In this new article, published in Restoration Ecology and led by Jordi Honey-Rosés (University of British Columbia), we examine land-use change in central Mexico and we relate such change to agricultural and socio-economic patterns. Recent land cover analysis reveals significant forest recovery around the world, suggesting that some countries may be in a forest transition. However, remotely sensed imagery does not reveal the driving causes of forest recovery, which may be due to active reforestation efforts or natural successional processes (passive reforestation).
Through fieldwork research conducted by ICTA-UAB former MSc student, Marlene Maurer, we aimed to distinguish these two processes in the priority temperate forests surrounding the Monarch Butterfly Biosphere Reserve (342,773 ha) in the state of Michoacán. We combined an analysis of remotely sensed imagery with field interviews to examine the mechanisms and drivers of observed forest recovery.
Our analysis of the satellite imagery reveals a net increase of 3,798 ha of forest between 1986 and 2012, yet the rate of recovery is slowing. Interview data suggests that the vast majority of the recovered forests are the result of natural regrowth (passive reforestation), with most of this regrowth observed on previously degraded forest lands. Therefore, we estimate that between 58 and 429 ha have been recovered from active reforestation efforts in the 1986–2012 period. We find that reduced logging and grazing pressures are important drivers of forest recovery, while agricultural abandonment may be less influential than often believed.
These results speak to conservation policy and reforestation programs in different ways. First, they suggest that the cost-effectiveness may be a major constraint to scaling up active reforestation, particularly if the latter represents a small contribution to observed forest regrowth. Second, the findings indicate that previously degraded forest lands should be considered environmental assets in forest restoration programs, given its significant contribution to forest recovery. Last, and most importantly, we think that whenever site, landscape, and social environments allow for passive restoration, forest restoration programs should consider supporting, facilitating, or accelerating natural regrowth instead of active reforestation. Reforestation investments might be wisely spent supporting and maintaining the natural resilience of forests rather than on costly reforestation programs.
Photo copyright: Marlene Maurer.