The impacts of current forest management methods on surface water quality, especially in northern parts of Sweden, are largely unexplored. In this review reports linked to logging impacts on catchment biogeochemistry, (with special emphasis on boreal ecosystems) has been assessed. Logging disturbances in boreal forest catchments can change biogeochemical processes in soils by alter transpiration, soil conditions, temperature, soil microbial activities and water fluxes. Combined these changes can cause increased soil nutrient leaching to receiving waters. In the studies reviewed, dissolved organic carbon (DOC) concentrations and export generally increased after logging. Similar responses followed for phosphorous (P), but to a lesser extent for nitrogen (N). Streamflow and peakflow and the export of suspended matter (SM) can also be altered after logging. Removal of streamside vegetation may result in increased stream water temperatures and potentially affect lake water temperature, deepen the epilimnion and deplete oxygen (O2) concentrations. Increased wind exposure can resuspend sediments and potentially release bioavailable P. Affected lake water concentrations of N can be considered negligible after logging, whereas tot-P concentrations has shown to increase to an almost twofold level in some studies. The overall impact on the pelagic productivity are therefore most likely those connected to increased DOC and SM concentrations. The general impact on fish biomass can be considered insignificant. In conclusions, to improve future forest management and for further understanding concerning the biogeochemical environmental impacts that forestry might have on freshwaters, additional studies are still required.

Ecological restoration is the practice of assisting the recovery of a degraded, damaged or destroyed ecosystem. The aim of this study was to analyse the effects of two different restoration techniques on instream bryophyte abundance, species richness and diversity as well as community composition, in streams channelized for timber-floating. Instream bryophytes were collected from 10 tributaries of the Vindel River in boreal northern Sweden, from five stream reaches each of channelized reaches, which had not been restored; reaches restored in the early 2000s, using best-practice techniques; and reaches restored in the early 2000s and then re-restored in 2010 using the new “demonstration” techniques. A multitude of environmental variables were also measured at the sites. Bryophyte abundance was lower in demonstration restored sites than unrestored or best-practice restored sites but no significant difference was found in bryophyte species richness, diversity or species composition. Environmental variables correlated with bryophyte abundance, species richness, diversity and composition largely reflected effects of restoration, and probably the disturbance associated with restoration. Small sediment grain sizes also had a negative effect on species richness. Other environmental variables that influenced bryophyte species composition were the large-scale factors of latitude, longitude and elevation and reach-scale factors of potassium concentration and light absorbance. It is not yet possible to fully evaluate the effectiveness, in terms of bryophyte response, of the new demonstration restoration compared with best-practice since the recovery time between them differs and has not been sufficient. Long-term monitoring of the effects of restoration is needed in order to better evaluate success.

Atmosphere carries multi-faceted meaning when considered in the context of spatial design. In an architectural sense, we may speak of atmosphere as a spatial quality or in the way the built or natural environment is capable of moving us emotionally. Yet, when considered in a scientific register, atmosphere may be described as a complex of observable and measurable energies, which give air substance, behavior and force. The practice of landscape architecture entails a heightened awareness of exposure, namely the exposure to meteorological processes that in turn shape much of our perceptual and haptic experience of the ‘outside’ world. The intent of this practicum will be to draw attention to the importance of both designations of atmosphere, particularly within the discipline of landscape architecture, and set within the context of phenomenology. The context of this work begins at the scale of the circumpolar boreal forest and examines a particular biological and chemical phenomenon that occurs between the atmosphere and the boreal forest biome. The scale of focus will be drawn to a site at the southern transition zone between the boreal forest and St. Lawrence mixed forest within the Temagami region of northeast Ontario, Canada. Here, the phenomenon in question is quite palpable. / May 2017

