Northern Minnesota Research Articles

Effects of snow and climate on soil temperature and frost development in forested peatlands in minnesota, USA

Black spruce (Picea mariana) peatlands play important ecologic and economic roles in the temperate-boreal region of North America, providing a valuable timber resource while also performing important ecosystem functions. Climate models project decreases in the amount of snowfall received throughout the temperate-boreal region by 2100, as average wintertime temperatures increase. We used a paired-plot experimental design to assess the effect of snow removal on soil temperature and frost development at six forested peatland sites in northern Minnesota, USA, during the three winters from 2017 to 2020. Treatments consisted of 1) removal of snow throughout the winter, or 2) ambient snow cover conditions. During the three years of the study, there was a significant effect of snow removal by mid-winter that continued into late winter and spring, where removal of snow increased soil frost depth compared to plots with ambient snow cover treatment. Soil temperatures in the removal plots were highly responsive to air temperature fluctuations to depths of 20 cm or more, whereas the ambient snow cover soils exhibited little fluctuation and maintained temperatures near or above 0° C for much of the winter season. We found that each cumulative freezing degree day resulted in an average of 0.36 cm of soil frost development in snow removal plots, as compared to 0.07 cm depth in the ambient treatment plots. Soils were significantly colder through much of the summer growing season in the removal treatment compared to the ambient treatment, with detectable soil frost in the soil profile as late as mid- to late-June. These results indicate that predicted changes in wintertime precipitation may result in increased development of soil frost in forested peatland systems, although some of this effect may be offset by predicted concurrent increases in air temperature. We did not measure indicators of biological activity, but the large and prolonged reduction in soil temperature with snow removal is likely to depress biological activity throughout the growing season and the many ecosystem functions it influences. Because of the role that soil temperature and frost play on the hydrologic and ecological processes of peatlands, as well as the crucial role of soil frost in peatland forest management, findings of this study provide important insight into the potential effects of altered winter conditions on these expansive and ecologically important ecosystems.

Hydrological and meteorological data from research catchments at the Marcell Experimental Forest, Minnesota, USA

AbstractThe Marcell Experimental Forest (MEF) in northern Minnesota, USA, with hydrological research and monitoring of peatland catchments in a low‐topographic relief landscape, contrasts with the mountainous terrain that typifies most research catchments. Six research catchments were instrumented and hydrological and meteorological monitoring was initiated during 1960. Paired‐catchment studies, which started during 1969, have been used to assess land management and environmental change effects on forests, water availability, and biogeochemistry. Over the decades, the research and collaborations have proliferated to include new monitoring and ecosystem experiments. We provide an overview of available datasets and access information for hydrological and meteorological data. Data on streamflow, water table elevation, precipitation, snow, ground frost, air temperature, soil moisture, upland runoff, and water chemistry are discoverable with associated metadata and are archived through several Web‐based, community repositories. The research programme is ongoing and we anticipate updates on an annual or more frequent basis. Additionally, we aim to release other physical, chemical, and isotopic measurements associated with long‐term catchment monitoring and studies at the MEF.

