Hungry herbivores, fungal diseases and long hot summers are just a few of the challenges land managers face when attempting to re-introduce a threatened
plant species. But the biggest challenge of all may lie in calculating whether a reintroduction program has been successful.
“When we reintroduce a threatened plant species, we do so with the goal of creating a viable population that will be self-sustaining into the future,” says project leader Dr David Coates, from the Department of Parks and Wildlife, WA.
“The aim of our project [Project 4.3] is to examine the methods we use in our programs, in order to improve our success rates.”
Dr Coates and his team face a series of inter-related problems that begin with the challenges of propagation.
“Some of these species require unusual techniques to get them going, for example we need to use fire to extract the seeds from banksia cones.
“Sometimes seeds don’t propagate easily, either due to the specific soil mix or the difficulty of creating the right conditions. And other times we just don’t know why a particular species struggles to get going.
“We must always remain conscious that in the case of particularly rare species, we don’t have large amounts of seed to begin with, so we need to be very careful. Our margin for error is small.”
Even if the propagation is successful, the team must work to find a suitable habitat to reintroduce the young plants, and ensure there are no immediate threats.
“In Western Australia we are always on the lookout for dieback, which is an introduced pathogen and devastating soil-borne fungal disease. For the most part we can’t really combat it, other than by preventing access by people to affected areas to minimise its spread,” says Dr Coates.
“Both feral and native animal grazing are also threats, they are typically curious about our activities and have a taste for young seedlings. If we don’t fence them out, they will eat everything.
“We also need to keep an eye on the weather. Long hot summers can quickly undo all of our hard work and initial watering may be needed to assist establishment.”
In order to achieve the ultimate goal - a self-sustaining and viable population, a critical number of plants must survive to reproductive maturity.
“This will be a major focus of our research, looking at ways we can both measure and model levels of pollination, reproduction, recruitment and genetic variation. This will be challenging in some cases where the lifespan of a number of the shrubs and trees will usually outlast the lifespan of any given project.”
“We can then benchmark these results against natural populations.”
“It’s essentially a numbers game, where we need to discover how many plants need to be established in order to ensure a species’ survival. At the moment we aim for at least 250, but depending on the species, we may need many more.”
“Our research aims to provide the answers to these questions.”
Image: Lambertia orbifolia - Round-leaf Honeysuckle by Tatters/Flickr (CC BY-NC 2.0)
Professor John Woinarski of Charles Darwin University discusses the importance of averting extinctions of less charismatic animals.
The 2019–20 wildfires have severely impacted animals of all major species groups. Here, national experts on mammals, birds, reptiles, frogs and freshwater fish and crayfish present some of the key challenges for each group and how these will influence management and research priorities in the aftermath of the fires.
Cultural fire management is the way that Indigenous people have used fire to care for Country for thousands of years, and it continues today. The devastation wreaked by the 2019–20 bushfires across millions of hectares was a wake-up call for Australia and the world. Oliver Costello from the Firesticks Alliance explains how the fires demonstrated the need to listen to and care for Country.
Australia has one of the highest rates of plant endemism of any country globally. After the catastrophic fire season of 2019–20, Dr Rachael Gallagher and Professor David Keith are leading two teams to find out which species and ecological communities are most in need of immediate recovery.
The 2019–20 bushfires burnt over 12 million hectares of south-eastern and south-western Australia, causing abrupt losses of biodiversity at a scale never seen before. Over a billion animals were estimated to have died, but the figure is likely much higher. The Australian Government’s Wildlife and Threatened Species Bushfire Recovery Expert Panel is guiding the work of prioritising species and ecological communities for emergency interventions and determining what those actions should be. Hub Deputy Director and Expert Panel member Professor Sarah Legge takes us though the hows and whys of this prioritisation, and some of its challenges.