Thomas Grant Pypker

The primary aim of institutional learning outcomes assessment is the creation of a culture of assessment where faculty use evidence-based data to validate and improve teaching and learning for the benefit of students. Faculty are key to these processes and yet, they are often woefully disengaged from them. This paper presents findings from an action research project that utilized a collaborative self-study approach to engage faculty in the strategic assessment of institutional learning (SAIL). SAIL is an immersive professional development opportunity that bridged quality assurance with meaningful improvements in the classroom. Findings indicated that cross-disciplinary dialogue about assessment increased faculty awareness of the (mis)alignment between course, program, and institutional learning aims while also identifying and informing potential gaps in curriculum and program design. SAIL is an excellent mechanism to engage faculty in an immersive assessment of student achievement that may then lead to meaningful improvement in teaching and learning.

Northern peatlands are globally important long‐term sinks of carbon due to their predominantly saturated conditions. However, these ecosystems are expected to become drier with climate change, potentially leading to shrubification. As such, the response of the shrubification–evapotranspiration (ET) feedback may be of critical importance to future peatland energy, water and carbon dynamics. We examined the effect of multi‐decadal peatland water table (WT) alteration at three adjacent sites with increasing depth to WT (WET, INTermediate, and DRY). In order to better understand the WT–shrubification–ET feedback, we measured peatland vegetation composition, microtopography and ET partitioning, where ET was measured at the ecosystem, microform, and leaf level using eddy covariance (EC), chambers and porometry, respectively. Averaged across microforms and WT treatments, there was a difference in the median measured leaf resistance (r_leaf) between plant functional types ranging from 213 s m⁻¹ for erect dwarf shrubs, 325 s m⁻¹ for graminoids/sedges, and 520 s m⁻¹ for prostrate dwarf shrubs. Scaled based on LAI, the low r_leaf of erect dwarf shrubs dominated hummocks, where sites with a higher proportion of hummocks had lower median canopy resistance (r_v) of 141, 133 and 130 s m⁻¹ at the WET, INT and DRY sites respectively. Nevertheless, ET was highest at the WET site and similar between the INT and DRY sites, with greater evaporation from the moss surface at the WET site. Porometry and EC data along with a three‐source model were used to independently assess the evaporative contribution from the moss surface, which ranged from 17% to 40%. For moderate and persistent changes in WT from land‐use or climate change, our results suggest vegetation succession is minimal, but the microtopographic development and the concomitant differences in LAI for the various plant functional types is key to understanding changes in total ET and partitioning.

We investigated the effect of foliar application of potassium nitrate (KNO₃) and zinc sulfate (ZnSO₄) on the fruit quality of pomegranate (Punica granatum L. cv. Malas-E–Torsh in Saveh). Potassium was applied as KNO₃ at concentrations of 0%, 0.25%, and 0.5% and zinc was applied as ZnSO₄ at concentrations of 0%, 0.5%, and 1% in a completely randomized block design. To determine the effect of the treatments on fruit quality, we measured fruit weight, peel thickness, aril diameter, phenol content of the juice, pH, total soluble solids (TSS), titratable acidity (TA), and antioxidant capacity. Foliar application of KNO₃ significantly increased fruit weight, 100 aril weight, peel weight, peel thickness, TTS, and antioxidant capacity. In contrast, pH, TA, TSS/TA, and phenol content of the juice were not influenced by foliar application of KNO₃. ZnSO₄ significantly increased fruit weight, aril diameter, and phenol content of the juice. KNO₃ 1% and ZnSO₄ 0.5% were identified as the most appropriate treatments in improving quality and quantity of pomegranate. The fatty acid profile of the pomegranate oil was primarily composed of punicic acid, linoleic acid, oleic acid, palmitic acid, and stearic acid.

The rapid and extensive expansion of emerald ash borer (EAB) in North America since 2002 may eliminate most existing ash stands, likely affecting critical ecosystem services associated with water and carbon cycling. To our knowledge, no studies have evaluated the coupled response of black ash (Fraxinus nigra Marsh.) wetland water tables, soil temperatures, and soil gas fluxes to an EAB infestation. Water table position, soil temperature, and soil CO₂ and CH₄ fluxes were monitored in nine depressional headwater black ash wetlands in northern Michigan. An EAB disturbance was simulated by girdling (girdle) or felling (ash-cut) all black ash trees with diameters greater than 2.5 cm within treated wetlands (n = 3 per treatment). Soil gas fluxes were sensitive to water table position, temperature, and disturbance. Soil CO₂ fluxes were significantly higher, and high soil CH₄ fluxes occurred more frequently in disturbed sites. Soil CH₄ fluxes in ash-cut were marginally significantly higher than girdle during post-treatment, yet both were similar to control sites. The strong connection between depressional black ash wetland study sites and groundwater likely buffered the magnitude of disturbance-related impact on water tables and carbon cycling.

The emerald ash borer (EAB) is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western Great Lakes region. Using two companion studies that are simulating short- and long-term EAB infestations and what is known from the literature, we synthesize our current limited understanding and predict anticipated future impacts of EAB on black ash wetlands. A key response to the die-back of mature black ash will be higher water tables and the potential for flooding and resulting changes to both the vegetation and animal communities. Although seedling planting studies have shown some possible replacement species, little is known about how the removal of black ash from the canopy will affect non-ash species growth and regeneration. Because black ash litter is relatively high in nitrogen, it is expected that there will be important changes in nutrient and carbon cycling and subsequent rates of productivity and decomposition. Changes in hydrology and nutrient and carbon cycling will have cascading effects on the biological community which have been scarcely studied. Research to address these important gaps is currently underway and should lead to alternatives to mitigate the effects of EAB on black ash wetland forests and develop management options pre- and post-EAB invasion.

