Forest Degradation Associated with Logging Frontier Expansion in the Amazon: The BR-163 Region in Southwestern Pará, Brazil

Abstract

Forest degradation is the long-term and gradual reduction of canopy cover due to forest fire and unsustainable logging. A critical consequence of this process is increased atmospheric carbon emissions. Although this issue is gaining attention, forest degradation in the Brazilian Amazon has not yet been properly addressed. The claim here is that this process is not constant throughout Amazonia and varies according to colonization frontiers. Moreover, the accurate characterization of degradation requires lengthy observation periods to track gradual forest changes. The forest degradation process, the associated timeframe, spatial patterns, trajectories, and extent were characterized in the context of the Amazon frontiers of the 1990s using 28 years (1984–2011) of annual Landsat images. Given the large database and the characteristic of logging and burning, this study used data mining techniques and cell approach classification to analyze the spatial patterns and to construct associated trajectories. Multitemporal analysis indicated that forest degradation in the last two decades has caused as many interannual landscape changes as have clear-cuts. In addition, selective logging, as a major aspect of forest degradation, affected a larger amount of forest land than did forest fire. Although a large proportion of logged forest was deforested in the following years, selective logging did not always precede complete deforestation. Instead, the results indicate that logged forests were abandoned for approximately 4 years before clearance. Throughout the forest degradation process, there were no recurrent forest fires, and loggers did not revisit the forest. Forest degradation mostly occurred as a result of a single selective logging event and was associated with low-intensity forest damage.

Multiple Patterns of Forest Disturbance and Logging Shape Forest Landscapes in Paragominas, Brazil

“…When associated with Geographic Information System (GIS) data, such as the Brazilian Rural Environmental Cadastre (CAR), it offers an applied tool to understand the impacts and corresponding responsibilities of different land use practices and actors on the modelling of the current forest landscape. Approaches using cell grids could also represent an interesting manner in which to characterize spatial and temporal patterns of forest degradation at a landscape scale without having knowledge of the local land tenure [46].…”

“…Thereby, we could better understand the different patterns of forest disturbance shaping the forest landscapes at the regional level, which is essential not only for the promotion of integrated landscape management, but also for better addressing the carbon losses linked to the process of forest degradation. As carbon losses caused by forest degradation depend on the intensity and persistence of human-induced disturbances through time [47], it seems essential that future research on the relationships between forest degradation and carbon losses foster discussion and analysis of spatial and temporal patterns of forest degradation [46].…”

Deforestation-Induced Fragmentation Increases Forest Fire Occurrence in Central Brazilian Amazonia

“…This region is known as a frontier of deforestation because of high rates of deforestation in the last 10 years. The vegetation is predominantly composed of the Dense Ombrophilous Forest, with trees that can reach heights up to 50 m [29].The initial occupation of this area was associated with governmental settlement projects and the construction of road infrastructure, mainly the construction of BR-163 highway [30]. During the 70s and 80s, a spontaneous colonization phenomenon occurred in the region, which was characterized by the occupation of land by small subsistence farmers and gold miners [30].…”

“…The vegetation is predominantly composed of the Dense Ombrophilous Forest, with trees that can reach heights up to 50 m [29].The initial occupation of this area was associated with governmental settlement projects and the construction of road infrastructure, mainly the construction of BR-163 highway [30]. During the 70s and 80s, a spontaneous colonization phenomenon occurred in the region, which was characterized by the occupation of land by small subsistence farmers and gold miners [30]. There are three main deforestation patterns that are present in the study area (i) fishbone, associated with settlements, Forests 2018, 9, 305 3 of 16 (ii) rectangular patches, related to large rural properties, and (iii) stem of the rose pattern that is associated with mining areas, mainly in .…”

Towards a Reproducible LULC Hierarchical Class Legend for Use in the Southwest of Pará State, Brazil: A Comparison with Remote Sensing Data-Driven Hierarchies

“…Distribution pattern also seems to be useful to distinguish different types of alteration that lead to modified forests. Some examples of different patterns of modified forests and how it alters the appearance of the classes in Remote Sensing images are illustrated in works like Asner et al [71] and Pinheiro et al [72].…”