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": "10.5061/dryad.ns1rn8png", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-26T16:24:09Z", "type": "Dataset", "title": "Shrub encroachment decreases soil inorganic carbon stocks in Mongolian grasslands", "description": "1. Widespread shrub encroachment in global drylands may increase plant biomass and change soil organic carbon stocks of grassland ecosystems. However, the response of soil inorganic carbon (SIC), which is a major component of dryland carbon pools, to this vegetation shift remains unknown. 2. We conducted a systematic field survey in 75 pairs of shrub-encroached grassland and control plots at 25 sites in the grasslands of the Inner Mongolia Plateau to evaluate how shrub encroachment affects SIC density (SICD) in these ecosystems. 3. We found that shrub encroachment significantly reduced SICD in the upper 100 cm (3.85 vs. 4.74 kg C m-2, P < 0.05), especially in the subsurface soil (20-50 cm layer). The magnitude of SICD changes was related to the change in soil pH, shrub patch size, and initial SICD, reflecting that the reduction in SICD might be attributed to the shrub encroachment-related soil acidification. Our results also revealed that the lost SIC was mainly released into the atmosphere rather than redistributed into deeper soil layers. 4. Synthesis. We provide the first evidence for the soil acidification-induced SIC loss caused by shrub encroachment. Our findings highlight the non-negligible role of SIC dynamics in the C budget of shrub-encroached grassland ecosystems and the need to consider these dynamics in terrestrial C cycle research.", "keywords": ["2. Zero hunger", "carbon budget", "13. Climate action", "Soil inorganic carbon", "Temperate grassland", "carbon source", "soil acidification", "15. Life on land", "shrub encroachment", "Invasion ecology"], "contacts": [{"organization": "Liu, Shangshi, Zhou, Luhong, Li, He, Zhao, Xia, Yang, Yuanhe, Zhu, Yankun, Hu, Huifeng, Chen, Leiyi, Zhang, Pujin, Shen, Haihua, Fang, Jingyun,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5061/dryad.ns1rn8png"}, {"rel": "self", "type": "application/geo+json", "title": "10.5061/dryad.ns1rn8png", "name": "item", "description": "10.5061/dryad.ns1rn8png", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5061/dryad.ns1rn8png"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-10-03T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Invasion+ecology&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=Invasion+ecology&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=Invasion+ecology&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Invasion+ecology&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-06-27T13:23:25.552683Z"}