Recent research shows that earthworms can alter defense traits of plants against herbivores and pathogens by affecting soil biochemistry. Yet, the effects of invasive earthworms on defense traits of native plants from previously earthworm\uffe2\uff80\uff90free ecosystems as well as the consequences for multitrophic interactions are virtually unknown.
Here we use a combination of an observational study and a complementary experimental study to investigate the effects of invasive earthworms on leaf defense traits, herbivore damage and pathogen infection in two poplar tree species (Populus balsamifera and Populus tremuloides) native to North American boreal forests.
Our observational study showed that earthworm invasion was associated with enhanced leaf herbivory (by leaf\uffe2\uff80\uff90chewing insects) in saplings of both tree species. However, we only detected significant shifts in the concentration of chemical defense compounds in response to earthworm invasion for P. balsamifera. Specifically, leaf phenolic concentrations, including salicinoids and catechin, were lower in P. balsamifera from earthworm\uffe2\uff80\uff90invaded sites.
Our experimental study confirmed an earthworm\uffe2\uff80\uff90induced reduction in leaf defense levels in P. balsamifera for one of the defense compounds, tremulacin. The experimental study additionally showed that invasive earthworms reduced leaf dry matter content, potentially increasing leaf palatability, and enhanced susceptibility of trees to infection by a fungal pathogen, but not to aphid infestation, in the same tree species.
Synthesis. Our results show that invasive earthworms can decrease the concentrations of some chemical defense compounds in P. balsamifera, which could make them susceptible to leaf\uffe2\uff80\uff90chewing insects. Such potential impacts of invasive earthworms are likely to have implications for tree survival and competition, native tree biodiversity and ecosystem functioning.
", "keywords": ["0106 biological sciences", "multi-trophic interactions", "secondary metabolites", "15. Life on land", "01 natural sciences", "invasion ecology", "plant\u2013herbivore interactions", "13. Climate action", "international", "physical defense", "570 Life sciences; biology", "boreal forests", "Plan_S-Compliant_TA", "Research Articles", "belowground invasion"]}, "links": [{"href": "https://boris.unibe.ch/152111/1/1365-2745.13504.pdf"}, {"href": "https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2745.13504"}, {"href": "https://doi.org/10.1111/1365-2745.13504"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/1365-2745.13504", "name": "item", "description": "10.1111/1365-2745.13504", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/1365-2745.13504"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-10-09T00:00:00Z"}}, {"id": "10.1016/j.scitotenv.2021.148516", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:16:43Z", "type": "Journal Article", "created": "2021-06-19", "title": "Contrasting responses of major and minor volatile compounds to warming and gall-infestation in the Arctic willow Salix myrsinites.", "description": "Climate change is altering high-latitude ecosystems in multiple facets, including increased insect herbivory pressure and enhanced emissions of volatile organic compounds (VOC) from vegetation. Yet, joint impacts of climatic drivers and insect herbivory on VOC emissions from the Arctic remain largely unknown. We examined how one-month warming by open-top plastic tents, yielding a 3-4 \u00b0C air temperature increase, and the natural presence of gall-forming eriophyoid mites, Aculus tetanothrix, individually and in combination, affect VOC emissions from whortle leaved willow, Salix myrsinites, at two elevations in an Arctic heath tundra of Abisko, Northern Sweden. We measured VOC emissions three times in the peak growing season (July) from intact and gall-infested branches using an enclosure technique and gas chromatography-mass spectrometry, and leaf chemical composition using near-infrared reflectance spectroscopy (NIRS). Isoprene accounted for 91% of the VOCs emitted by S. myrsinites. Isoprene emission rates tended to be higher at the high than low elevation during the measurement periods (42 \u03bcg g-1 DW h-1 vs. 23 \u03bcg g-1 DW h-1) even when temperature differences were accounted for. Experimental warming increased isoprene emissions by approximately 54%, but decreased emissions of some minor compound groups, such as green leaf volatiles (GLV) and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT). In contrast, gall-infestation did not affect isoprene emissions but stimulated emissions of DMNT, sesquiterpenes and GLVs, particularly under ambient conditions at the low elevation. The NIRS-based chemical composition of the leaves varied between the two elevations and was affected by warming and gall-infestation. Our study suggests that under elevated temperatures, S. myrsinites increases emissions of isoprene, a highly effective compound for protection against oxidative stress, while an infestation by A. tetanothrix mites induces emissions of herbivore enemy attractants like DMNT, sesquiterpenes and GLVs. Under both conditions, warming effects on isoprene remain but mite effects on DMNT, sesquiterpenes and GLVs diminish.", "keywords": ["0301 basic medicine", "Volatile Organic Compounds", "0303 health sciences", "Willow", "Arctic