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)
It is Threatened Species Day on 7 September. If you are a threatened species in Australia, chances are you are on Indigenous-managed land, as it is the last stronghold for many species which have been lost from the wider landscape .
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Kanyirninpa Jukurrpa (KJ) Rangers in the Martu Determination have collaborated with Threatened Species Recovery Hub scientists to design a monitoring program for mankarr (the greater bilby). Martu people identified priorities for the bilby monitoring program, then worked with Dr Anja Skroblin from The University of Melbourne to co-develop a monitoring method which brings together Martu knowledge and practice with Western conservation science.
I am a proud Murri from the Kamilaroi Nation in north-west New South Wales. I grew up in western Sydney on Darug land and now live in Canberra on Ngunnawal land.
A new project is aiming to increase city kids’ connections with nature, threatened species conservation and Indigenous culture. Dr Georgia Garrard from RMIT University talks about this project, which will see Wurundjeri Woi-wurrung Traditional Owners working with kids at Carlton North Primary School in Melbourne and Gunditjmara Traditional Owners working with kids at Heywood Consolidated School in western Victoria.