Rozprawy doktorskie na temat „Dune lakes”

Given the rapidly increasing visitation levels to Fraser Island, there is increasing concern that tourist activities may threaten the long-term ecological health of the region's unique dune lakes. This project aimed to investigate the consequences of tourist use of Fraser Island's dune lakes and to develop appropriate monitoring tools and management objectives in light of the projected increases in visitation levels in the foreseeable future. The initial phase of this research aimed to identify the relative importance of some of the most popular dune lakes on the island as key destinations for tourists. Tourist surveys, in conjunction with the development of a Tourist Pressure Index (TPI), which quantifies logistic, social and natural variables, identified Lakes McKenzie, Allom and Birrabeen as the lakes most at risk from excessive tourist use. In addition, analyses of water quality in 15 lakes on Fraser Island aimed to determine the current trophic status of dune lakes on Fraser Island and the ecological implications of tourist use of these systems. Detailed comparisons of nutrient and chlorophyll a concentrations in five popular dune lakes in February 1990 (data from Arthington et al. 1990) and February 1999 suggested that productivity has increased significantly in the past decade. More detailed examinations of nutrient and algal variables in five popular perched dune lakes revealed that while ambient nutrient and phytoplankton chlorophyll a concentrations remained relatively stable, periphyton chlorophyll a concentrations increased over the course of the 1999-2000 summer in most lakes. Significantly, these increases were found only in heavily visited (disturbed) sites in the clear lakes examined (McKenzie and Birrabeen). In these lakes, where algal growth is likely to be only limited by nutrient availability, tourist nutrient additions may stimulate excessive periphyton production. Experimental algal bioassays identified that phytoplankton and to a lesser degree periphyton growth was stimulated by nutrient additions in all five perched dune lakes. However, the degree to which growth was stimulated was both lake and nutrient (nitrogen versus phosphorus versus nitrogen + phosphorus) dependent, highlighting the variable nature of systems within a relatively small geographic range. Since periphyton biomass was higher in heavily visited areas of lakes and was likely to be stimulated by nutrient additions by tourists, stable isotope analyses of littoral zone food webs were conducted to quantify the percent contribution of periphyton to consumer diets. There was a trend towards higher periphyton contributions in systems identified as key tourist locations (on the basis of their TPI scores) and this indicates that increasing visitation may increase the contribution of periphyton to littoral zone food webs, both via increases in the quantity and quality of periphyton as a food resource. To further explore the contribution of periphyton in littoral zone food webs of heavily visited lakes, a 15N-tracer addition experiment was conducted to establish the fate of nutrient additions within the littoral zone. Nutrients were added in quantities that mimicked those likely from tourists, to enable a realistic appraisal of the fate of tourist additions. As expected, periphyton rapidly assimilated the added 15N-tracer and was found to be the first and most significant sink for nutrients entering the littoral zone. Finally, the results from this research were used to develop a conceptual model of nutrient enrichment for perched dune lakes on Fraser Island. The model indicates that although nutrient additions from tourists may lead to undesirable increases in periphyton biomass, the degree to which this is deemed to be a detrimental ecological outcome is likely to be mediated by water level fluctuations and the consumptive capacity of grazers. Given that excessive periphyton growth is likely to be seen as negative impact of tourism, regular periphyton monitoring (biomass and percent contribution to littoral zone food webs) should be built into an updated monitoring program for this series of dune lakes. Whilst the implementation of periphyton monitoring is likely to enable the early detection of deleterious impacts of excessive tourist use, it is likely that the long-term conservation of the region will, in the future, require the implementation of strict visitation level guidelines, to ensure that the irreversible consequences of long term additions of nutrients are ameliorated.

This was an applied ethnographic study of natural and cultural resources of contemporary significance for American Ojibway' tribes and Canadian Ojibway First Nations that are or were once present within or in the immediate vicinity of four National Park Service (NPS) units in the Midwest Region: Sleeping Bear Dunes National Lakeshore (SLBE), Michigan; Pictured Rocks National Lakeshore (PIRO), Michigan; Apostle Islands National Lakeshore (APIS), Wisconsin; and Voyageurs National Park (VOYA), Minnesota. The main objective of this study, according to the Scope of Work (SOW) of 1996, was to develop a documented basis of knowledge regarding historic and current use of resources by culturally affiliated Native American tribes that should help park managers anticipate Native American resource use issues that may confront them in the future and thus be better prepared to deal with them in an informed and culturally sensitive manner. The study also was to provide recommendations regarding preservation, monitoring, mitigation, interpretation, and use access issues. The research was designed to provide a historical and ethnographic overview and assessment of Native American, Southwestern Ojibway in particular, land and resource use as it pertains to the region where the parks are located, and to each park unit. This study also provided an inventory of ethnographic resources known to have been significant for culturally affiliated Southwestern Ojibway tribes at different points in time.

