Growing New Forests in Mexico Could Help Protect Oyamel Forests and Monarch Butterflies

Climate change poses a significant threat to the oyamel fir forests in central Mexico, the crucial winter habitat for millions of migrating monarch butterflies. Recent research indicates that these forests may vanish by 2090. To counter this, scientists have initiated an experiment to cultivate new oyamel fir trees (Abies religiosa) in locations outside their native habitat. This project aims to ensure the survival of both the trees and the monarch butterflies that depend on them for hibernation.

The Experiment and Its Execution

Under the guidance of Dr Cuauhtémoc Sáenz-Romero, a forest geneticist at the Universidad Michoacana de San Nicolás de Hidalgo, researchers collected oyamel fir seeds from elevations between 3,100 and 3,500 metres within the Monarch Butterfly Biosphere Reserve in Michoacán state. The seeds were nurtured in a nursery before being planted in the community forest of Calimaya, located on the Nevado de Toluca volcano. Approximately 960 saplings were placed at different elevations—3,400, 3,600, 3,800, and 4,000 metres—allowing researchers to assess their adaptability to higher altitudes.

Promising Results After Three Years

After three years, the results are promising. Despite being smaller at higher elevations, nearly 70 per cent of the saplings survived, especially those in colder environments. This suggests that oyamel fir trees could potentially thrive in these new locations as climate conditions change. Dr Karen Oberhauser, a conservation biologist from the University of Wisconsin–Madison, supports the initiative, recognising the necessity of aiding species migration in the face of climate challenges.

Challenges Ahead for Conservation Efforts

While the experiment shows potential, there are hurdles ahead, including garnering support from local communities and government bodies. An additional concern is whether the migrating monarch butterflies will locate these new forests. Observations from the winter of 2023-2024 indicate that some monarchs have already begun seeking colder habitats outside the traditional reserves, hinting at their adaptability in a changing environment.