SYNERGY BETWEEN LANDSCAPE FRAGMENTATION AND FOREST FIRES IN EASTERN AMAZON

Tropical forests play an important role as a stockpile of biodiversity and carbon. Brazil has the largest continuous area of these forests. However, in the state of Maranhão, in the eastern Amazon, only 23% (25,000 km²) of the original coverage of mature forests remain. Although deforestation in the Maranhão Amazon is well documented and monitored on a monthly and annual scale, little is known about the synergistic effects between fragmentation and forest fires in the region. In this study, a remote sensing approach was used to integrate and analyze data sets of hot spots, burnt area, land use/land cover, rain and surface temperature. Results show that forest cover (mature and secondary) in the Maranhão Amazon decreased by 31,302 km² between 1985 and 2017, with 63% of the forest loss occurring in core areas of forest. During the same period, edge forests extent was reduced by 38%, while the extent of forest islets (isolated forest patches too small/narrow to contain core forests) increased by 239%. Analysis of fire regime metrics suggests that the observed deforestation/fragmentation trend is an important factor controlling temporal and spatial variability of forest fires in the region, and that fire-regime intensification is mostly associated with the more vulnerable fragmentation classes, particularly fire-prone edge forests. On average, about 1,031 ± 695 km² of edge class forests burned per year in the region between 2003 and 2017, the equivalent to about 60% of the total burned forest cover in the study.