Oceanic islands have been used as model systems for studies of evolution and speciation as the range of island sizes coupled with their known geological chronosequence make them ideal systems for the study of spatial and temporal variations in species diversity and distributions. These processes also occur on continental islands and mainland habitats but features of oceanic islands, notably their clearly delimited boundaries, natural isolation and simple geological composition make them more amenable to study. The perched dune lakes of Fraser Island, Australia share many of the properties of oceanic islands. The naturally isolated formation of the perched lakes, clearly delimited boundaries of the freshwater habitat and phase difference compared to the surrounding, terrestrial environment have significant implications for the biota these lakes support. Inhabitants of the perched dune lakes consist of the aquatic and semi-aquatic descendents of colonisers that were able to traverse a land barrier and survive in the oligotrophic, acidic waters over subsequent generations. Barriers to ongoing gene flow among lake populations, are however likely to be different for species with different life history characteristics. I therefore sought to assess the effects of three different life history characteristics on post-colonisation interpopulation gene flow. A representative species was selected to represent one of each of the following life history characteristics: * Aquatic species confined to lake for entire life cycle - freshwater shrimp Caridina indistincta. * Semi-aquatic species capable of terrestrial dispersal - freshwater turtle Emydura krefftii. * Semi-aquatic species capable of aerial dispersal - odonate Orthetrum Boumiera. 137-250 individuals were sampled per species across six lakes separated by 1-6km. Regions of the mitochondrial genome were targeted and molecular screening methods developed and employed to assess the relative levels of post-colonisation gene flow among lake populations. Parsimony analysis of the 25 unique haplotypes identified in the species with no apparent inter-lake dispersal mechanism, the freshwater shrimp Caridina indistincta, demonstrated that there was no sharing of derived haplotypes among lake populations. Star shaped genealogies were identified in four lake populations indicative of a population expansion and mismatch distribution analysis confirmed a recent population expansion estimated to have occurred no more than 200,000 years ago. This demonstrates that each of the perched dune lakes was colonised by C.indistincta soon after their inception but that no ongoing gene flow among lake populations has occurred. The population genetic structure of the species assessed which is capable of terrestrial dispersal suggests that although this species of freshwater turtle, Emydura krefftii, is capable of overland dispersal, gene flow among lake populations is limited. Even at the small spatial scale examined in this study, E.krefftii populations displayed a pattern of isolation by distance (r=0.854, p<0.03). Nested clade analysis also suggested a pattern of restricted gene flow with some long distance dispersal in recent times with long distance dispersal and a possible range expansion occurring historically. The species examined in this study that displayed the most extensive gene flow among lake populations was the dragonfly Orthetrum boumiera. No relationship was found between genetic and geographic distance (r= -0.0852, p>0.05) and nested clade analysis could not identify a geographical association among haplotypes, indicative of panmixia. While larval life stages of this species are fully aquatic, the winged adult stages of this species appear to be connecting seemingly isolated lake populations, at least at the spatial scale examined here. The results of this study have demonstrated that these perched dune lakes provide 'island like' models for recent biogeographic processes. The pattern of colonisation and subsequent diversification identified in these populations takes the form of insitu 'genetic radiations' with those populations that are isolated forming monophyletic clades endemic to a single lake. The genetic diversity and endemism identified in this study has occurred over much smaller temporal (<500,000 years) and spatial (<6.5km) scales than in studies of oceanic island fauna. However, the mode of formation of the perched dune lakes and the implications that their natural isolation and abiotic genesis have for the evolution of colonisers of these unique habitats has resulted in them being analogous to true oceanic islands.

