Age and hydrological significance of lichen limits on sandstone river channels near Sydney, Australia

Auteur(s) et Affiliation(s)

SAMMUT, J.

School of Biological, Earth and Environmental Sciences, Univ. of New South Wales, Sydney, Australie

ERSKINE, W.D.

School of Environmental and Life Sciences, Univ. of Newcastle, Ourimbah, Australie

Environmental Research Inst. of the Supervising Scientist, Darwin, Australie

Description :
Trimmed lichen communities (lichen limits) are abrupt changes from a lichen community to a scoured bare rock surface and have been used to determine bankfull channel capacity on bedrock channels and their response to the combined disturbances of flow regulation and climate change. They can also be used to set flushing flows in bedrock channels. In sandstone gorges of the Nepean River, Australia, the crustose lichen,Lecidea terrena Nyl, was common at both gorge and cemetery (sandstone headstones) sites, enabling construction of growth curves for above and below dam areas. Growth curves were used to date lichen colonisation of sandstone surfaces in rivers. It is showed that lichens colonised exposed sandstone between the level of frequent flows from 1949 to 1952, and the high lichen limit. On the Avon River, an additional lower limit reflected a massive downward shift in flow duration following the start of interbasin diversions to Wollongong in 1962.

Type de document :
Article de périodique

Source :
Geografiska annaler. Series A. Physical geography, issn : 0435-3676, 2013, vol. 95, n°. 3, p. 227-239, nombre de pages : 13, Références bibliographiques : 48 ref.

Date :
2013

Editeur :
Pays édition : Suede, Stockholm, Svenska sällskapet för antropologi och geografi

Langue :
Anglais