Arctic charr habitat in northern Iceland.

On Tuesday 5 November, Stefán Óli Steingrímsson, Professor at Hólar University College, Iceland, will visit Karlstad University and give a seminar titled “Salmonid behaviour in space & time: Some lessons from Iceland”. The seminar starts at 13:15 in room 5F416 at Karlstad University. Everyone who wants to are welcome to attend the seminar.

Hjaltadalur valley on northern Iceland, seen from Hólar.

Jeff (right) and a former colleague inspecting Santeria sacrifices in Miami, Florida, USA. Santeria worshipers use a variety of plants, herbs, and animals to perform religious sacrifices. Some hypothesize that the very invasive African land snail (Achatina fulica) was brought into the United States to use in these rituals. Photo by Kelsey Branch

Jeff Marker recently started his PhD at Karlstad University. Here he writes about his previous work and what he intends to do as a PhD student at Karlstad University:

“Hej and hello, my name is Jeff Marker and I am a PhD student here at Karlstad University in the NRRV Research Group. Originally hailing from the Great Plains region of the United States, I am now settled here in Sweden working on riparian ecology, food webs, spider predation, and forestry policy. I began my academic career focused on tropical plant science questions, specifically the best ways to grow and maintain a year round seed corn nursery in Hawaii. After a short stretch in the agribusiness industry, I turned my attention to invasive pests and plant disease monitoring with the United States Department of Agriculture.  As a Plant Protection and Quarantine Officer I was tasked with enforcing USDA quarantine laws related to invasive species, agricultural smuggling, and agricultural trade compliance. It was here that I rediscovered my love of insects, especially the beetles. Over the years I amassed a large working and personal collection of beetles from the Cerambycidae and Buprestidae families from the Midwest and Great Plains regions of the U.S. Eventually I left the beetles behind, put on a suit and tie, and ended up in Washington D.C. as an agricultural policy analyst where I focused on international quarantine regulations and the agricultural quarantine inspection process.

After meeting a wonderful Swedish woman and taking stock of my life, I was easily convinced to move to Gothenburg in 2016. Upon moving to Sweden, I restarted my graduate education and completed my MSc here at KAU through the Ecology and Conservation Biology Program. My thesis focused on the effects of urban areas on Swedish beetles that utilize dead or decaying wood for all or part of their life cycle. I believe that urban areas have a mixed, but often overlooked, effect on insect biodiversity. On one hand increased urbanization and a focus on specific types of habitat removal (i.e. dead or decaying wood) can be a direct threat to ecosystem health and/or function. However, urban areas often have significantly more plant and arthropod diversity when compared to the surrounding natural, managed, and rural landscapes. And while urban areas can be prone to invasive pest outbreaks and poor management decisions, with proper care and monitoring they also have potential to become biodiversity hotspots and some of the most resilient ecosystems in the face of a changing climate and changing attitudes about nature.

Jeff in Gothenburg admiring some giant hogweed/jätteloka (Heracleum mantegazzianum), a European and North American invasive species with the potential to cause a severe phototoxic effect on human skin. Photo by Johanna Jonstrand

As a researcher at KAU I will combine my love of arthropods and my background in public policy to analyze forestry management practices and their effects on riparian ecosystems. While here I hope to share my knowledge about insects and agriculture but more importantly, I am excited to learn about spiders and cutting edge genetic techniques including stable isotope analysis and DNA-barcoding. Under the supervision of Eva Bergman, Lutz Eckstein, Ann Erlandsson, Rachel Bowes, and Denis Lafage I will carry out a range of experiments to examine the link between riparian forest buffer width and its effect on predator community functional diversity, riparian ecosystem function, and food web complexity.  Currently I am conducting feeding experiments on wolf spiders (Lycosidae) to determine the time that specific prey DNA is detectable in their guts after predation events. This lab experiment will act as a primer for our future field studies in the Värmland and Örebro areas that will include intensive ecosystem sampling of terrestrial and aquatic communities. Our project will collaborate closely with forestry stakeholders, Swedish country administrative boards, Skogsstyrelsen, and other scientists involved in similar work. Ultimately we will work with these same groups to craft riparian buffer strip guidelines that intersect the needs of Swedish forestry with the health of Swedish riparian ecosystems to help build on sustainable forestry concepts.

