Lutz Eckstein is the lead author of a paper summarizing the current knowledge on the biology of the invasive legume Lupinus polyphyllus Lindley. The paper has recently been published in the journal Perspectives in Plant Ecology, Evolution and Systematics in the series “Biological Flora of Central Europe” (https://doi.org/10.1016/j.ppees.2022.125715). This work is a cooperation with Erik Welk (Martin-Luther-University Halle-Wittenberg and German Centre for Integrative Biodiversity Research (iDiv) Halle, Germany), Yves Klinger and Wiebke Hansen (both Justus Liebig University Giessen, Germany), Tommy Lennartsson and Jörgen Wissman (both Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden), Kristin Ludewig (University of Hamburg, Germany), and Satu Ramula (University of Turku, Finland).

The paper gives a thorough review of the species’ taxonomy, presents distribution maps for North America, Europa and the world (Fig. 1), illustrates the life cycle of L. polyphyllus, and it contains a comprehensive discussion of potential management options. During the research for this review, the authors encountered some doubtful information about L. polyphyllus that uncritically reiterates in several fact sheets, reports and webpages. One such erroneous piece of information refers to the apparently very high longevity of seeds, which was taken from a modelling study on seed longevity under optimal dry and cold storage conditions. Similarly, there is some uncertainty and large variation concerning the actual lifespan of the species. Another piece of doubtful information is the deep rooting depth of L. polyphyllus, which may rather characterize a maximum than a representative average value. Finally, the species is sometimes considered a “rhizomatous perennial” although it lacks true rhizomes. These points highlight some critical knowledge gaps, which partly relate to aspects of the species’ life cycle and morphology that may be either time-consuming or labor-intensive to study.

The authors conclude that there is currently no evidence-based strategy for a cost-efficient management of L. polyphyllus. The development of such control measures is necessary because L. polyphyllus is among the most problematic non-native plant species in Europe with respect to environmental and socio-economic impacts. The species has significant negative effects on community structure, composition, species richness and diversity, especially in nutrient-poor habitats such as alpic mountain hay meadows, alpic mat-grass swards but also nutrient-poor road verges or riparian terraces.

Lutz Eckstein, professor at Karlstad University, is involved in a recently published paper, studying techniques for control of the invasive Garden Lupine (Lupinus polyphyllus) and the introduction of target species in mountain meadow plant communities.

This paper with Wiebke Hansen as the lead author, published in the journal Restoration Ecology (https://doi.org/10.1111/rec.13682), tested the restoration techniques “seed bank activation” and “green hay transfer” in combination with “manual removal of the invasive L. polyphyllus” on three types of grassland (Nardus grassland, mesic and wet mountain hay meadows) in the Rhön UNESCO Biosphere Reserve in Central Germany.

The main implications for restoration practice are the following:

• Green hay application might not be a suitable tool for restoring Nardus grassland since small species might not be able to grow through the plant material layer.
• Lupinus polyphyllus cover on restoration sites can be reduced by manual removal of all parts of the plants, but a lasting reduction requires at least repeated applications
• Reinvasion of Lupinus polyphyllus into restoration sites must be prevented with an appropriate management, e.g. early and/or repeated mowing.
• Active restoration through seed bank activation failed to promote mountain meadow target species and reduced the cover of wet mountain hay meadow target species.

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Road verges act as important refuges for grassland species since the areas of semi-natural grassland have declined during the last century. However, as linear habitats, road verges increase connectivity in fragmented landscapes, which also makes them prone to colonization by non-native species. This is currently seen as the greatest threat to species-rich road verges. The invasive Garden Lupine is commonly found in road verges where it alters competitive interactions, reduces native populations, and even causes extinctions of native species. 

This project is funded by The Swedish Transport Administration (Trafikverket) and the aim is to improve ecosystem functions and services of species-rich road verges and green infrastructure through evidence-based control and monitoring of Garden Lupine at the landscape scale.

During this seminar, I’m going to introduce the background for the project, and talk about what has been done and what I am planning to do in the next years.

The seminar will be streamed live over zoom on Tuesday 26th April at 13.15 CET. The zoom link for the seminar is https://kau-se.zoom.us/my/kaubiology. You are welcome

Garden Lupine (Lupinus polyphyllus) native to North America has been classified as an invasive species in Sweden. In Sweden, they are mainly distributed in road verges. A group of researchers at Karlstad University led by Prof. Lutz Eckstein has been tasked with finding efficient management strategies to control their spread. The research aims at finding out when the garden lupine can be controlled most effectively. Watch Prof. Lutz Eckstein and doctoral student Elin Blomqvist talk about this research in a video interview as they collect and examine lupines at different stages of development.

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Watch the full video here : https://tinyurl.com/mbnjhmh