Monitoring the response of littoral and floodplain vegetation and soil moisture flux to weir pool raising -2015 

This data set is the result of the investigation on the response of littoral and floodplain vegetation and soil moisture flux to weir pool raising in 2015. The data was collected over 18 months between August 2015 and December 2016- before, during and after the weir pool levels were raised. The data set contains information on Tree Condition including crown extent and density, bark form, epicormic growth and state, reproduction, crown growth, leaf die off and damage, and mistletoe. Leaf Water Potential, taken predawn and in the middle of the day. Plant Area Index/Canopy Cover measurements using hemispherical photos. Soil Chemistry measurements- total soil moisture (gravimetric water content; %), soil suction (or soil matric potential), Electrical Conductivity and soil pH. 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. The authors would like to thank Josh Fredberg, Leonardo Mantilla, Chris Fulton and Emrys Leitch for their field assistance and to Daniel Hanisch, Karl Hillyard and Luciana Bucater for comments on earlier drafts. The authors would also like to thank Phil Strachan, Peter Haslett and Nicole Hahn for access to their properties and sites. This project has been managed by the Department of Environment, Water and Natural Resources, through the Riverine Recovery Project staff. Thank you to Emrys Leitch and Ben Sparrow from TERN (Terrestrial Ecosystem Research Network), University of Adelaide, for their consultation, advice and ongoing assistance regarding setting up the AusPlots. The authors would also like to thank Jason and Georgia Koerber for contributing the SpaceLAI software for analysis of plant area index from the canopy cover images and Josh Fredberg for making the maps used throughout the report. Funding was provided by the Riverine Recovery Project, South Australia. 

A series of 11 Locks and Weirs along the River Murray are managed to provide stable water levels for irrigation and navigation, resulting in reduced hydrological variability and complexity. Flow stabilization favors species adapted to comparatively stable, lentic conditions and potentially limits the life history processes of native biota adapted to intermittent and lotic environments. Flow regulation contributes to reduced river-floodplain connectivity leading to a subsequent decline in riparian and floodplain vegetation. Various water level management interventions have been trialed along the River Murray to provide environmental benefits by restoring a greater range of water regimes. The Weir pool surcharge used in this project is one method used to increase river channel water level variability and deliver water to temporary wetlands and low-lying floodplain. This can benefit vegetation that has reduced in condition, distribution and abundance because they are less tolerant of stable regulated conditions or have become water stressed as a result of a loss in river-floodplain connectivity or increased dry intervals between inundation events. 

Monitoring the response of littoral and floodplain vegetation and soil moisture flux to weir pool raising- 2015 Susan Gehrig, Kate Frahn and Jason Nicol SARDI Publication No. F2015/000390-2 SARDI Research Report Series No. 899 https://www.researchgate.net/publication/305702002_Monitoring_the_response_of_littoral_and_floodplain_vegetation_and_soil_moisture_flux_to_weir_pool_raising_-_2015