Disturbance can provoke a chronic (long-term) stress response in wildlife, and can contribute to population declines. I examined the stress response of boreal woodland caribou, moose, and wolves to disturbance in eastern Manitoba by measuring cortisol concentrations in hair. Caribou cortisol concentrations were greatest for the three most southern populations, and increased with decreasing home range size. Intermediate logging (6-21 years) provided the best explanation for individual variation in caribou cortisol concentrations. Disturbance did not affect moose cortisol concentrations, but cortisol concentrations were higher in moose killed by wolves than moose collected by humans, suggesting that chronic stress in moose is linked to poor body condition and increased vulnerability to wolf predation. Wolf cortisol concentrations increased in 2012 and 2013 compared to 2011 following increased harvest pressure, and were higher in females. However, neither winter severity nor variation in wolf diet affected wolf cortisol concentrations. / October 2016

Non-ferrous smelter emissions have prompted revegetation efforts near the border towns of Flin Flon, Manitoba and Creighton, Saskatchewan to facilitate regrowth of the surrounding boreal forest. Previously, several soil amendments were tested for plant response in soils from the smelter-impacted area and one amendment, a pyrolyzed meat and bone meal (MBM) biochar, was of particular interest because of its potential to immobilize Zn. Hydroxyapatite (HAP), with a small degree of carbonate substitution, was identified as the major component of the MBM biochar. The solubility of this Ca-mineral was pH dependent, with dissolution occurring at pH 6.3; consequently, adsorption experiments were performed at a slightly lower pH (6.1 ± 0.1). Zinc adsorption kinetics were bi-phasic and could be modeled using the Elovich equation, suggesting a diffusion limited reaction likely related to material aggregation. Adsorption also was modeled using the Langmuir equation, which indicated a moderate affinity of the biochar for Zn and an adsorption maximum of 0.650 mmol Zn g-1. Synchrotron-based Zn K-edge x-ray absorption spectroscopy (XAS) indicated an inner-sphere monodentate, tetrahedral bonding of Zn to phosphate groups in the MBM biochar. This was consistent with Zn adsorbed to a HAP standard, indicating that the same sorption mechanism was involved. The ability of MBM biochar to affect Zn speciation in soils was investigated using four soils from four locations in the smelter-impacted region around Flin Flon. A 1:10 (w/w) mixture of the MBM and soil was suspended in 200-mL deionized water (pH 6.1 ± 0.1) and equilibrated for 30 d. Whereas all the soils showed a decrease in extractable Zn following equilibration, only one exhibited a change in Zn speciation—with ca. 25% of the Zn adsorbed onto the MBM biochar. Ore-derived minerals were present in all soils and strong backscattering made identification of minor Zn species difficult. However, using microprobe-based x-ray absorption near edge structure (XANES) spectroscopy, several minor Zn species were identified; including hopeite, a ZnPO4 mineral. The presence of both hopeite and adsorbed Zn are indicative of a direct Zn-phosphate reaction. These results indicate that, under certain condition, MBM biochar can be an effective soil amendment.

Albertas oil sands are located in the boreal forest where surface mining disturbs huge tracts of land. One such area, Syncrude Canada Ltd.s Mildred Lake mine, contains waste overburden (OB) piles which can be saline and sodic (SSOB). The objectives of this research were to 1) determine SSOB material impacts on planted tree root distributions, 2) quantify root activity to identify plant species growing at depth, and 3) document coarse woody root structure for planted trees. Root distributions for three mixedwood stands on reclaimed OB in relation to electrical conductivity (EC) and sodium absorption ratio (SAR) were examined using soil cores. Root distributions followed a similar pattern with soil depth as those from undisturbed boreal forest stands and appeared unaffected by the SSOB at this stage; however, future monitoring will be required as the stands mature. Root activity was assessed for jack pine (jP) and white spruce (wS) stands on tailings sand (TS) and OB using a strontium (Sr) chloride tracer. Understory and tree foliage was collected prior to and after application to measure Sr concentration in the control, broadcast, and depth treatments. A small proportion of roots grew in the OB material regardless of its chemical properties. Results from the Sr tracer study suggested that these roots were probably from the clover, sow thistle, and grasses. Planted trees showed little to no change in Sr tissue content suggesting that there were little to no roots in the treatment zones, the understory species out-competed the trees for Sr accessibility, or the tracer was diluted in the tree biomass to undetectable levels. Root systems of planted jP trees older than 10 years and older than 20 years on TS and OB were excavated and the number and diameter of lateral roots, the degree of kinking and coiling, and the presence of a taproot were recorded. Excavated trees showed poor taproot development on 70% of the trees and numerous root deformities, suggesting that more emphasis is needed in correct planting techniques and good planting stock to ensure proper root development. Roots are critical components of boreal forest ecosystems; without healthy root systems productivity may decline, stands may be susceptible to windthrow, and general forest health may suffer.

