Vegetation Communities of the City of Banyule by Cam Beardsell June, 2000 Contents 1 INTRODUCTION 1 2 PHYSICAL ENVIRONMENT 2 2.1 Physiography 2 2.2 Landforms 3 2.3 Climate 5 3 METHODS 6 3.1 Field Survey and vegetation mapping 6 4 VEGETATION COMMUNITIES 7 4.1 Banyule vegetation community classification 7 4.2 Vegetation community definitions 8 4.3 Vegetation community descriptions 11 5 ACKNOWLEDGEMENTS 48 6 REFERENCES 48 Appendix 1 Indigenous species that occur (or are likely to have occurred) in Banyule, their significance and their distribution across vegetation communities 1 INTRODUCTION The author was commissioned by Banyule City Greater Melbourne and Port Phillip Catchment. In Council to prepare a vegetation community map common with other lowland areas, it has had a high and accompanying report. The City of Banyule is impact from human settlement. This has occurred located 12 km north east of Melbourne and in every conceivable form. Land clearing, urban contains 63 sq km. A preliminary survey was housing and industrial development, recreation and conducted to assist in the preparation of a service utilities, vermin, weeds and pollution. vegetation community classification. This and existing data sets were reviewed to prepare an Banyule still supports a high diversity of inventory of plant species for Banyule. The indigenous plants. 401 species (possibly 70% of information will assist in the identification of the original flora) have been confirmed over the significant species and stands of vegetation and the last five years (category 1 plants in status column formulation of appropriate management procedures of Appendix 1). Most of these were observed and revegetation programs by land managers and during field work for this study conducted between the general public. May 1999 and March 2000. However, 176 species (44%) are known from Banyule only at few locations and in small numbers (e.g. most of the forty or so species of orchids). These species are Scope of the Study: considered locally rare or threatened and may not The consultant was required to - survive beyond the short-term unless appropriately managed (category 1 m of Appendix 1). 1) describe the vegetation communities and sub- communities that occur or have occurred in Up to 170 other species still known from the Banyule. Define their landforms, status, surrounding district may have been eliminated distribution, character species and structure, from Banyule since settlement. Some remain only provide ecological descriptions and identify as re-established populations. Systematic botanical significant stands. survey will locate a proportion of these species in Banyule. They will most likely include spring 2) prepare a vegetation map of the City of ephemerals (e.g. Hypoxis, Levenhookia) and others Banyule. including Veiled Fringe-sedge, Grassy Bindweed 3) prepare a descriptive report and plant list to and Tufted Bluebell which were located just accompany the vegetation map. beyond the municipal boundary. This will provide a foundation to a conservation Banyule now contains less than 10% of its original management program for the preservation and native vegetation cover. Half of this is degraded enhancement of indigenous vegetation and and only a tiny proportion is considered intact. All conservation values of Banyule. Central to this is surviving stands of native vegetation are significant the protection of streamways and improvement of in this context. This is particularly so for the habitat links to adjacent stands by restoration and reserves with highest indigenous species diversity revegetation programs. (St Helena and Harry Pottage). This report provides a companion flora and Another point of interest is that 28 of the 35 sub- vegetation community study to the Sites of Faunal communities (80%) recorded for Banyule are and Habitat Significance of North East Melbourne considered threatened in Victoria. Accordingly, (NEROC study; Beardsell 1997). This examines Banyule has (or had) a high proportion of the zoological significance of sites in the City of threatened species. Communities best preserved in Banyule (NEROC sites 23-28, 31-34, 44 and 45- the City of Banyule include floodplain riparian 48). Flora studies by the author in adjacent areas woodland and riparian scrub of the Yarra River include Yarra Valley Parklands and Plenty Gorge and seasonal and permanent wetlands of the Yarra Park. floodplain. High quality remnants occur of box - stringybark woodland in St Helena Flora Reserve and plains grassy woodland (alluvial plains) at Simpson Army Barracks and Harry Pottage Summary Reserve. Communities least preserved include plains grassy woodland (volcanic plains) of the The foothills and riverine plains are the most Darebin Valley and gully woodland and valley diverse area for native plants and animals in the grassy forest of the St Helena foothills. 