Black ash (Fraxinus nigra Marsh.) exhibits canopy dominance in regularly inundated wetlands, suggesting advantageous adaptation. Black ash mortality due to emerald ash borer (Agrilus planipennis Fairmaire) will alter canopy composition and site hydrology. Retention of these forested wetlands requires understanding black ash’s ecohydrologic role. Our study examined the response of sap flux to water level and atmospheric drivers in three codominant species: black ash, red maple (Acer rubrum L.), and yellow birch (Betula alleghaniensis Britt.), in depressional wetlands in western Michigan, USA. The influence of water level on sap flux rates and response to vapor pressure deficit (VPD) was tested among species. Black ash had significantly greater sap flux than non-black ash at all water levels (80–160% higher). Black ash showed a significant increase (45%) in sap flux rates as water levels decreased. Black ash and red maple showed significant increases in response to VPD as water levels decreased (112% and 56%, respectively). Exploration of alternative canopy species has focused on the survival and growth of seedlings, but our findings show important differences in water use and response to hydrologic drivers among species. Understanding how a replacement species will respond to the expected altered hydrologic regimes of black ash wetlands following EAB infestation will improve species selection.

Emerald ash borer (EAB) continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations in depressional black ash wetlands in the Ottawa National Forest in Michigan to mimic the short-term and long-term effects of EAB. These wetlands were planted with 10 alternative tree species in 2013. Based on initial results in the Michigan sites, a riparian corridor in the Superior Municipal Forest in Wisconsin was planted with three alternative tree species in 2015. Results across both locations indicate that silver maple (Acer saccharinum L.), red maple (Acer rubrum L.), American elm (Ulmus americana L.), and northern white cedar (Thuja occidentalis L.) are viable alternative species to plant in black ash-dominated wetlands. Additionally, selectively planting on natural or created hummocks resulted in two times greater survival than in adjacent lowland sites, and this suggests that planting should be implemented with microsite selection or creation as a primary control. Regional landowners and forest managers can use these results to help mitigate the canopy and structure losses from EAB and maintain forest cover and hydrologic function in black ash-dominated wetlands after infestation.

Our goal was to determine how epiphytic lichens and bryophytes affect canopy latent heat fluxes in an old‐growth Douglas‐fir forest when the canopy was dry. The epiphyte water content (WC_e expressed as a percent of dry weight) of representative epiphytic foliose lichens, fruticose lichens, and bryophytes was measured in the laboratory after 1 to 12 hr of exposure at five different values of vapor pressure deficit (VPD). After 12 hr of exposure, WC_e increased fivefold to sixfold as VPD decreased from 1849 to 132 Pa. In addition, we measured WC_e in the field using strain gauges. These field measurements were used to calibrate the models described below. Two models were created to estimate the potential latent heat flux from epiphytes at the canopy scale (LE_e). The first model combined measured total biomass of epiphytes with a model that estimated the laboratory determined VPD‐dependent changes in WC_e of the lichens/bryophytes (VPD method). The second model estimated LE_e by scaling the change in WC_e of epiphyte‐laden branches that were continuously monitored in situ in the canopy by a strain gauge (SG method). Both methods showed a strong diurnal trend in LE_e when VPD was less than 645 Pa. Prior to sunrise, the epiphytes absorbed water, corresponding to a latent heat flux of 5 to 15 W/m² per unit ground area, whereas after sunrise, the epiphytes lost water at a rate of −10 to −20 W/m². For short periods, epiphytes may contribute a significant portion of the latent heat flux from Douglas‐fir forests.

We monitored CO₂ and CH₄ fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH₄ from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH₄ over the measurement period. Net daily CH₄ fluxes increased from 70 mg CH₄ m⁻² d⁻¹ to 220 mg CH₄ m⁻² d⁻¹ from mid May to mid July. After July, CH₄ losses steadily declined to approximately 50 mg CH₄ m⁻² d⁻¹ in late September. During the study period, the peatland lost 17.4 g CH₄ m⁻². Both abiotic and biotic variables were correlated with CH₄ fluxes. When the different variables were analyzed together, the preferred model included mean daily soil temperature at 20 cm, daily net ecosystem exchange (NEE) and the interaction between mean daily soil temperature at 20 cm and NEE (R² = 0.47, p value < 0.001). The interaction was important because the relationship between daily NEE and mean daily soil temperature with CH₄ flux changed when NEE was negative (CO₂ uptake from the atmosphere) or positive (CO₂ losses to the atmosphere). On days when daily NEE was negative, 25% of the CH₄ flux could be explained by correlations with NEE, however on days when daily NEE was positive, there was no correlation between daily NEE and the CH₄ flux. In contrast, daily mean soil temperature at 20 cm was poorly correlated to changes in CH₄ when NEE was negative (17%), but the correlation increased to 34% when NEE was positive. The interaction between daily NEE and mean daily soil temperature at 20 cm indicates shifting environmental controls on the CH₄ flux throughout the growing season.