dc.description.abstract |
Tropical forests represent the terrestrial ecosystem with the highest biodiversity. Despite the importance of tropical forest to human species survival, these are frequently at risk, mainly because of the dynamic use of the land. The objective of this study is to assess and analyze the deforestation process in the nucleus zone of the Bosawas Biosphere Reserve, in Nicaragua, Central America, by means of remote sensing image classification and interpretation.
Landsat images from 2011, 2015 and 2016 were classified using an object-based approach. The resulting land-cover classification maps were then utilized to conduct a deforestation assessment, which revealed a loss in forest cover, going from 6206.77 km2 in 2011, to 5825.14 km2 in 2015. Moreover, with applying GIS (Geographic Information System), this study incorporated environmental factors into the Maximum Entropy model (MaxEnt) to assess areas most susceptible to deforestation, including clear-cut and vegetated areas. Deforestation patches from 2015-2016 were used to validate the models. The Area Under the Curve of Receiver Operating Curve (AUC) for the clear-cut patch model was 0.71, and 0.88 for the vegetated patch model. The results indicate that MaxEnt is a reliable method to identify the areas more likely to be affected by deforestation within the Bosawas nucleus zone.
Results show that distance to soil and distance to other types of vegetation are the most important variables for the clear-cut and vegetated patch models, respectively. This indicates that the two types of patches have different deforestation dynamics because they represent different stages of the deforestation process. Clear-cut patches belong to the early stages of deforestation, they are clustered and diffuse, and their appearance can be related to the availability of purchasable lands in the area. On the other side, vegetated patches represent more advanced phases of the deforestation process, and they tend to expand through the years. In both models, however, variables including distance to communities, roads and rivers do not show significant contribution to deforestation, meaning that accessibility is not a vital factor in the deforestation process of Bosawas. In addition to analyze the relationship between deforestation and environmental factors, to study the characteristics of the patches (e.g. morphology, type, evolution) is also suggested an important approach to broaden the understanding of the complex issue of deforestation in tropical rainforest. | en_US |