Posted on 11 October 2016
The tropical montane cloud forest has been considered as a priority for conservation since it occurs in less than 1% of the Mexican territory and harbors more than 10% of the plant species that exist in Mexico.
The Clavijero Botanical Garden was founded in 1977, and maintains and manages a Cloud Forest Sanctuary – a natural protected area that has 30 ha of preserved forest and young and old-secondary forest. The CBG and the Sanctuary goals are focused on conservation efforts through environmental education and ecological restoration. There have been propagation programmes for threatened cloud-forest trees such as Symplocos coccinea, Podocarpus guatemalensis and Styrax glabrescens since 1990. Rescue and propagation of two endangered species Magnolia dealbata and Talauma mexicana has been a success story for the garden. Seed storage and propagation techniques for these species were developed and the species established in cultivation for the first time. Seedlings have been re-introduced into the adjoining ecological park as well as distributed to state and municipal nurseries as future seed trees for the propagation of the species.
Adjacent to the Clavijero Botanical Garden, a new project began in 2011, when the Instituto de Ecología (INECOL) bought an abandoned pasture with a small area of forest with a spring. The forest fragment, as well as the adjacent Sanctuary are the closest propagule sources. Although no major disturbances occurred while being a pasture (e.g., fires, floods), the introduced grass is an exotic species (Cynodon plectostachyus), tall and very competitive, with a high growth rate that has arrested the successional process.
The forest restoration project has two main objectives 1) to understand the ecological processes and actions that may accelerate the recovery of a cloud forest, and 2) to inform the public about the long and complex process behind the restoration of a peri-urban cloud forest from an abandoned pasture.
Passive restoration plot, dominated by exotic grass
Within the restoration project (2.9 ha), we established four permanent parcels (40 × 40 m) where all existing woody vegetation was identified and tagged. Within each parcel we established two paired plots (15 × 15 m), where active and passive restoration processes are displayed. In the active restoration plot, four native forest tree species were introduced; the passive restoration plot was left undisturbed. After three years of the project, the difference in both restoration plots are striking; passive restoration plots are still monodominated by the presence of the tall exotic grass, while tree species in the active restoration plots have had high survival and growth.
In addition to the restoration project, within the site we have conducted seed bank and seed rain evaluations, as well as grass removal nucleation experiments. Preliminary base line results suggest that given the vegetation structure and composition, as well as the propagules availability (both in seed bank and seed rain), the area has a high recovery potential. However, recovery is highly limited due to the presence of the African grass and active restoration strategies are necessary to overcome woody plant establishment barriers.
The area will be open soon and be part of the permanent and dynamic exhibitions of the CBG with the long term goal (50 years) of recover and establish a peri-urban cloud forest patch.
Active restoration plot planted with native trees