Why are there few gas bubbles in deep peat in British raised and blanket peat bogs?

Abstract

(1) There is evidence of gas-filled voids - ‘bubbles’ - in deep (> 50–100 cm) peat in North America. (2) I used corers, designed to collect samples of accurately known volume, to sample peat profiles down to maximum depth 700 cm at five varied bog sites in northern England and southern Scotland, and measured the proportion of space apparently occupied by bubbles. (3) Of 126 samples in peat below 50 cm depth, three had bubbles occupying 12–15 % of the volume (and one of these was at only 55 cm depth). The other 123 had apparent bubbles distributed in Gaussian fashion, positively and negatively, about zero proportion of total volume and with standard deviation less than 2 %, consistent with these ‘bubbles’ being measurement error. (4) In northern England and southern Scotland, compared with North America, less variable temperature and cooler summers may lead to concentrations of dissolved gas that are generally too low to allow bubbles to form. Even where bubbles do form in summer, they may re-dissolve at winter temperatures