Centre for Hydrological and Ecosystem Science, Department of Geography, Loughborough University, Loughborough, UK.
New Phytol. 2012 Jul;195(1):182-8. doi: 10.1111/j.1469-8137.2012.04139.x. Epub 2012 Apr 16.
• 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.
植物的肉食性被认为是对低营养环境的一种适应。随着根系氮素供应的增加，肉食性植物从捕食中获取的氮素预计将成为氮素预算中不太重要的组成部分。
在这里，我们通过自然丰度稳定同位素质量平衡技术，研究了在瑞典沿纬度氮沉降梯度的营养沼泽中生长的肉食性植物茅膏菜（Drosera rotundifolia）通过根系吸收氮与捕食猎物之间的关系。
接受最低氮沉降水平的茅膏菜植物从猎物中获得的氮比例（57%）高于氮沉降较高的沼泽植物（中间水平为 22%，最高水平为 33%）。当考虑植物质量差异时，当考虑总猎物氮吸收时，这种模式也存在（低、中、高氮沉降点的植物分别为 66、26 和 26μg 猎物氮）。经过质量调整的根氮吸收模式与此相反（分别为 47、75 和 86μg N 植物）。
由于大气氮沉降增加了氮素的有效性，本研究中的茅膏菜植物从依赖猎物氮素转变为依赖根系氮素。
