Hostname: page-component-848d4c4894-jbqgn Total loading time: 0 Render date: 2024-07-06T21:35:46.530Z Has data issue: false hasContentIssue false

Shoreline vegetation distribution in relation to wave exposure and bay characteristics in a tropical great lake, Lake Victoria

Published online by Cambridge University Press:  24 April 2007

Nicholas Azza
Affiliation:
Department of Water Resources Management, Uganda
Johan van de Koppel
Affiliation:
Centre for Estuarine and Marine Ecology, Netherlands Centre for Ecology, Yerseke, The Netherlands
Patrick Denny
Affiliation:
UNESCO-IHE Institute for Water Education, Delft, The Netherlands
Frank Kansiime
Affiliation:
Makerere University, Institute of Environment and Natural Resources, Kampala, Uganda

Abstract

We investigated the presumption that wind-wave exposure is a major regulator of vegetation distribution within lakes. Along a 675-km stretch of shore in northern Lake Victoria (Uganda), the pattern of vegetation distribution in relation to shoreline features, and the variation of shoreline swamp area along a gradient of wave exposure were examined. The ability of wave exposure, when combined with bay morphometric characteristics, to predict the lakeward limit of vegetation distribution was assessed. Data were collected through a shoreline survey and from maps. Maximum effective fetch, computed from topographic maps, was used as a surrogate for wave exposure. Our results reinforce and amplify the notion that wave exposure is an important regulator of the within-lake distribution of vegetation. We found shoreline plants to either occupy stretches of shore shielded by coastal islands or hidden by convolutions of the lake margin. The area of shoreline swamps declined exponentially with increasing wave exposure. Of the coastal characteristics examined, bay area had the strongest influence on the lakeward expansion of vegetation. Wave exposure acting together with bay area, accounted for 64.4% of the variance in the limit of lakeward vegetation advancement.

Type
Research Article
Copyright
2007 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)