Carbon dioxide evolution from two temperate, deciduous woodland soils.
Describes a study in Bleans Woods National Nature Reserve, north-east Kent, to investigate the effects of seasonal and temporal variations in soil temperature and moisture on decomposition processes in the soil under two coppice stands, dominated by Castanea sativa and Fagus sylvatica respectively and aged 40-60 years. CO2 production was highly correlated with temperature and showed a logarithmic increase in both sites with rising soil temperatures. Neither of the experimental areas showed a close relation between CO2 evolution and soil moisture or rainfall, except during drought conditions. Cumulative annual totals of CO2 release were not significantly different for the two sites. A carbon budget is constructed for the two systems and considered in relation to net litter and root production and root metabolism. Some of the errors involved in soil respirometry are indicated, and the value of CO2 measurements as a diagnostic parameter of soil types and their dynamic status is discussed. A method of reducing variance in soil-moisture measurements is described.