Honey locust tree

Article by Rhea Phalan, vector and pest plant officer, Sunshine Coast Council

Spikey food tree of ancient megafauna found on the Sunshine Coast

There are not many plants found on the Sunshine Coast that’s spikes can compare to those of the honey locust tree (Gleditsia spp.). It is thought that the honey locust evolved its spikes during the Pleistocene period to help avoid being eaten by megafauna like the mammoth and the mastodon. The spikes must have worked well to fend off these giants because it survives to this day in its native range in North America where it grows in both temperate and subtropical forest ecosystems. Modern day North American animals such as deer and squirrels are able to eat the leaves and pods of the honey locust tree as they are small enough to manoeuvre in between the spiky stems to access them, unlike the megafauna of the Pleistocene who were not so agile. Mites, moths and other bugs also play a role in eating the honey locust tree so it doesn’t become too dominant in its native forests.

Deer, squirrels, rabbits and bugs were not the only ones to use the honey locust tree, it also became valued by people for its wood, as an ornamental and as a nitrogen fixing plant, for medicine and a fodder plant for domestic animals like cows, horses and goats. This led to it being exported from North America to other countries across the world including Australia where unfortunately the favourable climate and lack of predators has meant that it has become a weed. Honey locust is high on the priority list for Biosecurity Queensland and the Sunshine Coast Council as it has not yet become established here but does have the potential to cause significant damage to our ecosystems including wildlife, to farms and people.

A couple of honey locust trees were recently found in the Sunshine Coast hinterland. Council has been working with residents to eradicate them. Here is Katie Quirk’s story

"After recently purchasing a small farm we were keen to educate ourselves on local issues and reference to the Sunshine Coast Regional Council's website and local chat groups on social media were a helpful source. From here, we were alerted to the invasive honey locust tree that had been reported locally. During a routine check of the paddocks we identified a tree that looked similar to the species that council was warning residents about. We followed the procedure that was set out on council's website and reported our finding.

After some discussions with Biosecurity Queensland and Queensland Herbarium, we received confirmation that the photos provided were a 90% match to the honey locust tree, but a sample was required for certainty. Following this, we started discussions with the vector and pest plant team within council who arranged for a site visit to confirm the species. The attending council officer was very helpful and accommodating and provided us with informative brochures about the honey locust tree and other invasive species that may be in the area along with appropriate management and removal techniques.

We appreciated council's support during this process and we look forward to working with them in implementing a weed and pest plant management programme for our farm. We also aim to consult with local wildlife and landcare groups to revegetate certain parts of our property with appropriate species that will benefit both our stock and native wildlife."

Sunshine Coast Council has weed control hire equipment available free of charge to assist you to manage invasive plants on your property. If you think you may have a honey locust tree on your property it is important to report it to Biosecurity Queensland and Sunshine Coast Council. For more information on priority invasive plants on the Sunshine Coast please visit our website.

References

• Blair R.M. 1990 ‘Gleditsia triacanthos L. Honey locust’ United States Department of Agriculture Publications
• Boggs J. 2018 ‘Honeylocusts and Mastodons’ The Ohio State university Extension.