- Secondary cloud forests are vital to hydrological cycles and the prevention of soil erosion.
- However, in Mexico, the expansion of livestock and agriculture has increased their vulnerability.
- Researchers from the Institute of Ecology at Mexico’s University of Veracruz suggest that encouraging sustainable forest management in these ecosystems will help ensure that they don’t disappear.
In 2009, scientists estimated that Mexico’s tropical montane cloud forests — hillside woodlands blanketed in fog and rain — were down to 28% of their original extent. Fifty-three percent of what was left was considered secondary forest, regenerated from primary forest that had been cleared for agriculture or lost due to fires or storms.
Conserving these cloud forests, even the secondary ones, maintains tree cover and protects mountain basins and soil from erosion. It also helps forest corridors develop, connecting the landscape for wildlife to roam.
Despite their importance, these ecosystems have largely been forgotten and poorly studied; and, to some extent, they are disappearing. In Mexico, they are not recognized in legal frameworks for forest use, resulting in a dearth of programs aimed at addressing their sustainable management.
To raise awareness of these forests and to promote actions that support their conservation and management, researchers Tarin Toledo and Luciana Porter of the Institute of Ecology and Patricia Gerez of the Institute of Biotechnology and Applied Ecology of the University of Veracruz in Mexico conducted a study published by the Mexican Civil Council for Sustainable Silviculture. The research and resulting recommendations arose from an April 2019 workshop attended by academics, forest technicians, members of civil society organizations and owners of land with secondary forests.
Secondary forests, no less important
Cloud forests typically occur in areas that are foggy for much of the year, though each forest has its own special characteristics depending on where it’s located.
Cloud forests in Africa, for example, are very different to those of Mexico’s Veracruz state, which in turn are different to those of the states of Guerrero, Jalisco and Chiapas.
“They may have different plants,” Toledo, a tropical forest ecologist, said in an interview. “It depends on the elevation and rain.”
Common among all cloud forests is the great biodiversity they support. In Mexico, they’re home to 12% of the country’s plants and 755 species of land vertebrates. Cloud forests are also very vulnerable ecosystems. Researchers estimate that, each year, Mexico loses around 1.1% of its cloud forest coverage due to changes in land use for livestock farming and agriculture.
Secondary cloud forests have younger trees, usually between 10 and 20 years old, that sprouted after older growth had been cleared away.
“They are areas that are regenerating after a damaging event, such as a hurricane, a fire, storms, deforestation or agricultural-related use,” Toledo said. “At the global level, these forests are the ones that are mostly found in landscapes.”
Although these secondary forests are in the process of regenerating, they are critical homes for abundant biodiversity, and they play a crucial role in hydrological cycles. In addition, their vegetation reduces the impacts of rain on soil, minimizing erosion and the risk of landslides. They also stich together disparate parts of the forest, creating corridors for wildlife and providing refuge for many pollinators. What’s more, these cloud forests also capture a lot of carbon.
Cloud forests are also a daily source of forest resources, including timber, firewood and charcoal, primarily for the low-income families who live in or around these forests.
The researchers warn that one of the many risks of timber extraction without proper management is that species that prevent trees from regenerating, such as climbing plants or the tropical bracken fern (Pteridium arachnoideum), can proliferate, diminishing the likelihood that the forest will recover.
Ignored in forestry legislation
The researchers say that favorable conditions for encouraging sustainable forest management need to be developed urgently to conserve these secondary cloud forests and help their regeneration.
As a start, they emphasize that these conditions would need to be considered within a legal framework. The present general law on sustainable forest development does not recognize secondary forests. The researchers suggest that forestry legislation should include a definition of “secondary forest vegetation.”
“This will allow the owners of these lands to be able to access various support and to implement sustainable forest management practices,” they said. Laws should include secondary forests as a type of vegetation “with potential for productive and ecological recovery.”
Although these secondary forests can’t withstand the same heavy use as coniferous forests, strategies can be developed to ensure that these areas are used sustainably. The alternative is to lose them altogether.
“If forest extractions occur without any planning, these secondary forests degrade and lose some of their ecosystem functions,” Toledo said. There is also the risk that they can be cleared for farmland or ranches, as livestock subsidies incentivize communities to cut them down.
Places of forest diversity
The researchers note that, with appropriate forest management, these secondary forests could contribute to providing high-quality timber, resins, firewood, charcoal and non-timber forestry resources that could generate income for the landowners, while also providing ecosystem services.
For example, plantations of commercially valuable local species, such as black alder, walnut, palo zopilote and oak, could be developed.
According to Toledo, if there is one thing that characterizes these areas, it is their high levels of diversity, not only in terms of flora, but also fauna, especially amphibians and insects.
According to Toledo, if there is one thing that characterizes these areas, it is their high levels of diversity, not only in terms of flora, but also fauna, especially amphibians and insects.
Conserving and encouraging sustainable development
In their study, the researchers recommend promoting new strategies for restoring forests through the growth of new trees and forest management that incorporates multiple uses. This approach will allow for the use of diverse species with different ecological functions.
In addition, the team points to the urgent need to design management strategies that include the people who own and manage these forests who “have been marginalized” from forest management systems. The forest is typically broken down into communal plots and small properties, pointing to the need for organizational schemes and further research to design useful strategies, the study’s authors said.
Banner image of secondary cloud forest in Las Cañadas, Huatusco, in the Mexican state of Veracruz, by Tarin Toledo.
This article was first published by Mongabay Latam on January 23, 2020.