Records from the Quaternary period are used to confirm possible inferred climatic changes, reveal the responses of species to these changes, and serve as an archive against which modern environmental dynamics can be assessed. Fueled by a need to understand current climatic changes, the call for palaeoclimatic research in the southern African subregion has become more compelling. In southern Africa, such research has been largely restricted to springs and swamps as the subregion lacks natural lakes, with some exception of a few coastal lakes such as Lake Sibaya and Lake Eteza. Due to the arid and semi-arid landscapes which prevail in southern Africa, there is a paucity of suitable sedimentary deposits in the region. The highly organic peat deposit of Mutale Wetland, situated in the Tate Vondo region of the northeastern Soutpansberg presents an ideal opportunity for conducting palaeoenvironmental research. The Mutale Wetland contains relatively old sediments dating back to >30,000 cal years BP, placing this record within the late Quaternary period. Palaeoenvironmental techniques including radiocarbon, pollen and charcoal analyses were applied to produce a palaeoenvironmental reconstruction for Tate Vondo. A 302 cm sedimentary core was extracted from the Mutale Wetland. Detailed analyses show that prior to ca. 34,000 cal yr BP, conditions were fairly warm and dry. This is inferred from a dominance of open grassland vegetation. An expansion of Podocarpus forests together with an increase in fynbos elements suggest a shift to cool, subhumid conditions during the LGM. Cooler conditions persisted until ca. 12,000 cal yr BP. Thereafter, a climatic amelioration was experienced. The appearance of low charcoal concentrations throughout the late Pleistocene suggests that fire was infrequent. Between ca. 4000 – 1500 cal yr BP, conditions became warmer and drier, inferred from the development of arid savanna vegetation. The sharp increase in charcoal after ca. 4000 cal yr BP, broadly coinciding with the arrival of the first agriculturalists in the area, has implications for the history of human occupation in the Soutpansberg rather than shifts in climate. The succession from savanna to fynbos vegetation together with expanded forests implies a return to cool and moist conditions from ca. 1500 – 400 cal yr BP. Arid savanna persists from ca. 400 to the present, implying warmer and drier conditions towards the present day. Furthermore, from ca. 400 cal yr BP, the pollen and charcoal record indicate that the majority of recent changes in vegetation have been driven by anthropogenic activity. This record has contributed to an improved understanding of late Quaternary changes in climate, vegetation history and human impact in the northeastern Soutpansberg. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2014.

A high-resolution pollen record from Path Lake (43°87’00”N, 64°92’42”W, 10m asl) in Port Joli Harbour, Nova Scotia, Canada, was used to provide a paleo-ecological perspective on Holocene climate and vegetation variability within the context of local archaeological research. Pollen assemblages in the early Holocene reflect a post-glacial forest dominated by Pinus, Tsuga, Betula and Quercus. Shallow water aquatic and wetland taxa increased after 3400 cal. yr. BP in response to wetter climatic conditions. Increased settlement intensity of native inhabitants coincides with late-Holocene climate change at a regional scale, suggesting that environmental conditions may have influenced prehistoric human activities. European settlement, after 350 cal. yr. BP, was marked by a rise in Ambrosia, and peak charcoal accumulation rates after this time showed evidence of human disturbance on the landscape. This study suggests that environmental changes affected human exploitation of the landscape, and human activity altered forest composition in the late Holocene.

This investigation uses dendrochronologic and radiometric techniques to infer the timing of glacier advance for four ice lobes that are drained by Manatee Creek in a remote valley located in the southern Coast Mountains, British Columbia. Dendroglaciologic evidence exposed by retreating glaciers provides evidence for increasing complexity in the Holocene glacial record, particularly for mid-late Holocene events. Since Holocene ice fronts periodically extended below treeline in the region, previous glacier advances overrode and buried forests beneath till deposits. The dendroglaciologic evidence presented here corroborates the record of glacier advances described for other southern British Columbia Coast Mountain glaciers and details ice front position at ca. 4270 14C yr BP, 3430 14C BP and 2350 14C yr BP. Well-preserved sequences of lateral, nested moraines were mapped and profiled to delineate the boundaries of Manatee and Oluk glaciers. Relative dates provided by lichenometry and dendrochronology were used as limiting dates for the deposition of 5-6 moraines during the late 14th, early 16th, early 18th, 19th, and early-20th Century. Reconstructions of Holocene glacial history offer insight into the regional, climatic regime and add to the discussion about pervasive, millennial-scale cycles.