Survive, Revive, Thrive: Chapter 5: Shakedown Cruise

I am very resourceful, as any woman would be. - Valentina Tereshkova, Russian cosmonaut, born 1937 (first woman in space, Vostok 6, 16 June 1963) What is a Shakedown Cruise? Learning is not compulsory ... neither is survival. - W. Edwards Deming, American engineer, 1900-1993 (His management practices revived Japan.) For those unfamiliar, a “shakedown cruise,” also known as a sea trial, is performed to test a ship’s operational systems, both mechanical and human. I became painfully aware of the term “shakedown” when I went on my first trip to the Charles L. Sommers Canoe Base operated by the Boy Scouts in northern Minnesota in 1974. The guides had us (literally) dump everything out of our travel bags and then selected only the essential items we could take. Weight was at a premium, and, if I may confess, I did lie a little about my age. The minimum age was 12, and I turned 12 during the trip, but it was a brutal physical experience for us. We were left with a compass, a few utensils for eating, a sleeping bag, and one change of clothes. I actually recall drinking, eating, and cooking out of a single stainless steel cup. Bluntly, I don’t think I have ever been colder, hungrier, or more tired in my life. But, of course, the guides were correct. You only need the essentials to survive. Many of you are probably thinking, “I’ll bet I know where he is going with this …,” and you are right. As individuals and as an industry, we need to focus on the essentials. Our industry is on a shakedown cruise like no other in our history. We must jettison the nonessentials and test the machinery (i.e., our technical knowledge and capabilities) as we restart and re-engage. Most importantly, we must focus on those actions/paths that ensure our effectiveness, efficiency, and long-term survival. At SPE, we, too, are in shakedown mode, which has been painful for all and excruciating for some. We have had to redirect resources, and, perhaps most importantly, we have had to focus on the reality that our business model must undergo substantial changes. The essentials will remain, such as technical conferences, workshops, and our primary intellectual asset, technical publications. However, assistance to sections and student chapters has been reduced, as well as support for academic and public service programs. The reality is that SPE is financially sound, but, like any ship in a storm, it has to batten its hatches and, if the pandemic prevails, make further program reductions. On a positive note, SPE has been able to avoid reducing its workforce, as we have created a financial path that avoids personnel reductions. As the 2021 SPE President, I congratulate the SPE’s senior management for their efforts to achieve this outcome.

Mycolicibacterium nivoides sp. nov isolated from a peat bog.

A fast-growing, non-chromogenic, acid-fast-staining bacterium (DL90T) was isolated from a peat bog in northern Minnesota. On the basis of 16S rRNA gene sequence similarity (99.8 % identity with Mycolicibacterium septicum and 98 % with Mycolicibacterium peregrinum) and chemotaxonomic data (fatty acid content), strain DL90T represents a member of the genus Mycolicibacterium. Physiological tests (growth curves, biofilm formation, antibiotic sensitivity, colony morphologies and heat tolerance) and biochemical analysis (arylsulfatase activity and fatty acid profiles) distinguish DL90T from its closest relative M. septicum. Phylogenomic reconstruction of the ‘Fortuitium–Vaccae’ clade, digital DNA–DNA hybridization (DDH) values of 61 %, and average nucleotide identity (ANI) values of approximately 95 % indicate that DL90T is likely to be diverged from M. septicum. Thus, we propose that DL90T represents a novel species, given the name Mycolicibacterium nivoides with the type strain being isolate DL90T (=JCM 32796T=NCCB 100660T).

Universal Cholesterol Screening among Pediatric Primary Care Providers within California and Minnesota: A Qualitative Assessment of Barriers and Facilitators

To assess current pediatric cholesterol screening practices, and attitudes, among pediatric primary care providers (PCPs) via qualitative semistructured interviews designed to identify barriers and facilitators to universal cholesterol screening practices recommended by the National Heart Blood and Lung Institute and the American Academy of Pediatrics. An online survey and subsequent 30-minute semistructured phone interview were completed with PCPs from regions in Northern California and Minnesota (survey n=25, interview n=12). Interviews were qualitatively analyzed using the consolidated framework for implementation research to categorize barriers, facilitators, and strategies to increase pediatric cholesterol screening among PCPs. PCPs from California (n=8) and Minnesota (n=4) consistently identified cost of cholesterol screening, particularly the cost of time due to competing visit priorities, as a barrier. A supportive learning environment, feelings of self-efficacy, access to resources, and well-established clinical networks with specialists (eg, cardiologists) were facilitators to screening. The perceived level of endorsement behind cholesterol screening within the clinic, perceived validity of national guidelines, and ability to adapt guidelines to existing clinical workflow were notable differentiators between high vs low self-reported screen rates. Findings of this study suggest that efforts to increase universal pediatric cholesterol screening will likely require the development of strategies to increase provider education about the long-term benefits of cholesterol screening (knowledge and beliefs), and ensuring providers feel supported and empowered when assessing/acting on the results of this screening (self-efficacy, engaging leaders, networks, and communication).

