ABSTRACT
This chapter provides an assessment of the past and present variability and extent of fire with emphasis on the occurrences of swidden agriculture and biomass burning in the Philippines. Based on the available in situ and satellite measurements, it is evident that there is a significant decline in the frequency of fire from 1992 to 2018. This suggests that swidden agriculture is being reduced considerably since biomass burning in most agricultural areas is a yearly practice and not likely to change. This is supported by the observed strong seasonality and high occurrences of fire in agricultural areas. Case studies indicate that swidden farming is still practiced but primarily in the uplands and in regions occupied by indigenous communities. This, together with biomass burning and grass fires, is cited as the primary reason for fire damages in forest plantations under the National Greening Program. Emission estimates of biomass burning of rice straw have been observed to be high especially in Isabela, Pangasinan, Tarlac, and Nueva Ecija. Biomass burning needs to be minimized because of health impacts including occurrences of chronic obstructive pulmonary diseases in households from agricultural areas.
