Climate Change and Human Impact on the Landscape Studies in palaeoecology and environmental archaeology

I am pleased to present this volume of invited reviews and research case studies, produced to mark the retirement of Professor A. G. Smith - one of the leading researchers in Holocene palaeoecology. A. G. Smith took his first degree at the University of Sheffield, graduating in 1951 with a first-class honours degree in Botany. His doctorate was awarded in 1956 for a study in late-Quaternary vege­ tational history, based in the Sub-Department of Quaternary Research at the University of Cambridge, under the supervision of the late Sir Harry Godwin, FRS. He then researched and taught at Queen's University, Belfast, from 1954, leading the Nuffield Quaternary Research Unit there, becoming Co-Director of the Palaeoecology Laboratory from 1964. He was appointed Professor and Head of the Department of Botany (later, Plant Science) at University College, Cardiff, in 1973, and retired from the School of Pure and Applied Biology at the renamed University of Wales College, Cardiff, in August 1991. Although his principal interests have been concerned with the post-glacial environmental history of the British Isles, Professor Smith has significantly in­ fluenced many researchers elsewhere in their interpretation of biological and other evidence for human modification of the natural environment.

One: Precision and Accuracy in Studies of Climatic Change and Human Impact.- 1 Precision, concepts, controversies: Alan Smith’s contributions to vegetational history and palaeoecology.- 1.1 Introduction.- 1.2 Precision.- 1.3 Concepts.- 1.4 Controversies.- 1.5 Personal reflections.- 2 Forward to the past: changing approaches to Quaternary palaeoecology.- 2.1 Introduction.- 2.2 Inductive investigation in Quaternary palaeoecology.- 2.3 Deductive studies: the acid rain research.- 2.4 The future.- 3 Radiocarbon dating and the palynologist: a realistic approach to precision and accuracy.- 3.1 Introduction.- 3.2 The pioneer phase.- 3.3 The routine phase.- 3.4 The questioning phase.- 3.5 Is there a future?.- 3.6 A hypothetical project.- 4 Great oaks from little acorns...: precision and accuracy in Irish dendrochronology.- 4.1 Introduction.- 4.2 First case study.- 4.2.1 An Ulster crannog.- 4.3 Discussion.- 4.3.1 Precise dating.- 4.3.2 Climatic and environmental effects.- 4.3.3 The ‘suck-in’ effect.- 4.3.4 Proxy data: quantitative climatic records.- 4.4 Second case study.- 4.4.1 An attempt to apply dendrochronology to the dating of the inner ditch at Haughey’s Fort.- 4.4.2 Attempts to ‘date’ Q-7971.- 4.4.3 Inferences.- 4.5 Third case study.- 4.5.1 Early 16th century defoliations in Ulster.- 4.5.2 Localized effects and lessons therefrom.- 4.6 Conclusions.- Two: Climatic Change on the Landscape.- 5 Peat bogs as sources of proxy climatic data: past approaches and future research.- 5.1 Introduction.- 5.2 Past approaches.- 5.2.1 The Blytt-Sernander scheme.- 5.2.2 Recurrence surfaces.- 5.2.3 The search for new methods.- 5.3 The present position.- 5.4 Future research.- 5.4.1 Dating techniques.- 5.4.2 Sites.- 5.4.3 Methods.- 5.5 Conclusions.- 6 Forest response to Holocene climatic change: equilibrium or non-equilibrium.- 6.1 Introduction.- 6.2 Case studies.- 6.2.1 Lake Michigan and the migration of Fagus in the USA.- 6.2.2 The western limits of Pinus sylvestris in Europe.- 6.2.3 The boreal-nemoral ecotone in central Sweden.- 6.3 Conclusions.- 7 Isolating the climatic factors in early- and mid-Holocene palaeobotanical records from Scotland.- 7.1 Introduction.- 7.2 Pollen records and the Holocene vegetational history of Scotland.- 7.2.1 Pioneer phase (c. 10 300 to 8500 bp).- 7.2.2 Afforestation phase (8500 to 5000 BP).- 7.2.3 Deforestation phase (5000 BP to present).- 7.3 Pollen stratigraphy and palaeoclimatic inferences.- 7.3.1 Blytt-Sernander scheme.- 7.3.2 Time-lagged responses.- 7.3.3 Indicator-species approach.- 7.3.4 Conclusions.- 7.4 Isolating the climatic factors in Holocene palaeobotanical records.- 7.4.1 Early Holocene climatic revertance.- 7.4.2 Holocene range limits of pine.- 7.4.3 Variations in pine macrofossil abundance.- 7.4.4 Conclusions.- 8 Radiocarbon dating of arctic-alpine palaeosols and the reconstruction of Holocene palaeoenvironmental change.- 8.1 Introduction.- 8.2 Field sites.- 8.3 Problems of soil dating and the importance of laboratory pretreatment.- 8.4 Time elapsed since burial.- 8.5 Time since the onset of soil formation.- 8.6 Holocene glacier and climatic variations.- 8.6.1 Climatic implications.- 8.7 Soil history at Haugabreen and Vestre Memurubreen.- 8.7.1 Podsol development.- 8.7.2 Brown Soil.- 8.8 Vegetation history.