Research Interests: Physiology, and general and population ecology, of the bog-moss, Sphagnum. The bog-moss makes its environment acid (pH typically 3 to 4) by cation exchange of H+ produced by the plants with cations such as Na+, K+, Ca2+, and Mg2+ in rain. Sphagnum grows well with a surprisingly small supply of N and P which it gets from rain and dust (amounts which would be insufficient for most rooted plants are toxic to Sphagnum) Only a few specialised other species of plant can survive with Sphagnum. In the waterlogged conditions created by Sphagnum, decay is very slow and the dead remains of the plants accumulate as peat, of which Sphagnum is the main component. Arguably, there is more carbon in Sphagnum, dead and alive, than in any other plant genus. The structure of Sphagnum is unique, and its populations, which appear superficially to be stable, change much more rapidly than is generally realised. There is much to be discovered about the population dynamics. Ecology and the rate of growth of peatlands. This interest grew out of that in Sphagnum. Peatlands cover about 3% of the Earth’s land surface. There is more carbon in peat than in all tropical rain forests together, and nearly as much as in CO2 in the whole of the atmosphere. About 10 to 20% of the carbon fixed in photosynthesis survives decay before being buried, by continuing growth of the plants above, in the anoxic waterlogged peat proper. Decay does continue there although very slowly. What is the relative rate of peat accumulation and of the cumulative rate of decay? As the peat gets deeper does the cumulative rate of loss come to equal the rate of addition at the surface? These are important questions in the context of climate change, in the study of which peatlands have been neglected.