Oceanic islands have been used as model systems for studies of evolution and speciation as the range of island sizes coupled with their known geological chronosequence make them ideal systems for the study of spatial and temporal variations in species diversity and distributions. These processes also occur on continental islands and mainland habitats but features of oceanic islands, notably their clearly delimited boundaries, natural isolation and simple geological composition make them more amenable to study. The perched dune lakes of Fraser Island, Australia share many of the properties of oceanic islands. The naturally isolated formation of the perched lakes, clearly delimited boundaries of the freshwater habitat and phase difference compared to the surrounding, terrestrial environment have significant implications for the biota these lakes support. Inhabitants of the perched dune lakes consist of the aquatic and semi-aquatic descendents of colonisers that were able to traverse a land barrier and survive in the oligotrophic, acidic waters over subsequent generations. Barriers to ongoing gene flow among lake populations, are however likely to be different for species with different life history characteristics. I therefore sought to assess the effects of three different life history characteristics on post-colonisation interpopulation gene flow. A representative species was selected to represent one of each of the following life history characteristics: * Aquatic species confined to lake for entire life cycle - freshwater shrimp Caridina indistincta. * Semi-aquatic species capable of terrestrial dispersal - freshwater turtle Emydura krefftii. * Semi-aquatic species capable of aerial dispersal - odonate Orthetrum Boumiera. 137-250 individuals were sampled per species across six lakes separated by 1-6km. Regions of the mitochondrial genome were targeted and molecular screening methods developed and employed to assess the relative levels of post-colonisation gene flow among lake populations. Parsimony analysis of the 25 unique haplotypes identified in the species with no apparent inter-lake dispersal mechanism, the freshwater shrimp Caridina indistincta, demonstrated that there was no sharing of derived haplotypes among lake populations. Star shaped genealogies were identified in four lake populations indicative of a population expansion and mismatch distribution analysis confirmed a recent population expansion estimated to have occurred no more than 200,000 years ago. This demonstrates that each of the perched dune lakes was colonised by C.indistincta soon after their inception but that no ongoing gene flow among lake populations has occurred. The population genetic structure of the species assessed which is capable of terrestrial dispersal suggests that although this species of freshwater turtle, Emydura krefftii, is capable of overland dispersal, gene flow among lake populations is limited. Even at the small spatial scale examined in this study, E.krefftii populations displayed a pattern of isolation by distance (r=0.854, p<0.03). Nested clade analysis also suggested a pattern of restricted gene flow with some long distance dispersal in recent times with long distance dispersal and a possible range expansion occurring historically. The species examined in this study that displayed the most extensive gene flow among lake populations was the dragonfly Orthetrum boumiera. No relationship was found between genetic and geographic distance (r= -0.0852, p>0.05) and nested clade analysis could not identify a geographical association among haplotypes, indicative of panmixia. While larval life stages of this species are fully aquatic, the winged adult stages of this species appear to be connecting seemingly isolated lake populations, at least at the spatial scale examined here. The results of this study have demonstrated that these perched dune lakes provide 'island like' models for recent biogeographic processes. The pattern of colonisation and subsequent diversification identified in these populations takes the form of insitu 'genetic radiations' with those populations that are isolated forming monophyletic clades endemic to a single lake. The genetic diversity and endemism identified in this study has occurred over much smaller temporal (<500,000 years) and spatial (<6.5km) scales than in studies of oceanic island fauna. However, the mode of formation of the perched dune lakes and the implications that their natural isolation and abiotic genesis have for the evolution of colonisers of these unique habitats has resulted in them being analogous to true oceanic islands.

Both poly- and perfluoroalkylated substances (PFASs) and mercury (Hg) are persistent bioaccumulative, and toxic substances (PBTs) of great concern due to their health effects on humans.  These pollutants are ubiquitously occurring in the global aquatic environment and dietary intake of fish is the major exposure pathway for humans. PFASs and Hg are widely studied in the temperate zones, but little is known from the tropical aquatic systems in Africa. Lake Tana, Ethiopia, is of high ecological value and predicted to increase its fish production and export during following years, but knowledge of human health effects due to bioaccumulated pollutants loading from this lake is lacking. The objective of this study was therefore to compare Hg and PFAS concentrations between sites and species, evaluate accumulation patterns and assess the human health risk with increased fish consumption.    During October 2014, a total of 97 fish specimens from five species (Labeobarbus megastoma, Labeobarbus gorguari, Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) were collected from seven sites in Lake Tana. The fish was dissected in Bahir Dar, where a muscle sample was taken from the dorsal line, and later analyzed at the Swedish University of Agricultural Sciences. To determine differences and correlations between sites and species as well as for Hg and PFASs, statistical analyses were conducted and to determine the health risks in increased fish consumption a hazard ratio (HR) was calculated for both substances.   The results showed several similarities between Hg and PFASs, including higher concentrations in piscivorous fish species (L. megastoma and L. gorguari) than non-piscivorous and also spatial distribution similarities. Hg concentrations ranged from 0-639 ng g-1 wet weight (ww) with an overall mean of 137 ng g-1 ww for all species. Seven PFASs were detected (PFNA, PFDA, PFUnDA, PFDoDA, PFTeDA, PFBS, PFOS), and the ∑PFSA concentrations ranged from non-detected to 3.61 ng g-1 ww. PFDA was found in all sites and species, compared to PFOS, which only was found in piscivorous species in elevated levels. The positive correlation between Hg and PFOS imply that these substances have similar accumulation patterns. The HRs showed that increased fish consumption is harmless to the Ethiopian population regarding PFAS and Hg contamination. Varied fish consumption is of importance though since several individuals from the piscivorous species contained Hg concentrations exceeding the WHO marketing limit of 0.5 μg g-1 (500 ng g-1).