Long-Term Trends in Regional Wet Mercury Deposition and Lacustrine Mercury Concentrations in Four Lakes in Voyageurs National Park

Although anthropogenic mercury (Hg) releases to the environment have been substantially lowered in the United States and Canada since 1990, concerns remain for contamination in fish from remote lakes and rivers where atmospheric deposition is the predominant source of mercury. How have aquatic ecosystems responded? We report on one of the longest known multimedia data sets for mercury in atmospheric deposition: aqueous total mercury (THgaq), methylmercury (MeHgaq), and sulfate from epilimnetic lake-water samples from four lakes in Voyageurs National Park (VNP) in northern Minnesota; and total mercury (THg) in aquatic biota from the same lakes from 2001–2018. Wet Hg deposition at two regional Mercury Deposition Network sites (Fernberg and Marcell, Minnesota) decreased by an average of 22 percent from 1998–2018; much of the decreases occurred prior to 2009, with relatively flat trends since 2009. In the four VNP lakes, epilimnetic MeHgaq concentrations declined by an average of 44 percent and THgaq by an average of 27 percent. For the three lakes with long-term biomonitoring, temporal patterns in biotic THg concentrations were similar to patterns in MeHgaq concentrations; however, biotic THg concentrations declined significantly in only one lake. Epilimnetic MeHgaq may be responding both to a decline in atmospheric Hg deposition as well as a decline in sulfate deposition, which is an important driver of mercury methylation in the environment. Results from this case study suggest that regional- to continental-scale decreases in both mercury and sulfate emissions have benefitted aquatic resources, even in the face of global increases in mercury emissions.

Sources and biodegradability of dissolved organic matter in two headwater peatland catchments at the Marcell Experimental Forest, northern Minnesota,USA

AbstractWhere they are present in catchments, peatlands are a dominant source of dissolved organic matter (DOM) to surrounding waterways due, in part, to high production rates. Despite the preponderance of peatlands in northern latitudes and expected peatland vulnerability to climate change, little is known about peatland DOM degradation relative to a more comprehensive understanding of degradation when DOM is sourced from upland‐dominated catchments. We compared DOM biodegradability of various sources of stream water in two catchments having peatlands (22%–33% of the area) surrounded by upland forests (70%–90% of the area, either deciduous or coniferous). We measured total organic carbon (TOC), and biodegradable dissolved organic carbon concentrations; bacterial respiration rates; streamflow; and upland runoff during and after snowmelt (March to June, 2009–2011). We also explored if DOM in upland runoff stimulated biodegradation of peatland‐derived DOM (i.e., a priming effect), and if forest cover type affected DOM biodegradability. As expected, the peatlands were the largest sources of both water (72%–80%) and TOC (92%–96%) to the streams although more area in each catchment was in uplands (70%–90%). Several results were unexpected, yet revealing: (1) DOM from peatlands sometimes had the same biodegradability as DOM from uplands, (2) upland sources of DOM had negligible effects on biodegradability in the peatland and downstream, and (3) upland deciduous cover did not yield more degradable DOM than conifer cover. The most pronounced effect of upland runoff was dilution of downstream TOC concentrations when there was upland runoff. Overall, the effects of upland DOM may have been negligible due to the overriding effect of the large amount of biodegradable DOM that originated in bogs. This research highlights that peatland‐sourced DOM has important effects on downstream DOM biodegradability even in catchments where upland area is substantially larger than peatland area.

