The difficulty had been that suitable sites for pollen analysis, the standard way of studying past vegetation, are scarce in the chalklands, so there had been no challenge to the idea that the soils were too thin and droughty for trees, and that the importance of the chalklands in the prehistoric settlement of Britain was that early farmers sought open land.
John Gwynne Evans was born in St Albans in 1941, the son of the microbiologist David Evans. After attending University College School in London, then taking a degree in Zoology at Reading University, John Evans joined the Institute of Archaeology, London University, to study under F.E. Zeuner. He remained at the institute after Zeuner's early death in 1963 to work for his PhD, taking up the study of sub-fossil land snails, advised by M.P. Kerney of Imperial College, who had developed the methodology in the study of naturally formed deposits, focusing mainly on changing distribution of species and climatic conditions.
Evans's innovation was to concentrate on structures built by people, and to look for sequences within the buried soils and ditch fills. By grouping species into shade-loving, open-country, those of disturbed ground, and so on, he could show how, with local variations, the snail fauna had changed as forest developed in the early post-glacial period, was cleared for cultivation, and the land later used for pasture.
By working with excavators, getting permission to dig small holes in monuments and conducting excavations himself, he got enough material to complete his PhD in a very short time, and, with a period of research funding, to write his first book, Land Snails in Archaeology (1972), which is both a research monograph and, still, the only textbook on the subject.
In 1970, Evans was appointed to a lectureship in environmental archaeology at University College Cardiff, the first such post outside London. He became involved in the subject more widely through the Experimental Earthworks project, and through the Council for British Archaeology, jointly with myself organising and then publishing the proceedings of two seminal conferences on "The Effect of Man on the Landscape", "The Highland Zone" in 1975 and "The Lowland Zone" in 1978. His book The Environment of Early Man in the British Isles (1975) provided essential reading for archaeologists and for students in a field becoming much more widely taught, and he followed this with a textbook, An Introduction to Environmental Archaeology (1978).
He extended his research into areas such as coastal dunes where shell sand provided good sequences, and in the 1980s, partly in response to challenges to interpretations which hinged on the poorly defined processes by which his sequences could have formed within stable soils subject to worm action, he began to focus on the chalkland river valleys. In a collaborative project, we made detailed studies of the alluvial sequences around Avebury, the land and riverine snail faunas providing ecological context for the processes of soil development, erosion, and the build up of floodplains.
The aim was to tackle the question of whether climatic change or human activity was responsible for erosion – too simplistic an approach, as Evans comments in a recent book, but a detailed synthesis of landscape and soil history in relation to land use was produced (with the results published in The Proceedings of the Prehistoric Society, 1993). Evans went on to conduct more extended valley projects, developing the methodology and refining interpretative approaches, and had major success in the exploration of former valley environments and evidence for their early occupation and exploitation.
John Evans was promoted to Senior Lecturer in 1978 and Reader in 1982, and awarded a personal chair in 1994, retiring in 2002. He was, right up to his last days, a phenomenally hard worker. Starting as a zoologist, he became equally a palaeoecologist and an archaeologist, training students in the techniques of field archaeology as well as in his own research field.
His more recent books include a textbook written with Terry O'Connor, Environmental Archaeology: principles and methods (1999), a revised edition of which is just completed, and two more reflective works, Land & Archaeology (1999) and Environmental Archaeology and the Social Order (2003). Some of his later ideas are a bit bizarre, but they stem from his fertile imagination and his wrestling to apply ideas derived from reading in sociology and psychology, and his deep knowledge of ecology, to questions of evolution of societies within, and in dynamic interaction with, their environment.
His drive and his temperament – seemingly constantly adrenalin-fuelled – had their downside, and his career and personal life were punctuated by crises. He was, however, a warm and supportive friend and a stimulating and sociable colleague. He had calmed down a bit, enjoying the retirement now cut so sadly short, with his allotment and the beloved dogs, and the gentle support of his second wife, Vivian, who survives him, as do his daughter, Ailinor, and sons, Dickon and Thomas.
John Gwynne Evans, environmental archaeologist: born St Albans, Hertfordshire 11 November 1941; Lecturer in Environmental Archaeology, University College Cardiff (later University of Wales College of Cardiff) 1970-78, Senior Lecturer 1978-82, Reader 1982-94, Professor 1994-2002 (Emeritus); married first Pam Figgis (two sons, one daughter; marriage dissolved), second 1981 Vivian Wossidlo; died Cardiff 13 June 2005.