Reliance on prey‐derived nitrogen by the carnivorous plant Drosera rotundifolia decreases with increasing nitrogen deposition

• DOI: 10.1111/j.1469-8137.2012.04139.x
• Publication Date: 2012-04-16T16:09:10Z
• Authors: J. Millett; B. M. Svensson; J. Newton; H. Rydin
• Keywords: Sweden; 0106 biological sciences; 2. Zero hunger; Nitrogen Isotopes; Atmosphere; Nitrogen; 15. Life on land; Drosera; Plant Roots; 01 natural sciences; Carnivory; Predatory Behavior; Wetlands; Animals

Summary Carnivory in plants is presumed to be an adaptation to a low‐nutrient environment. Nitrogen (N) from carnivory is expected to become a less important component of the N budget as root N availability increases. Here, we investigated the uptake of N via roots versus prey of the carnivorous plant Drosera rotundifolia growing in ombrotrophic bogs along a latitudinal N deposition gradient through Sweden, using a natural abundance stable isotope mass balance technique. Drosera rotundifolia plants receiving the lowest level of N deposition obtained a greater proportion of N from prey (57%) than did plants on bogs with higher N deposition (22% at intermediate and 33% at the highest deposition). When adjusted for differences in plant mass, this pattern was also present when considering total prey N uptake (66, 26 and 26 μg prey N per plant at the low, intermediate and high N deposition sites, respectively). The pattern of mass‐adjusted root N uptake was opposite to this (47, 75 and 86 μg N per plant). Drosera rotundifolia plants in this study switched from reliance on prey N to reliance on root‐derived N as a result of increasing N availability from atmospheric N deposition.