SOMATIC COST OF REPRODUCTION IN 3 CARNIVOROUS PINGUICULA SPECIES

We estimated the cost of reproduction and reproductive effort in three iteroparous plant species, Pinguicula alpina, P. villosa and P. vulga ris, in a subarctic environment. The phenotypic costs of reproduction were quantified by comparing resource pools (dry weight, nitrogen or p hosphorus) in reproductive and non-reproductive plants. Two types of n on-reproductive plants were used; plants whose reproductive parts had been removed (RR) at the start of the growing season and naturally non -reproductive plants (NR). The reproductive effort was calculated as t he resources invested in reproduction in relation to the total resourc e pool (somatic + reproductive parts). For P. vulgaris the amount of r esources available was manipulated by feeding plants with insects and/ or by leaf removal in a factorial design. A somatic cost of reproducti on was found for all species and treatments since reproductive plants had smaller somatic resource pools than non-reproductive plants (both RR and NR). The total resource pool was higher in reproductive plants than in non-reproductive plants. Due to this difference, the reproduct ive effort exceeded the somatic cost of reproduction. This suggests th at mechanisms may exist for decreasing the cost of reproduction. Mecha nisms that potentially could explain the discrepancy between reproduct ive effort and the somatic cost are discussed.