Some Field Observations Relating the Growth of Bog Plants to Conditions of Soil Aeration

Publisher Website
Google Scholar
Abstract
The aeration of a flushed and stagnant soil regime in a Sutherland valley bog has been studied by means of oxygen diffusion measurements. Oxygen diffusion values were higher in the flush, with oxygen present to a depth of 16-18 cm, whereas oxygen was not detected below 6 cm in the stagnant soil. The growth and chemical composition of Molinia caerulea growing in the habitat were recorded. Molinia was vigorous in the flush but stunted where conditions were stagnant. The stunted Molinia plants were extremely low in leaf phosphorus, but iron and manganese levels compared favourably with those in vigorous plants. A further attempt to measure aeration conditions in situ and relate them to plant behaviour is described for a north Yorkshire valley bog. Aeration was measured in broader terms, redox potentials and hydrogen sulphide estimations being made in addition to those of oxygen diffusion. Plant distribution was found to vary with the state of reduction in the soil. Living Molinia roots occurred only where hydrogen sulphide was absent and where the rH exceeded 1.1-1.2, but Menyanthes tolerated conditions where the rH was 0.98 and where free sulphide in the soil solution approached 8 mg/l. The findings of both sections of the investigation are discussed and particular emphasis placed on the potential oxidizing activity of roots, a factor which has hitherto received little attention in explaining plant distribution in waterlogged soils.

This publication has 0 references indexed in Scilit: