Plants of the Goulburn Wetlands

 

 

Present day Goulburn: life on Mars and very pretty for at least a few weeks a year

Present day Goulburn: life on Mars and very pretty for at least a few weeks a year

 

Imagine if one of the Cookmai families — that once called Goulburn home for a few thousand years until a couple of hundred years ago — suddenly reappeared in the wetlands. We’ll put them there because it would be a lot safer than anywhere else in the neighbourhood … and besides, if they were to appear on Rocky Hill they’d be heartbroken to see their ancient corroborree ground smashed into bits and made part of a stone temple to war, while their young men’s initiation ground is fertilised with leaking oil from poorly serviced motor cars standing on the asphalt that now occupies the site. But even in the wetlands they would be amazed at the new plant dreaming. Gone is the old grassy forest and the two wide, deep waterhole-studded rivers. Instead there is a new hole where they previously might have gathered yam daisies. The kangaroos are still there, but the hare wallabies (Tasmanian Bettongs), bandicoots, koalas, brolgas, bustards and the soul of the plains, the stone curlews, have vanished leaving little or no trace. Above all, that sparse commodity, other humans, would have gone from wandering groups of 30 or so to the over 20,000 concentrated here today, that never wander off to give the land a spell. And all around them would be weeds from Europe, Turkey, the Holy Land, Armenia, America and Africa. Where the rush-lined river banks rang with the deafening chorus of bell frogs until the 1960s, only a few pobblebonks and small ratchet frogs remain, waiting for the rains. The plague minnows imported from the Caribbean Islands (even the Carib Indians are now extinct there) have eaten all the bell frog tadpoles, and there are millions of plague minnows since the last flood. They would recognise Rocky Hill, the Cookbundoons and Mount Narrangarill (that prominent peak unnoticed and unheard of by most modern day residents of Goulburn), and they would recognise a few familiar plants, but most plants there might have come from Mars, so separate are they from evolution in Australia. Even the part of Rocky Hill nearest the wetlands is covered by eucalypts that don’t belong here: blue gums from Tasmania and bangalays from the south coast that spread into the mined hillside from street plantings many decades ago. Only the area south of the Memorial contains its old native plants and even they may have been consigned to be part of a possible future lump of suburbia.

Hawthorn, Large-leaf Privet and a host of other weeds were among the most visible signs of life in the wetlands in 2010.

Hawthorn, Large-leaf Privet and a host of other weeds were among the most visible signs of life in the wetlands in 2010 …

So it is today that we present residents of Goulburn look at the wetlands and are only able to wonder what the vegetation there might have been. There are clues. Where the brick pits and old river course are, water plants have come to live, many of them native. But that is the result of change. After all the area was an industrial site and a paddock ploughed many times and grazed repeatedly by domestic stock long after the last big trees were felled. Old photographs show a few of the old trees and, importantly, there still remain a couple of locally indigenous trees in the neighbouring golf course: some ribbon gums and a cabbage gum or two, as well as yellow box and apple box in the steeper terrain. But we can only guess at the understorey. The closest intact riverside forests of any size persist with only a few weeds in the Towrang Valley. Their structure and composition gives us more substantial clues. If we had a bottomless pit of finances we might seek sediments in the river flat over 200 years old and pay a specialist in pollens to identify the changing vegetation, as was once done at Lake George.

The short of it is that when we came to the Goulburn Wetlands, we came to a weed infested paddock with some pools containing native freshwater plants. Over the few years we have been working on the site the ancient seed has re-emerged to surprise us every now and then, as with a clump of that native water fern, the four-leafed clover or nardoo, that appeared in one of the temporary pools in the old river. So we have had to do our best to reconstruct the vegetation that was probably there, within reason. Of course, we could have turned the place into another short-lived flower bed or weedy willow or elm patch, but one of our principal aims is to showcase the local flora and at the same time to restore lost habitat in the wetlands. This means we are utilising local provenance native plants.

But finding viable seed can be a problem. This is what happens when you live in one of the most biodiverse areas in Australia, but with a catch. While our forests, waterways and box woodlands contain possibly more plant species than the tropical rainforests, they are seldom apparent. This is because, unlike the stable climate of the wet tropics, Goulburn is subject to long droughts, floods, frosts, snow, heatwaves, fires and shrivelling winds. As a result our flora is mostly deciduous. Not the kind of deciduous seen at the top of the page, but far more subtle. While our few species of gums and wattles are always visible, our non-woody or herbaceous plants are numerous but shy. They may disappear not just for several seasons, but sometimes for many years. For one week in 2005 the hills around my own home were covered in little red orchids, a species not seen by the neighbourhood containing at least three properties with avid naturalists in them, for  at least 15 years. And they haven’t been seen since. When we first surveyed the Goulburn wetlands, the water was covered in ferny azolla and pocked by large stands of great bulrush and cumbungi. None of these species have been seen since the 2010/11 floods, but they are likely to come back. Aesthetically and physically, Goulburn presents a moving feast of native plants. You can never be sure what the place will look like, but the appearance of certain plant species is sure to reflect something going on in the environment.

