Resource economy of carnivorous plants: Interactions between prey capture and plant performance in three subarctic Pinguicula species

Sammanfattning: In this thesis, I have studied in situ the resource economy of the three carnivorous plant species Pinguicula alpina, P. villosa and P. vulgaris in a subarctic environment. The prey capture varied among individual plants, years and species. It was higher in young leaves then in old ones. P. vulgaris captured more prey that the other species and reproductive individuals of P. vulgaris captured more than non-reproductive ones. There was no response to increased fertiliser to the soil. When these plants were supplied with supplementary prey they responded by increased growth, reproduction and survival. All species experienced a cost of reproduction in terms of decreased growth. For all species the reproductive effort was larger than the cost of reproduction. High altitude plants were less affected by supplementary feeding and previous reproduction. P. alpina was less affected by defoliation and previous reproduction and responded less to supplementary feeding than P. vulgaris and P. villosa. P. alpina showed characteristics typical of capital breeder whereas P. vulgaris and P. villosa behaved like income-breeders.