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.


Fig 1. Distribution of Lupinus polyphyllus s.l. (A) In North America, the native segregates in the west partly overlap in their distribution and are delimited by outlines according to the color scheme in the legend. Non-native, synanthropic occurrences are indicated by black dots. Distribution data based on digitally available herbarium specimen locations and county records (for data sources see Table 1 in the paper). (B) In Europe, numbers give the first records for the species in different countries/regions (cf. Table 6 in the paper). (C) Numbers refer to the textual descriptions (for details, see the paper) of the non-native naturalized distribution across the globe

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 is the senior author of a multi-author paper on the phenology and morphology of the invasive legume Lupinus polyphyllus along a latitudinal gradient in Europe. He has also been the project coordinator, while Kristin Ludewig (Hamburg University) has led the preparation of the paper, recently published in the journal NeoBiota (https://doi.org/10.3897/neobiota.78.89673). In total, 30 authors (researchers, students, consultants, conservation agency employees) have been involved in this project and the publication. Each co-author contributed data of a lupine population and the whole project covered a >2000 km long latitudinal gradient including the countries Luxembourg, Germany, Poland, Denmark, Sweden and Norway (Fig. 1).

Fig. 1. Position of the 22 study sites (for site abbreviations, see Table 1 in the paper). Background map depicts climatic zones. ATC – atlantic central, ATN – atlantic north; ALS – alpine south; CON – continental; NEM – nemoral; BOR – boreal; ALN – alpine north. For certain analyses sites in BOR and ALN were pooled.

Plant phenology is the timing of seasonal events, such as budburst, greening, flowering, and fruit ripening. Phenology influences the fitness of individual plants, controls species distribution ranges, and may have cascading effects on communities and ecosystems. Temperature is one of the most important drivers of plant phenology together with day length. However, the potential for adaptation of phenology may also be key to understanding the success of invasive plant species, which will benefit from ongoing global change. Lupinus polyphyllus Lindl. (Fabaceae) is a perennial herbaceous hemicryptophyte originating from western North America that was introduced in Central Europe as an ornamental plant in the 19th century. From Central Europe and Scandinavia, the species spread very successfully to almost all parts of Europe, now ranging from the Pyrenees in the West to the Ural (and beyond) in the East (Eckstein et al., unpublished data). From North to South, L. polyphyllus is currently covering the full range of Europe, except for Mediterranean zones such as the Iberian Peninsula and Italy.

The overall aim of the paper was to understand how the timing, temperature dependence of flow­ering and fruiting, and performance (canopy height, potential seed production and seed release height) of L. polyphyllus change along the latitudinal gradient from Central to Northern Europe. The authors tested differences between populations from different climatic zones and quantified variation in phenology in relation to latitude. The present study is probably the first attempt to quantify variation in phenology of an invasive plant across a large latitudinal gradient in the field.

The paper studied variation in growth and phenology of flowering and fruiting of L. polyphyllus using measurements and >1600 digital photos of inflorescences from 220 individual plants observed weekly at 22 sites. While canopy height of plants did not vary significantly along the latitudinal gradient, the day of the year (doy) at which different phenological phases were reached, increased 1.3–1.8 days per degree latitude (Fig. 2), whereas the growing degree days (gdd) required for these phenological phases decreased 5–16 gdd per degree latitude. However, this difference disappeared, when the day length of each day included in the calculation of gdd was accounted for (Fig. 2). The day of the year of the earliest and the latest climatic zone to reach any of the four studied phenological phases differed by 23–30 days and temperature requirements to reach these stages differed between 62 and 236 gdd. Probably, the invasion of this species will further increase in the northern part of Europe over the next decades due to climate warming. For invasive species control, the results suggest that in countries with a large latitudinal extent, the mowing date should shift by ca. one week per 500 km at sites with similar elevations to target the species in the same phenological phase.

Fig. 2. Summary figure showing canopy height (cm), day of the year (doy) of first open flowers and growing degree hours (gddhours) first open flowers of populations of L. polyphyllus in different climatic zones. For abbreviations of climatic zones, see Fig. 1.
Louis Addo, (Ph.D. Student in Biology)

Louis Addo (a Ph.D. student in Biology at Karlstad University) will be giving a talk about the interaction of salmonids fry with changing flows. The talk will be a presentation of a recently published article entitled “Growth and mortality of sympatric Atlantic salmon and brown trout fry in fluctuating and stable flows” by Louis and others from the River Ecology and Management Research group working with salmonids ecology and IBM’s.

