758400 758600 758800 759000 759200 759400 759600 759800 760000 760200 760400 760600 760800 761000 Map 14: Rare and threatened flora and fauna recorded at 6053000 6053000 Third Lake February 2013 6052800 6052800 Legend Rare and Threatened Flora Species Herbs Callitriche brachycarpa (Short Water-starwort) 6052600 6052600 Senecio cunninghamii var. cunninghamii (Branching Groundsel) Trees and Shrubs Atriplex lindleyi subsp. lindleyi (Flat-top Saltbush) Duma horrida subsp. horrida (Spiny Lignum) 6052400 6052400 Rare and Threatened Fauna Species Brown Treecreeper (south-eastern ssp.) (Climacteris picumnus victoriae) Caspian Tern (Hydroprogne caspia) 6052200 6052200 Eastern Great Egret (Ardea modesta) Royal Spoonbill (Platalea regia) White-bellied Sea-Eagle (Haliaeetus leucogaster) 6052000 6052000 Transportation Highway Sealed Arterial Road 6051800 6051800 Sealed Road Third Lake Unsealed Road 2WD Road 6051600 6051600 4WD Road 6051400 6051400 0 100 200 300 400 500 600 700 800 900 metres Coordinate System: GDA 1994 MGA Zone 54 Projection: Transverse Mercator 6051200 6051200 Datum: GDA 1994 2011 Aerial Imagery courtesy of the North Central CMA 6051000 6051000 Project: Ecological Vegetation Class Assessment for Reedy Lake, Middle Lake, Third Lake, Little Lake Charm and Racecourse Lake and surrounding areas in the Kerang Wetlands Ramsar Site Client: North Central Catchment Management Authority 6050800 6050800 Author: Holocene Environmental Science Map Prepared: 25th March 2013 Surveyors: Damien Cook, Elaine Bayes and Karl Just (Rakali Consulting Pty Ltd) and Paul Foreman (Blue Devil Consulting) Survey Period: February 2013 6050600 6050600 Disclaimer: while every care has been taken care to ensure the accuracy of this product, no representations or warranties about its accuracy, completeness or suitability for any particular purpose Middle Lake is made. Liability of any kind for any expenses, losses, damages and/or costs which are or may be 6050400 6050400 incurred as a result of this product being innacurate, incomplete or unsuitable in any way and for any reason will not be accepted. 758400 758600 758800 759000 759200 759400 759600 759800 760000 760200 760400 760600 760800 761000 758400 758600 758800 759000 759200 759400 759600 759800 760000 760200 760400 760600 760800 761000 761200 Map 15: Spatial distribution of high threat 6053000 6053000 weeds Third Lake February 2013 Legend High Threat Environmental Weeds 6052800 6052800 Graminoids *Cyperus eragrostis (Drain Flat-sedge) *Juncus acutus subsp. acutus (Spiny Rush) 6052600 6052600 Herbs *Echium plantagineum (Paterson's Curse) *Phyla canescens (Fog-fruit) Trees and Shrubs 6052400 6052400 *Fraxinus angustifolia (Desert Ash) *Lagunaria patersonia subsp. patersonia (Pyramid Tree) *Lycium ferocissimum (African Box-thorn) *Marrubium vulgare (Horehound) 6052200 6052200 *Salix spp. (Willows) *Tamarix ramosissima (Tamarisk) Patches or Infestations 6052000 6052000 *Fraxinus angustifolia (Desert Ash) *Juncus acutus subsp. acutus (Spiny Rush) Transportation 6051800 6051800 Third Lake Highway Sealed Arterial Road Sealed Road 6051600 6051600 Unsealed Road 2WD Road 4WD Road 6051400 6051400 0 100 200 300 400 500 600 700 800 metres 6051200 6051200 Coordinate System: GDA 1994 MGA Zone 54 Projection: Transverse Mercator Datum: GDA 1994 2011 Aerial Imagery courtesy of the North Central CMA 6051000 6051000 Project: Ecological Vegetation Class Assessment for Reedy Lake, Middle Lake, Third Lake, Little Lake Charm and Racecourse Lake and surrounding areas in the Kerang Wetlands Ramsar Site 6050800 6050800 Client: North Central Catchment Management Authority Author: Holocene Environmental Science Map Prepared: 25th March 2013 Surveyors: Damien Cook, Elaine Bayes and Karl Just (Rakali Consulting Pty Ltd) and Paul Foreman (Blue Devil Consulting) 6050600 6050600 Survey Period: February 2013 Disclaimer: while every care has been taken care to ensure the accuracy of this product, no representations or warranties about its accuracy, completeness or Middle Lake suitability for any particular purpose is made. Liability of any kind for any expenses, 6050400 6050400 losses, damages and/or costs which are or may be incurred as a result of this product being innacurate, incomplete or unsuitable in any way and for any reason 758400 758600 758800 759000 759200 759400 759600 759800 760000 760200 760400 760600 760800 761000 761200 will not be accepted. 