Description of wetland ecological character Yanga National Park © Copyright State of NSW and the Office of Environment and Heritage, Department of Premier and Cabinet With the exception of photographs, the Office of Environment and Heritage, Department of Premier and Cabinet (OEH) and State of NSW are pleased to allow this material to be reproduced in whole or in part for educational and non-commercial use, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs. This publication has been compiled in good faith, exercising all due care and attention. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. OEH shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. Readers should seek appropriate advice when applying the information to their specific needs. This project was funded by the Rivers Environmental Restoration Program which is jointly funded by the NSW Government and the Australian Government’s Water for the Future Program. It aims to arrest the decline of wetlands through water recovery, effective management of environmental water and the sustainable management of our wetlands. The authors would like to thank the following people who contributed to this report: Paul Childs: Wetland Ecologist, OEH James Maguire: Senior Wetlands and Rivers Conservation Officer, OEH Russell Hampton, Paul McInnes and Narelle Jones: Yanga National Park, OEH Tom Davy: State Water Corporation Jennifer Spencer, Jordan Iles, Lisa Knowles and others: Rivers and Wetlands Unit, OEH Wen L, Saintilan N and Ling J 2011. Description of wetland ecological character: Yanga National Park. Rivers and Wetlands Unit, Office of Environment and Heritage, Department of Premier and Cabinet. Sydney, Australia. Cover photographs Main: Two Bridges Swamp – J Kelleway/OEH Right: top: Pococks Swamp, centre: River red gums at Two Bridges Swamp, bottom: Azolla at Pococks Swamp – L Wen/OEH Published by: Office of Environment and Heritage Department of Premier and Cabinet 59–61 Goulburn Street, Sydney PO Box A290, Sydney South 1232 Report pollution and environmental incidents Environment Line: 131 555 (NSW only) or [email protected] See also www.environment.nsw.gov.au Phone: (02) 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks, climate change and energy efficiency information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au ISBN 978 1 74293 398 6 OEH 2012/0165 Published February 2012, based on information compiled in 2009 Summary Yanga National Park forms part of the Lowbidgee floodplain which is listed in the Directory of Important Wetlands in Australia. This description of ecological character focuses on the national park with reference to the broader Lowbidgee floodplain. It is based on the national framework and guideline for describing the ecological character of Australia’s Ramsar wetlands and has identified ecosystem benefits and services, ecological components and processes and their limits of acceptable change at its current state. Yanga National Park meets five of the six criteria for determining nationally important wetlands. There are 12 wetland types according to Ramsar classification (10 according to Environment Australia) in the park. The dominant wetland type, river red gum (Eucalyptus camaludensis) forest/woodland, forms one of the largest stands in Australia. Other significant wetlands include Yanga Lake, Piggery Swamp and seasonal flooded lignum (Muehlenbeckia florulenta) woodland. Approximately 17 vegetation communities have been identified in Yanga National Park ranging from river red gum riparian open forest, old man saltbush (Atriplex nummularia), lignum shrub to spike rush (Eleocharis sphacelata) swamp. Over time, 303 vascular plant species, including four endangered and one vulnerable, have been recorded within these communities. The diverse ranges of vegetation provide habitats for various animals. There are 269 fauna species (excluding fish) which have been recorded in the site, including 25 mammals, 24 reptiles, 11 amphibians and 210 birds. Yanga National Park supports the populations of a number of internationally and nationally threatened species included in the global ‘red list’ of the International Union for Conservation or listed under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. There is a total of 21 endangered and vulnerable species, 12 of which are waterbirds, which have been recorded in Yanga National Park, such as Australasian bittern (Botaurus poiciloptilus), freckled duck (Stictonetta naevosa) and blue-billed duck (Oxyura australis). The southern bell frog (Litoria raniformis), which is considered to be endangered at state level, has been recorded in Piggery Swamp, Mercedes Swamp and Twin-bridge Swamp. There are 61 species of waterbirds observed using the site as roosting, feeding and nesting/breeding habitat. Important areas include Tarwillie Swamp, Shaw’s Swamp, Piggery Lake, Two-Bridge Swamp located between Redbank Weir and Lambing Down Hill, and river red gum forests within 10 km of Redbank Weir along the Murrumbidgee River. The site also supports a broad range of recreational, educational and scientific activities, and has a high social and cultural value. The site has become a major national focus for floodplain ecological research activities since 2007 when it was gazetted as a national park. Substantial levels of scientific study and investigation have been undertaken in the park, particularly relating to natural heritage values. Sites of Aboriginal and European heritage are also found within the area. Currently, the site is highly stressed as evidenced by large scale degradation of vegetation condition, sharp decrease in the abundance of waterbirds, and wide dispersion of the exotic European carp. Hydrological alteration due to upstream water division and fragmentation caused by engineering works within the floodplain are identified as the major threatens. The geological setting of the site means that environmental water provision is the most practical method for recovering and maintaining the ecological character of the site. There are a number of knowledge gaps and monitoring requirements regarding the important components and critical processes of the site which limit the current capacity to establish benchmarks, detect changes and set ‘limits of acceptable change’ for ecological character. Flow path and inundation pattern, extent of aquatic vegetation communities, number of waterbird species and abundance, and condition of river red gum forest are given high priorities. Management (D) Climate (D) Geomorphology (D) Human disturbance (D) EWAs Rainfall Fractures and faults River regulation Re-snagging Temperature Surface geology (bedrock Water diversion Dam removal Evaporation & soil types) Drainage network Levee breach Wind Topography Infrastructure Weed and pest control Solar radiation Aquifers Grazing Erosion control Extreme events Clearing Burning Hydrogeologic Settings (D) Agricultural runoff Hydrological regimes (C) Wetland Frequency, duration and depth of inundation Ecosystem Groundwater recharge/discharge Dry-wet cycles Soil (sediment) Chemistry Physical forms (C/P) Water Chemistry (C/P) (C/P) Erosion Salinity N, P, Ca, Si etc availability Sedimentation Nutrients Nutrient cycle Wetland size and distribution Turbidity Carbon cycle Habitat availability Water quality Soil type and distribution Habitat connectivity Primary Production and Trophic Structure (C) Decomposers Producers (C) Primary / secondary (C) Tertiary consumers (C) (C) Phytoplankton consumers Reptile and mammals Fungi Periphyton Zooplankton Fish Vegetation Macroinvertebrates Land bird and Waterbird Bacteria Invertebrates Amphibians Services and Benefits Biodiversity conservation: unique wetland types, diverse habitats, ecological communities, drought refuge Nature observation: education and scientific research Recreation and tourism Cultural The overall ecological conceptual model developed for the description of ecological character of Yanga National Park. Feedback from biota to their environment and interactions among biological communities were omitted for simplicity. D, Driver; C, Component; P, Process. 8r Th D qpv 1.1 Brief description of Yanga National Park ........................................................... 1 1.2 Objectives of description of ecological character............................................... 3 1.3 Concepts applied and approaches for description of ecological character........ 3 1.3.1 Ecological character............................................................................... 3 1.3.2 Approaches taken in a description of ecological character .................... 5 1.4 Policy framework................................................................................................ 6 ! Pr vrs`hthIhvhyQh x ( 2.1 Site location and its catchment .......................................................................... 9 2.1.1 Site location and boundary..................................................................... 9 2.1.2 Murrumbidgee catchment ...................................................................... 9 2.2 Climate............................................................................................................