In a peat stratigraphy, the sudden transition from a highly humified peat to a fresh unhumified peat. This change reflects the resumption of wetter conditions and peat growth following a drier period when heath rather than bog plants colonized the older humified peat. Increasingly, these features of peat stratigraphy are coming to be regarded as important indications of past climate change. Objective identification of recurrence surfaces in a stratigraphic profile is best achieved by measuring the degree of humification of peat. This involves extracting humic acid and measuring its density by spectrophotometry.
Subjects: Plant Sciences and Forestry — Ecology and Conservation.