Evaluating species-specific responses to camera-trap survey designs

Camera traps are widely used to collect information on the distribution and abundance of multiple species simultaneously. However, we still lack important guidance for designing camera-trap surveys to monitor multiple species, and the consequences of species-specific responses to survey design strategies are often overlooked. Using camera-trap data collected on ten medium-to-large North-American carnivores in northern Minnesota, USA, between 2016 and 2018 (23 337 active trap-days), we evaluated: 1) two different survey-design frameworks (random- versus road-based), 2) two different lure types (salmon oil versus fatty acid scent oil), 3) two different placement strategies (completely random versus randomly-selected sites with feature-based placement), 4) survey timing (spring versus fall) and 5) temporal trends in daily encounter probabilities. Using generalized linear mixed models, we found evidence of differential responses to all of these design strategies. For 9 out of 10 species, we found strong responses to survey design frameworks: red foxes Vulpes vulpes, coyotes Canis latrans, bobcats, Lynx rufus, striped skunks Mephitis mephitis, wolves C. lupus and gray foxes Urocyon cinereoargenteus, had estimated encounter frequencies that were 9- to 106-fold higher at unlured sites along secondary roads; black bears Ursus americanus, martens Martes americana and fishers Pekania pennanti had estimated encounter frequencies that were 15- to > 3600-fold higher at lured, randomly selected sites. For six species, salmon oil provided 2- to 4-fold more encounters than fatty acid scent oil, but feature-basedplacement only improved detections of fishers. Daily encounter probabilities differed between spring and fall for all species, and usually decreased slightly within each sampling period Our study confirms that even similar-sized or closely-related species respond differently to survey-design choices. To maximize encounter frequencies, we recommend that multi-species camera-trap studies use a mix of survey-design strategies and include these design features during statistical analysis.

Wide-spread vulnerability of black ash (Fraxinus nigraMarsh.) wetlands in Minnesota USA to loss of tree dominance from invasive emerald ash borer

AbstractThe emerald ash borer (EAB) has killed ash species (Fraxinus L.) in much of eastern North America, but it has yet to reach the vast ash wetlands in northern Minnesota, USA. In these wetlands, a single species, black ash (Fraxinus nigra Marsh.) comprises a majority of trees and has a foundational role in controlling ecosystem function. Given the likelihood of wide-spread mortality of black ash from EAB and the likelihood of severe ecosystem impacts, we examined the potential for co-occurring tree species to replace black ash, either through gap filling in the overstory or release from the understory. We addressed this objective by examining woody plant communities in 32 mature black ash sites located across a large geographic region and inclusive of two distinct wetland types as defined by hydrologic regime. Our results indicate a region-wide lack of species capable of replacing black ash in both wetland hydrologic types; thus there is very low existing potential for replacement of black ash from expansion in the overstory or through release in the understory. These results point to an urgent need for silvicultural intervention to identify and establish future-adapted non-ash tree species so as to promote resilience in the face of EAB by maintaining aspects of the foundational role of black ash in controlling ecosystem functions.

The Cadottes: A Fur Trade Family on Lake Superior by Robert Silbernagel

Reviewed by: The Cadottes: A Fur Trade Family on Lake Superior by Robert Silbernagel Roger L. Nichols Robert Silbernagel. The Cadottes: A Fur Trade Family on Lake Superior. Madison: Wisconsin Historical Society Press, 2020. Pp. 352. Bibliography. Illustrations. Maps. Notes. Paperback: $28.95. In this thoughtful book, the author gives himself a difficult task. Robert Silbernagel wants to follow the lives and activities of the Cadotte family in the international fur trade on the southern shore of Lake Superior. Beginning with the actions of Mathurin Cadot during the 1670s, he traces the roles of family members to the near present. This is a tall order because there are virtually no documents, except for some trade account ledgers, no collections of personal letters, no diaries or family reminiscences to help put "meat on the bones" of this family. Silbernagel recognizes this and describes feeling as though he saw "the Cadottes through a veil." (xiii) If this were the story of a single person, it would be labeled a "life and times" rather than a biography. Yet the lack of personal material has not distracted the author from showing the family's contributions to the history of the region. His central thesis is that prior to late nineteenth century industrialization, the fur trade was the largest and most significant part of the regional economy. Coupled with that, he presents the roles played in the trade by French Canadian and French Indian métis, the Cadottes belonging to both groups, as being essential to the international success of that trade. These people and their Indian trading partners gathered and [End Page 158] transported the furs gathered in northern Michigan, Wisconsin, and Minnesota to Montreal on their way to European markets. While tracing the fur trade, the author ties the Cadottes to the shifting international competition between the British and French in Canada, and later between the British and the Americans effectively. He also depicts the family as competent translators and diplomats who helped keep peace between the Ojibwe and their Dakota neighbors. Family members had two strong motivations. First, several of them married Ojibwe. Second, warfare disrupted the trade, so they saw diplomacy as essential. The narrative highlights the Cadottes' business skills, honesty, and general competence in a dangerous world of frequent challenge and change. The narrative gives most attention to Michel Cadotte and his Ojibwe wife Equaysayway and their lives on Madeline Island. Married into a prominent Indian family, Michel became a successful and respected trader, interpreter, and forest diplomat. The couple fit well into the mixed-race society that the trade fostered, and late in life had a church wedding, probably to protect their land claims and those of their children after the Americans had taken control of the area. Based on extensive research, this book is both readable and informative. While the names of men important in regional history including James Doty, Alexander Ramsey, Henry Dodge, and John Jacob Astor all appear, the Cadottes tie the narrative together. Their actions for nearly two centuries give a framework to the story. Because he lacks much personal or family data, the author fills out the family story by deft use of local details related specifically to the fur trade. He discusses wilderness travel and means of transportation such as snowshoes and the varieties of canoes, illustrates the difficulties of long, exhausting portages, and considers the roles of maple sugar making and wild rice harvesting for local Indians and their trade partners. To help guide the reader through the family history, the book includes a Cadotte family tree as well as a timeline that covers the two hundred years of family history. It has clear and effective maps and photos of people and places being discussed. This is an interesting and careful history that focuses on an era, a business, and people who rarely get much attention. [End Page 159] Roger L. Nichols Emeritus Professor of History and Affiliate in American Indian Studies University of Arizona Copyright © 2021 Historical Society of Michigan

