The Monkey Puzzle tree (Araucaria Araucana), also known as Chile pine, is an evergreen conifer tree that is native to the Andes Mountains of South America. It was declared a natural monument in Chile in 1976 to protect it from logging because of its endangered status. The name, Monkey Puzzle tree, was given because of the fact that monkeys are unable to climb it due to the trees’ appearance. Its appearance consists of spiral arrangements of rigid needle-pointed leaves along its branches that are attached to the trunk, creating a sort of puzzle-like appearance for monkeys.
The article, Large-scale impacts of multiple co-occurring invaders on monkey puzzle forest regeneration, native seed predators and their ecological interactions, explains the combined and multi-faceted impacts of several exotic mammals on the monkey puzzle trees’ ecosystem. The article mentioned that the tree species have a small distribution range, and its endangered status is due to several threats, such as deforestation through logging for plantation of exotic tree species and human-made fires which caused a 40% reduction and fragmentation of its range. Another key fact that may have played a role in the lack of regeneration of the species, is seed harvesting done by animals.
The seeds are traditionally consumed by indigenous Mapuche people and a small community of native seed predators. Their main predator is the Austral parakeet because they remove matured seeds directly from female cones over several months whereas native mice species eat the seeds that have fallen onto the ground. The authors observed 516 female trees that are located across the species’ distribution and identified the signals of native and exotic species that visited each tree. Along with that, they also studied the diet and foraging behavior of Austral parakeets to figure out their potential indirect effect of exotic mammals through disruption of key ecosystem service (seed dispersal) by the parakeets.
Their results showed that Austral parakeets and mice predated seeds from 85% and at least 45% of the trees, respectively, with both the number of remaining seeds and seedlings being larger when only parakeets or mice fed on the seeds compared to exotic mammals that visited. At least 90% of the trees were visited by one or more exotic species and the number of seeds and seedlings decreased drastically if about two or four exotic species visited. They mention that the increase of exotic mammals may reduce the populations of native seed-predators in the long-term along with the regeneration of the monkey puzzle forests, directly through a reduction of seed availability and seedling survival and directly through the disruption of dispersal processes. They concluded from the results that strategies based on protection of the areas where the tree species are, may help in the survival of individuals but the forest regeneration and community of native seed-predators and related ecological processes further depend on how humans manage the exotic mammal invasions.
Article Reference:
Tella, J. L., Lambertucci, S. A., Speziale, K. L., & Hiraldo, F. (2016). Large-scale impacts of multiple co-occurring invaders on monkey puzzle forest regeneration, native seed predators and their ecological interactions. Global Ecology and Conservation, 6, 1–15. https://doi.org/10.1016/j.gecco.2016.01.001
Applied Plant Ecology Winter 2020 