The intent of the research described in this thesis was to reconstruct and document Holocene glacier activity in the central British Columbia Coast Mountains. Despite ongoing efforts to describe glacier fluctuations in the southern and northern Coast Mountains, only limited attention has been directed to revealing the Holocene histories of glaciers in the central Coast Mountain region. The goals of this research were twofold: firstly, to describe mid-Holocene glacier advances at five remote glacier sites in the central Coast Mountains, and secondly, to detail Little Ice Age (LIA) glacier fluctuations at four glacier sites in the central Coast Mountains. The mid-Holocene behaviour of Canoe, Fyles, Jacobsen, Tchaikazan and Icemaker glaciers was investigated using dendroglaciological techniques and stratigraphic analysis. Subfossil wood evidence suggests these glaciers were expanding into standing forests prior to 6.63, 4.90 and 4.20 ka. Stratigraphically constrained woody detritus at Fyles Glacier records the progradational history of a Gilbert-type delta forming in response to glacial expansion between 7.02-5.47 ka. Glacial expansion occurring between 7.50-4.00 ka has regional correlatives, suggesting coherent broad-scale climate forcing mechanisms influenced glacial mass balance at this time. Insight into the LIA behaviour of central Coast Mountain glaciers was provided by conducting lichenometric surveys of Rhizocarpon spp. across LIA moraines at Pattullo, Fyles, Deer Lake and Jacobsen glaciers. The presence of a second, lesser known, lichen species at some sites necessitated the construction of a Xanthoria elegans growth curve. An assessment of lichenometric measurements from the southern and central Coast Mountains provided the opportunity to build a X. elegans growth curve constrained by 18 control points. Lichenometric surveys revealed dominant moraine building episodes at 890-1020, 1280-1320, 1490-1530, 1680-1720, 1780 and 1820-1870 AD, highlighting the complex nature of glacier fluctuations during the LIA. A regional subalpine fir tree-ring chronology (1610-2010 AD) was developed from four stands located in the central Coast Mountains for dendroclimatological investigations. Correlation analyses show that the radial growth of trees corresponded to variations in the mean June/July air temperature and May 1st snowpack. This relationship was used to reconstruct these climate parameters for the duration of the tree-ring record. Intervals of cooler summer air temperatures and above average snowpack were found to broadly correspond with dominant periods of LIA moraine building from 1610-1930 AD. This reconstruction of mid-Holocene and LIA glacial history offered insights consistent with the emerging record of glacial activity described for the southern Coast Mountain glaciers. It also provides the first evidence for mid-Holocene glacial expansion in the central and northern Coast Mountains. The application of lichenometry in the central Coast Mountains documents the regional LIA behaviour of glaciers and the construction of a Xanthoria elegans growth curve for the Coast Mountains provides a framework for future geobotanical dating using this species. / Graduate

Paleoecological analyses of an alkaline fen in the southern Interior Plateau of British Columbia, Canada were undertaken in association with ancient earth ovens. Local and regional vegetation and natural disturbance regimes were reconstructed using pollen, plant macrofossils and macroscopic charcoal. At White Rock Springs, Artemisia-Poaceae steppe occurred in the early Holocene and the inferred climate from this period was warmer and drier than present. Increasing moisture at 6000 14C yr BP fostered development of open Pinus ponderosa forests surrounding the fen, with Pinus contorta var. latifolia expanding at higher elevations. A slope-wash event likely resulting from root processing activities occurred in the late Holocene that resulted in 13% Asteraceae Tubuliflorae pollen at 2200 ± 80 14C yr BP. Macroscopic charcoal concentrations increased following this disturbance. Shortly after this time a modern open mixed conifer forest with Pseudotsuga menziesii was likely established. A second major ecological disturbance perhaps occurred within the last 200 years as indicated by fluctuating pollen values of P. ponderosa, Poaceae, Asteraceae Liguliflorae and wetland species. The fen’s vegetation history is consistent with regional records, but rapid changes during the late Holocene apparently occurred in response to disturbances. These disturbances are most likely linked to human root food harvesting and earth oven use, and later to ranching. Differentiation of P. ponderosa and P. contorta pollen types reveals intervals of local forest change that were not detected in previous studies. This study is part of a larger research project at Upper Hat Creek Valley including lithics, phytoliths, and patterns of earth oven structure. / Graduate

