During periods of drought, a native Australian grass, Tripogon loliiformis, “plays dead” to reserve its energy for when it is later resurrected by water, according to researchers from the Queensland University of Technology (QUT). While a few other plants do this too, all of them known as “resurrection plants,” the QUT team notes that this ability may provide genetic keys to designing plants with a tolerance for increasing global temperatures.
“Global climate change, increasingly erratic weather and a burgeoning global population are significant threats to the sustainability of future crop production, but resurrection plants present great potential for the development of stress tolerant crops,” Dr. Brett Williams, one of the study researchers from the QUT, said in a news release, adding that their findings could be applied to world food crops such as chickpeas.
by Willem Van Cotthem (Ghent University – Belgium)
When preparing for the Olympic Games in 2000, the authorities of the City of Sydney decided to create a dramatic change in certain parts of the city by introducing spectacular plantations of trees, shrubs and flowering plants. To name only two wellknown areas in the city center that turned completely green in a very short period : Cockle Bay Wharf and Darling Harbour. The secret for this fantastic success : the use of TerraCottem soil conditioner (TC) in the containers at the waterside of Cockle Bay Wharf and on the roof top of Darling Harbour, where a huge hanging garden was created (www.terracottem.com).
TerraCottem soil conditioner was applied to solve the problems of regular watering of the containers with trees, shrubs and ornamental plants, used to embellish the waterfront at Cockle Bay. The potting soil in the containers was mixed with TC at a dosage of 5 g TC per kg of substrate. As TC stocks water and nutrients, it limits the need for regular irrigation in a significant way. As it also stimulates root growth and microbiological activities in the substrate, it improves plant growth in a spectacular way, whilst reducing water and fertilizer consumption.
For the same need of limiting the volume of irrigation water and fertilizers, the City of Sydney decided to mix TC soil conditioner with the substrate on the rooftop (also less weight !). A number of weeks after planting and seeding with typical species of the 5 continents, this rooftop garden became a splendid success. It is visited every year by tenthousands of visitors.
A birdseye view on Darling Harbour rooftop garden
These two success stories with TerraCottem soil conditioner in landscaping projects of a city like Sydney show that TC can be used in extreme conditions for saving water and fertilizer. What was realized within the “concrete desert” of this city, can also be achieved in other cities of the world and in all desertlike areas of the drylands.
Greening of a rooftop or an avenue is submitted to the same irrigation problems as a reforestation project or a vegetable garden in the drylands. TC can be used as an effective tool in the combat of desertification.
Janet Brook believes it is time for greater recognition of women in agriculture. (Michael Dulaney – ABC)
Outback women leading way for arid land management
By Michael Dulaney
Janet Brook has watched the slow progress on issues facing women in the outback – from feral animals to gender politics and the tyranny of distance.
She lives with her husband, Anthony, and their four children on Cordillo Downs, an 8000 square kilometre cattle station in the far north east of South Australia.
For the past six years, Janet has been the presiding board member of SA Arid Lands Natural Resources Management (NRM), a group that works to balance the needs of the environment and those of people living in remote areas.
She joined other women working in land management throughout rural SA at the Arid Lands Women’s Retreat in Marree last month to chew over the issues facing pastoral businesses.
Janet told ABC North and West’s Sarah Tomlinson networking events like the retreat are helping to shift the traditional view of agriculture from being male-dominated.
“I think we need to change that stereotyped image of men in agriculture, it’s definitely not the case,” she said.
“Maybe men in the past have been more visible and maybe the ladies have taken the behind the scenes type roles but I think that’s changing more and more as time goes on.
“Women are getting more opportunities to take part and maybe technology has helped that too.”
While the view of gender roles in agriculture is slowly shifting, Janet said the challenges facing natural resource managers have remained largely the same for many years.
