Abstract
When plants compete what influences that interaction? To answer this we measured belowground competition directly, as the simultaneous capture of soil ammonium and nitrate by co‐existing herbaceous perennials, Dactylis glomerata and Plantago lanceolata, under the influence of: species identity; N uptake and biomass of focal and neighbour plants; location (benign lowland versus harsher upland site); N availability (low or high N fertilizer); N ion, ammonium or nitrate production (mineralisation) rate, and competition type (intra‐ or interspecific), as direct effects or pairwise interactions in linear models. We also measured biomass as an indirect proxy for competition. Only three factors influenced both competitive N uptake and biomass production: focal species identity, N ion and the interaction between N ion and neighbour N uptake. Location had little effect on N uptake but a strong influence on biomass production. N uptake increased linearly with biomass only in isolated plants. Our results support the view that measuring resource capture or biomass production tells you different things about how competitors interact with one another and their environment, and that biomass is a longer‐term integrative proxy for the outcomes of multiple separate interactions—such as competition for N—occurring between plants.
Original language | English |
---|---|
Pages (from-to) | 1268-1277 |
Number of pages | 10 |
Journal | Plant, Cell & Environment |
Volume | 44 |
Issue number | 4 |
Early online date | 11 Nov 2020 |
DOIs | |
Publication status | Published - Apr 2021 |
Bibliographical note
ACKNOWLEDGMENTS:We thank the James Hutton Institute, the Macaulay Development Trust, the National Trust for Scotland Mar Lodge Estate, Heather Armitage, Iain Mackie, Miranda Prendergast‐Miller, Annette Raffan, Shaila Rao, Gail Riekie, Allan Sim, Derek Simpson and the Natural Environment Research Council, UK (NE/F004591/1). Michael Perring and others provided helpful comments on previous versions.
Keywords
- N
- ammonium
- Dactylis glomerata
- direct uptake
- INTERSPECIFIC COMPETITION
- intraspecific competition
- isotope pool-dilution
- nitrate
- Plantago lanceolata
- interspecific competition