XVI International Botanical Congess

Botanists have recently recognized the need to assess rarity based on biological processes rather than on patterns of geographic distribution. Of those processes affected by small population size, increased inbreeding depression and decreased heritability have received special attention. To obtain field-based measurements of fitness characters, we utilized molecular marker data to estimate relatedness among pairs of individuals within populations. This enabled us to appraise whether small populations are characterized by immediate reduction in performance (increased inbreeding depression) and/or a lack of ability to respond to selection (decreased heritability). Significantly, this is the one of the first studies using measurements of quantitative genetics in field environments.