Regeneration is poorly understood for most common riparian plant species of inland Australia, despite their ecological and cultural significance, widespread distributions and concern, in many places, over their condition and status. Where research has been conducted, it has tended to focus on effects of flooding and drought on regeneration, often with a view to informing water management at catchment or wetland scales. In contrast, little attention has been given to influences of local factors on recruitment, or their effects in determining regeneration responses to hydrological conditions. With respect to farm-scale management, however, it is the local factors (e.g. canopy and ground cover or grazing pressure) where interventions can best be targeted to maintain or improve riparian ecosystem condition.

This project will investigate the influence of local, farm-scale factors on the regeneration of common riparian plant species from the northern Murray-Darling Basin (e.g. river red gum, coolibah, river cooba, lignum). A range of glasshouse experiments will be conducted to examine the effects of a suite of local environmental factors on germination and seedling establishment responses to broad hydrological conditions (e.g. flooding, waterlogging, drying). Local, farm-scale factors to be explored may include: i) canopy cover (i.e. shade); ii) various ground covers (e.g. litter, wood, sediment); iii) grazing pressure (e.g. trampling, mechanical damage, clipping), iv) sediment characteristics (e.g. soil type, burial) and v) weeds (e.g. competition with Noogoora burr). Final experimental treatments will be determined in consultation with Stacey Vogel and the CRDC in relation to those most likely to be influenced by riparian management practices.

The project will utilise an existing seed collection which will be supplemented with field collections as necessary along with any additional materials required with which to conduct experimental treatments.

Results will be interpreted with respect to best management practices and monitoring guidelines for cotton farms with riparian lands.