Indigenous Antinuclear Literary Resistance: Jim Northrup’s Satire and Anishinaabe Trans/nationalism

“Indigenous Antinuclear Literary Resistance: Jim Northrup’s Satire and Anishinaabe Trans/nationalism” examines the way Jim Northrup (1943–2016), an Anishinaabe writer from the Fond du Lac Band of Lake Superior Chippewa in northern Minnesota, engages Anishinaabe trans/nationalism as he combats nuclear colonialism in his satirical columns. The fundamental nature of Anishinaabe trans/nationalism, described by Joseph Bauerkemper and Heidi Kiiwetinepinesiik Stark in “Trans/National Terrain of Anishinaabe Law and Diplomacy,” forms the basis of Northrup’s resistance to nuclear colonialism as he critiques the nuclear power plant and radioactive waste threatening the Mdewakanton Dakota residents of the Prairie Island Indian Community. He adds another layer to the politics of Indigenous trans/nationalism when he ridicules plans to send the radioactive waste from Prairie Island to be stored on the land of other Indigenous nations such as the Western Shoshone and Mescalero Apache. On another level, by emphasizing the bonds between Anishinaabe people in the United States and Canada, Northrup implies that Anishinaabe nationhood precedes the borders of nation states, defying the ideology of “transnational” in a conventional sense. With Indigenous trans/nationalism at the center of its argument, this essay considers Northrup’s use of satire and humor as an atomic age strategy to manifest Anishinaabe nationhood as well as to establish transnational Indigenous alliances to combat nuclear colonialism. Northrup situates his antinuclear opposition as part of an enduring multilateral Indigenous resistance to settler colonialism, and, in so doing, he emphasizes the importance of exercising treaty rights and insisting on the inherent sovereignty of the Anishinaabe people.

Influence of eastern spruce dwarf mistletoe on stand structure and composition in northern Minnesota

Black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) is one of the most common tree species in the boreal forest. However, there is limited information on one of the major disturbance agents, eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck; EDM) a native, parasitic plant that influences stand development especially at the southwestern range limit of black spruce in Minnesota. The goal of our study was to quantify overstory and understory (sapling and seedling) structure and composition in productive black spruce stands across three EDM severity categories: uninfected (0% EDM), low (<50% of stand infected with EDM), and high (>50% of stand infected with EDM) across northern Minnesota during the summer of 2017. The presence of EDM infection in stands shifted species composition and structure compared to uninfected stands. Uninfected stands were dominated by black spruce in both overstory and understory and on average had a uni-modal diameter distribution. Both low and high EDM severity stands had significantly greater overstory species richness, Shannon’s diversity index, and Shannon’s Evenness compared to uninfected stands. However, stands with high EDM infections had the most black spruce infected with EDM in both the overstory and sapling layer, which will likely kill the infected trees within seventeen years and may result in a shifting in forest composition or a transition to non-forested conditions. The presence and severity of EDM influences stand structure and composition and subsequently stand development. Depending on the goals and objectives and ultimate desired future conditions both at the stand and the broader landscape level, natural resource managers may choose more or less intensive management of EDM.