This study compared the effects of fire severity and salvage logging on early successional vegetation in the mixedwood boreal forest upland of Saskatchewan. The effects of salvage logging on post-fire forest stands are poorly understood. Few studies have investigated the short-term effects of salvage logging on the regeneration of boreal plant species or the long-term impact on overall forest composition and diversity. This study examines salvage logged and wildfire leave stands across three burn severity classes (no burn, low/moderate burn, and high burn) over two time periods (1 year post-fire and 10 years post-fire). The results indicate that salvage logging has a significant impact on the early regeneration of burned mixedwood boreal plant communities with the effect still evident in forest stands ten years post-fire. Salvage logging has long-lasting residual effects on boreal forest plant community development. Salvage logging one year post-fire reduced the number, diversity, and abundance of species within each of the burn severities, creating a less abundant and simplified plant community. It was also shown that salvage logging one year post-fire tended to create more homogenous plant communities similar to those communities typical of areas of moderate burn severity, constraining the effects of burn severity and decreasing the range of the vegetation communities. These findings are less pronounced, but still evident, within salvage logged stands ten years post-fire as three regrowth cover types have developed, characterised by no disturbance, moderate disturbance either by fire or salvage logging, and severe disturbance. The convergence of plant community characteristics between burn severity classes across logging treatments suggests that the effects of salvage logging do not have long lasting effects within areas of high burn severity.

Environmental conditions on wintering or spring-staging areas may influence subsequent reproductive performance in migratory birds. These cross-seasonal effects may result from habitat loss and degradation (e.g., via contamination) which in turn reduce reproductive success, particularly in waterfowl that use stored nutrients for reproduction. North American lesser scaup (<i>Aythya affinis</i>) and white-winger scoter (<i>Melanitta fusca</i>) numbers have declined over the past 20 years, particularly in the boreal forest, and remain well below conservation goals, whereas ring-necked duck (<i>A. collaris</i>) numbers have increased. Environmental changes on scaup and scoter wintering and staging areas have raised concern about possible cross-seasonal effects on birds arriving on breeding grounds. The spring condition hypothesis (SCH) purports that many female scaup fail to acquire sufficient nutrients in late winter and spring, causing a decrease in breeding propensity and productivity. The contaminant hypothesis proposes that increased exposure to contaminants (particularly selenium [Se]) on wintering and staging areas has decreased scaup productivity. Accordingly, I compared body condition and studied Se concentrations in scaup, scoters and ringnecks to test the condition and contaminant hypotheses. <p>Scaup had similar body condition to ringnecks, and had similar body mass compared to scaup collected near Yellowknife, NT, in 1968-70. There was no relationship between scaup and ringneck nutrient levels and claw tip carbon, nitrogen or hydrogen isotope values, suggesting that arrival body condition likely was not related to location or diet several months prior. Instead, scaup and ringnecks nutrient levels may be more affected by feeding or habitat conditions on or near the breeding grounds. Scaup had slightly higher liver Se concentrations than ringnecks, but levels in both species were below recognized harmful threshold concentrations; I found no relationship between Se and breeding propensity, or between Se and somatic lipid or protein stores. Scoters had much higher Se concentrations, yet contrary to predictions, there were positive relationships between Se and both lipid stores and breeding status. Follicle [Se] in scaup was below threshold concentrations; despite high liver Se in scoters, egg and follicle levels also were well below threshold concentrations. Using both body composition analysis and stable-isotope analysis I determined that scoters derive egg protein from their breeding ground diet, which likely prevents Se deposition from somatic protein to eggs, and egg lipids are apparently derived from somatic tissues. In all three species, liver Se concentrations were significantly correlated with claw tip ä15N. As the claw tip likely represents assimilated diet from 2-5 months prior to sampling, this correlation suggests that Se in these boreal breeding species is carried over from wintering and staging areas. <p>Overall, results did not support either the spring condition or contaminant hypotheses. Scaup and scoters are late-nesting species, with highest pair densities occurring at the northern extent of their range. Maximum ring-neck pair densities occur at more southern latitudes. Ring-necks also nest earlier and appear to be more flexible in timing of nest initiation. Therefore, it is possible that due to climate change, early spring conditions alter the optimal timing of nest initiation to the detriment of late-nesting species such as scaup and scoters, and favour earlier nesters like ringnecks. Further research into this mismatch hypothesis is warranted.

