Latest news with #gazania
Yahoo
3 days ago
- Science
- Yahoo
Imported flower escalating $5 billion threat in Australia: 'Massive problems'
Invasive species experts are sounding the alarm over a nasty weed continuing to sting the Australian economy, that outcompetes native vegetation, is extremely difficult to remove and is even still being sold at nurseries. The South African native flower gazania has proven far more adaptable than once believed, emerging as a serious invasive threat to Australia's native grasslands and grain-growing regions, a recent La Trobe University study has found. Dr Ali Bajwa's Weed Science group at La Trobe Institute for Sustainable Agriculture and Food (LISAF) collected thousands of seeds from environments across the country and studied how they grew under various conditions. He spoke to Yahoo News and said that what makes the gazania problem particularly urgent is the fact it has very few weaknesses. Invasive plants like gazania are already a major burden on Australian agriculture, contributing to over $5 billion in losses each year. Although popular as a drought-tolerant ornamental plant, gazania is highly invasive and thrives in disturbed soils and coastal habitats, where it spreads quickly by seeds. This aggressive growth allows it to outcompete native groundcovers and wildflowers, leading to a loss of native plant diversity. The dense mats it forms also alter soil composition and prevent the regeneration of indigenous species. Additionally, it provides limited habitat or food value for native insects and animals, further disrupting local ecosystems. Gazania, also known as treasure flowers, has now spread extensively across South Australia and parts of Western Australia, and it can be found colonising everything from coastal dunes and creek banks to wastelands, open grasslands, roadsides, and even cultivated and irrigated farmland. "We know they are quite widespread, but what we wanted to understand was if there are certain climatic conditions or soil types that are more favourable to gazanias compared to others," Bajwa said. Bunnings under fire for selling $5.50 item considered 'massive problem' Alarm sounded over toxic plant assisting in $4.3 billion issue Aussies told to hunt for invasive threat 'lurking' in gardens "And what we found is it has quite flexible germination potential across different temperatures, soil types, moisture gradients, and there aren't many limiting factors, unfortunately, in terms of its early establishment and germination. "One of the things we noticed was that if you bury them beyond a certain depth, they can't emerge from those deeper soil layers. Other than that, unfortunately, there aren't many weaknesses to exploit." Although gazania has long been recognised as an environmental weed, it has recently begun to invade grain cropping zones in South Australia's lower rainfall areas. Farmers are now struggling to manage its spread, as standard herbicides are proving largely ineffective. Initially introduced to Australia in the 1950s and '70s as a decorative garden plant, two varieties of gazania made their way here through discarded garden waste, including lawn clippings, seeds, and other plant material, enabling them to establish along roadsides and to take over native ecosystems. In regions with sandy, marginal soils, gazania infestations are rendering the land unproductive. Its hardy, drought-tolerant nature allows it to outcompete young crops, leading to widespread agricultural losses. "They've now started jumping the fence and getting into those really high-value conservation areas, but also into grain production systems, where they're causing massive problems and yield losses — and revenue losses in terms of the money spent to manage them," Bajwa said. "Restricting the sale and also declaring them a weed of some importance would go a long way — because then it all of a sudden raises more awareness among the public, and also gives weed management authorities a bit more focus to manage this. "We have a lot of other invasive species, and resources are quite limited, so further legislation on restricting their sale, propagation and planting would help. But we also need funding to do some of the research — the sort of work we're doing — to actually get ahead of the invasion curve and try to figure out what the potential management strategies could be. Bajwa encouraged the public to be aware of its dangers and the negative impacts the species can have. "Further planting, propagation and dispersal should also be discouraged," he said. The study, led by PhD student Muhammad Adnan from Dr Bajwa's Weed Science group at the La Trobe Institute for Sustainable Agriculture and Food (LISAF) and the Department of Ecological, Plant and Animal Sciences, was published in Frontiers in Agronomy. Do you have a story tip? Email: newsroomau@ You can also follow us on Facebook, Instagram, TikTok, Twitter and YouTube.
News.com.au
4 days ago
- Science
- News.com.au
La Trobe researchers warn gazania garden plant sold at Bunnings is ‘highly invasive'
A popular garden plant sold at Bunnings is even more invasive and potentially dangerous to Australia's natural environment than originally thought, new research has revealed. La Trobe scientists, writing in the Frontiers journal, warn that gazania daisies, a brightly coloured ornamental plant sold in nurseries nationwide, is a 'highly-invasive plant' that is beginning to impact grain production and grasslands across southern Australia. The plant can germinate and thrive in almost all conditions, the report shows, regardless of moisture, temperature or salinity levels. 'Due to its flexible growth requirements, gazania is now widespread and naturalised in a variety of habitats including coastal sand dunes, stream banks, wastelands, open grasslands, along roadsides and on cultivated and irrigated sites,' the report states. 'While gazania has long been considered as an environmental weed in Australia, a trend of 'jumping the fence' has been observed in recent years, infesting grain crop production fields in low-rainfall regions of South Australia. 'The presence of gazania in cropping fields is proving highly problematic, with farmers finding it difficult to control with common herbicides.' The researchers warn the weed is now 'rapidly spreading' across Australia and urgent long-term management strategies are needed to control the invasion. Gazania is native to South Africa and was introduced into Australia in the 1950s and 1970s. Invasive Species Council advocacy manager Imogen Ebsworth said the daisies should be banned from sale immediately. 'Gazanias are the perfect example of an escaped invasive garden plant that needs to be banned from sale,' she said. 'They are already banned in South Australia, but it's clear we need them pulled nationally. 'I urge the nursery industry to act on this new evidence and stop selling it … we've seen this story unfold far too many times. Ornamental plants that turn into unstoppable weeds, costing us billions in control efforts and wiping out native species in the process.' The council estimates more than 30,000 plant species have been imported into Australia for gardening, but 'fewer than a quarter' have been assessed nationally for their weed risk. Weeds cost the country more than $5bn a year in agricultural and environmental damage, the council said, with 'escaped' ornamental plants making up more than 70 per cent of the country's environmental weeds. Garden plants can escape and germinate in the wild via garden waste, lawn clippings and seed dispersal. Bunnings continues to sell gazanias, NewsWire has confirmed. According to the retail giant, each state and territory has its own list of declared weeds and laws and regulations for invasive weeds. The plants Bunnings sells across its stores differ depending on where they are sold and their declaration status. 'Like many nurseries and retailers, we sell a wide range of locally sourced plants across our stores and we work hard to create an assortment that caters to customer preferences and demand,' Bunnings director of merchandise Cam Rist said. 'As always, we closely follow all relevant local biosecurity regulations and the advice of regulators about the plants we sell.' The plant is also sold at other nurseries, including online marketplaces. The council argues 'self-regulation' has not worked and wants a federal government response. 'We've spent decades relying mainly on self-regulation, which just doesn't work,' Ms Ebsworth said. 'You can still legally buy plants that are banned in neighbouring states or overseas. 'Unless governments act, we'll keep selling the next lantana, the next gazania, straight into our backyards and bushland.'
