Our knowledge of whether hurricanes cause lasting changes in forest composition and the patterns and role of fire in Caribbean dry forests are lacking. This project combines paleoecological and paleotempestological methods to document the disturbance and environmental history of the last 1000 yrs at Laguna Alejandro, situated in the lowland dry forests of arid SW Dominican Republic. I analyzed multiple proxy data sources of a 160 cm coastal lagoon sediment profile. High-resolution (1 cm) sampling for loss-on-ignition and magnetic susceptibility indicated multiple erosion and hurricane events, including a hurricane ~996 cal YBP, and several erosion events and hurricanes between ~321 cal YBP and present day. Pollen analysis documented 32 plant families with most levels dominated by pollen of Fabaceae (legumes), the Urticales order, and Cyperaceae (sedges), though families of upland and montane vegetation are also present ~510-996 cal YBP. All pollen slides contained microscopic charcoal indicating the occurrence of regional or extra-local fires over the last ~1000 yrs. Local fires, as indicated by macroscopic charcoal, occurred before ~434 cal YBP and may be tied to hurricanes, increased moisture in the region (thereby increased fuel and ignition chances), or prehistoric human activities. Pollen spectra representing periods before and after disturbance events were similar and may support the idea of forest resilience, but more samples are needed. Multiple erosion events between ~294 cal YBP and present may be tied to hurricanes or tropical storms and increasing late-Holocene aridity in the region as documented by several studies from the Caribbean. / Master of Science

Landscape transformation that occurred during the Middle Ages in western and central Europe is reflected in all pollen diagrams. An event that was so striking and widespread was used by Firbas to distinguish a biostratigraphical period called the Younger Subatlantic (zone X; Firbas 1949). High Medieval landscape transformation is connected with rapid colonization in our area that resulted in extensive deforestation and intensified agriculture. During the first half of the 13th century, the settlement network was already stabilized and was very similar to the current state and was reaching also mountain areas (Klápště 1994). New organization and changes in land ownership, as well as a need for more effective agriculture, resulted in the connecting of small fields into larger ones and in an increase of cultivated area (Klápště 2006). The use of the land was different, and for the first time complete (Bakels 2009). During a few centuries anthropogenic factors that were enormously enhanced throughout the 13th century, formed a cultural landscape that was much more similar to the landscape of today than to the landscape of, for instance, the 9th century. This doctoral thesis is focused on the Early Medieval landscape in the Czech lands and its transformation that culminated during the 13th and 14th...

<p>This thesis focuses on dwelling sites with hearths dating from the period 600-1900 AD, located in the coniferous forest areas of Northern Sweden. The term dwelling sites with hearths refers to sites where stone-lined hearths occur. These hearths are of a type that became very common in Northern Sweden during the first millennium after the birth of Christ.</p><p>The main aim of this study is to apply environmental archaeological methods to the investigation of dwelling sites with hearths in order to attain new information on the organisation and use of these sites, as well as to discuss and evaluate earlier strategies of settlement and subsistence. For this study, soil chemical survey and pollen analysis methods are used. Soil chemical surveys have been conducted at a total of 13 sites from the period 1000/1100-1900 AD at locations in the inland areas of the counties of Norrbotten, Västerbotten and Jämtland, while pollen analyses have been conducted at 4 sites located in the county of Norrbotten.</p><p>Interpretations of the results are related to previous archaeological research, surveys and excavations. In addition, historical and ethnographical documentation as well as historical research concerning the conditions in the area during later periods are considered.</p><p>The results show that environmental archaeological methods can provide information about settlements with hearths that is not normally possible to discern through archaeological surveys or excavations. Regarding the environmental impact at the settlement areas, there are clear differences between different dwelling sites with hearths. These differences seem to be independent of the number of hearths at the sites. Thus, it is not possible to make interpretations regarding these dwelling sites based purely on the number of hearths at the sites. The results also imply that these sites have been part of a settlement system where different types of dwelling sites were in use for shorter periods of time, for different purposes, and by a limited number of people. With the exception of the 17th century church and market place in Arvidsjaur, none of the examined dwelling sites could be interpreted as being a gathering site for a large number of people. Compared to descriptions of the conditions in the Sami area (Sa. Sápmi) during historical periods, this type of settlement pattern is comparable to the Forest Sami settlement pattern of late historical times. Moreover, soil chemical surveys conducted in areas adjacent to a number of hearths show similarities to the Sami hut (Sw. kåta). </p><p>To sum up, the use of dwelling sites with hearths shows continuity from the 7th century settlements to Sami settlements of the 20th century, with respect to the environmental impact at the dwelling sites. On the basis of these results, it is suggested that a settlement pattern and subsistence similar to that of the Forest Sami economy and settlement of late historical times are characteristic for settlements with hearths and may have occurred as early as 600 AD.</p>

