Oral Presentation 7th Australian Stream Management Conference 2014

How can the regeneration of vegetation from riparian seed banks support river rehabilitation in degraded ecosystems? (11558)

Kirstie Fryirs 1 , Jessica O'Donnell 1 , Alexandra Carthey 1 , Michelle Leishman 1
  1. Macquarie University, North Ryde, NSW, Australia

Riparian vegetation provides important habitat and is a critical influence on geomorphological and ecological processes by increasing habitat quality and heterogeneity, as well as reducing erosion through the capture and stabilisation of sediment. Consequently, the re-establishment of riparian vegetation has become a major focus of international rehabilitation strategies. Recent interest has focussed on whether naturally occurring soil and sediment seed banks can be used as a seed source for the revegetation of degraded ecosystems as part of a passive rehabilitation approach.

Here we present work on the characteristics and dynamics of the riparian seed bank of a sand-bed stream in southeastern Australia (Wollombi Brook). Firstly, we will focus on the characteristics of the seed bank, namely the type, abundance and distribution of seeds in the riparian zone of Wollombi Brook and discuss whether these seed banks have the capacity to support the regeneration of diverse riparian vegetation. We will then examine two key controls (or limiting factors) on riparian seed bank regeneration; local-scale controls (i.e. disturbance and seed availability from local vegetation) and catchment-scale controls (i.e. seed floating capacity from seed sources). Finally, we present a range of practical implications for on-the-ground activity that aims to better utilise the riparian seed bank in river management practice.

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