Seed-bank dynamics of 'Eleocharis': can spatial and temporal variability explain habitat segregation?

Title
Seed-bank dynamics of 'Eleocharis': can spatial and temporal variability explain habitat segregation?
Publication Date
2004
Author(s)
Bell, Dorothy
Clarke, Peter John
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/BT03024
UNE publication id
une:2855
Abstract
Four 'Eleocharis' species exhibit habitat partitioning in both extant vegetation and in the soil seed bank of upland temporary wetlands on the Northern Tablelands of New South Wales. Explanations for this partitioning were sought in seed-bank dynamics at three shore levels in two wetlands. Habitat partitioning (zonation) was explained in part by seedling recruitment but not by either persistence of seeds in the soil or by dormancy patterns. All four species recruited at wetland edges but only the deepwater species, 'Eleocharis sphacelata', recruited in deeper water. Viability of buried seeds was consistently high and species had very low decay rates and half-lives greater than 50 years. Two types of dormancy patterns with burial were shown. Most seeds of 'Eleocharis sphacelata' and 'E. pusilla' were non-dormant after a 3-month burial, whereas for 'E. acuta' and 'E. dietrichiana' seed germination percentages gradually increased over a number of years. These two dormancy patterns may contribute to coexistence, since coexistence is enhanced by a long-lived resistant phase in the life history of species and by temporal variability in germination. There were also spatial inconsistencies in patterns of dormant fractions. Burial in the deeper zones of the marsh-like Billybung Lagoon had an inhibitory effect both on germinability and on germination rates of 'E. acuta' and 'E. dietrichiana' seeds. All but 'E. acuta' showed some degree of seasonal dormancy, but this pattern was also not consistent in space. Explanations for zonation should concentrate on other life-history phases, such as dispersal and seedling survival.
Link
Citation
Australian Journal of Botany, 52(1), p. 119-131
ISSN
1444-9862
0067-1924
Start page
119
End page
131

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