A demographic assessment of local adaptation in a grassland perennial herb

• Habitat heterogeneity in abiotic and biotic factors drives the evolution of adaptive population differentiation. Assessments of local adaptation among populations of perennial plants are commonly based on estimates of one or a few fitness components in reciprocal transplant experiments. However, natural selection does not act on fitness components but on life-time fitness, and local adaptation should therefore ideally be assessed based on integrated measures of the performance during the entire life cycle. We transplanted seedlings and adult plants reciprocally among four populations of the perennial herb Primula farinosa differing in abiotic and biotic conditions on the island of Öland, SE Sweden. We recorded survival, growth, flowering and fruit production during three consecutive years (2010-2012) and used integral projection models to quantify variation in total fitness, estimated as population growth rate. Transplant site had large effects on most aspects of plant performance, and the effects of population of origin on survival, growth, flowering propensity and fruit production varied among sites for several year × cohort combinations. However, no evidence of local adaptation, expressed through single fitness components or total fitness, was found. The results suggest that populations of P. farinosa differ genetically in traits influencing fitness, but these differences do not match current selection regimes. This study provides a template for how reciprocal transplant experiments can be combined with long-term demographic studies and population models to assess local adaptation in long-lived species based on estimates of total fitness.

Subject headings

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Evolutionsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Evolutionary Biology (hsv//eng)

Keyword

Demography

Integral Projection Models

Life-time fitness

Primula farinosa

Reciprocal transplant

Publication and Content Type

vet (subject category)

ovr (subject category)