GSA Connects 2021 in Portland, Oregon

Paper No. 221-1
Presentation Time: 9:00 AM-1:00 PM


BUNA, Arisson T.M., Mestrado em Meio Ambiente, Universidade Ceuma, Av. São Luís Rei de França, 50, Bairro Turu, São Luís, MA, 65065-470, Brazil, SILVA JUNIOR, Celso H.L., Remote Sensing Division, Instituto Nacional de Pesquisas Espaciais (INPE), Avenida dos Astronautas, 1758, São José dos Campos, SP, 12227-010, Brazil, COSTA Jr., Ozeas, School of Earth Sciences, The Ohio State University at Mansfield, 1760 University Drive, Mansfield, OH 44906 and BEZERRA, Denilson S., Departamento de Oceanografia e Limnologia, Universidade Federal do Maranhão (UFMA), Av. dos Portugueses, 1966, Vila Bacanga, São Luís, MA, 65080-805, Brazil

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.