When Bill Heal, who has died aged 86, began studying soil decomposers in the 1950s, researchers aimed to understand the ecosystem in which they functioned. Growing awareness of global heating in the decades since has given this work increased urgency: the very slow rates of decomposition of plant material in peat enable the removal of great quantities of heat-trapping carbon dioxide from the atmosphere, as well as storage of carbon in its acidic and waterlogged conditions.
Soil decomposers constitute the “factory of life”. Below-ground organisms, ranging in size from bacteria and nematodes to earthworms and molluscs, comprise a quarter of Earth’s living species. In order to study how they break down dead plants and animals, researchers inserted cotton fabric strips vertically into soil, with the degree of decomposition assessed by the loss of the strip’s tensile strength.
In 1974, Bill led the publication of a paper that for the first time reported the use of such cotton strips to compare decomposition rates across Arctic, Antarctic and alpine sites. More recently, scientists have built on this work to point to decomposition – or lack of it – in northern regions, especially across peatlands. Vital ecosystem restoration work to halt the loss of carbon from degrading peatlands has followed.
Also in 1974, Bill was appointed head of soil science at the Institute of Terrestrial Ecology (ITE), based in Cambridge, where he made key contributions to the Unesco International Biological Programme (IBP). Formed to develop understanding of the biological basis of productivity and human welfare, this marked the beginning of scientists unravelling how such ecosystems work, and the extent to which people influence them.
With Don Perkins he edited Production Ecology of British Moors and Montane Grasslands (1978), the culmination of much of the IPB’s work, and with Mike Swift and Jo Anderson he wrote Decomposition in Terrestrial Ecosystems (1979), on the diversity of soil decomposers.
A conversation at a meeting of the Arctic Council in 1997 led to the formation of a new framework for this sort of environmental research. Bill and a Swedish colleague Lars-Erik Liljelund (who became president of the EU’s environment agency) discussed how to secure the long-term continuity of Arctic environmental research. What was needed, Bill argued, was something that could “combine the limited resources of the eight Arctic countries but not be limited by national policies and attitudes – a University of the Arctic”. A year later its establishment was announced, and Bill was lead editor of a feasibility study, published by the University of Lapland. Now a network of 143 mainly university institutions, all but 21 of them in Arctic states, it promotes education and research in the region, placing emphasis on empowering indigenous people through collaborative research and sharing knowledge.
Born in Gateshead, in Tyne and Wear, Bill was the son of Oliver Heal, a customs officer, from whom he learned attention to detail, and Elsie (nee Tate), who nurtured an unfailingly positive attitude to life. While at Gateshead grammar school, Bill met Elsie Stephenson on a school trip to Paris, and they eventually married, in 1958.
At Hatfield College, University of Durham, Bill studied zoology and excelled in sport, captaining rugby and cricket teams. After graduating in 1956, he took up a nature conservancy PhD scholarship supervised by Jim Cragg, studying protozoans found in wetlands in what is now Moor House – Upper Teesdale national nature reserve, covering the northern Pennines in Cumbria and County Durham. There, Bill joined a team of field ecologists based in the highest inhabited house in England, whose climate he described as resembling that of southern Iceland. He also studied under Muriel Robertson at the Lister Institute of Preventive Medicine in London.
Rapidly developing internationally recognised expertise in soil microbes, Bill helped Moor House to become Unesco’s centre for understanding sub-tundra biomes and, in 1967, to devising a new ecosystem model for describing pathways and flows of energy and nutrients in upland ecosystems.
In 1982, Bill was appointed ITE’s director for the north of the UK, and moved to Edinburgh. He galvanised colleagues to work across organisational and subject boundaries.
Working tirelessly over the next decade, in 1992 he led the establishment of the UK Environmental Change Network (ECN), now a world-leading, long-term monitoring network drawing on physical, chemical and biological datasets. The 11 terrestrial and 45 freshwater sites provide long-term data on environmental change, which informs government policies on the climate crisis, pollution and biodiversity loss. The ECN belongs to the International Long-Term Ecological Network, operating across 600 sites with the aim of solving international ecological and socio-economic problems.
An honorary professor at Edinburgh University and a fellow of the Royal Society of Biology, Bill was appointed to the circle of elders of the University of the Arctic. His popularity and capacity for networking made him an outstanding multidisciplinary collaborator, and it was a great loss when he began to suffer from Alzheimer’s disease.
He is survived by Elsie, his sons, Stephen and Duncan, and five grandchildren.