Palaeochannels of the Exe catchment Their age and an assessment of their archaeological and palaeoenvironmental potential

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Mid- to late-Holocene vegetation history of Greater Exmoor, UK: estimating the spatial extent of human-induced vegetation change

This paper presents the results from three pollen profiles from a group of small spring mire sites on the southern edge of Exmoor in south west England. The size and topography of these sites allow detailed local landscape histories around each site to be reconstructed which broadly cover the mid- to late-Holocene. Comparison of the individual local landscape histories demonstrates the scale of spatial variation in vegetation around the upland edge, and facilitates understanding of human-landscape interactions from the early Neolithic onward. In the early Neolithic significant short-term woodland disturbance is recorded around the upland fringe, including clearance of oak-hazel-elm woodland, suggesting that the shift from Mesolithic to Neolithic is not marked by a gradual environmental transition. Following this, there is clear evidence of Neolithic management of upland heath using fire, presumably for the management of upland grazing. Woodland clearances are recorded throughout the later Prehistoric period; however, the use of multiple profiling suggests that woodland clearance is spatially discrete, even within an area of 4 km2. Pastoral land use is dominant around the uplands until around 900–1,000 a.d., and there is no discernible Roman or post-Roman period impact in the vegetation, suggesting cultural stability from the late Iron Age to the early Medieval period. By 1,100 a.d., there is a shift to mixed arable-pastoral farming which appears to continue well into the post-Medieval period

Beyond villages and open fields: the origins and development of a historic landscape characterized by dispersed settlement in South-West England

Pollen evidence has, to date, made little contribution to our understanding of the origins and development of the medieval landscape. Compared to the prehistoric period, relatively few long palaeoenvironmental sequences provide a continuous record for the past two millennia, and those that have been analysed are mostly located in upland locations that lay beyond areas settled during this period. The nine sequences reported here from central Devon and the edges of Exmoor start to redress that imbalance. They suggest substantial clearance of woodland in lowland areas and the upland fringe by the Late Iron Age, and that the incorporation of this region into the Roman world had little impact on patterns of landscape exploitation. In a region that lay beyond the main area of Romanisation, it is not surprising that the 5th century saw little discernible change in management of the landscape. These palaeoenvironmental sequences suggest that around the 7th-8th centuries, however, there was a significant change in the patterns of land-use, which it is suggested relates to the introduction of a regionally distinctive system of agriculture known as 'convertible husbandry'. This may also have been the context for the creation of today's historic landscape of small hamlets and isolated farmsteads set within a near continuous fieldscape, replacing the late prehistoric/Romano-British/post-Roman landscape of small, enclosed settlements with only very localised evidence for field systems. This transformation appears to be roughly contemporary with, or even earlier than, the creation of nucleated villages in the 'Central Province' of England, suggesting that the 'great replanning' was just one of several regionally distinctive trajectories of landscape change in the later 1st millennium A.D

Vegetational change and human activity in the Exe Valley, Devon, UK

This paper presents the results of the first investigation of vegetation change and human activity from a river valley west of the Somerset Levels. The record is contrasted with the pollen and archaeological record from South West uplands (Dartmoor and Exmoor) and the Somerset Levels. Vegetation change and archaeological evidence are shown to be generally consistent, with evidence from the middle valley of Mesolithic vegetation disturbance (with nearby lithics), Neolithic clearance of terraces and slopes in the lower valley and Neolithic-Bronze Age ceremonial and domestic activity, but in the upper reach the maintenance of wooded valley floor conditions probably with management until historic times. The valley floor and surrounding slope vegetation history is found to be significantly different to that of the uplands with lime and elm being significant components of the prehistoric woodland record. The data suggest that lime is restricted to terraces and lowlands below 200 metres OD throughout the prehistoric period. The pollen data from the valley suggests the lowlands had a rich and mixed ecology providing a wide range of resources and that, despite less visible archaeological remains, human activity is manifest through palynological evidence from the Mesolithic to the Bronze Age. The largest expanse of valley-floor terrace, the Nether Exe Basin, which was at least partially deforested in the early Neolithic contains a rich assemblage of Neolithic-Bronze Age ceremonial, funerary and domestic archaeology associated with an early and clear palynological record of woodland clearance, arable and pastoral activity

European forest cover since the start of Neolithic agriculture: a critical comparison of pollen-based reconstructions

International audienceEurope was extensively wooded prior to the arrival of Neolithic agriculture. Forests have since been cleared and fragmented by humans. Here we compare different approaches to transforming fossil pollen data into quantitative past forest cover estimates on a continental scale

Semi-automatic Measure and Identification of Allergenic Airborne Pollen

Part 6: Classification Pattern RecognitionInternational audienceCurrent lifestyle in developed countries makes the practice of outdoor activities to be almost mandatory. But, since these practices such as trekking, biking, horseback, or simply running or walking in urban parks, are made in nature (at least outdoors) not everyone can practice them in optimal physical conditions at any time of the year. We are referring to those who suffer from pollinosis or “hay fever”.This work present the first stages in the development of a semi-automatic system for counting and identifying airborne pollen, using artificial intelligence techniques for recognizing four of the most representative allergenic pollen types. The system consists of a first stage for the location of pollen grains in the slides, and a second whose goal is the identification using Independent Component Analysis (ICA) and neural nets or SVM. The overall success results achieved with our system are about 88%, averaging for all classes

Past regional vegetation cover of Britain and Ireland.

The vegetation of Europe has undergone substantial changes during the course of the Holocene epoch, resulting from range expansion of plants following climate amelioration, competition between taxa and disturbance through anthropogenic activities. Much of the detail of this pattern is understood from decades of pollen analytical work across Europe, and this understanding has been used to address questions relating to vegetation-climate feedback, biogeography and human impact. Recent advances in modelling the relationship between pollen and vegetation now make it possible to transform pollen proportions into estimates of vegetation cover at both regional and local spatial scales, using the Landscape Reconstruction Algorithm (LRA), i.e. the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) and the LOVE (LOcal VEgetation) models. This paper presents the compilation and analysis of 73 pollen stratigraphies from the British Isles, to assess the application of the LRA and describe the pattern of landscape/woodland openness (i.e. the cover of low herb and bushy vegetation) through the Holocene. The results show that multiple small sites can be used as an effective replacement for a single large site for the reconstruction of regional vegetation cover. The REVEALS vegetation estimates imply that the British Isles had a greater degree of landscape/woodland openness at the regional scale than areas on the European mainland. There is considerable spatial bias in the British Isles dataset towards wetland areas and uplands, which may explain higher estimates of landscape openness compared with Europe. Where multiple estimates of regional vegetation are available from within the same region inter-regional differences are greater than intra-regional differences, supporting the use of the REVEALS model to the estimation of regional vegetation from pollen data