
doi: 10.1111/nph.12080
pmid: 23174037
Summary The stress‐gradient hypothesis (SGH) postulates an increase in the frequency of positive species interactions at increasing amounts of stress. While the SGH has been extensively tested in plant–plant interactions along abiotic stresses, it remains unclear whether this hypothesis could apply to higher trophic levels, such as herbivores, along biotic stress gradients. To address this issue, we investigated how the interaction between two potato herbivores may change along a stress gradient created by an assortment of potato varieties with different tuber palatability. We used a tuber resistance trait as a measure for biotic stress and one herbivore as the facilitator to gain access to the tuber of the other herbivore. Our experiment revealed a switch from neutral to positive interactions with increasing stress, confirming for the first time the predictions of the SGH for herbivores. Moreover, the intensity of facilitation decreased at high stress levels, suggesting that benefits by the facilitating species were dampened in the most stressful environment. In view of the ubiquitous role played by positive interactions among herbivores, broadening our search image for facilitative effects among other plant enemies will allow a better awareness of the importance of the SGH in structuring plant communities.
[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, compétition biologique, antagonisme, Moths, ravageur des plantes, stress, http://aims.fao.org/aos/agrovoc/c_917, [SDV.EE.ECO] Life Sciences [q-bio]/Ecology, environment/Ecosystems, Biomass, http://aims.fao.org/aos/agrovoc/c_7221, interactions biologiques, Pupa, http://aims.fao.org/aos/agrovoc/c_16196, Phylogenetics and taxonomy, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Gelechiidae, stress biotique, Larva, http://aims.fao.org/aos/agrovoc/c_30197, L20 - Écologie animale, stress‐gradient hypothesis (SGH), environment/Ecosystems, http://aims.fao.org/aos/agrovoc/c_7452, http://aims.fao.org/aos/agrovoc/c_35769, http://aims.fao.org/aos/agrovoc/c_35768, 570, herbivore, Models, Biological, facteur du milieu, facilitation, [SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics, biotic stress, Species Specificity, plant antagonists, Stress, Physiological, [SDV.BID.SPT] Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, Animals, http://aims.fao.org/aos/agrovoc/c_3567, Herbivory, http://aims.fao.org/aos/agrovoc/c_2594, Solanum tuberosum, species interaction, stress abiotique, http://aims.fao.org/aos/agrovoc/c_49896, http://aims.fao.org/aos/agrovoc/c_465, H10 - Ravageurs des plantes, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, stress-gradient hypothesis (SGH)
[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, compétition biologique, antagonisme, Moths, ravageur des plantes, stress, http://aims.fao.org/aos/agrovoc/c_917, [SDV.EE.ECO] Life Sciences [q-bio]/Ecology, environment/Ecosystems, Biomass, http://aims.fao.org/aos/agrovoc/c_7221, interactions biologiques, Pupa, http://aims.fao.org/aos/agrovoc/c_16196, Phylogenetics and taxonomy, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Gelechiidae, stress biotique, Larva, http://aims.fao.org/aos/agrovoc/c_30197, L20 - Écologie animale, stress‐gradient hypothesis (SGH), environment/Ecosystems, http://aims.fao.org/aos/agrovoc/c_7452, http://aims.fao.org/aos/agrovoc/c_35769, http://aims.fao.org/aos/agrovoc/c_35768, 570, herbivore, Models, Biological, facteur du milieu, facilitation, [SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics, biotic stress, Species Specificity, plant antagonists, Stress, Physiological, [SDV.BID.SPT] Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, Animals, http://aims.fao.org/aos/agrovoc/c_3567, Herbivory, http://aims.fao.org/aos/agrovoc/c_2594, Solanum tuberosum, species interaction, stress abiotique, http://aims.fao.org/aos/agrovoc/c_49896, http://aims.fao.org/aos/agrovoc/c_465, H10 - Ravageurs des plantes, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, stress-gradient hypothesis (SGH)
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 34 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