Are shrubs really a sign of declining ecosystem function? Disentangling the myths and truths of woody encroachment in Australia
by David J. Eldridge and Santiago Soliveres
in Australian Journal of Botany 62(7) 594-608
Since European settlement, there has been a dramatic increase in the density, cover and distribution of woody plants in former grassland and open woodland. There is a widespread belief that shrub encroachment is synonymous with declines in ecosystem functions, and often it is associated with landscape degradation or desertification. Indeed, this decline in ecosystem functioning is considered to be driven largely by the presence of the shrubs themselves.
This prevailing paradigm has been the basis for an extensive program of shrub removal, based on the view that it is necessary to reinstate the original open woodland or grassland structure from which shrublands are thought to have been derived. We review existing scientific evidence, particularly focussed on eastern Australia, to question the notion that shrub encroachment leads to declines in ecosystem functions. We then summarise this scientific evidence into two conceptual models aimed at optimising landscape management to maximise the services provided by shrub-encroached areas. The first model seeks to reconcile the apparent conflicts between the patch- and landscape-level effects of shrubs. The second model identifies the ecosystem services derived from different stages of shrub encroachment. We also examined six ecosystem services provided by shrublands (biodiversity, soil C, hydrology, nutrient provision, grass growth and soil fertility) by using published and unpublished data. We demonstrated the following: (1) shrub effects on ecosystems are strongly scale–, species- and environment-dependent and, therefore, no standardised management should be applied to every case; (2) overgrazing dampens the generally positive effect of shrubs, leading to the misleading relationship between encroachment and degradation; (3) woody encroachment per se does not hinder any of the functions or services described above, rather it enhances many of them; (4) no single shrub-encroachment state (including grasslands without shrubs) will maximise all services; rather, the provision of ecosystem goods and services by shrublands requires a mixture of different states; and (5) there has been little rigorous assessment of the long-term effectiveness of removal and no evidence that this improves land condition in most cases. Our review provides the basis for an improved, scientifically based understanding and management of shrublands, so as to balance the competing goals of providing functional habitats, maintaining soil processes and sustaining pastoral livelihoods.
The Big Scrub is gone; destroyed by loggers and cattle farmers a century ago. What was once Australia’s largest subtropical rainforest—900km2 of biodiversity—is now largely home to cows and grass. Even between these two components many landowners still struggle to enforce balance. Thistle-covered paddies, eroded hillsides, compacted soils with sparse vegetation—scars from this struggle cover the region’s rolling lowlands..
Yet the struggle is an unnecessary one, as one farm in the region is demonstrating. Observe nature; learn to work with it rather than against it. These are principles of permaculture and the basis of the Grazing Method at Zaytuna farm (ZGM). We know that the most sustainable—the most balanced—designs are those that most closely mimic natural ecosystems. As Joel Salatin observes:
“Herbivores in nature exhibit three characteristics: mobbing for predator protection, movement daily onto fresh forage and away from yesterday’s droppings, and a diet consisting of forage only.”1Hence the ZGM practices short-term cell rotations.
Given the predicted changes in rainfall patterns for many Mediterranean climate regions, identifying seed tolerance to moisture stress in the earliest phase of plant development is an important consideration for species conservation, management and restoration.Here, we used polyethylene glycol (PEG 8000) to induce plant water deficit similar to drought stress in a field situation.
Seeds of four Western Australia Banksia R.Br. (Proteaceae) species were incubated at seven levels of moisture potential (0 to -1.5 MPa) and three constant temperatures (10°C, 15°C and 20°C).
In the absence of moisture stress, germination was uniformly high, but increasing drought stress led to reduced and delayed germination in all species. Overall, the threshold moisture potential value for a significant decline, and delay, in germination was –0.25 MPa.
Results suggested that one species (B. coccinea) is likely to be most vulnerable to germination failure under predicted changes in rainfall patterns, whereas another (B. media) is likely to be less vulnerable.
There was significant variation in population response to drought stress. However, this variation could not be explained by rainfall across species distributions. We discuss the PEG approach for assessing seed sensitivity to moisture stress, particularly in the context of shifting rainfall under climate change.