The current study has evaluated shoreline dynamics and environmental change at St. Catherines Island, Georgia, with attention to the two major controls of barrier island formation and modification processes. These major controls include the increase in accommodation space, or the rate of sea level rise for the Georgia Bight which has remained constant in 20th and 21st century tide gauge data and dynamically changing rates of sediment supply based on anthropogenic modifications to land cover (Trimble, 1974) that are reflected in sediment transport (McCarney-Castle et al., 2010). Vibracoring and radiocarbon data provided valuable insights into the stratigraphy and development of St. Catherines Island. A stratigraphic model has been developed for the sediments associated with the Late Holocene accretional terrains where multiple small scale fluctuations in sea level have resulted in the formation of a sedimentary veneer punctuated with transgressive surfaces and regressive sequences. A working model for an interpolated Late Holocene sea level curve has been constructed using direct evidence from vibracore data as constraining points and indirect evidence from other regional sea level studies to provide additional structure. The relationship between the timing of the regressions versus periods of beach ridge formation and implications from the current shoreline dynamics study regarding the role of sediment supply complement each other. The ages of beach ridge formation strongly correlate to periods that are associated with regressions in sea level based on the sedimentary record and an evaluation of Late Holocene sea level conditions. The evaluation of anthropogenic modifications to the rate of sediment supply performed under the current study indicates that in spite of significant changes in sediment flux rates of +300% (pre-dam era) and -20% (post-dam era), shoreline retreat was continuous during the study period with an acceleration noted in the rates of shoreline retreat associated with spit and berm landforms during the post-dam or modern era. The two associations indicate strongly that the rate of sediment supply plays a secondary role to the major control of the rate of sea level rise in the formation and modification processes at St. Catherines Island.

The current study has evaluated shoreline dynamics and environmental change at St. Catherines Island, Georgia, with attention to the two major controls of barrier island formation and modification processes. These major controls include the increase in accommodation space, or the rate of sea level rise for the Georgia Bight which has remained constant in 20th and 21st century tide gauge data and dynamically changing rates of sediment supply based on anthropogenic modifications to land cover (Trimble, 1974) that are reflected in sediment transport (McCarney-Castle et al., 2010). Vibracoring and radiocarbon data provided valuable insights into the stratigraphy and development of St. Catherines Island. A stratigraphic model has been developed for the sediments associated with the Late Holocene accretional terrains where multiple small scale fluctuations in sea level have resulted in the formation of a sedimentary veneer punctuated with transgressive surfaces and regressive sequences. A working model for an interpolated Late Holocene sea level curve has been constructed using direct evidence from vibracore data as constraining points and indirect evidence from other regional sea level studies to provide additional structure. The relationship between the timing of the regressions versus periods of beach ridge formation and implications from the current shoreline dynamics study regarding the role of sediment supply complement each other. The ages of beach ridge formation strongly correlate to periods that are associated with regressions in sea level based on the sedimentary record and an evaluation of Late Holocene sea level conditions. The evaluation of anthropogenic modifications to the rate of sediment supply performed under the current study indicates that in spite of significant changes in sediment flux rates of +300% (pre-dam era) and -20% (post-dam era), shoreline retreat was continuous during the study period with an acceleration noted in the rates of shoreline retreat associated with spit and berm landforms during the post-dam or modern era. The two associations indicate strongly that the rate of sediment supply plays a secondary role to the major control of the rate of sea level rise in the formation and modification processes at St. Catherines Island.

The Mediterranean has long been recognised as an area that is particularly sensitive to climate change. It is also an area that has been impacted by human activity for millennia. Disentangling climatic and anthropogenic influences on the history of vegetation change in the Mediterranean remains an important challenge. As a contribution to this ongoing debate, this thesis explores the late Holocene environment of part of the coast in Central Italy using a multiproxy approach to investigate the archives of change preserved in dune slack deposits. Distinguishing between natural and anthropogenic signals presents a real challenge in most environmental reconstruction work; however, due to the extensive archaeological research carried out at Castelporziano, it is possible to examine human-environmental interactions in some detail. In order to understand these interactions part of the thesis examines how management has affected recent environmental changes and the current vegetation and whether there is a legacy of Roman landuse at the Castelporziano estate. The key findings of the thesis showed that dune slacks are suitable for palaeoenvironmental reconstruction with proxies such as plant macrofossils, ostracods, molluscs and bryozoans statoblasts. However, the pH and seasonality of the slacks meant proxies such as pollen were badly preserved or absent, and diatoms did not preserve due to the high levels of carbonate on site. Overall the results show the impact of the Romans on site in terms of localised eutrophication and increased fires, but with abandonment, came the formation of wet woodlands.