1 2 PHYSICAL ENVIRONMENT 2.1 Physiography Eight major geological formations occur in the City surfaces (e.g. river alluvium). Over time the of Banyule (Geological Survey of Victoria, 1972). In basalt decomposed to deep black soils. The descending age these are: land surface has been heavily weathered and all that remains are cappings around the rim of 1 Silurian mudstone/siltstone. The Silurian river alluvium deposits. Distribution: Greenhill formations are deposition beds from ancient Road to Diamond Creek Road and between seas which have undergone uplift and erosion south end of Beales Road and Beale Reserve at phases over the last 150 million years to form St Helena. the foothills of North East Melbourne. Siltstone is the oldest and lowest stratum of the Silurian 5 Tertiary marine sand-crest. Brighton Group formation (446-430 million years old) and stranded coastal dune system (Red Bluff Sands) typically occurs in proximity to anticlines from marine transgressions (phases of high sea (upfolds in the earths crust). Weathering has level) of the Upper Pliocene Epoch.. removed the upper Silurian strata, exposing the Distribution: south from Mont Park along siltstone stratum. Distribution: north-east Waiora Road to Ivanhoe. section. 6 Quaternary volcanics. These formed from lava 2 Silurian sandstone/shale. Sandstone is the flows in the early Quaternary Period (1.8 youngest (upper) strata of the Silurian million to 800 000 years ago during the formation (430-416 million years old). It is Pleistocene Epoch). The flows which related to the presence of synclines (downfolds originated from volcanic cones north of in the earths crust) which bury the upper Epping, moved down the Darebin Valley, Silurian strata, preserving them from erosion. burying older land surfaces (e.g. Silurian Much of the sandstone strata has been eroded sandstone). In Banyule, the lava flows form the away in the uplifted foothills to the north and leading edge of the Western Volcanic Plains. east of the City of Banyule. This has exposed They have been subsequently covered by a silt the deeper mudstone/siltstone strata. plain derived from eroding higher land surfaces Distribution: all sections except the north-east on sedimentary formations to the east. and the volcanics west of Waterdale Road; Distribution: Waterdale Road to Darebin Creek notably the central section east of Plenty River and in the north at Bundoora. and smaller outcrops of the alluvial plains west 7 Older Quaternary high level alluvium. of Plenty River. Pleistocene Epoch (1.8 million to 10 000 years 3 Tertiary river sand-plain. This formed in the ago) alluvial escarpments and high terraces of early Tertiary Period (Palaeocene Epoch of 65- Yarra River and outwash plain-slopes above 54 million years ago). A large ancestral stream major tributaries. Deposition from prior rising in the Great Dividing Range, deposited courses of the Yarra eroding into the valley alluvium as it meandered across the plain. This develops broad alluvial fans. These are most was later covered by late Tertiary lava flows. evident on the neck of meander terraces. Over the Quaternary Period (last 1.8 million Outwash plain-slopes consist of colluvial years) the terrain has uplifted. The basalt has deposits eroding from higher land surfaces. The been eroded away to expose the underlying alluvium consists of gravel, silt and sand while Silurian formations and disjunct exposures of the colluvium is composed of clay and silt. river alluvium. The sand-plain consists of Distribution: restricted to rivers and major broad sand-ridges interspersed with seasonally creeks. damp saddles in gully headwaters. Distribution: 8 Newer Quaternary alluvium. Recent Epoch hill-crests between Greensborough and St (last 10 000 years) river and swamp alluvium Helena. of the lower terrace and floodplain of Yarra 4 Tertiary volcanics. Hill-crest cappings remnant River and Plenty River and valleys of their from Greensborough Phase lava flows of the tributaries. The strongly dissected valleys are late Tertiary Period. The precise age is being actively entrenched by youthful creeks. uncertain, estimates ranging from the Miocene This is developing floodplains of depositional Epoch (24-5 million years ago) to as late as the clay, coarse and fine grained sands and organic Upper Pliocene Epoch (3-1.8 million years silts. Distribution: widespread along river, ago). The latter being continuous with the creek and gully floodplains. Pleistocene flows of the Quaternary volcanics (see below). The flows buried earlier land 2 2.2 Landforms The City of Banyule occurs on the transition of the VOLCANIC PLAIN Coastal Plains, Western Volcanic Plains and the foothills of the Eastern Uplands physiographic Quaternary volcanic silt plains: low-lying areas of regions. Three physiographic zones have been flat to gentle relief on the leading edge of the identified as occurring in the City of Banyule by Western Volcanic Plains east of Darebin Creek. The Beardsell (1997). These are the Yarra Lowland silt plains lack stony crests and gilgais occurring on Alluvial Plains, Plenty Lowland Volcanic Plains and stony plains west of Darebin Creek. Soils on more Plenty Lowland Hills. elevated sections are grey-black duplex containing surface loams derived from nearby volcanic and Landform groups have been correlated to vegetation sedimentary sources.