasting in patterns of genetic diversity and phenotypic plasticity at their southern distribution limit with a more central location. Models were Ascophyllum nodosum (L.) Le Jol. (whose extreme longevity and generation overlap may buffer genetic loss by drift) and Fucus serratus L. (with low genetic diversity at southern margins). At edge locations, both species exhibited trends in life-history traits compatible with population persistence but by using different mechanisms. Marginal populations of A. nodosum had higher reproductive output in spite of similar mortality rates at all life stages, making edge populations denser and with smaller individuals. In F. serratus, rather than demographic changes, marginal populations differed in habitat, occurring restricted to a narrower vertical habitat range. We conclude that persistence of both A. nodosum and F. serratus at the southern-edge locations depends on different strategies. Marginal population persistence in A. nodosum relies on a differentiation in life-history traits, whereas F. serratus, putatively poorer in evolvability potential, is restricted to a narrower vertical range at border locations. These results contribute to the general understanding of mechanisms that lead to population persistence at distributional limits and to predict population resilience under a scenario of environmental change.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12