Archaeological investigations at Edwards Air Force Base (AFB) have been ongoing for more than 40 years. Yet the findings from the vast majority of those efforts are available only as grey literature that is known only to a relative few. The primary purpose of this thesis was to investigate a late Holocene decline in obsidian frequency reported by researchers working in the Bissell Basin and Rosamond Dry Lake region of Edwards AFB near the turn of the 21st century. A secondary purpose of this thesis was to shine a light on an area of the western Mojave Desert that is not widely known despite more than four decades of research. In order to explore the reported decline in obsidian frequency, I created an obsidian database using data gleaned from nearly 50 cultural resources management reports and supplemented those data with sourcing and hydration information for 39 additional obsidian artifacts. Those data were organized into tables, charts, and histograms to look for patterns that would support or refute the claim that obsidian use decreased significantly after the Gypsum time period (4000 to 1500 Before Present [B.P.]). Two patterns emerged from my analysis. The first was one where the overall abundance of obsidian at Edwards AFB did not decrease during the late Holocene, thus contradicting the conclusions made in the previous research. The second was one where the obsidian abundance shifted among the various regions of the installation. Yet these shifts are nowhere near as significant as the previously reported decline. Therefore, while the total amount of obsidian that entered the archaeological record at Edwards remained relatively stable from 1500 to 100 B.P., the amount of obsidian decreased in certain regions and increased in others. Although not within the scope of my original intent, my research also identified two areas for future research. The first involves an apparent pattern where the number of archaeological sites from which obsidian was recovered gradually decreases during the middle-Holocene even as the overall quantity of obsidian remains essentially unchanged. The second relates to the lack of a well-established hydration rate formula for obsidian recovered from archaeological sites on Edwards AFB. Ultimately, I concluded that the previous findings that obsidian declined during the late Holocene were affected by sampling bias and faulty data organization. Most archaeologists understand that poorly implemented sampling can lead to poorly derived findings and conclusions. What may not be as well understood is that a perfectly appropriate sample where the data are not organized well can also lead to flawed results and conclusions. It is hoped that this thesis will inform archaeologists not only about how the manner in which they organize their data can affect their interpretation of past human behavior, but also about additional research opportunities at Edwards AFB.

Pollen profiles from two lakes, Tawny Pond (44°48’59”N, 77°10’54”W, 276m) and Stoll Lake (44°58’16”N, 77°17’22”W,303m) in Addington Highlands, eastern Ontario, Canada were analyzed to understand the effects of late-Holocene climate change and European settlement on eastern Ontario’s forests. Both lakes were analyzed at high temporal resolution and record vegetation dynamics over the last 1000 years. Throughout the past 1000 years, Pinus, Tsuga, Betula, Quercus, Acer and Fagus were the dominant taxa in the pollen record. The pollen records show vegetation response in relation to the Medieval Warm Period and the Little Ice Age. From 970-1200 AD the forest was dominated by hemlock, beech and maple trees. From 1200-1870 AD the forest composition changed as pine and boreal trees became more abundant and/or had increased relative pollen production. Most recently, since 1870 AD, herbaceous plants (weeds) increased, whereas softwoods decreased and hardwoods increased, due to landscape changes associated with European settlement. These results show that high resolution studies of unvarved lakes, with an appropriate chronology, can detect multi-decadal climate variability. This thesis was also concerned with making management suggestions to the forestry community. Future climate change will likely create a forest composition more similar to that of the Medieval Warm Period than the time of European colonization, and thus should be the basis for forest planning.