- 8.8.1 Haugabreen (podsol) sites.- 8.8.2 Vestre Memurubreen (Brown Soil) sites.- 8.9 Conclusions.- Three: Evidence for Human Impact.- 9 Earliest palynological records of human impact on the world’s vegetation.- 9.1 Data.- 9.2 Commentary.- 9.2.1 The nature of human impact.- 9.2.2 Gaps on the map.- 9.2.3 Time span.- 9.2.4 Oldest disturbance.- 9.3 Celebration.- 10 Vegetation change during the Mesolithic in the British Isles: some amplifications.- 10.1 Introduction.- 10.2 The background.- 10.2.1 The earlier Mesolithic.- 10.2.2 The later Mesolithic.- 10.2.3 The Mesolithic-Neolithic transition.- 10.3 Two more-detailed examples.- 10.3.1 Bonfield GUI and North Gill, North York Moors.- 10.4 A wider context.- 11 The development of high moorland on Dartmoor: fire and the influence of Mesolithic activity on vegetation change.- 11.1 Introduction.- 11.2 The Black Ridge Brook model.- 11.3 Pinswell.- 11.3.1 Site location and pollen and charcoal results.- 11.3.2 Vegetation change and peat initiation.- 11.4 Comparison with Black Ridge Brook and other Dartmoor sites.- 12 Models of mid-Holocene forest farming for north-west Europe.- 12.1 Introduction.- 12.2 Models of early farming activity.- 12.2.1 The landnam model.- 12.2.2 The leaf-foddering model.- 12.2.3 The expansion-regression model.- 12.2.4 The forest-utilization model.- 12.3 Conclusions.- 13 The influence of human communities on the English chalklands from the Mesolithic to the Iron Age: the molluscan evidence.- 13.1 Introduction.- 13.2 Molluscan analysis.- 13.3 The Mesolithic period.- 13.4 The earlier Neolithic.- 13.5 The later Neolithic.- 13.6 The Bronze Age and Iron Age.- 13.7 Research strategy.- 14 Mesolithic, early Neolithic, and later prehistoric impacts on vegetation at a riverine site in Derbyshire, England.- 14.1 Introduction.- 14.2 The site.- 14.3 Methods and presentation of results.- 14.3.1 Field sampling.- 14.3.2 Pollen analysis.- 14.3.3 Radiocarbon dating.- 14.3.4 Statistical analysis.- 14.4 Vegetation history.- 14.4.1 General.- 14.4.2 Reconstruction.- 14.5 Discussion.- 15 Holocene (Flandrian) vegetation change and human activity in the Carneddau area of upland mid-Wales.- 15.1 Introduction.- 15.2 Study area.- 15.3 Research strategy.- 15.4 Methods.- 15.5 Regional pollen assemblage zones.- 15.6 Vegetation and landscape change in the Carneddau region.- 15.6.1 Early- and mid-Flandrian woodland development.- 15.6.2 Mid- and late-Flandrian woodland decline: evidence of human impact.- 15.7 Conclusions.- 16 Early land use and vegetation history at Derryinver Hill, Renvyle Peninsula, Co. Galway, Ireland.- 16.1 Introduction.- 16.2 Sites investigated.- 16.3 Methods.- 16.4 Results and interpretation: short profiles on Derryinver Hill.- 16.4.1 Description of soil profiles.- 16.4.2 Pollen and macrofossil analysis.- 16.4.3 Chronology, and significance in terms of land use, of events recorded in profiles DYR I, II, III and VI.- 16.5 Discussion.- Four: Climatic Change and Human Impact: Relationship and Interaction.- 17 Rapid early-Holocene migration and high abundance of hazel (Corylus avellana L.): alternative hypotheses.- 17.1 Introduction.- 17.2 The hypotheses.- 17.2.1 Succession and soil development.- 17.2.2 Migrational lag.- 17.2.3 The position of ‘glacial refugia’.- 17.2.4 Late-glacial expansion.- 17.2.5 Human assistance.- 17.2.6 Climate.- 17.2.7 Plateaux in the radiocarbon timescale.- 17.3 Discussion.- 17.3.1 Rapid expansion of geographical range.- 17.3.2 Anomalous early-Holocene abundance.- 17.4 Conclusions.- 18 The origin of blanket mire, revisited.- 18.1 Introduction.- 18.2 Mechanisms of blanket mire inception.- 18.3 Extent and intensity of prehistoric forest modification.- 18.4 Replacement of forest by blanket mire.- 18.5 Conclusions.- 19 Climatic change and human impact during the late Holocene in northern Britain.- 19.1 Introduction.- 19.2 The late-Holocene environment of northern Cumbria.- 19.3 The Roman impact on the landscape of the frontier zone.- 19.3.1 Historical accounts.- 19.3.2 Palynological evidence.- 19.4 Testing and extending the record of climatic change.- 19.5 Conclusions.- 20 Palaeoecology of floating bogs and landscape change in the Great Lakes drainage basin of North America.- 20.1 Introduction.- 20.2 Early investigations.- 20.3 Ecological variation.- 20.4 Distribution.- 20.5 Hydrological variation.- 20.6 Stratigraphic variation.- 20.7 Human activities.- 21 Late Quaternary climatic change and human impact: commentary and conclusions.- 21.1 Introduction.- 21.2 Precision and accuracy.- 21.2.1 Precision and accuracy in taxonomy and sampling.- 21.2.2 Precision and accuracy in dating.- 21.3 Climatic change and vegetational response.- 21.3.1 Climate changes of t