Vegetation propagule dynamics and fluvial geomorphology

TY - CHAP

T1 - Vegetation propagule dynamics and fluvial geomorphology

AU - Bennett, S J

AU - Simon, A

AU - Angold, P G

AU - Morrissey, I P

AU - Petts, G E

AU - Steiger, J

PY - 2004

Y1 - 2004

N2 - The character of river landscapes is primarily a product of fluvial processes. However, this paper synthesises published research by the authors to illustrate that riparian vegetation can also have important direct influences on these landscapes. The hydrodynamic properties of vegetation propagules influence the way in which they are transported by river systems. Riparian zone form and roughness and flood properties constrain both propagule and sediment deposition patterns. Thus analogies can be drawn between sediment and propagule dynamics in fluvial systems. Riparian trees are particularly important in influencing rates of riparian zone aggradation and degradation. The reproductive strategies adopted by riparian trees, particularly the timing of propagule release in relation to the river flow regime, and the rate at which propagules can develop into an established vegetation cover, are both extremely important in affecting the level of control imposed by tree species on the fluvial system. Sexual and vegetative propagules may establish at different rates under the same environmental conditions. Sheltering effects of large wood that is deposited with the propagules can modify the microenvironment to enhance rates of vegetation establishment by sheltering young plants and encouraging the deposition of fine sediment and additional vegetation propagules. Thus variations in riparian tree species and their management may have a significant influence on the character of a river and on the interplay between fluvial processes and vegetation in both time and space.

AB - The character of river landscapes is primarily a product of fluvial processes. However, this paper synthesises published research by the authors to illustrate that riparian vegetation can also have important direct influences on these landscapes. The hydrodynamic properties of vegetation propagules influence the way in which they are transported by river systems. Riparian zone form and roughness and flood properties constrain both propagule and sediment deposition patterns. Thus analogies can be drawn between sediment and propagule dynamics in fluvial systems. Riparian trees are particularly important in influencing rates of riparian zone aggradation and degradation. The reproductive strategies adopted by riparian trees, particularly the timing of propagule release in relation to the river flow regime, and the rate at which propagules can develop into an established vegetation cover, are both extremely important in affecting the level of control imposed by tree species on the fluvial system. Sexual and vegetative propagules may establish at different rates under the same environmental conditions. Sheltering effects of large wood that is deposited with the propagules can modify the microenvironment to enhance rates of vegetation establishment by sheltering young plants and encouraging the deposition of fine sediment and additional vegetation propagules. Thus variations in riparian tree species and their management may have a significant influence on the character of a river and on the interplay between fluvial processes and vegetation in both time and space.

M3 - Conference paper

SN - 0-87590-357-6

T3 - WATER SCIENCE AND APPLICATION

SP - 209

EP - 219

BT - WATER SCI APPL

PB - AMER GEOPHYSICAL UNION

CY - WASHINGTON

T2 - AGU 2001 Fall Meeting

Y2 - 1 January 2004

ER -