Både poly- och perfluoralkylerade ämnen (PFASer) och kvicksilver (Hg) är persistenta, bioackumulerande och toxiska (PBT) ämnen som kan utgöra stor hälsorisk för människor. PFASer och Hg förekommer globalt i den akvatiska miljön och den mest betydande källan för mänsklig exponering av dessa ämnen är fiskkonsumtion. Studier av PFASer och Hg är vanligt förekommande i de tempererade zonerna, men väldigt lite är känt från de tropiska akvatiska systemen i Afrika. Lake Tana, Etiopiens största sjö, har stort ekologiskt värde och fiskproduktion och export från sjön förutspås öka under kommande år. Däremot saknas kunskap om hur denna föroreningsbelastning med ökat fiskintag kommer påverka befolkningen i landet. Syftet med denna studie var därför att jämföra Hg- och PFAS-koncentrationer mellan områden och arter, utvärdera ackumuleringsmönster och bedöma hälsoriskerna med ökad fiskkonsumtion i landet.   Under oktober 2014 samlades totalt 97 individer in från fem arter (Labeobarbus megastoma, Labeobarbus gorguari, Labeobarbus intermedius, Oreochromis niloticus och Clarias gariepinus) och från sju olika platser i Lake Tana. Dissektionen utfördes i Bahir Dar (där muskelprover togs från dorsala rygglinjen) och sedan fördes proverna till Sveriges lantbruksuniversitet (SLU) för analys. För att bestämma skillnader och korrelationer mellan områden och arter, samt mellan Hg och olika PFASer, utfördes statistiska analyser och för att utvärdera hälsorisken av en ökad fiskkonsumtion beräknades riskfaktorer för båda ämnena.    Resultaten påvisade flertalet likheter mellan Hg och PFASer, bland annat högre koncentrationer i piskivora fiskarter (L. megastoma and L. gorguari) än icke-piskivora och även likheter i koncentrationer mellan provområdena. Hg-koncentrationerna varierade mellan 0-639 ng g-1 våtvikt (vv), med ett medel på 137 ng g-1 vv för alla arter. Sju PFASer detekterades i analysen (PFNA, PFDA, PFUnDA, PFDoDA, PFTeDA, PFBS, PFOS), där ∑PFSA koncentrationerna varierade mellan icke-detekterbara till 3,6 ng g-1 vv. PFDA förekom i alla arter och områden, medan PFOS bara fanns i förhöjda värden i piskivora arter. Den funna positiva korrelationen mellan PFOS och Hg antyder att dessa ämnen har liknande ackumulationsmönster. De beräknade riskfaktorerna visade att en fiskkonsumtions-ökning inte skulle utgöra en risk för den etiopiska befolkningen med avseende på Hg- och PFAS-halter. En varierad fiskkonsumtion är dock av stor vikt eftersom flertalet individer från de piskivora arterna innehöll högre Hg-koncentrationer än den av WHO rekommenderade gränsen på 0,5 μg g-1 vv.

The aim of this report was to investigate the potential effects of sulfide oxidation in sediments of an arctic lake, N Luossajärvi, induced by lowered water level. Lake water, potentially contaminated by metals, was pumped into a mine tailings impoundment. The water quality in the receiving water was evaluated to see if the drainage have had an effect on the water quality. Six sediment profiles were sampled. Each profile were divided into 5 cm sections and analyzed for major elements and trace metals. Water chemistry were analyzed at six sites. As, Ni and Cu had high concentrations within undrained sediments, where As levels were classified as highly contaminated (> 27 mg kg-1 dw). Trace metals had strong statistical correlation to each other indicating a common source. The PCA analyzes performed suggests that trace metals are controlled by a common factor and drained sediments showed two additional factors controlling the variance of metals. Water chemistry had overall good status, but As, Cd, Ni and Cu exceeded natural background values. Historical data on the other hand showed no statistical difference from measured values. No effects on water quality could therefore be seen after draining of the lake, proposing high precipitation of metals within the tailing or that metals is still prevailing in the drained sediments. Metal mobility were seen within the drained sediments, where only As and Cd were presumed connected to chemical weathering and where erosion and soil properties seems to be responsible for most metal mobility.