 

... but the old river and brick pit were brim-full of native plants, in this case, ribbon weed.

… but the old river and brick pit were brim-full of native plants, in this case, ribbon weed.

What are local provenance native plants?

Banksia spinulosa June 2004

Hairpin Banksia, a useful and hardy local native, but sometimes very hard to find viable seed

Australia is a big continent and plants that are native to one part of the country may have bad ecological effects when transplanted to another site.

A classic example of this is Cootamundra Wattle Acacia baileyana. Although a stunningly attractive plant in flower, this species has been shown to readily hybridise with other local feathery-leaved wattles, sometimes creating sterile hybrids between the two species. These hybrids are more vigorous than either parent and are likely to eventually outlive them. This leaves behind few of the local native plants, a few Cootamundra wattles and lots of longer lived, sterile plants. After some years these sterile plants die out, leaving no wattles in their place. Since feathery leaved wattles are one of the food resources most relied on by native insects, birds and small mammals (such as sugar gliders), the ecosystem as a whole can start to collapse. A different type of problem is caused by the commonly grown Rosemary Grevillea Grevillea juniperina. This species readily hybridises with local grevilleas, like the wattle, but unlike them, causes fertile hybrids. These fertile hybrids go on to change the entire genetic structure of species that have evolved together with local species of insects, birds, mammals and sometimes reptiles. Again a biological tragedy.

As a result, government funding and supervisory agencies do their best to ensure that replanting and restoration of areas is carried out using genetic material that is closest to what may have been there. This is called local provenance.

What does that mean when it comes to planting stuff in the Goulburn Wetlands?

  • For most plants that grow on land, we need to obtain genetic material (seeds, cuttings, etc.) ideally from within 20 kilometres of the planting site. For instance, the ribbopn gums found at Lake George, just a few minutes away by car, are quite genetically distinct from the ones growing in Goulburn and Towrang. We therefore try to obtain material that was originally native to that area (and not from street trees or park trees that may have come from somewhere else).
  • For grasses and many graminoids (grass-like plants such as rushes, reeds, grass-trees, etc.), seeds are far more widely dispersed in nature, so we can look further afield, such as from Canberra to Mittagong.
  • Aquatic plants are often dispersed by ducks and other waterfowl, which fly very long distances. In their case we can probably look to areas with similar climates that are joined, such as from Melbourne to Bathurst, but not to the coast.
Great bulrush, floating fern (azolla) and grey teal. Only the grey teal are still here at the moment.

Great bulrush, floating fern (azolla) and grey teal. Only the grey teal are still here at the moment.

What plants are now present in the wetlands?

As a result the plants occurring in the wetlands can be classified into three groups:

  1. Originals: native plants that remain or have re-invaded the site (such as water ribbons, nardoo and a little speargrass)
  2. Planted local provenance natives: native plants that have had their seeds collected from nearby by members of the Australian Plants Society, grown on and planted out in the wetlands
  3. Weeds: plants that have come from other places with much lower or even negative ecological values and many of which are classed as noxious by governing authorities (such as hawthorn, Armenian blackberry or African lovegrass).

Below is a list of plants that occur in the wetlands. They are listed alphabetically by botanic name and identified as belonging to one of these three groups. This list will be updated from time to time. Internet technology permitting, I will list each species at the bottom of this page and eventually link it to its own page with a photo, or a page devoted to its group.

 

  • Acacia baileyana, Cootamundra Wattle, 3, a few young plants, being removed
  • Acacia paradoxa, Kangaroo Thorn, 1, one plant in remote corner
  • Acetosella vulgaris, Sorrell, 3, scattered common weed, part of routine management
  • Arctotheca calendula, Capeweed, 3, seasonally common but scattered ephemeral weed, best managed when readily apparent
  • Austrodanthonia spp., Wallaby Grass, 1 and 2, a few survivors suffering friendly fire with many more direct seeded in 2012, some emerging and seeding
  • Austrostipa spp., Spear Grass, 1 and 2, a few surviving stands suffering friendly fire with more direct seeded in 2012
  • Azolla pinnata, Ferny Azolla, 1, covered the entire pondage a few years ago, now scarce or absent
  • Banksia marginata, Silver Banksia, 2, about 50 planted in 2012
  • Banksia spinulosa, Hairpin Banksia, about 50 to be planted in 2013
  • Bromus catharticus, Prairie Grass, 3, abundant weed of fertile sites, part of routine management
  • Bromus diandrus, Great Brome, 3, scattered thickets, many of which are part of routine management
  • Callistemon sieberi, River Bottlebrush, 2, 100 planted 2013 at south-western edge of main pond
  • Carex appressa, Tall Sedge, 1 and 2, one of our most valuable assets, fast growing and hardy tussock providing excellent habitat and water treatment
  • Cerastium glomeratum, Mouse-eared Chickweed, 3, small common weed, widely scattered, part of routine management
  • Chenopodium pumilio, Small Crumbweed, 1, fast appearing summer colonist, often suffering friendly fire
  • Chloris truncata, Windmill Grass, 1 and 2, direct seeded 2012, has shown up both in and well outside seeded areas in 2013
  • Chrysocephalum apiculatum, Yellow Buttons, 1, uncommon survivor of past disturbance
  • Cirsium vulgare, Spear Thistle, 3, serious noxious weed, especially colonising dried pondage, part of routine management
  • Conyza canadensis, Canadian Fleabane, 3, serious noxious weed of berms only appearing en masse in late 2012/3, difficult to manage effectively, needs good strategy
  • Craspedium variabilis, Billy Buttons, 2, 20 planted in 2012, flowered then disappeared; hopefully they will return
  • Crataegus monogyna, Hawthorn, 3, widespread small tree or shrub, initially meant to retain some for retaining small bird habitat, but nearly all now dead
  • Cynodon dactylon, Couch, possibly 1, a cosmopolitan species including the Southern Tablelands, who knows what the provenance of our plants may be, useful lawn and weed competitor, though invasive
  • Dianella longifolia, Smooth Flax-lily, 2, 50 planted in 2012, sudden rapid growth spurt in late summer 2012/3, good tussock species
  • Dichanthium sericeum, Queensland Bluegrass, 2, direct seeded in 2012, several plants have emerged and set seed
  • Dodonea viscosa, Sticky Hop-bush, 2, 50 planted in 2012, rapid growth in pink guards, 1.5 metres in 5 months
  • Echinochloa sp., Millet, direct seeded as part of nurse crop, provides seeds to small granivores
  • Echium plantagineum, Paterson’s Curse, 3, serious noxious weed, scattered but common in weedy grassland, part of routine management
  • Egeria densa, Dense Waterweed, 3, occasional in old watercourse, management options to be considered
  • Eleocharis atricha, Tablelands Spikerush, 1, common colonist of muddy shores, excellent waterfowl food and habitat
  • Elodea canadensis, Canadian Pondweed, 3, several thickets in old watercourse, management options to be considered
  • Eragrostis curvula, African Lovegrass, 3, serious noxious weed requiring herbicides tougher than bioactive roundup, part of routine management
  • Eucalypts globulus, Tasmanian Blue Gum, 3, on sapling/small tree to be removed
  • Eucalyptus amplifolia, Cabbage Gum, 2 (probably once 1), excellent very fast growing habitat tall tree, 3 planted to date, growing to 2 metres in 3 months, this species loves this site
  • Eucalyptus gregsoniana, Wolgan Snow Gum, 2, 2 planted in 2012, fell over when guards removed, may consider coppicing to produce mallee form
  • Geranium solanderi, Native Geranium, 1, common among tall grasses, a major victim of friendly fire
  • Hakea salicifolia, Willow-leaved Hakea, 2,  50 planted in 2012, fast growing dense habitat shrub
  • Hakea sericea, Silky Hakea, 2, 100 planted 2012/3, hopefully our main prickly shrub providing habitat for small birds, several fell over when guards removed
  • Hakea teretifolia, Dagger Hakea, 2, 50 planted 2013, good habitat and daunting particularly prickly shrub
  • Hemarthria uncinatum, Mat grass, 1, occasional patches in grassland, suffering friendly fire