The major objective of this thesis was to produce descriptions of the land vegetation-cover in Europe for selected time windows of the Holocene (6000, 3000, 500, 200, and 50 calendar years before present (BP=1950)) that can be used in climate modelling. Land vegetation is part of the climate system; its changes influence climate through biogeophysical and biogeochemical processes. Land use such as deforestation is one of the external forcings of climate change.  Reliable descriptions of vegetation cover in the past are needed to study land cover-climate interactions and understand the possible effects of present and future land-use changes on future climate. We tested and applied the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) model to estimate past vegetation in percentage cover over Europe using pollen records from lake sediments and peat bogs. The model corrects for the biases of pollen data due to intraspecific differences in pollen productivity and pollen dispersion and deposition in lakes and bogs. For the land-cover reconstructions in Europe and the Baltic Sea catchment we used 636 (grouped by 1˚x1˚ grid cells) and 339 (grouped by biogeographical regions) pollen records, respectively. The REVEALS reconstructions were performed for 25 tree, shrub and herb taxa. The grid-based REVEALS reconstructions were then interpolated using a set of statistical spatial models. We show that the choice of input parameters for the REVEALS application does not affect the ranking of the REVEALS estimates significantly, except when entomophilous taxa are included. We demonstrate that pollen data from multiple small sites provide REVEALS estimates that are comparable to those obtained with pollen data from large lakes, however with larger error estimates. The distance between the small sites does not influence the results significantly as long as the sites are at a sufficient distance from vegetation zone boundaries. The REVEALS estimates of open land for Europe and the Baltic Sea catchment indicate that the degree of landscape openness during the Holocene was significantly higher than previously interpreted from pollen percentages. The relationship between Pinus and Picea and between evergreen and summer-green taxa may also differ strongly whether it is based on REVEALS percentage cover or pollen percentages. These results provide entirely new insights on Holocene vegetation history and help understanding questions related to resource management by humans and biodiversity in the past. The statistical spatial models provide for the first time pollen-based descriptions of past land cover that can be used in climate modelling and studies of land cover-climate interactions in the past.

The purpose of this study is to present the results of mineralogical and petrochemical analyses of the solid phase components and the inorganic chemistry of the interstitial waters of the Recent anoxic sediments of Kaneohe Bay, Oahu. Nineteen shallow 1-4 meter gravity cores of the lagoonal sediments of Kaneohe Bay were analyzed for pore water chemistry and seven were subjected to detailed mineralogical and petrochemical analyses. The pore waters of the sediment column show depletions in dissolved SO =4, Ca++, Mg++ and Sr++ accompanied by increases in titration alkalinity, NH4 + , PO 4 -3 and Si02 with respect to the overlying seawater with increasing subbottom depth. Na+, Cl-, K+ and Fetot exhibit minor departures from overlying bay waters assuming that depletions of Na+ and Cl- are the result of an influx of meteoric ground water from beneath the bay's floor. The bay may be divided into two parts on the basis of the rates of pore water diagenesis: in the southern part of the bay, S0 =4 is completely depleted within 80cm subbottom depth, whereas in the northern part, complete S0 =4 reduction does not occur at depths to 350cm. The southern sediments are contaminated by raw, high C/N sewage, resulting in an increased metabolic reduction rate of S0 =4 by anerobic bacteria over that observed in the unpolluted northern bay. Calculation of S0 =4 consumed versus alkalinity plus NH=4 produced indicates a relationship in which roughly one-half of the "produced alkalinity" has been consumed in the formation of authigenic minerals, primarily nontronite and aragonite. Quantitative mineralogical and petrochemical analyses of the solid phase components reveal the loss of amorphous iron-oxyhydroxides, biogenic opaline silica, and amorphous aluminosilicate with increasing subbottom depth. Pyrite formation occurs immediately below the sedimentwater interface. Scanning Electron Microscope observations show a hierarchy of morphologies with depth: single l-micron crystals to 30- micron diameter framboids. Pyrite formation accounts for the lack of detectable S= within the pore waters and is dependent on the availability of pore water iron derived from the dissolution of amorphous iron-oxyhydroxides. The amount of pyrite present below 40cm subbottom depth exceeds the amount which could be formed by the complete reduction of buried pore water S0=4 suggesting the importance of bioturbation in the mixing of pore and overlying seawaters. Authigenic nontronite and mixed-layer smectite-illite are being formed as the result of the reaction of amorphous aluminosilicate with pore water Si02 from opal dissolution and pore water Fe and/or other cations. In those cores where sufficent dissolved iron exists in the pore water, nontronite forms, whereas when dissolved iron is not present as evidenced by the presence of dissolved S= in the pore water, a mixed-layer smectite-illite is formed. The amount of smectite formed is limited by the amount of opal which dissolves. For Kaneohe Bay sediments an average of 0.12 weight percent authigenic smectite is added annually to the sediment column. Minor amounts of authigenic plagioclase, phillipsite, clinoptilolite, analcime, sepiolite, siderite and apatite are also being formed within the sediments. The relationship between reduced pore water Fe and smectite formation suggests that reverse weathering reactions resulting in either authigenic nontronite or mixed-layer smectite-illite may occur in all anoxic marine sediments rich in terrigeneously-derived, poorly-crystalline "kaolinite" and containing enriched pore water Si02. Assuming that 10 percent of the total flux of the world river sediments delivered to the ocean is deposited in Kaneohe Bay-type environments and that rates of reaction are similar to those observed in Kaneohe Bay, then approximately 6 percent of the CO2 consumed by rock weathering may be returned annually to the atmosphere by these reactions. / Bibliography: leaves 258-281.

Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The aims of this investigation on the Holocene carbonate successions of three shallow, ephemeral lakes from the Cooring coastal plain were: to determine the timing of the sapropel ’events’ in the three lakes; to determine the origin of the sapropelic organic matter and evaluate changes; to establish whether sapropel deposition in these shallow, coastal lakes primarily reflects increased organic matter delivery to the sediments during periods of enhanced terrestrial input and/or aquatic productivity, and; to relate sapropel deposition in these three lakes to both regional and global palaeoenvironment reconstructions. --p. 23-24. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1324064 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The aims of this investigation on the Holocene carbonate successions of three shallow, ephemeral lakes from the Cooring coastal plain were: to determine the timing of the sapropel ’events’ in the three lakes; to determine the origin of the sapropelic organic matter and evaluate changes; to establish whether sapropel deposition in these shallow, coastal lakes primarily reflects increased organic matter delivery to the sediments during periods of enhanced terrestrial input and/or aquatic productivity, and; to relate sapropel deposition in these three lakes to both regional and global palaeoenvironment reconstructions. --p. 23-24. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1324064 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

This thesis resulted in the development of robust chironomid-based transfer-functions for February mean air temperature and the concentration of total nitrogen (TN) in lake-water. The New Zealand transfer-functions for both variables compare favourably with chironomid-based transfer-functions for equivalent variables from elsewhere in the world, and diatom-based transfer-functions for nutrients and lake production from New Zealand. The application of the temperature and TN transfer-functions provided insight into New Zealand climate conditions during the last glacial and served as validation for the reconstructions. Chironomid-based Temperature reconstructions from lake silts preserved in the banks of Lyndon Stream indicate a maximum cooling of ca 4 ℃ between 26.6 and 24.5 ka BP, which is consistent with estimates based on beetles and plant macrofossils. A cooling of 4 ℃ is insufficient to explain the lack of canopy tree pollen in many New Zealand pollen records at this time. Other environmental parameters additional to temperature may have limited the expansion forest cover. The chironomid-based TN reconstructions infer a trend of rapidly deteriorating water-quality in a small doline in north-west Nelson, in the South Island of New Zealand following deforestation immediately surrounding the lake ca. 1970 AD. The overall trend and timing of eutrophication inferred from the chironomids was consistent with other biological proxies and actual observations of changes in lake water quality. The chironomid-based transfer-functions provide a valuable new tool for the study of longterm climate variability and improving our understanding of the response of aquatic ecosystems to long-term natural and human induced environmental change in New Zealand lakes. I have identified some possibilities for future research which should improve the performance of these transfer-functions. The improvement of the chironomid taxonomy and the expansion of the training set should be the highest priorities.