Past studies have shown that diffuse nutrient loading from agricultural activities is an important cause of lake eutrophication. The degree to which this relationship can be scaled-up (e.g. at an inter-regional scale) has not, however, been widely addressed. My thesis objectives were therefore to define the generality and the impact of agriculture land use and lake morphometry on lake water quality. Analyses along spatial and temporal scales were conducted to evaluate the significance of these effects. In the first manuscript, we tested whether agricultural activities explain a significant proportion of the variation in lake water quality at a broad inter-regional scale. The degree to which lake mean depth modulates this response was also assessed. From our meta-analyses of 358 lakes, we noted a significant correlation between total phosphorus concentration and the extent of agricultural catchment development. This relationship was further strengthened by including lake mean depth as a second predictor. We also observed among-study variability in the relationship between these three variables. Thus, although there is a general relationship between total phosphorus concentrations and our two predictors, agriculture catchment development and lake mean depth, regional baseline nutrient differences modify this relationship. To address the issue of lake morphometry more closely, we adopted a spatio-temporal approach to investigate whether the effect of agricultural catchment development on water quality differed between dimictic and polymictic Albertan lakes. We found that the correlation between surface water total phosphorus concentration and the percent of agriculture in a lake's catchment was strongly modified by lake mixis patt
Les études antécédentes ont démontré que les chargements de nutriment diffus parvenant d'activités agricoles sont une cause importante de l'eutrophisation des lacs. Par contre, le degré auquel cette relation peut être extrapolé à l'échelle interrégionale n'a pas été largement étudié. Ma thèse a pour but de définir la généralité et l'impact de l'usage des terres agricoles et la morphométrie des lacs sur la qualité d'eau. Des analyses selon des échelles spatiale et temporelle ont évalué la significativité de ces effets. Dans ce premier manuscrit, nous avons examiné si les activités agricoles pouvaient expliquer une proportion significative de la variation de la qualité de l'eau sur une vaste échelle interrégionale. Notre métaanalyse, basée sur des données parvenant de 358 lacs, a démontré une corrélation significative entre la concentration de phosphores totaux et le pourcentage de terres agricoles des basins versants. Cette corrélation a été améliorée en incluant la profondeur moyenne comme seconde variable prédictive. Nous avons aussi observé une variabilité parmi les études pour la relation entre ces trois variables. Donc, étant donné qu'il y a une relation générale entre la concentration de phosphores totaux et deux indices, le développement de l'agriculture des bassins versants et la profondeur moyenne des lacs, des différences de niveau de référence régionales modifie cette relation. Pour déterminer l'importance de la morphométrie des lacs plus en détaille, nous avons adopté une approche spatio-temporelle pour vérifier si les effets du développement de l'agriculture des bassins versants sur la qualité de l'eau sont différents entre les systèmes dimictiques et$

Thesis (Ph. D.)--University of Wisconsin--Madison, 1992.
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The effects of salt expelled by surface ice upon formation are investigated in the laboratory to determine whether it promotes merolnixis in lakes. The experiments consist of creating surface ice in an insulated container and letting it melt, while taking a time series of temperature measurements at different depths. The model lake has dimensions 0.34m x 0.18m x 0.3m depth and is sufficiently well insulated to allow the formation of an reverse temperature stratification in the water column. The experiments start with well-mixed saline solution at room temperature. Initial salinity ranges from 0 g L⁻¹ to 15 g L⁻¹ of potassium chloride. In all experiments, significant mixing occurred beneath the ice during its formation. The ice expels salt creating colder, more saline and hence denser water below the ice, which then mixes with warmer water located at depth. An unstable temperature stratification, supported by the accumulation of saline waters near the bottom of the lake, is present after the ice is completely melted. The proportion of salt expelled from the ice is a function of the initial lake salinity, as are the details of the circulation under the ice.
Applied Science, Faculty of
Civil Engineering, Department of
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Thesis (M.S.)--University of Wisconsin--Madison, 2002.
