On 15-6-2021 Sebastian Rock will be giving a talk introducing his work on the host-parasite interactions of unionid mussels. Within the broader LifeConnects projects, this work will improve mussel conservation and reintroduction efforts of this little studied order of bivalves in Sweden and around the world.

River Vramsån, a spot for future mussel reintroduction (photo by Sebastian Rock).

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.

Mattias Hansson, Lovisa Lind, Andreas Vernby, Larry Greenberg and Johan Watz from Karlstad University have a new paper out! It describes how Hester-Dendy samplers perform under different flow regimes. This was tested in a laboratory experiment by studying the colonization of the Hester-Dendy samplers in relation to a predetermined benthic macroinvertebrate composition in a fluctuating (and increasing) flow regime and in a constant flow regime.

An aquarium setup for the fluctuating and increasing flow regime with a Hester-Dandy sampler on the bottom. Photo by Mattias Hansson.

The results showed that flow conditions didn’t affect the number of colonizing individuals, but the sampled species diversity was negatively affected by the fluctuating flow regime. This indicates that sampling benthic macroinvertebrates from rivers and streams with sub-daily flow changes, for example downstream of hydropeaking power plants, may be subject to a negative sampling bias.

You can read the full paper here: https://onlinelibrary.wiley.com/doi/10.1002/rra.3805.

Professor Lutz Eckstein is co-author in a new paper in the journal Applied Vegetation Science led by Yves Klinger (Justus-Liebig-University Giessen, Germany). The authors assessed the role of mowing machinery and endozoochory by migratory sheep as dispersal vectors in semi-natural grasslands by comparing the species compositions and traits of species found in the vectors to the regional above-ground vegetation and soil seed bank. Plant material from mowers (n = 12 from one date) and dung samples from migratory sheep (n = 39 from 13 dates) were collected and the dispersed plant species were determined using the emergence method. We compared the species compositions to the regional above-ground vegetation and seed bank using non-metric multidimensional scaling (NMDS) and indicator species analysis. Furthermore, we compared functional traits of the dispersed species to traits of non-dispersed species of the regional species pools by calculating log-response ratios and performing metaregressions.

Sheep in the Rhön Mountains. Photo by Yves Klinger.

We found that mower samples were more similar to the above-ground vegetation whereas dung samples were more similar to the seed bank. Mowers and sheep endozoochory favored the dispersal of species with different traits and phenologies. Species with small seed sizes were prevalent in both vectors. Mowers were less selective concerning most traits, but favored high-growing grasses such as Alopecurus pratensis and Trisetum flavescens. Sheep dung samples contained less grasses and more palatable species, such as Urtica dioica.

Log-response ratios dispersal vectors vs species pools of sheep vs above-ground. LDMC = Leaf Dry Mass Content, EIV N = Ellenberg Indicator Value for Nutrients. Zero indicates the mean value of the non-dispersed species from the respective species pool, bars show mean log-response ratios ± confidence intervals. Figure is part of Figure 3 in the paper.

Sheep endozoochory and mowing machinery are complementary dispersal vectors favoring species with differing functional traits. Sheep endozoochory enables dispersal of species that have unfavorable traits (e.g. low releasing heights) or phenologies for dispersal by mowing machinery. To ensure the dispersal of a high number of plant species in semi-natural grasslands, the interplay of different vectors should be considered.

Read more about the paper here: https://doi.org/10.1111/avsc.12579.

On 25 May, Sara Cousins, professor in Physical Geography and associate professor in Plant Ecology at Stockholm University, will give a talk entitled “How does landscape change affect plant diversity?”. Sara combines plant community ecology and landscape history to improve the understanding of how land use changes affects plant dispersal and community composition, and also focuses on how climate change affects these processes.

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.

Professor Lutz Eckstein is involved in a new article led by Eva Svensson (Dept. of Political, Historical, Religious and Cultural Studies, KaU) and co-authored by Jan Haas (Geomatics, KaU) in the journal Landscapes (Taylor & Francis). They tested the potential of a low-budget method for integrating information on human impact and natural responses in the vegetation of boreal forested Scandinavia. The information from two national databases in Sweden – the National Inventory of Landscapes in Sweden (NILS) covering surveyed vegetation, and the Register of Ancient Monuments (Fornsök) – were combined and visualized using Geographical Information Systems (see Figure).

