Historically, a major threat to the Catalina mahogany was the introduction of herbivores, such as goats, deer and pigs, to Santa Catalina Island. Goats and deer ate the seedling shoots and the leaves of the tree, while pigs rooting through the ground destroyed seedlings and the roots (6).
Hybridisation with the closely related California mountain mahogany (Cercocarpus betuloides) is currently a significant threat to the Catalina mahogany (6). Already, there are five hybrid plants alongside the seven pure individuals in Wild Boar Gully (4). Hybridisation between different species will result in a loss of genetic diversity which could impact upon the future survival of the Catalina mahogany (6).
Another possible threat comes from non-native invasive plant species. Unfortunately, erecting fences around the remaining Catalina mahogany individuals to exclude herbivores has resulted in a build-up of both native and non-native plant species within the enclosure (6).
The increase in vegetation in the fenced area has also resulted in a potential increase in the risk of fires. Fires on Santa Catalina Island are fairly infrequent, although fires from lightning strikes have occurred, and such events are known to be a threat to seedlings and saplings (6).