The monarch butterfly sanctuary is facing a significant challenge due to the impact of climate change, which is transforming its annual journey of nearly 5,000 kilometers into an uncertain trip. Without the oyamel forests, butterflies will face serious risks during their migration. Recently, scientific research highlighted the vulnerability of this sanctuary to climate change, as it provides the ideal conditions of humidity and temperature that these butterflies need to survive the winter. However, climate projections are alarming, and the disappearance of the mountaintop trees and their relocation to lower areas is expected by the end of the century as a result of global warming.
The research indicates that the habitat of the monarch butterfly will be compromised by droughts, rising global temperatures, the proliferation of bark beetles, and soil stress. In the short term, habitat loss is already manifesting through deforestation, urbanization, pesticide use, the presence of parasites, and intensive agriculture. In response, the monarch butterfly is seeking new refuges against climate change, establishing colonies in cooler and higher places, such as Nevado de Toluca, due to its traditional sites becoming too warm.
Experts are evaluating the possibility of establishing "new forests" in other regions to protect the butterflies. They have used native shrubs such as Senecio cinerariodes, Lupinus montanus, and Pinus hartwegii as "nurse plants" to shield them from the cold and the sun. This effort has demonstrated that seedlings have survived the habitat change, and their growth varies according to altitude. Areas between 3,600 and 3,800 meters could become future refuges for the monarch butterfly.
To aid in this adaptation, the technique of "assisted migration" has been implemented, planting Abies religiosa sprouts in areas that will have a climate similar to that of Michoacán in the coming decades. Additionally, a study from the Universidad Michoacana de San Nicolás de Hidalgo is investigating the possibility of establishing a new forest of fir trees in Nevado de Toluca, which could provide a new home for these wonderful butterflies in the future in the face of the challenges of climate change.
