Climate controls on the variability of fires in the tropics and subtropics

摘要: In the tropics and subtropics, most fires are set by humans for a wide range of purposes. The total amount burned area fire emissions reflects complex interaction between climate, human activities, ecosystem processes. Here we used satellite-derived data sets active detections, area, precipitation, fraction absorbed photosynthetically radiation (fAPAR) during 1998–2006 to investigate this interaction. number detections was highest in areas that had intermediate levels both net primary production (NPP; 500–1000 g C m−2 year−1) precipitation (1000–2000 mm year−1), with limits imposed length season wetter ecosystems fuel availability drier ecosystems. For wet tropical forest developed metric called fire-driven deforestation potential (FDP) integrated information about intensity dry season. FDP partly explained spatial interannual pattern across regions. This climate-fire link combination higher rates interior Amazon suggests negative feedback on may exist as front moves inward. Africa, compared Amazon, smaller values sufficiently low prevent use. Tropical forests mainland Asia were highly vulnerable fire, whereas equatorial had, average, lowest values. substantially increased Asia, however, El Nino periods. contrast these found positive relationship fAPAR, NPP, arid strongest northern Australia regions Africa. Highest activity observed savanna limited neither nor However, relations annual or drought extent often poor here, hinting at important role other factors, including land managers, controlling temporal variability fire.