Outside of the research arena I spend my time teaching my daughter to love and respect all the småkryp and playing and collecting board games. If you ever want to talk beetles or board games feel free to swing by my KAU office any time. You can follow my research and occasional musing on Instagram or Twitter both @sverige_saps.”

250+ wolf spider females in the lab at KAU. Inset: a Pardosa sp. (Lycosidae) paralyzing a collembola prey. Photos by Jeff Marker

On Tuesday 8 October, Ann Erlandsson, Assistant Professor at Karlstad University, will give a seminar titled “DNA barcoding of spider gut contents”. The seminar starts at 13:15 in room 5F416. Everyone who wants to are welcome to attend the seminar.

The paper led by scientists of the Department of Engineering and Chemical Sciences, Karlstad University, was co-authored by Lutz Eckstein, professor of biology at the Department of Environmental and Life Sciences.


He writes about their work:

“Sweden has about 28 million hectares of forests, and pine trees constitute 40% of the total standing volume. Since the country is the world’s second largest exporter of pulp, paper and wood products, a total of 400 million containerized tree seedlings are produced by Swedish forest nurseries to restock forests each year. However, intensive annual forest harvests remove essential soil nutrients, which may cause problems for forest productivity.

In Sweden, container-grown seedlings are dominantly produced in peat and peat-based growth media. Peat-based substrates have many advantages such as long-term drainage ability, good aeration for tree seedling roots, good fertilizer absorbance and release capability. However, peat-based media are considered non-sustainable as their extraction have adverse environmental impacts. Therefore, sustainable approaches towards forest production and plantation management are urgently needed.

Therefore, the aim of this paper was to study the effects of hydrochar, derived from paper mill biosludge, on growth, quality, mycorrhizal associations and nutrient/heavy metal uptake of pine tree seedlings. We analyzed whether effects varied significantly between hydrochar forms (powder or pellets) or hydrochar proportions mixed with peat (10% or 20% hydrochar v/v). The effects of hydrochar addition on pine tree seedling was evaluated under three fertilization regimes (no fertilizer, 50% fertilizer and 100% fertilizer). We hypothesized that the growth, quality and mycorrhizal colonization of pine tree seedlings grown in substrate mixed with hydrochar would improve. We also expected pine tree seedlings grown with hydrochar to require less fertilizer to achieve similar or higher growth, mycorrhizal colonization and associated nutrient uptake relative to seedlings grown without hydrochar but with optimum rates of fertilizer (100% fertilizer). To our knowledge, this current study is the first paper to explore the potentials of hydrochar powder and pellets for being used as a growing media component in production of containerized pine tree seedlings.

Application of hydrochar had positive or neutral effects on shoot biomass and stem diameter compared with control seedlings (without hydrochar) under tested fertilizer levels. Analysis of the natural logarithmic response ratios (LnRR) of quality index and nutrient and heavy metal uptake revealed that application of 20% (v/v) hydrochar powder or pellet with 50% fertilizer resulted in same quality pine seedlings with similar heavy metal (Cu, Ni, Pb, Zn and Cr) and nutrient (P, K, Ca and Mg) contents as untreated seedlings supplied with 100% fertilizer. Colonization percentage by ectomycorrhizae significantly increased when either forms of hydrochar were applied at a rate of 20% under unfertilized condition. The results of this study implied that application of proper rates of hydrochar from biosludge with adjusted levels of liquid fertilizer may reduce fertilizer requirements in pine nurseries.”

Read the paper for free here!