Chaco region: Forest loss and fragmentation in the context of the territorial planning law. Remote sensing assessment in Formosa, Argentina application case

Agricultural expansion is the primary cause of forest loss and fragmentation. It threatens the conservation of its biodiversity as well as the capability to provide ecosystem services. Land-use policies, such as zonation programs, have been traditionally used as a tool for promoting a sustainable natural resource management; however, we still lack standardized methodologies that can be applied world-widely to achieve this purpose. In the current context of rampant deforestation over the tropical forests, there is an urgent need of identifying policies that steer agricultural land-use change into a reduced pressure on forests. This study focuses on the outcomes of the first territorial planning law in the Province of Formosa (Argentina) located within the Chaco region, one of the world’s deforestation hotspots. The research questions were: a) How did agriculture expand in Formosa before, during and after the enactment of the territorial planning law? b) Did the introduction of the law affect the spatial distribution of land-use change?; and c) How did the sanction of the law affect forest loss and forest fragmentation? Landsat imagery was used to map land-use change, and to calculate the cover loss and cover loss rate considering the zoning and physiognomic classification of the law. The forest fragmentation was evaluated in terms of forest loss spatial configuration, classified as perforation or shrinkage, forest edge generation, patch size distribution, and patch isolation. The territorial planning law effect over agricultural expansion was tested using a difference in difference model. After the law was passed, a reduced land-use pressure was observed for the forest within the conservation designated zone; however, the forest presented the highest cover loss rates among the physiognomic categories of the law. Land-use change within the conservation designated zone was predominantly made according to a perforation spatial configuration, which promoted the forest edge generation. The isolation between forest patches decreased and its size distribution changed towards a less large-patch-centered pattern, indicating that Formosa is experiencing an early fragmentation process. Overall, the territorial planning law in Formosa succeeded in the relief of land-use pressure on forest, but highlighted the need of incorporating spatial configuration guidelines for long-term forest conservation. The case of Formosa case could be useful in the design of future sustainable natural resource management policies and implies the importance of early natural resource planning.