Forest quality in the southwest of Mexico City: Assessment towards ecological restoration of ecosystem services
Introduction and problem statementMost forests have already been modified by people. Complete ecological integrity is a historical concept in most parts of the world. The distinction between ‘natural’ and ‘disturbed’ forests is less important than the degree and type of disturbance. Attempts have been made to define criteria and indicators (C&I) for the assessment of sustainable forest management (SFM) at various scales. In 1998, the WWF and the IUCN developed the forest quality C&I initiative to assess SFM at the landscape level. The initiative relies on the forest quality principle and encompasses criteria from three categories: (1) forest authenticity, (2) environmental benefits and (3) other social and economic benefits. Mexico City, one of the world’s most populated metropolises, still possess some forest area in its surroundings. The forests under study were given protection status primarily because they are a major source of drinking water, as well as for their provision of other ecosystem services for the inhabitants of Mexico City. The urban sprawl of the city poses a continuous threat to this area, and although protected, it is not free from human influence, represented by isolated illegal settlements, extensive livestock management, illegal logging, fires, air pollution and poorly organised local tourism.
Method and main results Data relating to the criteria, indicators and verifiers of forest quality were collected from 116 sample plots. To assess forest quality, field and laboratory verifiers of forest composition, pattern, function, process, tree health, area and fragmentation, management, as well as ecosystem services were integrated and weighted by a group of experts. Interviews (n=57) were held with representatives of the main stakeholder groups of the area, in order to determine their perceptions of the relative importance of the ecosystem services provided and the environmental issues. The information developed on the amount of carbon storage, water infiltration potential, biodiversity conservation and recreational activities, will allow for the implementation of a more precise and better adapted ecosystem services payment programme, as an economic instrument for the conservation and ecological restoration of the forests in the area. People in general are aware of the importance of the forests in the area, but there is a lack of environmental education and information, and the responsibilities for management and conservation are not clear. Interpolated maps for all the indicators and an integrative one of forest quality were generated. General guidelines for a more sound management geared towards the ecological restoration and conservation of the main ecosystem services are presented, together with a proposal for an environmental education programme, and a zoning of the area.
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