Pollen profiles from two lakes, Tawny Pond (44°48’59”N, 77°10’54”W, 276m) and Stoll Lake (44°58’16”N, 77°17’22”W,303m) in Addington Highlands, eastern Ontario, Canada were analyzed to understand the effects of late-Holocene climate change and European settlement on eastern Ontario’s forests. Both lakes were analyzed at high temporal resolution and record vegetation dynamics over the last 1000 years. Throughout the past 1000 years, Pinus, Tsuga, Betula, Quercus, Acer and Fagus were the dominant taxa in the pollen record. The pollen records show vegetation response in relation to the Medieval Warm Period and the Little Ice Age. From 970-1200 AD the forest was dominated by hemlock, beech and maple trees. From 1200-1870 AD the forest composition changed as pine and boreal trees became more abundant and/or had increased relative pollen production. Most recently, since 1870 AD, herbaceous plants (weeds) increased, whereas softwoods decreased and hardwoods increased, due to landscape changes associated with European settlement. These results show that high resolution studies of unvarved lakes, with an appropriate chronology, can detect multi-decadal climate variability. This thesis was also concerned with making management suggestions to the forestry community. Future climate change will likely create a forest composition more similar to that of the Medieval Warm Period than the time of European colonization, and thus should be the basis for forest planning.

Pollen profiles from two lakes, Tawny Pond (44°48’59”N, 77°10’54”W, 276m) and Stoll Lake (44°58’16”N, 77°17’22”W,303m) in Addington Highlands, eastern Ontario, Canada were analyzed to understand the effects of late-Holocene climate change and European settlement on eastern Ontario’s forests. Both lakes were analyzed at high temporal resolution and record vegetation dynamics over the last 1000 years. Throughout the past 1000 years, Pinus, Tsuga, Betula, Quercus, Acer and Fagus were the dominant taxa in the pollen record. The pollen records show vegetation response in relation to the Medieval Warm Period and the Little Ice Age. From 970-1200 AD the forest was dominated by hemlock, beech and maple trees. From 1200-1870 AD the forest composition changed as pine and boreal trees became more abundant and/or had increased relative pollen production. Most recently, since 1870 AD, herbaceous plants (weeds) increased, whereas softwoods decreased and hardwoods increased, due to landscape changes associated with European settlement. These results show that high resolution studies of unvarved lakes, with an appropriate chronology, can detect multi-decadal climate variability. This thesis was also concerned with making management suggestions to the forestry community. Future climate change will likely create a forest composition more similar to that of the Medieval Warm Period than the time of European colonization, and thus should be the basis for forest planning.

Indiana University-Purdue University Indianapolis (IUPUI) / The frequency and magnitude of flooding events on the Lower Ohio River and their relationship with climate are investigated using a ca. 2000-year-long sediment core collected from Goose Pond, Indiana. Using high-resolution radiocarbon dating (n = 25), late Holocene sedimentation rates were calculated for Goose Pond. Changes in sediment accumulation rates are attributed to variations in the frequency of flooding events on the lower Ohio River. Elevated sedimentation rates immediately following the formation of Goose Pond ca. 2000 years ago persisted until 680 CE, suggesting regular flooding during this interval. Between 680 and 1190 CE, sedimentation rates decreased dramatically and abruptly, indicating a reduction in flood frequencies. Sedimentation rates subsequently increased again at ca. 1190 CE and persisted at a similar level until 1850 CE, suggesting that flooding frequencies increased during a time that overlapped with the Little Ice Age (LIA; 1250-1850 CE). Sedimentation rates increased again at ca. 1850 CE, reaching a 2000-year high (3.33 cm/yr) at 1970 CE and indicating a period characterized by frequent flooding and landscape erosion. The flood record from Goose Pond shows similarities with other Lower Ohio River flood reconstructions from Avery Lake, IL, and Hovey Lake, IN, suggesting the Goose Pond record reflects the regional flooding history for the lower Ohio River. Comparison with paleoclimate records from the Midwest supports the idea that lower Ohio River flood frequencies prior to Euro American occupation in the 1800s increased during times when winter precipitation predominated as a result of atmospheric circulation changes resembling the Pacific North vii American mode (PNA) that appear to have been driven in part by the Pacific Decadal Oscillation (PDO). Following Euro-American land clearance, lower Ohio River flooding increased dramatically despite a decrease in winter precipitation. This likely reflects an increase in runoff and erosion as a result of deforestation and landscape conversion to intensive row crop agriculture. As climate continues to change and the Midwestern United States continues to see an increase in precipitation, both winter and summer, flood frequencies could be expected to increase still further.