The hydraulic conductivity of peat with respect to scaling, botanical composition, and greenhouse gas transport: Mini-aquifer tests from the Red Lake Peatland, Minnesota

Hydraulic conductivity (K) is a key but problematic parameter in groundwater models particularly those that simulate flow in weak, readily deformable media, such as peat deposits. As a result, K represents a critical source of error in models that couple hydrological processes with the carbon balance of peatlands, a globally important source for greenhouse gases. We therefore conducted mini-aquifer tests on two mesoscale bog landforms within the large 1300 km2 Red Lake Peatland of northern Minnesota. These tests offer the dual advantage of determining the fine-scale distribution of K within a large (>900 m3) model domain. In addition, the stress created by a 24 h pumping operation should be capable of mobilizing pools of biogenic gases thoughout a deep peat deposit. The pumping results were monitored by 24 to 38 wells in order to calibrate a 3D finite-volume groundwater model with the aid of PEST (Parameter Estimation Analysis). High K values were determined at a Bog Forest (10−5 to 10−6 m s−1) and Bog Lawn (10−3 to 10−4 m s−1) sites, throughout their deep (>4 m) peat profiles. These tests also detected vertically continuous zones of unexpectedly high or low K values in contrast to the horizontal bedding planes and increasing degree of decomposition with depth. The vertical K zones are suggestive of three different modes of bubble transport that either locally dilate or partially block the peat pores. In addition, the tests provided new insights on a conceptual model linking K to the development of all large (>20 km2) forested bog complexes in mid-continental boreal North America.

Phenological and isotopic evidence for migration as a life history strategy in Aeshna canadensis (family: Aeshnidae) dragonflies

1. Investigating dragonfly migration is important for understanding species' life history strategies, migratory connectivity, terrestrial‐aquatic linkages, and for successful species conservation. While migration patterns are well‐documented for some species (e.g., Anax junius), questions remain about potential migratory behaviour of others.2. We investigated the potential for migration of Aeshna canadensis (Walker, 1908; Canada darner) using phenological observations in three study ponds in central Minnesota, 2017–2019. We also conducted probabilistic assignment to natal origins by measuring stable hydrogen isotope values of wing tissue (δ2Hw) of dragonflies collected in Minnesota and acquired through Canadian museum collections.3. This species emerged May–June from study ponds in central Minnesota, with a 10–15 week lag after onset of emergence before mature adults were observed flying and ovipositing in late summer. The probabilistic assignment depictions of emerging tenerals overlapped with the sampling location, confirming accuracy of isotopic assignments of natal origin.4. Late‐flying mature adults collected at our study ponds likely originated from southern Manitoba, suggesting a north–south migration pathway. We found further evidence for migration by analysing δ2Hw of adult dragonflies collected in northern Minnesota and south‐central Canada. Their likely origins were farther north in central Canada (Manitoba/Quebec) or the northeastern reaches of this species' range in eastern Canada.5. We provide the first conclusive evidence of Aeshna migration in North America and demonstrate a robust approach, combining field observations with probabilistic assignment to origin using stable isotope analysis, which can test for migration in other dragonfly populations.

Improved Remote Sensing Methods to Detect Northern Wild Rice (Zizania palustris L.)