You are invited to join this seminar live on zoom and at the biology department at Karlstad University (5F416) at 13:15 CET on 6th December 2022. To join in via zoom use the link: https://kau-se.zoom.us/my/kaubiology

Caroline Durif

Caroline Durif , a Research Scientist from Bergen University, Norway will be giving a seminar live on Karlstad University campus (Room: 21A349) and also over zoom via https://kau-se.zoom.us/my/kaubiology . The seminar entitled Eel magnetic orientation will start at 15:15 CET on Thursday 17th November 2022. You are all invited to attend this seminar for free. See you there!

Jeff Marker

Jeff Marker, Eva Bergman, Lutz Eckstein, and Denis Lafage of Karlstad University have recently published a paper titled “Forested riparian buffer environmental variables are more important than size for species functional diversity in production forests” in the journal Forest Ecology and Management.

In their paper they explore the effects of forested buffers along small streams on the links between diversity and ecosystem function using spiders and vascular plants. They collected over 150 species of spiders and 85 species of vascular plants in Swedish production forests to test their hypothesis that larger forested buffers around streams would result in high levels of functional diversity. Surprisingly, the forested buffers had no effect on system functional diversity or functional redundancy for spiders or vascular plants. However, taxonomic diversity was found to drive functional diversity and the authors suggest that forest managers work to conserve high levels of taxonomic diversity through proper forested buffer maintenance.

This paper is open access and can be found on https://doi.org/10.1016/j.foreco.2022.120599

Jenni Prokkola

On Tuesday 8 November, at 13:15 CET Jenni Prokkola from Academy Research Fellow, Natural Resources Institute (Luke), Finland will be giving a talk about The energetics of life-history variation in Atlantic salmon: a question of resource allocation and genetic constraints. Pioneering genetic association studies have identified genomic regions strongly linked to the enormous life-history variation found in Atlantic salmon (Salmo salar). Jenni will describe how she uses genomic prediction in follow-up empirical studies to test if life history variation in salmon may be constrained by whole animal and tissue-level energetic pathways.

The seminar will be held at Karlstad University House 21, room 349, and also live on zoom at (https://kau-se.zoom.us/my/kaubiology). You are invited to physically attend this seminar at Karlstad University campus building 21 or live on zoom.

On 15 November, Isolde Puts will be giving a talk on her work in northern lakes. She conducted her Ph.D. at the Department of Ecology and Environmental Science (EMG) at Umeå University and improved our understanding of how primary production in lakes is affected by climate change. Isolde looked at both direct and indirect effects of climate change on free-floating and attached algae production, and investigated the implications of changes in pelagic-benthic algae production for energy- and nutrient transfer to higher consumers in lakes. In future projects, she’ll broaden her view a bit as she will include coastal linkages in her work.

Isolde Puts

Find Isolde’s publications here and attend the seminar in on campus (room 21A349) or on Zoom (https://kau-se.zoom.us/my/kaubiology) at 13:15 CET on 15 November.

Louis Addo (Ph.D. Student at Karlstad University)

Louis Addo (Doctoral Student), Mahboobeh Hajiesmaeli (Post-doctoral Researcher), John Piccolo (Professor) and John Watz (Associate Professor in Biology) all from the River Ecology and Management Research Group RivEM, Department of Environmental and Life Sciences at Karlstad University have recently published a paper entitled “Growth and mortality of sympatric Atlantic salmon and brown trout fry in fluctuating and stable flows” with the journal Ecology of Freshwater Fish.

In their paper, they explore the potential effects of hydropeaking or short-term regulated rivers on the growth and mortality of sympatric Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) at the fry life stage.

This paper is open-access and can be found at https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.12685

On 25 October 2022 at 13.15 CET over zoom, Koh Hasegawa will be giving a talk about the ecological effects of invasive salmonids and interactions between hatchery-reared and wild fish in Japan.

Koh Hasegawa

Koh Hasegawa is a Fish Conservation Ecologist working with the Salmon Research Department of the Japan Fisheries Research and Education Agency. Koh in his talk will answer questions about what brown trout do in the urban streams in Sapporo and whether it is a good idea or not to let hatchery-reared and wild population of salmon mix. You are welcome to join this seminar over zoom on Tuesday 25 October at 13:15 CET via https://kau-se.zoom.us/my/kaubiology