Rännberget, Northern Värmland, close to the study area described in the paper. Photo taken by Lutz Eckstein.

No relationships between human impact and vegetation were found at any of the five investigated sites. The authors discuss potential reasons for this, among others mismatches in time and scale between databases but also sectorized survey methods not paying attention to biocultural heritage, landscape perspectives or long-term processes. The paper concludes that further development of survey methods and registers targeting contexts and processes are called for. “This is a good example of `negative´ results, i.e. a study that does not demonstrate any significant patterns being published in an international scientific journal”, says Lutz Eckstein. Read more about the paper here: https://doi.org/10.1080/14662035.2020.1905202.

A group of international researchers, among which Martin Österling, have a new paper out! The authors, led by Ronaldo Sousa from the University of Minho in Portugal, investigated the role of anthropogenic habitats as refuges for freshwater mussels. The dataset of 709 sites comprised 228 mussel species, of which 34 are threatened, in a broad variety of anthropogenic habitat types. The authors assessed the conservation importance of these anthropogenic habitats, which included both refuges and ecological traps, and provide guidance for the conservation of freshwater mussels. Read the full paper here: https://onlinelibrary.wiley.com/doi/10.1111/gcb.15549

Irrigation canal in Morocco (river Bouhlou) colonized by Margaritifera marocana, one of the rarest species on the planet. Photo by Ronaldo Sousa.

On 6 April, Ted Morrow will give a talk entitled “Sexually antagonistic genes in flies and humans”. Sexually antagonistic selection occurs when natural selection on traits shared by males and females operates opposite directions in the two sexes. Sexually antagonistic genetic variation is apparently common and taxonomically widespread and yet very few specific genetic loci have been identified. The talk will give an overview of experimental work that has been carried out in the Morrow lab to find these genes in the fruit fly model as well as ask why no sexually antagonistic genes have been reported from humans.

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.

RivEM is looking for a PhD candidate to work on evidence-based control and monitoring of Garden Lupine for the conservation of species-rich road verges. The project is part of a larger commitment of the Swedish EPA, the Swedish Transport Administration and Formas on management and control of invasive organisms. The work will take place in southern Sweden and you will be supervised by Lutz Eckstein, Lovisa Lind Eirell (Biology) as well as Jan Haas and Jan-Olov Andersson (Geomatics).

A species-rich roadside in Sweden (photo taken by Lutz Eckstein).

The main tasks of the successful candidate involve to plan, conduct and analyze field experiments directed at controlling the cover and spread of the invasive Garden Lupine. This will include (i) identifying the optimal timing of management, (ii) evaluating the use of different mowing techniques (timing and the regime) as a controlling agent for the Garden Lupine, and (iii) exploring unconventional control measures on the Garden Lupine and their effects on the native vegetation. Additionally, using data derived from geographic information systems (GIS) and un-crewed aerial vehicles (UAV), the candidate will (iv) develop a method for cost efficient monitoring of lupine populations and for evaluating the success of control measures at the landscape scale. Read more about the position and apply at https://kau.varbi.com/en/what:job/jobID:379605/

On March 30th Jeff Marker, PhD student in our group, will be giving a talk on his work involving stable isotopes in spiders. He investigated the feasibility of using non-lethal samples in laboratory and field-collected spiders finding, in general, spider legs are reliable proxies for stable isotope values in whole bodies. Jeff will discuss some of the implications including more robust conservation efforts and the possibility of endangered species sampling.

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.

On Tuesday 9 March, Einar Kärgenberg, a senior researcher in Wildlife Estonia, will give an overview of their recently published studies. These describe the movement patterns of lithophilous migratory fish in Estonian free-flowing and fragmented rivers using acoustic telemetry. Behavioural patterns of little-studied cyprinids (asp (Leuciscus aspius) and vimba bream (Vimba vimba)) were identified. In addition, the effectiveness of potential and implemented mitigation measures (removal of dams, building fishways, the effectiveness of bar-racks) was assessed. Additional methods (incl. fyke-nets, diving) were used to directly estimate the mortality of Atlantic salmon smolts (Salmo salar) caused by Kaplan-type turbines.

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.