A5007999278- Geology and Paleoclimatology Research
- Ecology and Vegetation Dynamics Studies
- Tree-ring climate responses
- Archaeology and ancient environmental studies
- Pleistocene-Era Hominins and Archaeology
- Evolution and Paleontology Studies
- Geological formations and processes
- Species Distribution and Climate Change
- Genetic diversity and population structure
- Lichen and fungal ecology
- Botany and Plant Ecology Studies
- Peatlands and Wetlands Ecology
- Isotope Analysis in Ecology
- Botany, Ecology, and Taxonomy Studies
- Archaeological Research and Protection
- Plant Diversity and Evolution
- Ecology and biodiversity studies
- Coastal wetland ecosystem dynamics
- Plant Ecology and Soil Science
- Plant and animal studies
- Marine and environmental studies
- Forest Ecology and Biodiversity Studies
- Outsourcing and Supply Chain Management
- Allergic Rhinitis and Sensitization
- Forensic and Genetic Research
Los Alamos National Laboratory
2024
University of Warwick
2023
University of St Andrews
1999-2019
Queen's University Belfast
2009-2018
Uppsala University
2004-2015
Quaternary Research Association
1983-2001
Bath Spa University
1999
Andrews University
1999
University of Cambridge
1990-1998
The Scarborough Hospital
1983-1986
SUMMARY Current methods for numerical zonation of biostratigraphic sequences neither assess the reliability zones identified nor provide any means determining number that are ‘significant’ (based on structure in data set, rather than stochastic element). These problems can be overcome by using broken‐stick model to significance against a random distribution within sequence. The is described and its application demonstrated actual sets. Additionally, simulation modelling used uncertainty...
An attempt is made to investigate the nature of cold-stage distributions for those forest trees which today extend northem Europe. Evidence taken from pollen record present and earlier interglacials, a model past climate, modem tree distributions, physi- ography southem The occupied mid- altitude sites in mountains Europe, espe- cially westem Balkans Italy during last cold stage. These areas would have had suitable it argued that could easily survived there at densities low enough escape...
It is commonly believed that trees were absent in Scandinavia during the last glaciation and first recolonized Scandinavian Peninsula with retreat of its ice sheet some 9000 years ago. Here, we show presence a rare mitochondrial DNA haplotype spruce appears unique to highest frequency west-an area sustain ice-free refugia most age. We further survival from this lake sediments pollen Trøndelag central Norway dating back ~10,300 chloroplast pine adjacent Andøya refugium northwestern as early...
Summary Priority question exercises are becoming an increasingly common tool to frame future agendas in conservation and ecological science. They effective way identify research foci that advance the field also have high policy relevance. To date, there has been no coherent synthesis of key questions priority areas for palaeoecology, which combines biological, geochemical molecular techniques order reconstruct past environmental systems on time‐scales from decades millions years. We adapted...
The Quaternary ice ages were paced by astronomical cycles with periodicities of 20–100 k.y. (Milankovitch cycles). These have been present throughout earth history. fossil record, marine and terrestrial, near to remote from centers glaciation, shows that communities plants animals are temporary, lasting only a few thousand years at the most. Response populations climatic changes Milankovitch can be taken as typical way behaved thus force an instability climate other aspects biotic abiotic...
Abstract Aim The Holocene spread of Picea abies in Fennoscandia is well established from many sites and thus provides an opportunity for detailed study the dynamics tree population expansion. Early‐ mid‐Holocene macrofossil evidence presence P. has questioned traditional interpretations timing direction its spread. This paper aims to determine when, where by which pathways into Fennoscandia. Understanding character this may give insight general understanding Location north‐western...
A Holocene palaeoecological sequence from Villaverde, south-central Spain, is presented. The pollen stratigraphy used to infer past vegetation changes within a catchment area that represents the boundary between semi-arid, plateau and mountain vegetation. From c. 9700-7530 cal. yr BP, Pinus dominant, probably as result of combination relatively dry climate natural fire disturbance. 7530-5900 moderate invasion by Quercus appears be migrational response following increased moisture...
Distribution sampling from sequences of radiocarbon ages is used to obtain confidence intervals for intermediate age estimates, sediment deposition times, and thence pollen rates. Three types age-depth model are explored by this approach, it demonstrated that the choice has implications on results. Line-fitting polynomials least- squares will produce narrower than interpolation models. It shown should be evenly spaced, results towards ends have wider intervals. Of total width rates, up half...
1. Pollen, charcoal, chemical, physical, magnetic and tephra analyses of 14 C-dated Holocene lake sediments from Dallican Water, Catta Ness, north-east Shetland, are presented interpreted in the light models climatic change, Shetland archaeological record, local documentary evidence. The sequence was subdivided analysed using principal components analysis, a numerical zonation pollen data optimal binary divisive techniques, measures palynological richness rates change between samples
The spread of Fagus grandifolia in eastern North America illustrates the assumptions behind mapping species distribution changes. Recognition distinction between population expansion and arrival a is crucial for interpreting pollen diagrams. F. probably occurred during Wisconsin full-glacial (18 000 BP) as scarce tree over much southeastern America, did not have localized 'refugium'. By 14 BP it had begun spreading north, still at very low densities. Between 14000 10000 reached high...
Warming at the last glacial termination in North Atlantic region was interrupted by a period of renewed activity during Younger Dryas chronozone (YDC). The underlying mechanism this cooling remains elusive, but hypotheses turn on whether it global or phenomenon. Chronological, sedimentological, and palaeoecological records from sediments small lakes oceanic southern Chile demonstrate that there no YDC Chile. It is therefore likely little Pacific surface waters hence regional, rather than global,
During the last decade Quaternary pollen analysis has developed towards improved pollen-taxonomical precision, automated identification and more rigorous definition of assemblage zones. There have been significant efforts to model spatial representation records in lake sediments which is important for precise interpretation terms past vegetation patterns. We review difficulties matching modelled post-glacial plant migration patterns with pollen-based palaeorecords discuss potential DNA...
The last major ice-sheets in northern Europe and North America reached their maximum extent about 18000 years ago. With the retreat of ice-sheets, changing climates permitted many plants to expand ranges onto freshly deglaciated ground. spread these can be followed across continents by means pollen preserved suitable sediments. Two aspects this will discussed. First, at individual sites, it is possible compare way which populations increase with theoretical models population growth. It...
For interpreting past changes on a regional or global scale, the timings of proxy-inferred events are usually aligned with data from other locations. However, too often chronological uncertainties ignored in proxy diagrams and multisite comparisons, making it possible for researchers to fall into trap sucking separate one illusionary event (or vice versa). Here we largely solve this ‘suck smear syndrome’ radiocarbon ( 14 C) dated sequences. In Bayesian framework, millions plausible...
Understanding climate change and its potential impact on species, populations communities is one of the most pressing questions twenty-first-century conservation planning. Palaeobiogeographers working Cenozoic fossil records other lines evidence are producing important insights into dynamic nature equally response communities. Climatic variations ranging in length from multimillennia to decades run throughout palaeo-records Quaternary earlier have been shown had impacts changes genetic...