<p>In quantitative palaeoecology modern species-environmental relationships can be statistically modelled, and recent development has made the calibration models more statistically robust. These models are used to transform fossil assemblages to quantitative estimates of past environmental conditions. The aim of this thesis is to infer Holocene temperatures from fossil pollen data sampled from lakes in central and southern Sweden. This reconstruction is done by using a north-European pollen-climate calibration model, which was extended with 37 modern pollen samples from the southern deciduous vegetation zone in Sweden within this project. A statistical method is used for deriving the pollen-climate calibration model, weighted averaging partial least square (WA-PLS) method. The long term trends in pollen inferred temperatures from this study reflect low, but rapidly rising temperatures in the early-Holocene, a trend that was temporarily interrupted by a cool period about 8500 cal yr BP, but continued after 8000 cal yr BP. A Holocene thermal maximum (HTM) with temperatures roughly 2°C higher than at present was recorded about 7000 cal yr BP and by 4000 cal yr BP pollen inferred temperatures starts to decline. In order to create a more comprehensive picture of past climate patterns in the investigated area inferred temperatures from this study are compared with independent palaeorecords, a stable oxygen isotope record for moisture variability (paper I) and chironomids for summer temperature (paper II). Taken all together, these records reflect a coherent Holocene climate pattern which also is supported by several studies from Scandinavia and the north Atlantic region. Pollen inferred temperatures and the moisture record are indicating markedly dry, continental climate conditions in southern Sweden during the HTM possibly as a result of reorganisations in regional atmosphere circulations. The local observations in this study of regional climate events, such as the cold period at about 8200 cal yr BP and the dry period at about 7000 to 4000 cal yr BP are of particular interest because they suggest that vegetation in the study region has responded sensitively both to long-term climatic trends and more transient climate events.</p>

This thesis focuses on dwelling sites with hearths dating from the period 600-1900 AD, located in the coniferous forest areas of Northern Sweden. The term dwelling sites with hearths refers to sites where stone-lined hearths occur. These hearths are of a type that became very common in Northern Sweden during the first millennium after the birth of Christ. The main aim of this study is to apply environmental archaeological methods to the investigation of dwelling sites with hearths in order to attain new information on the organisation and use of these sites, as well as to discuss and evaluate earlier strategies of settlement and subsistence. For this study, soil chemical survey and pollen analysis methods are used. Soil chemical surveys have been conducted at a total of 13 sites from the period 1000/1100-1900 AD at locations in the inland areas of the counties of Norrbotten, Västerbotten and Jämtland, while pollen analyses have been conducted at 4 sites located in the county of Norrbotten. Interpretations of the results are related to previous archaeological research, surveys and excavations. In addition, historical and ethnographical documentation as well as historical research concerning the conditions in the area during later periods are considered. The results show that environmental archaeological methods can provide information about settlements with hearths that is not normally possible to discern through archaeological surveys or excavations. Regarding the environmental impact at the settlement areas, there are clear differences between different dwelling sites with hearths. These differences seem to be independent of the number of hearths at the sites. Thus, it is not possible to make interpretations regarding these dwelling sites based purely on the number of hearths at the sites. The results also imply that these sites have been part of a settlement system where different types of dwelling sites were in use for shorter periods of time, for different purposes, and by a limited number of people. With the exception of the 17th century church and market place in Arvidsjaur, none of the examined dwelling sites could be interpreted as being a gathering site for a large number of people. Compared to descriptions of the conditions in the Sami area (Sa. Sápmi) during historical periods, this type of settlement pattern is comparable to the Forest Sami settlement pattern of late historical times. Moreover, soil chemical surveys conducted in areas adjacent to a number of hearths show similarities to the Sami hut (Sw. kåta). To sum up, the use of dwelling sites with hearths shows continuity from the 7th century settlements to Sami settlements of the 20th century, with respect to the environmental impact at the dwelling sites. On the basis of these results, it is suggested that a settlement pattern and subsistence similar to that of the Forest Sami economy and settlement of late historical times are characteristic for settlements with hearths and may have occurred as early as 600 AD.

In quantitative palaeoecology modern species-environmental relationships can be statistically modelled, and recent development has made the calibration models more statistically robust. These models are used to transform fossil assemblages to quantitative estimates of past environmental conditions. The aim of this thesis is to infer Holocene temperatures from fossil pollen data sampled from lakes in central and southern Sweden. This reconstruction is done by using a north-European pollen-climate calibration model, which was extended with 37 modern pollen samples from the southern deciduous vegetation zone in Sweden within this project. A statistical method is used for deriving the pollen-climate calibration model, weighted averaging partial least square (WA-PLS) method. The long term trends in pollen inferred temperatures from this study reflect low, but rapidly rising temperatures in the early-Holocene, a trend that was temporarily interrupted by a cool period about 8500 cal yr BP, but continued after 8000 cal yr BP. A Holocene thermal maximum (HTM) with temperatures roughly 2°C higher than at present was recorded about 7000 cal yr BP and by 4000 cal yr BP pollen inferred temperatures starts to decline. In order to create a more comprehensive picture of past climate patterns in the investigated area inferred temperatures from this study are compared with independent palaeorecords, a stable oxygen isotope record for moisture variability (paper I) and chironomids for summer temperature (paper II). Taken all together, these records reflect a coherent Holocene climate pattern which also is supported by several studies from Scandinavia and the north Atlantic region. Pollen inferred temperatures and the moisture record are indicating markedly dry, continental climate conditions in southern Sweden during the HTM possibly as a result of reorganisations in regional atmosphere circulations. The local observations in this study of regional climate events, such as the cold period at about 8200 cal yr BP and the dry period at about 7000 to 4000 cal yr BP are of particular interest because they suggest that vegetation in the study region has responded sensitively both to long-term climatic trends and more transient climate events.