5.3 Comparison of 2006 and current vegetation mapping A comparison of mapping output for Third Lake in 2006 and 2013 reveals numerous similarities and differences in vegetation type and extent. Differences in the total mapped area of each vegetation unit are presented in Figure 22. Broad-scale and fine scale anomalies are itemised in the following paragraphs. Figure 22: Histogram of total area by vegetation type at Third Lake as mapped in 2006 and 2013 Summary of broad-scale similarities and differences: • Overall slight decrease in extent of vegetation – from ~33 ha to ~32 ha is probably due to a difference in the definition of the study area. • The complete disappearance of Aquatic Herbland and Dwarf Floating Aquatic Herbland in 2013 is possibly the result of changes resulting from recent flooding (i.e. rapid hydrological fluctuations). • There has been a net reduction on the extent of mapped Tall Marsh since 2006 (~48% down to ~34.5%), once again possibly attributable to hydrological change. Note also the finer scale resolved mapping of species dominance within Tall Marsh with nine mapping units in 2013 compared with five in 2006. Ecological Vegetation Class (EVC) Assessment of the Kerang Lakes Ramsar Site Page 65 • Tall Marsh/Cumbungi (colonising) has apparently completely disappeared since 2006. However, this is inconclusive because this unit was regarded as problematic to identify in the field in 2013 at this wetland. • The apparent significant increase in Intermittent Swampy Woodland (in 2006 mapped as Red Gum Swamp, Red Gum Woodland, Red Gum Woodland and non-native trees, and Native remnant) is probably due to differences in the definition of the study area or differences in the interpretation of the boundary with Tall Marsh. Examination of the 2006 imagery may help resolve this question. • The apparent reduction in extent of Lignum Swamp (mapped as Lignum Swampy Woodland in 2006) is probably attributable to differences in mapping resolution and the interpretation of the boundary with surrounding EVCs. Summary of fine-scale similarities and differences: • A side-by-side comparison of the wetland vegetation units assigned to the south-western section of Third Lake in 2006 and 2013 is presented in Map 16. • Areas of Aquatic Herbland on the western side of the wetland around the outlet mapped in 2006 were no longer present in 2013. This is likely to be showing real change in vegetation distribution, influenced by the 2011 floods. • In 2006 Tall Marsh on the western edge of the wetland, north of the outlet channel, is mapped as being dominated by Cumbungi. In 2013 this Tall Marsh still supported extensive stands of Cumbungi but also incorporated a large proportion of River Club- rush. This either indicates an expansion in the distribution of River Club-rush between 2006 and or 2013, or that the presence of River Club-rush was overlooked in 2006. Ecological Vegetation Class (EVC) Assessment of the Kerang Lakes Ramsar Site Page 66 Map 16: Comparison of wetland Ecological Vegetation Classes Third Lake 2006 (left) and 2013 (right) Legend Ecological Vegetation Classes and [Mapping Units] Aquatic Herbland (EVC 653) [3; 4] Intermittent Swampy Woodland (EVC 813) [36] Lignum Swamp (EVC 104) [30; 42] Tall Marsh (EVC 821) [Ho et al. unit only] Tall Marsh / Cumbungi (EVC 821) [1; 11] Tall Marsh / River Club Rush (EVC 821) [6; 7] Tall Marsh / Cumbungi and Giant Rush (EVC 821) [18] Tall Marsh / Cumbungi and River Club Rush (EVC 821) [16] Tall Marsh / Cumbungi, Giant Rush and River Club Rush (EVC 821) [26] Tall Marsh / River Club Rush and Giant Rush (EVC 821) [43] Note: only EVCs that are visible in the current map extent are displayed on the legend Note: 2006 mapping (Ho et al., 2006) was provided by the North Central CMA Third Lake Third Lake 0 100 200 300 400 500 600 metres Coordinate System: GDA 1994 MGA Zone 54 Projection: Transverse Mercator Datum: GDA 1994 2011 Aerial Imagery courtesy of the North Central CMA Project: Ecological Vegetation Class Assessment for Reedy Lake, Middle Lake, Third Lake, Little Lake Charm and Racecourse Lake and surrounding areas in the Kerang Wetlands Ramsar Site Client: North Central Catchment Management Authority Author: Holocene Environmental Science Map Prepared: 25th March 2013 Surveyors: Damien Cook, Elaine Bayes and Karl Just (Rakali Consulting Pty Ltd) and Paul Foreman (Blue Devil Consulting) Survey Period: February 2013 Disclaimer: while every care has been taken care to ensure the accuracy of this product, no representations or warranties about its accuracy, completeness or suitability for any particular purpose is made. Liability of any kind for any expenses, losses, damages and/or costs which are or may be incurred as a result of this product being innacurate, incomplete or unsuitable in any way and for any reason will not be accepted. 5.4 Index of Wetland Condition Two IWC assessments were undertaken at Third Lake (Table 10). The first was assessed against the benchmarks of the original EVC’s while the second was assessed against the currently recognisable EVC’s. Assessment against the original vegetation Using the IWC methodology, the