Waterlogging and survival in Sesleria albicans

Abstract

The performance of Sesleria albicans Kit. ex Schultes, a species usually found in dry limestone habitats, but also recorded in wet places, was examined over a period of 2 yr along a soil-water gradient. This supplied a 'dry' end with the water-table 22 cm below the surface, grading to a 'wet' end with the water-table at the surface, providing static waterlogged conditions. The performance of plants (judged from measurements of tussock diameter, plant height, panicle length, counts of the number of panicles and spikelets per panicle, and shoot and root d. wt) was progressively impaired with increasingly waterlogged conditions. Previously waterlogged ramets recovered when removed to non-waterlogged soil, showing that waterlogging had stunted but not killed the roots. The effects of waterlogging were demonstrated by a pot experiment to be similar in three different types of soil. Differences in the performance of S. albicans in these (determined by counts of the number of tillers, number of nodal axes and measurements of leaf length, root length, and shoot and root d. wt) were a result of factors other than waterlogging, since the differences were maintained in both waterlogged and normally watered soil. Although performance of S. albicans was adversely affected in static waterlogged soils, none of the plants died, even after 2 yr. Possible explanations for the survival of S. albicans were sought.