  • Hirschfeldia incana, Buchan Weed (Mustard), 3, serious abundant weed, rapid colonist of cleared areas, part of routine management
  • Holcus lanatus, Yorkshire Fog, 3, scattered patches throughout, part of routine management
  • Hypochoeris radicata, Flatweed, 3, abundant cosmopolitan weed found in even natural bush, too hard list for management yet
  • Juncus spp., Rushes, 1 and 3, common and basic component of wetlands, good mud colonist, utilised by several native bird species
  • Lachnagrostis filiformis, Blowaway Grass, 1, common summer/autumn colonist of bare ground, prolific seeder, good granivore plant
  • Leptospermum lanigerum, Woolly tea-tree, 2, fast growing when using pink guards, 50 planted 2012 by water’s edge
  • Lomandra longifolia, Spiny Matrush, 2, 50 planted 2012, slower growing tussock but hopefully good habitat plant
  • Lotus suaveolens, Hairy Birds-foot Trefoil, 3, uncommon weed, part of routine management
  • Lycium ferocissimum, African Boxthorn, 3, once common habitat and nesting site for birds
  • Marsilea mutica, Nardoo, 1, one colony in the pool of the old river nearest the bridge, floating/submerged when pool full, groundcover when pool dried
  • Melaleuca parvistaminea, Highlands Honey-myrtle, 2, 150 planted 2012/3 along waterline, major cover for waterfowl, hopefully tolerates immersion
  • Microlaena stipoides, Weeping Grass, 1 and 2, direct seeded in grassland October 2012, a few plants emerged so far
  • Modiola caroliniana, Red-flowered Mallow, 3, abundant summer weed, needs targeted management plan
  • Nasella neesiana, Chilean Needlegrass, 3, major serious noxious weed covering 90% of land before restoration, prolific reseeder, part of routine management
  • Nasella trichotoma, Serrated Tussock, 3, scattered patches, serious noxious weed with long-lived seed, part of routine management
  • Onopordum illyricum, Illyrian Thistle, 3, scattered plants appeared in summer 2012/3, part of routine management
  • Ottelia ovalifolia, Swamp Lily, 1, uncommon in pools of old river, we need to establish more of this species
  • Oxalis chnoodes, Fuzzy Wood-sorrel, 1, common naturally occurring colonist
  • Panicum effusum, Hairy Panic, 1, widespread summer colonist
  • Paspalidium aversum, Panic Grass, 2, uncommon, direct seeded 2012
  • Paspalum dilatatum, Paspalum, 3, common and aggressive summer weed, part of routine management
  • Paspalum distichum, Water Couch, 1, common floating/ground cover species in north-western pools, remaining when dried out
  • Persicaria lapathifolia, Pale Knotweed, 1, valuable bird habitat and winter fodder for coots and moorhens, abundant in 2011, most accidentally poisoned 2012
  • Persicaria prostrata, Creeping Knotweed, 1, common colonist of dried pools
  • Phalaris aquatica, Phalaris, 3, serious aggressive weed, until tall native grasses establishes, provides good cover for migratory waders, part of routine management
  • Phragmites australis, Common Reed, 1, large stand to the south-west of the main pond
  • Poa labillardieri, River Tussock, 2 (likely also 1), fast growing, canopy forming tussock, good habitat, 100m planted 2012
  • Poa pratensis, Kentucky Bluegrass, 3, occasional weed in grassland, part of routine management
  • Polygonum plebeium, Small Knotweed, 1, common coloniser of dried pools
  • Potamogeton crispus, Curly Pondweed, 1, occasional, occurs in still ponds
  • Ranunculus papulentis, Large River Buttercup, 1, dominates north-western pool, attractive flowering plant
  • Ranunculus sceleratus, Celery Buttercup, 3, abundant around main pondage, management strategy needed
  • Rubus armenica, Armenian Blackberry, 3, serious and widespread weed, burnt and poisoned in 2011/2, some recurring, small bird, fox and rabbit habitat, removal of this removed rabbits effectively
  • Schoenoplectus validus, Great Bulrush, 1, several clumps, vanished since 2010 floods
  • Setaria sp., Pigeon Grass, 3, common autumn weed, not a major problem, part of routine management
  • Sonchus asper, Prickly Sowthistle, 3, common weed throughout, part of routine management
  • Sonchus oleraceus, Sowthistle, 3, uncommon weed throughout, part of routine management
  • Themeda triandra, Kangaroo Grass, 2, not yet observed, direct seeded 2012
  • Triglochin procera, Ribbon Weed, 1, abundant, major water plant feeding coots and moorhens and providing food and habitat for most other waterfowl, excellent nutrient filter, very fast growing in summer
  • Typha orientalis, Broad-leafed Cumbungi, 1, several clumps, vanished since 2010 floods

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