Regions", "Salix", "15. Life on land", "Plant Leaves", "03 medical and health sciences", "13. Climate action", "Climate change", "Gall-forming herbivory", "Volatile organic compounds", "Herbivory", "Plant\u2013herbivore interactions", "Tundra", "Ecosystem"]}, "links": [{"href": "https://doi.org/10.1016/j.scitotenv.2021.148516"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.scitotenv.2021.148516", "name": "item", "description": "10.1016/j.scitotenv.2021.148516", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.scitotenv.2021.148516"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-11-01T00:00:00Z"}}, {"id": "10.5061/dryad.54ht3", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:21:24Z", "type": "Dataset", "title": "Data from: Effects of plant diversity on the concentration of secondary plant metabolites and the density of arthropods on focal plants in the field", "description": "Open Access1. The diversity of the surrounding plant community can directly affect the abundance of insects on a focal plant as well as the size and quality of that focal plant. However, to what extent the effects of plant diversity on the arthropod community on a focal plant are mediated by host plant quality or by the diversity of the surrounding plants remains unresolved. 2. In the field, we sampled arthropod communities on focal Jacobaea vulgaris plants growing in experimental plant communities that were maintained at different levels of diversity (1, 2, 4 or 9 species) for three years. Focal plants were also planted in plots without surrounding vegetation. We recorded the structural characteristics of each of the surrounding plant communities as well as the growth, and primary and secondary chemistry (pyrrolizidine alkaloids, PAs) of the focal plants to disentangle the potential mechanisms causing the diversity effects. 3. Two years after planting, the abundance of arthropods on focal plants that were still in the vegetative stage decreased with increasing plant diversity, while the abundance of arthropods on reproductive focal plants was not significantly affected by the diversity of the neighbouring community. The size of both vegetative and reproductive focal plants was not significantly affected by the diversity of the neighbouring community, but the levels of PAs and the foliar N concentration of vegetative focal plants decreased with increasing plant diversity. Structural equation modelling revealed that the effects of plant diversity on the arthropod communities on focal plants were not mediated by changes in plant quality. 4. Synthesis. Plant quality can greatly influence insect preference and performance. However, under natural conditions the effects of the neighbouring plant community can overrule the plant quality effects of individual plants growing in those communities on the abundance of insects associated to this plant.", "keywords": ["Phytochemistry", "Jacobaea vulgaris", "plant\u2013herbivore interactions", "plant quality", "insect community", "plant species richness", "Verwerkte data", "phytochemistry", "Processed data", "15. Life on land", "plant-herbivore interactions", "biodiversity"], "contacts": [{"organization": "Kostenko, O., Mulder, P.P.J., Courbois, Matthijs, Bezemer, T.M.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5061/dryad.54ht3"}, {"rel": "self", "type": "application/geo+json", "title": "10.5061/dryad.54ht3", "name": "item", "description": "10.5061/dryad.54ht3", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5061/dryad.54ht3"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-01-01T00:00:00Z"}}, {"id": "10.5061/dryad.gv2qr76", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:21:29Z", "type": "Dataset", "title": "Data from: Positive plant-soil feedbacks trigger tannin evolution by niche construction: a spatial stoichiometric model", "description": "unspecifiedspatial implicitPython 2 code to reproduce Fig. 3. The prediction for tannin evolution in the spatial implicit approach, as a function of turnover rate and soil fertility.cellular_automatonPython 2 code of the cellular automaton, used to generate Fig. 2 and Fig. 4.coevolutionPython 2 code to smile;ulate the coevolutionary dynamics of symbiotic capacity and tannin production.", "keywords": ["2. Zero hunger", "spatial dynamics", "plant\u2013herbivore interactions", "Niche construction", "15. Life on land", "Plant secondary metabolites", "mycorrhizae", "Stoichiometry"], "contacts": [{"organization": "Arnoldi, Jean-Fran\u00e7ois, Coq, Sylvain, K\u00e9fi, Sonia, Ibanez, Sebastien,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5061/dryad.gv2qr76"}, {"rel": "self", "type": "application/geo+json", "title": "10.5061/dryad.gv2qr76", "name": "item", "description": "10.5061/dryad.gv2qr76", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5061/dryad.gv2qr76"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-19T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=plant%E2%80%93herbivore+interactions&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=plant%E2%80%93herbivore+interactions&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=plant%E2%80%93herbivore+interactions&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=plant%E2%80%93herbivore+interactions&offset=4", "hreflang": "en-US"}], "numberMatched": 4, "numberReturned": 4, "distributedFeatures": [], "timeStamp": "2026-05-26T12:07:57.436165Z"}