The overall aim of this thesis was to explore the impact of environmental changes (relative sea level increase and climate) on coastal communities and to investigate how these environmental factors controlled subsistence economies through the Holocene. The hypothesis tested was that relative sea level rise is a key factor influencing location and subsistence strategies of coastal communities throughout the Holocene and that, due to environmental conditions, these changes will be more evident in islands. The Isles of Scilly, located 27 miles off the south west coast of England, provide a good case study for the response of communities to marine inundations and environmental changes. This project aimed also to obtain a high resolution record of vegetation and storminess during the last 3000 years in Scilly, with a robust chronological setting, and also to offer an accurate shape of the coastline of Scilly since the early Holocene. Three terrestrial pollen stratigraphic sequences from the Isles of Scilly were obtained, covering the past 3000 years, from the two main wetland areas of Scilly (one in Higher Moors and two in Lower Moors) with the potential to reveal changing patterns of vegetation reflecting intensity and type of land use. Detailed palaeoenvironmental interpretation has been provided by high resolution pollen analysis. These pollen diagrams suggest that the landscape of Scilly has been an open landscape, heavily managed for both pastoral and arable agriculture since the Bronze Age. There is evidence that the climate during the Holocene period was highly varied. The occurrence of blown sand in the sample cores has been used as an indicator of past storm intensity, by high resolution particle size analysis and Loss-On-Ignition. The three cores show dissimilarities in the storminess indicator during the same periods. It is argued that this reflects that sand deposition and transport is highly site specific and controlled by topography, sediment availability, wind directions and vegetation cover. An important part of this thesis was to determine the impact of relative sea level rise in Scilly and the extent of the islands over time. A new sea level curve for Scilly has been generated through GIA (Glacial Isostatic Adjustments) using the Bradley et al (2011) method. Palaeogeography maps were produced applying the sea level curve to a new combined bathymetric and topographic model for Scilly. Scilly separated from the mainland around 11500 cal BP, and the islands obtained their modern configuration around 4000 cal BP. The palaeogeography, palaeoecological and the archaeological records of Scilly show that changes in the coastal configuration and storminess had little apparent influence on society from the 1st millennium AD into medieval times. Both, the archaeological and palaeoenvironmental record, have demonstrated that Scillonian societies had a strong resilience and were able to adapt to environmental changes by diversifying their economic strategies and taking advantage of the new conditions, such as new coastal margins. This adaptability was strong until the development of more complex societies and major land reduction conditions that probably led to a tipping point in resilience. There is no apparent discontinuity in land-use on Scilly during the last 3,000 years, although there have been important social and environmental changes.

Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined. / Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai.

Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai. / Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined.

Pollen and charcoal analyses were used to reconstruct the Holocene vegetation and fire history of Pender Island (48°46’59” N, 123°18’11” W), located in the southern Gulf Islands on the south coast of British Columbia. A 9.03 m sediment core was retrieved from Roe Lake, a small, deep lake on Pender Island. Four AMS radiocarbon ages, the stratigraphic position of the Mazama tephra and a series of 210Pb ages were used to produce an age-depth model that estimated the base of the sediment core to be 9880 ± 126 calendar years before present (cal yr BP). The vegetation history from Roe Lake is similar to other paleoecological studies from the region. The early Holocene (10,000-7500 cal yr BP) was characterized by mixed woodlands with abundant Pseudotsuga menziesii and a diverse understory that included abundant Salix shrubs and Pteridium aquilinum ferns in these open canopy communities. An open Quercus garryana-dominated community with Acer macrophyllum and Arbutus menziesii in the canopy and xeric associations in the understory occurred from 7500-5500 cal yr BP. By 3500 cal yr BP, modern mixed Pseudotsuga menziesii forests with an increasingly closed canopy were established on Pender Island. Charcoal analyses of the uppermost sediments revealed low charcoal accumulation in the Roe Lake sediment core over the last 1300 years with a mean fire return interval of 100 years for the period before modern fire suppression, suggesting that fire was not a major control on plant community composition on Pender Island on this timescale. Fires were more frequent (i.e., every 47 years on average) during the Medieval Climate Anomaly with warm, dry conditions facilitating a higher fire frequency. Few fires (i.e., every 141 years on average) occurred between 1200-1850 AD, coinciding with the Little Ice Age. As climate was cooler and wetter during the Little Ice Age, fires during this time may reflect intentional burning by First Nations. In general, changes in vegetation and fire dynamics on Pender Island correlate well with changes in climate throughout the Holocene period, suggesting that climate change was likely the principal mechanism driving plant community composition and changes in the fire regime. / Graduate