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Pine plantations have been established on secondary grassland on the dune systems of the Eastern Shores of Lake St Lucia, KwaZulu-Natal, South Africa for the past 40 years. These plantations have been progressively felled for the past six years, and will continue to be felled until the year 2011, by which time they will be eliminated. Space-for-time substitution was used to determine the direction of both woody and herbaceous vegetation succession and to predict possible future management implications for the Eastern Shores. Soil samples were taken from undisturbed grassland, grassland with trees, dune forest, pine plantations, and clearfelled areas at various successional stages. To determine the effects of the pine plantations on the soils of the area, soils were subjected to particle size analysis, and determination of pH, organic carbon, phosphorus, exchangeable bases, iron and aluminium. Minimal modification of the sandy soils by the pine plantations was found to have occurred. That which did occur was shown to be short-term, and to be ameliorated by the establishment of an indigenous woody understorey, resembling pioneer dune forest. Soil under plantations was shown to have a lower pH and cation exchange capacity than under opposite indigenous vegetation but no other direct effects were observed. The direction of succession was determined by the nature of the indigenous vegetation adjacent to the plantation. Pine plantations were shown to facilitate succession towards dune forest by the exclusion of fire, provision of perches and refugia for forest-dwelling animals, and creation of a forest environment for the establishment of trees. However, the extent of re-establishment of indigenous dune forest under pine plantations was shown to be directly related to the nature of the adjacent indigenous vegetation, be it grassland, grassland with trees or dune forest.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

There has been some debate recently about the cause of the decline of water hyacinth on Lake Victoria. While much of this evidence points to classical biological control as the major factor, the El Niño associated weather pattern of the last quarter of 1997 and the first half of 1998 has confused the issue. We argue first that the reductions in water hyacinth on Lake Victoria were ultimately caused by the widespread and significant damage to plants by Neochetina spp., although this process was increased by the stormy weather associated with the El Niño event; second that increased waves and current on Lake Victoria caused by El Niño redistributed water hyacinth plants around the lake; and third that a major lake-wide resurgence of water hyacinth plants on Lake Victoria has not occurred and will not occur unless the weevil populations are disrupted. We conclude that the population crash of water hyacinth on Lake Victoria would not have occurred in the absence of the weevils, but that it may have been hastened by stormy weather associated with the El Niño event.

Northeastern British Columbia was occupied by the Cordilleran (CIS) and the Laurentide (LIS) ice sheets, however, the timing and extent remains contentious. The late Quaternary and Holocene history of this area is examined by exploring geomorphic, stratigraphic, geochemical and geochronologic components of glacial, deglacial, paraglacial and non-glacial landsystems. New tools, such as GIS, LiDAR, and new geochronologic methods, such as optical dating are used to understand the Quaternary geology and geomorphology of the region. Bedrock topography represents the base of the Quaternary section and modelling shows that paleovalleys, common in this region, host extensive Neogene sedimentary records. Stratigraphies from the Murray and Pine valleys indicate glaciation prior to the Mid-Wisconsinan (MIS 3) and during the Late Wiconsinan (MIS 2). Glacial landforms record Late Wisconsinan ice-sheet coalescence and reflect the complex interaction of the LIS and CIS margins. During deglaciation, the LIS and CIS separated and glacial Lake Peace (GLP) formed. Shoreline features enable reconstruction of lake and ice configurations. Four phases of GLP are preserved. Optical ages from Phase II indicate GLP occupied the area some time between ca. 16 – 14 ka yrs ago. The apparent tilt on the shorelines provides a measure of isostatic adjustments and suggests asynchronous retreat of first the LIS, then the CIS. The transition from paraglacial to boreal conditions was driven by climate change and is recorded by vegetation sucession and cessation of paraglacial processes. Optical ages from stabilized dunes and radiocarbon ages from organics date the transition between 12 – 11.5 ka yrs ago with full boreal conditions established by 10 ka yrs ago. The Holocene is dominated by erosional processes, however some systems are aggrading. A case study on a floodplain demonstrates that resistivity (Ohmmapper) surveys provide a grain-size proxy to suppliant GPR studies, which is essential for geophysical fluvial architectural analysis. In the study, the discrepancy between planform style (classic meander model) and subsurface geophysical surveys (indicative of vertical accretion associated with braided and wandering fluvial styles) reiterates cautions that planform may not always be a functions of depositional process and one may not be used to predict the other.
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