Der Einfluss von invasiven Regenwürmern auf Pflanzeneigenschaften und die funktionelle Diversität von Pflanzengemeinschaften
Zusammenfassung der Projektergebnisse
Invasive earthworms cause dramatic shifts in understory plant community structure of northern North American forests. This project aimed at better understanding the mechanisms underlying these earthworm-induced changes in plant communities by taking a trait-based approach and considering multitrophic interactions. To achieve this research objective, we conducted complementary field observations, field and lab experiments, and literature syntheses. Observational studies in multiple North American forests and a field experiment provided robust empirical evidence that invasive earthworms alter native plant communities via changes in plant functional group composition with a pronounced shift between woody species (decrease) towards the dominance of grasses. These changes in species dominance and thus of the dominant and community-weighted mean trait values of the plant community impacted ecosystem processes like productivity, microbial biomass, and litter decomposition. We also disentangled the underlying mechanisms of these community changes by showing that even if the responses of plants are species-specific, earthworms invasion provided a competitive advantage to grass species. Our mesocosm (Ecotron) and microcosm experiments showed that invasive earthworms alter in plant-plant and plant-herbivore interactions in the understory plant community. Taken together, these findings advance the field of biological invasion research by combining plant trait-based approaches with non-trophic and multitrophic interactions. During the field campaign in Canada, we realized that some measurements were too time consuming and that it will not be possible to sample the second forest without further technical help and time. Thus, we decided to instead take this opportunity to sample the field experiment that was running since three years in the same forest in the context of the ECOWORM project. Regarding the climate chamber experiment, we had to change the experimental design due to limited availability of seeds, since we were unable to collect any seeds in the field due to the COVID-19 pandemic. Furthermore, the COVID-19 pandemic (and associated restrictions) caused delays in the set-up of the experiment and measurements. National Geographic: https://www.nationalgeographic.com/animals/article/earthwormsinvasive-north-america-hurt-insects Canadian Broadcasting Corporation: https://www.cbc.ca/news/science/invasive-earthworms-1.6403469 MDR Wissen: https://www.mdr.de/wissen/regenwurm-invasive-art-nordamerika-insekten-diversitaet-100.html National Public Radio: https://www.npr.org/2022/04/06/1091199423/invasive-earthworms-are-taking-over-forests-in-parts-of-the-u-s-and-canada DLF Kultur: https://www.deutschlandfunkkultur.de/kanada-regenwuermer-schaden-den-insekten-magazin-dlf-kultur-78fdf939-100.html The Globe and mail: https://www.theglobeandmail.com/canada/alberta/article-invasive-jumping-worms-canada/ SWR2: https://www.swr.de/swr2/wissen/der-europaeische-regenwurm-macht-in-nordamerika-probleme-100.html The Economist: https://www.economist.com/science-and-technology/invasion-of-the-earthworms/21808464 earth.com: https://www.earth.com/news/european-earthworms-hurt-biodiversity-in-northamerica/
Projektbezogene Publikationen (Auswahl)
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Invasive earthworms reduce chemical defense and increase herbivory and pathogen infection in native trees. Journal of Ecology, 109(2), 763-775.
Thakur, Madhav P.; Künne, Tom; Unsicker, Sybille B.; Biere, Arjen; Ferlian, Olga; Pruschitzki, Ulrich; Thouvenot, Lise; Türke, Manfred & Eisenhauer, Nico
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Do Invasive Earthworms Affect the Functional Traits of Native Plants?. Frontiers in Plant Science, 12 (2021, 3, 16).
Thouvenot, Lise; Ferlian, Olga; Beugnon, Rémy; Künne, Tom; Lochner, Alfred; Thakur, Madhav P.; Türke, Manfred & Eisenhauer, Nico
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Aboveground impacts of a belowground invader: how invasive earthworms alter aboveground arthropod communities in a northern North American forest. Biology Letters, 18(3).
Jochum, Malte; Thouvenot, Lise; Ferlian, Olga; Zeiss, Romy; Klarner, Bernhard; Pruschitzki, Ulrich; Johnson, Edward A. & Eisenhauer, Nico
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Invasive earthworms modulate native plant trait expression and competition. (2023, 1, 26). American Geophysical Union (AGU).
Schwarz, Rike; Eisenhauer, Nico; Ferlian, Olga; Maestre, Fernando; Rosenbaum, Benjamin; Uthe, Henriette & Thouvenot, Lise