Big Bone Lick (BBL) is a late Pleistocene and Holocene fossil locality in the Ohio River valley of Kentucky. This study utilized stable isotopes (δ13C, δ18O, and 87Sr/86Sr) in tooth enamel to reconstruct mobility and diet in Bison, as well as diet in Bootherium bombifrons. Isotopic results from seven Bison and two B. bombifrons are reported. Results suggest Pleistocene Bison and Bootherium occupied different dietary niches. Although both had C3-dominated diets, Bison occupied more open environments than B. bombifrons. Two bison from the late Holocene deposit had diets that consisted of more C3 vegetation than Pleistocene bison, which may indicate these individuals occupied a closed C3 landscape. However, one specimen previously identified as late Holocene had diet and mobility patterns consistent with Pleistocene bison, which could indicate temporal mixing. Pleistocene and Holocene Bison have 87Sr/86Sr values that suggest they spent most of their time in places other than BBL.

This thesis presents the results of contemporary limnological and palaeolimnological investigations of a series of crater lakes in order to reconstruct the palaeoenvironmental history of western Uganda, East Africa. The research examines questions of spatial and temporal heterogeneity of climate changes in the context of growing human impacts on the landscape over the last millennium. Sediment records from two lakes, Nyamogusingiri and Kyasanduka within the Queen Elizabeth National Park (QENP) were investigated to look at the long term records of climate and environmental change (spanning the last c. 1000 years). Five shorter cores across a land-use gradient were retrieved to assess the impact of human activity on the palaeoenvironmental record over the last ~150 years. High-resolution (sub-decadal), multiproxy analyses of lake sediment cores based on diatoms, bulk geochemistry (C/N and δ13C) and sedimentary variables (loss-on-ignition, magnetic properties and physical properties) provide independent lines of evidence that allow the reconstruction of past climate and environmental changes. This multiproxy approach provides a powerful means to reconstruct past environments, whilst the multi-lake approach assists in the identification and separation of local (e.g. catchment-scale modifications and groundwater influences) and regional effects (e.g. climatic changes). The results of a modern limnological survey of 24 lakes were used in conjunction with diatom surface sediment samples (and corresponding water chemistry) from 64 lakes across a natural conductivity gradient in western Uganda (reflecting a regional climatic gradient of effective moisture) to explore factors controlling diatom distribution. The relationships between water chemistry and diatom distributions were explored using canonical correspondence analysis (CCA) and partial CCA. Variance partitioning indicated that conductivity accounted for a significant and independent portion of this variation. A transfer function was developed for conductivity (r2jack = 0.74). Prediction errors, estimated using jack-knifing, are low for the conductivity model (0.256 log units). The final model was applied to the core sediment data.This study highlights the potential for diatom-based quantitative palaeoenvironmental reconstructions from the crater lakes in western Uganda. Sedimentary archives from the Ugandan crater lakes can provide high-resolution, annual to sub-decadal records of environmental change. Whilst all of the lakes studied here demonstrate an individualistic response to external (e.g. climatic) drivers, the broad patterns observed in Uganda and across East Africa suggest that the crater lakes are indeed sensitive to climatic perturbations such as a dry Mediaeval Warm Period (MWP; AD 1000-1200) and a relatively drier climate during the main phase of the Little Ice Age (LIA; c. AD 1500-1800); though lake levels in western Uganda do fluctuate, with a high stand c. AD 1575-1600). The general trends support the hypothesis of an east to west (wet to dry) gradient across East Africa during the LIA, however, the relationship breaks down and is more complex towards the end of the LIA (c. AD 1700-1750) when the inferred changes in lake levels at Nyamogusingiri and Kyasanduka are synchronous with changes observed at Lakes Naivasha (Kenya) and Victoria and diverge from local lake level records (from Edward, Kasenda and Wandakara). Significant changes in the lake ecosystems have occurred over the last 50-75 years, with major shifts in diatom assemblages to benthic-dominated systems and an inferred increase in nutrient levels. These changes are coincident with large sediment influx to the lakes, perhaps as a result of increasing human activity within many of the lake catchments.