Declining populations of Zizania palustris L. (northern wildrice, or wildrice) during the last century drives the demand for new and innovative techniques to support monitoring of this culturally and ecologically significant crop wild relative. We trained three wildrice detection models in R and Google Earth Engine using data from annual aquatic vegetation surveys in northern Minnesota. Three different training datasets, varying in the definition of wildrice presence, were combined with Landsat 8 Operational Land Imager (OLI) and Sentinel-1 C-band synthetic aperture radar (SAR) imagery to map wildrice in 2015 using random forests. Spectral predictors were derived from phenologically important time periods of emergence (June–July) and peak harvest (August–September). The range of the Vertical Vertical (VV) polarization between the two time periods was consistently the top predictor. Model outputs were evaluated using both point and area-based validation (polygon). While all models performed well in the point validation with percent correctly classified ranging from 83.8% to 91.1%, we found polygon validation necessary to comprehensively assess wildrice detection accuracy. Our practical approach highlights a variety of applications that can be applied to guide field excursions and estimate the extent of occurrence at landscape scales. Further testing and validation of the methods we present may support multiyear monitoring which is foundational for the preservation of wildrice for future generations.

A Curricular Bioinformatics Approach to Teaching Undergraduates to Analyze Metagenomic Datasets Using R

Biologists with bioinformatic skills will be better prepared for the job market, but relatively few biology programs require bioinformatics courses. Inclusion in the curriculum may be hindered by several barriers, including lack of faculty expertise, student resistance to computational work, and few examples in the pedagogical literature. An 8-week wet-lab and in silico research experience for undergraduates was implemented. Students performed DNA purification and metagenomics analysis to compare the diversity and abundance of microbes in two samples. Students sampled snow from sites in northern Minnesota and purified genomic DNA from the microbes, followed by metagenomic analysis. Students used an existing metagenomic dataset to practice analysis skills, including comparing the use of Excel versus R for analysis and visualization of a large dataset. Upon receipt of the snow data, students applied their recently acquired skills to their new dataset and reported their results via a poster. Several outcomes were achieved as a result of this module. First, YouTube videos demonstrating hands-on metagenomics and R techniques were used as professional development for faculty, leading to broadened research capabilities and comfort with bioinformatics. Second, students were introduced to computational skills in a manner that was intentional, with time for both introduction and reinforcement of skills. Finally, the module was effectively included in a biology curriculum because it could function as either a stand-alone course or a module within another course such as microbiology. This module, developed with Course-based Undergraduate Research Experience guidelines in mind, introduces students and faculty to bioinformatics in biology research.

Rapid-assessment test strips: effectiveness for cyanotoxin monitoring in a northern temperate lake

LeDuc JF, Christensen VG, Maki RP. 2020. Rapid assessment test strips: effectiveness for cyanotoxin monitoring in a northern temperate lake. Lake Reserv Manag, 36:444–453. Precise and rapid methods of determining toxin levels are needed in lakes used for recreation and drinking water to facilitate a quick risk assessment during cyanobacteria blooms. Therefore, we evaluated rapid-assessment test strips, a newer technology for estimating the toxicity of cyanobacterial blooms, in Kabetogama Lake, a popular recreational area of Voyageurs National Park in northern Minnesota (USA). Sixty-seven percent of the test strip results matched results of enzyme-linked immunosorbent assays, with individual toxin results of 75% (anatoxin-a), 80% (cylindrospermopsin), and 64% (microcystin). These results provide some evidence that the test strips may be effective for rapid detection of toxins in northern temperate lakes, although improvements to the test strips may be beneficial. Despite the intensive processing required and uncertainty of some results, the availability of a rapid and inexpensive field method allowed us to sample opportunistically in the fall, when we documented dangerously high toxin concentrations at places where waterfowl-retrieving dogs may be at particular risk of exposure.

Species-specific flowering phenology responses to experimental warming and drought alter herbaceous plant species overlap in a temperate–boreal forest community

Warmer temperatures and altered precipitation patterns are expected to continue to occur as the climate changes. How these changes will impact the flowering phenology of herbaceous perennials in northern forests is poorly understood but could have consequences for forest functioning and species interactions. Here, we examine the flowering phenology responses of five herbaceous perennials to experimental warming and reduced summer rainfall over 3 years. This study is part of the B4WarmED experiment located at two sites in northern Minnesota, USA. Three levels of warming (ambient, +1.6 °C and +3.1 °C) were crossed with two rainfall manipulations (ambient and 27 % reduced growing season rainfall). We observed species-specific responses to the experimental treatments. Warming alone advanced flowering for four species. Most notably, the two autumn blooming species showed the strongest advance of flowering to warming. Reduced rainfall alone advanced flowering for one autumn blooming species and delayed flowering for the other, with no significant impact on the three early blooming species. Only one species, Solidago spp., showed an interactive response to warming and rainfall manipulation by advancing in +1.6 °C warming (regardless of rainfall manipulation) but not advancing in the warmest, driest treatment. Species-specific responses led to changes in temporal overlap between species. Most notably, the two autumn blooming species diverged significantly in their flowering timing. In ambient conditions, these two species flowered within the same week. In the warmest, driest treatment, flowering occurred over a month apart. Herbaceous species may differ in how they respond to future climate conditions. Changes to phenology may lead to fewer resources for insects or a mismatch between plants and pollinators.

