Volumes 512–513, 15 April 2015, Pages 631–636
Highlights
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- We measured nutrition of the carnivorous plant Drosera rotundifolia across Europe.
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- We measured tissue nutrient concentrations and prey and root N uptake at 16 sites.
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- Tissue N concentrations were a product of root N availability and prey N uptake.
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- N deposition reduced the maximum amount of N derived from prey.
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- N deposition reduced the strength of a carnivorous plant–prey interaction.
Abstract
Nitrogen
(N) deposition has important negative impacts on natural and
semi-natural ecosystems, impacting on biotic interactions across trophic
levels. Low-nutrient systems are particularly sensitive to changes in N
inputs and are therefore more vulnerable to N deposition. Carnivorous
plants are often part of these ecosystems partly because of the
additional nutrients obtained from prey. We studied the impact of N
deposition on the nutrition of the carnivorous plant Drosera rotundifolia
growing on 16 ombrotrophic bogs across Europe. We measured tissue N,
phosphorus (P) and potassium (K) concentrations and prey and root N
uptake using a natural abundance stable isotope approach. Our aim was to
test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia
root N uptake was strongly affected by N deposition, possibly resulting
in reduced N limitation. The contribution of prey N to the N contained
in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia
tissue N concentrations were a product of both root N availability and
prey N uptake. Increased prey N uptake was correlated with increased
tissue P concentrations indicating uptake of P from prey. N deposition
therefore reduced the strength of a carnivorous plant–prey interaction,
resulting in a reduction in nutrient transfer between trophic levels. We
suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific.
Graphical abstract
Keywords
- Atmospheric nitrogen deposition;
- Carnivorous plants;
- Drosera rotundifolia;
- Plant–insect interactions;
- Round-leaved sundew;
- Stable isotopes
