Water for Nature Environmental Watering Site Monitoring Report by Dr Anne Jensen

Transcription

1 Water for Nature Environmental Watering Site Monitoring Report by Dr Anne Jensen Ramco River Terrace, South Australian Riverland July 2013 to June 2016 Nature Foundation SA is a not-for-profit nature charity that works to Save, Protect and Restore South Australia's natural biodiversity. Since 2008 one of our flagship programs, Water for Nature, has been delivering environmental water along the Murray River to help reduce the loss and stress to ecosystems and habitats caused by river regulation and drought. Over the last three years, our Water for Nature program has worked with 200 volunteers to deliver 4.56 gigalitres of environmental water to more than 35 wetland and floodplain sites along the Murray River. Healthy wetland and floodplain environments are important for environmental, economic, cultural and social reasons, providing an optimal environment for flora and fauna, improved water quality for human consumption and agricultural use, and opportunities for recreation and tourism. We work with private landholders, irrigators, community groups & local government on smaller sites to deliver environmental water, complementing larger government watering projects. Nature Foundation SA also works closely with the Commonwealth Environmental Water Holder to deliver environmental water. Ramco River Terrace Monitoring Report ( ) 1

2 Water For Nature Environmental Watering Site Monitoring Report Site name Ramco River Terrace, South Australian Riverland Reporting period July 2013 to June 2016 Date prepared July 2016 Location Contact Name Water Provider Partners Aim of watering project Planning Context Ramco River Terrace lies between the Murray River and Ramco Lagoon, 7 km downstream of Waikerie, at km from the Murray mouth. The site covers 15 hectares of Crown Land within a recreation reserve managed by the District Council of Loxton Waikerie, and the watered sites are accessible to the public. NFSA Water For Nature Program Manager Natalie Stalenberg Commonwealth Environmental Water Holder allocation to NFSA Mr Graham Zeigler & family Riverland West Landcare, District Council of Loxton Waikerie, Waikerie Men s Shed The current watering project is targeting regeneration of black box and lignum on the higher elevations of the floodplain in the centre of the site, and some red gums closer to the river. The existing scattered mature black box trees and riparian red gums are relatively stressed and the large numbers of black box and red gum seedlings are critical to the future health of the site. Telfer, A, Santich, M, Preiss, K & Schultz, G (2003). Waikerie Phase IIA SIS - Ramco Lagoon Impacts. Vegetation health assessment. Baseline data collection and collation. Report for SA Water. Australian Water Environments: Adelaide. Ramco River Terrace Monitoring Report ( ) 2

3 Key objectives Site Description Watering History Habitat Environmental watering at this site has the following objectives: 1. improve population viability of black box community by ensuring the survival of naturally recruited seedlings 2. maintain health of existing native vegetation 3. protect and maintain all vegetation layers (shrub communities, groundcover and tree layers) by reducing the impact of salinity. An elevated sandy river terrace has developed as the river has meandered across the floodplain over thousands of years and this separates the river mainstream from Ramco Lagoon. The terrace supports mature open black box woodland, with tall open red gum woodland at lower elevations along the riparian zone of the mainstream. Ramco Lagoon is connected to the river at pool level via the downstream channel. The upstream inlet has become silted and water only enters at river flows > 60,000 ML/day. Ramco River Terrace is now protected by a Salt Interception Scheme which lowers saline groundwater, which will reduce potential salinization effects on health and regeneration of floodplain species such as river red gum and black box. Watering commenced in October 2013 with the aim of delivering 20 ML per year. It was found that sprinklers were the most efficient mode of delivery, and lower than expected volumes were needed. 5 ML was delivered in , and 7.5 ML was delivered in The site was not watered in The purpose is to maintain soil moisture in areas of dense regeneration of black box on the river terrace, and to support red gum regeneration in the riparian zone of the mainstream. The elevated sandy river terrace supports open river red gum and black box woodlands over river coobah, lignum shrubs, saltbush and understory shrubs. These communities have suffered serious decline due to lack of flooding, drought and saline groundwater intrusion, and environmental watering can help to repair the ecosystems. Water Source NFSA allocation from Commonwealth environmental water ; delivered by pump and sprinkler irrigation by Riverland West Landcare (Project Officer Karen Bishop, volunteers Philip Bishop, Roger & Raelene Schmitke & their grandson Luke Frost), with assistance from Waikerie Men s Shed Event details Watering started October 2013, delivered 5 ML, operated by Riverland West Landcare ML delivered, operated by Riverland West Landcare Site not watered (volunteers working on another local site) Maximum area inundated (ha) Estimated area 15 ha Duration of the environmental watering project ( ) two seasonal waterings, in late spring through summer Ramco River Terrace Monitoring Report ( ) 3

4 Annual Observations against key objectives (including species of conservation significance (state or Commonwealth listed threatened species, or listed migratory species) observed at the site, any breeding of frogs, birds or other prominent species observed at the site and details of any observable responses in vegetation, such as improved vigour or significant new growth) Future Watering (report by RWLC staff & volunteers) seedling recruitment and growth improved condition of black box trees (observations by Anne Jensen) improved condition of mature black box trees and red gums limited flowering and development of seed crops sustained survival of all seedlings, watered and non-watered improved growth rate in watered seedlings (observations by Anne Jensen) not watered but continued improved condition of mature black box trees and red gums profuse flowering and development of medium volume seed crops continued sustained survival of all seedlings, watered and non-watered continued improved growth rate in watered seedlings Shift watering to strandline of black box seedlings and stressed mature black box; monitor condition of site to determine need for future watering; red gums will be watered by high flows in September 2016 open black box Ramco River Terrace Monitoring Report ( ) 4

5 Figure 1 Progressive growth of black box seedlings after watering at Ramco River Terrace in November 2013; photopoint RAM-1 taken in September 2014, March 2015 and November 2015 (photos: Karen Bishop Figure 2 Comparison between growth responses at Ramco River Terrace on watered site (left) to non-watered site (right) Ramco River Terrace Monitoring Report ( ) 5

6 Figure 3 Ramco River Terrace watering sites, showing two areas of black box seedlings (green) and riparian red gum seedlings (pink) in top photo; location of two groups of five mature black box trees being monitored, one group within the watered zone and the other group not watered. Ramco River Terrace Monitoring Report ( ) 6