Arum Lily - a real problem plant

Calla Lily, White Arum Lily, Lily of the Nile, Egyptian Lily, Jack in the Pulpit, Florist’s Calla, Garden Calla, Pig Lily, Trumpet Lily, St Joseph’s Arum Lily, Funeral Flower, Death Lily are just some of the common names of this dreadful weed.

Arum is a large genus of flowering plants originating mainly from South Africa. It is thought they arrived in Australia with early settlers in the mid-19^th century. They were present in the Adelaide Botanic Gardens in 1858. The Arum Lily was a standard garden specimen and has a history of being a popular funeral flower.

Arum Lily populations in the wild are the result of escaping from gardens and are now an environmental weed found in wetlands, roadsides, forests, and urban reserves in all states of Australia. The Arum Lily, Zantedeschia aethiopica, is a listed environmental weed in the Appendix C of the Baw Baw Shire Weed Management Strategy 2020-2025. The Arum Lily is a widespread, invasive weed inour district – not to mention: Agapanthus, Angled Onion, Blackberry, Hemlock, English Ivy, Sweet Pittosporum, Tree Tobacco, et al.

1-Longwarry  2-Alex Goudie Park  3-Flower

The Arum Lily likes to grow in swampy, degraded, neglected areas where it completely outgrows native species. In places it forms stands so dense that it blocks the flow of creeks and drains. All parts of the Arum plant are toxic to humans and stock.

Although rare, there are cases of humans dying from Arum Lily ingestion. The plant contains high lvels of calcium oxalate a common component of kidney stones, and coniine, a toxin that inhibits the nervous system leading to suffocation. 

1-Roberts Ct Bush  2-Bellbird Park  3-Soccer Fields

Despite the significant detrimental effects on the environment by this weed, the Arum Lily is still sold in nurseries, is a popular garden plant, and is used extensively in the florist industry.

 “One man’s flower is another man’s weed” 

The value of stand-alone trees

It is not unusual to sometimes consider a single tree standing on its own in a paddock to contribute little and for there to be minimal consequence if removed. A stand-alone tree has values way beyond those ascribed to it by farmers as shelter trees for stock.

Just like a tree in a forest, or a woodland, or a copse, or a roadside/creekside corridor, a stand-alone tree still sequesters carbon, produces oxygen, filters the air, helps to lower ambient temperatures, and provides habitat.

Because of their isolated positions, paddock trees are exceptional ‘water pumps’; they transpire water into the atmosphere more efficiently and reduce the risk of salinity.

Many stand-alone trees are old remnant relics that are full of habitat hollows for wildlife. Research has shown that a single paddock tree can contain an ‘ecological zoo’ of hundreds of different species; birds, mammals, reptiles, invertebrates, bacteria, moss, lichen, fungi, etc. A lone paddock tree will often provide a ‘stepping stone’ for wildlife in search of suitable habitat.

Scattered paddock trees contribute to farm productivity by providing shelter for stock, fertility to the soil, reducing erosion, and lowering acidification of the soil.

Even a lone dead tree can contribute significantly to the biodiversity of a region.

Like King Cnut, we are more or less powerless to turn the tide of development in our region, but is it too much to ask for greater consideration be given to the conservation of those magnificent paddock sentinels – the stand-alone trees?

 

Birds and biodiversity

Birds are not on this planet just for birdwatchers to enjoy or for twitchers to make lists. The benefits of birdwatching are well documented: it connects us with nature, reduces stress, makes us aware of our environment, gives us exercise, provides sensory and cognitive stimulation, and more. Birdwatching is very accessible and can be done around the world or in our own back yards.

Birds though, are not just useful for our cultural, emotional, or physical benefit. Birds play an essential role in keeping our natural environment healthy and productive, and they are good bio-indicators.

Birds help control pests. The Straw-necked Ibis and Australian White Ibis are often referred to as the farmer’s friend for their appetite for locusts. The Black-shouldered Kite is an excellent rodent hunter. Black-faced Cuckoo Shrike populations irrupt when there is a plague of caterpillars. Pardalotes, thornbills, whistlers, and other foliage species help to keep leaf-eating insects under control.

L: Australian White Ibis. R: Black-faced Cuckoo-shrike

Many birds are effective pollinators as they inadvertently transfer pollen from plant to plant. Nectar eaters, the honeyeater families, are particularly good at this – New Holland Honeyeater, Eastern Spinebill, Yellow-faced Honeyeater, the wattlebirds and dozens more, are good examples. Healthy plant communities rely on pollination for reliable reproduction and genetic vigour. Even insectivorous bird species – thornbills, wrens, flycatchers, etc. – will at times act as pollinating vectors because their insect diet is often obtained within the vicinity of pollen-bearing flowers.

L: New Holland Honeyeater. R: Little Wattlebird

Fruit and seed-eating birds are often responsible for the natural distribution of many plant species. Plants cannot migrate and so must rely on the wind, water, birds, or other animals to spread their seeds. Birds can travel large distances in a short time and so become a plant’s best friend when it comes to seed dispersal. Pigeons, bowerbirds, parrots, Silvereyes, Mistletoebirds, are all well-known seed dispersers.

L: Crested Pigeon. R: Mistletoebird

Scavenger species like eagles, kites, hawks, ravens, currawongs, etc., help prevent the spread of disease by breaking down the carcasses of dead animals and returning their nutrients to the environment. Scavengers help keep roadsides, farmlands, parks, forests, etc., free of carrion and detritus.

L: Wedge-tailed Eagle. R: Pied Currawong

Nowadays, birds are frequently used to monitor environmental conditions. Bird monitoring and bird surveys are frequently carried out to assess the habitat value, evidence of pollution, effects of climate change, outbreak of disease, degradation due to human interference, biodiversity, etc.

Not just beautiful. Useful too