New studies indicate that Marri trees are essential for the survival of over 80 native bee species in the South West of Western Australia. This area is known to be one of the world’s richest ecosystems, but it is also facing significant threats to its biodiversity.
Recent research led by Curtin University has highlighted the vital role Marri trees play in supporting more than 80 species of native bees in Western Australia’s South West region, a globally renowned biodiversity hotspot.
Dr. Kit Prendergast, the lead author and an Adjunct Research Fellow at Curtin’s School of Molecular and Life Sciences, noted that the Marri tree (Corymbia calophylla), native to this region and categorized as ‘near threatened’ in 2019, is a crucial food source for native bees and plays an important role in the local ecosystem.
“Our research shows that these trees support at least 81 distinct species of foraging bees, emphasizing their remarkable importance in ensuring the survival of native bee populations, particularly in late summer when most plants stop blooming,” Dr. Prendergast explained.
“The native bees found in WA’s South West are not only numerous but also very diverse, with many heavily reliant on native flora like the Marri for sustenance.
“Marri trees offer essential nectar and pollen, especially when there are few other plants in bloom. During this time of year, Marri often becomes the sole food source for many bee species.
“In addition to providing food, Marri trees also offer nesting options, with various species observed nesting in small holes and among their roots. The tree’s abundant red sap is utilized by Megachilidae bees to seal their nests.”
Dr. Prendergast pointed out that this research strengthens the idea that certain species, such as the Marri tree, function as ‘keystone species’ or ‘magnet species’, which are fundamental for maintaining biodiversity.
“The Marri tree serves as a critical resource for native bees, acting as a lifeline during crucial periods when other plants have withered,” Dr. Prendergast stated.
“These findings highlight the urgent necessity to safeguard Marri trees against threats like logging, mining, fire, disease, agriculture, and urban and industrial development. Without these trees, many native bee species would face serious survival challenges.”
The research also found that Marri trees are frequently the primary or only plant species that these bees visit throughout the year, making them integral to the local ecosystem. This underscores the need to protect this species, not only for the bees’ sake but for the overall health of the environment.
This study was funded by the Forrest Research Foundation, Zanthorrea Nursery, and the Department of Biodiversity, Conservation and Attractions.
The complete study, titled ‘Corymbia calophylla (Marri): A Major Resource for Native Bees in the Southwest Western Australian Biodiversity Hotspot‘, will be published in the journal Pacific Conservation Biology.