Despite the spatial significance of Canadas boreal forest, there is very little known about greenhouse gas emissions within it. The primary objective of this project was to study the atmosphere-soil exchange of CH4 and N2O in the boreal forest of central Saskatchewan. In the summers of 2006 and 2007, greenhouse gas emissions were measured along transects in three different mature forest stands (trembling aspen, black spruce and jack pine) using a sealed chamber method. In addition, the gross rates of mineralization and nitrification, and the relative contribution of nitrification and denitrification to N2O emissions, were measured at the trembling aspen site using a stable isotope technique in which 15N-enriched nitrate and ammonium were injected into intact soil cores. The amount of 14N found in the labeled pools was used to measure the gross rates, and the amount of 15N found in the emitted N2O was used to determine the relative contribution of the different N pathways to total N2O emissions. Results indicated that the jack pine and black spruce sites were slight sinks of CH4 (-1.23 kg CH4-C ha-1 yr-1and -0.17 kg CH4-C ha-1 yr-1 respectively in 2006 and -0.95 kg CH4-C ha-1 yr-1and 0.45 kg CH4-C ha-1 yr-1 respectively in 2007), whereas the trembling aspen site was a net source (46.7 kg CH4-C ha-1 yr-1 in 2006 and 196.0 kg CH4-C ha-1 yr-1 in 2007). All three sites had very low cumulative N2O emissions, ranging from -0.02 to 0.14 kg N2O-N ha-1 yr-1 in both years. Of the environmental controls examined for CH4, consumption at the jack pine site was correlated positively with organic carbon and negatively with water-filled pore space. Black spruce CH4 emissions were correlated negatively with both organic carbon and clay content, and emissions at the trembling aspen site were positively correlated with soil temperature and organic carbon, while also related to the presence of standing water (2006 and 2007 had very high precipitation, causing a high water table and ponding in depressions). The N2O emissions were not correlated with any of the environmental parameters measured at the jack pine or black spruce sites, but clay content was positively related to emissions at the trembling aspen site. The 15N results indicated that N cycling at the trembling aspen site was very rapid, allowing little N to escape the system as N2O; the majority of emissions that did occur were due to a nitrification-related process.

This study compared the effects of fire severity and salvage logging on early successional vegetation in the mixedwood boreal forest upland of Saskatchewan. The effects of salvage logging on post-fire forest stands are poorly understood. Few studies have investigated the short-term effects of salvage logging on the regeneration of boreal plant species or the long-term impact on overall forest composition and diversity. This study examines salvage logged and wildfire leave stands across three burn severity classes (no burn, low/moderate burn, and high burn) over two time periods (1 year post-fire and 10 years post-fire). The results indicate that salvage logging has a significant impact on the early regeneration of burned mixedwood boreal plant communities with the effect still evident in forest stands ten years post-fire. Salvage logging has long-lasting residual effects on boreal forest plant community development. Salvage logging one year post-fire reduced the number, diversity, and abundance of species within each of the burn severities, creating a less abundant and simplified plant community. It was also shown that salvage logging one year post-fire tended to create more homogenous plant communities similar to those communities typical of areas of moderate burn severity, constraining the effects of burn severity and decreasing the range of the vegetation communities. These findings are less pronounced, but still evident, within salvage logged stands ten years post-fire as three regrowth cover types have developed, characterised by no disturbance, moderate disturbance either by fire or salvage logging, and severe disturbance. The convergence of plant community characteristics between burn severity classes across logging treatments suggests that the effects of salvage logging do not have long lasting effects within areas of high burn severity.