The potential importance of methylated substrates in methane production within three northern Minnesota peatlands

Peatlands store close to half of the terrestrial soil carbon and release substantial amounts of the greenhouse gas methane (CH4) to the atmosphere. While CH4 is thought to be produced mainly by hydrogenotrophic and acetoclastic methanogenic pathways, methylotrophic methanogenesis may be a hidden, yet potentially important, source of CH4 in these globally significant ecosystems. To explore the importance of methylotrophic methanogenesis in northern peatlands, 13C-labeled methylated substrates (methanol, dimethylsulfide, and trimethylamine) were added to soils along a depth profile and the production of 13C–CH4 was measured. Additionally, the concentrations of methylated compounds were measured across a soil depth profile in situ.Results suggest that methylated substrates can be used by peatland microbes, resulting in CH4 production in all sites at all depths. Methanol was converted to CH4 in each site at all depths. In contrast, trimethylamine and dimethylsulfide were only converted to CH4 at the surface depth regardless of site. In situ concentrations of dimethylsulfide were below detection limit in all sites and depths. Monomethylamine and methanol were present in situ with concentrations ranging from 30 to 1225 nM.For the first time in peatlands, we have estimated contributions of methylated substrates to the total CH4 produced. Microbial processing of methylated substrates contributed a maximum of 11% of the total CH4 produced at depth in one peatland; but, in shallow soils with higher rates of CH4 production, the potential contribution of methylotrophic methanogenesis to overall CH4 production was minor.

Forest landscape structure influences the cyclic‐eruptive spatial dynamics of forest tent caterpillar outbreaks

AbstractA fundamental question in forest insect ecology is the role of forest landscape structure, particularly the amount and spatial configuration of host tree species, in shaping the dynamics of recurring forest insect outbreaks. For forest tent caterpillar (FTC), independent studies do not converge on a singular conclusion, although all indicate that forest structure influences outbreak dynamics. These studies also vary in how they treat climate as a covariate. We evaluated the relative importance of host forest landscape composition and configuration, as well as climate, for their influence on FTC outbreak cycling in the twentieth century. We predicted that FTC outbreaks would exhibit greater synchrony and intensity within areas associated with higher abundance of host trees. We reconstructed FTC outbreaks from 1928 to 2006 using tree‐ring analysis within a well‐structured experimental landscape located in northwestern Ontario and northern Minnesota. Time‐series clustering and spatial nonparametric covariance were used to determine whether similarities in time series and patterns in spatial synchrony corresponded with land management history. Using constrained ordination, we compared statistical properties of outbreak time series to landscape variables representing host abundance, forest configuration, and climate. We found no evidence of climatic effects at the scale of this study, but a significant albeit small influence of landscape structure on outbreak dynamics. Outbreaks were more synchronous and more cyclic within managed zones containing a greater relative abundance of aspen and other hardwood host tree species, compared with the more conifer‐dominated Wilderness area. Yet, we also observed asynchronous outbreak dynamics across the study area, such that correlations with slower‐changing forest landscape variables varied starkly among outbreak pulses. Consequently, the strength of relationship between landscape variables and FTC outbreak patterns varied strongly through time—a result that may explain why short‐term studies yield conclusions that are at odds with one another. Our results speak to the importance of long time series, contrasting landscape structure, use of multivariate methods, and controlling for climatic variation when investigating the effects of forest landscape structure on the cyclic‐eruptive spatial dynamics for forest defoliators.