Fire activity in Borneo driven by industrial land conversion and drought during El Niño periods, 1982–2010

• Published in: Global environmental change 2017-11, Vol.47, p.95-109
• Main Authors: Sloan, Sean, Locatelli, Bruno, Wooster, Martin J., Gaveau, David L.A.
• Format: Article
• Language: English
• Subjects: Agricultural development; Agricultural management; Burning; Change agents; Climate change; Conversion; Data logging; Deforestation; Degradation; Drought; El Nino; El Niño; Fire; Fires; Flammability; Forest degradation; Forest management; Forestry; Forests; Human settlement; Land cover; Land use; Landsat; Landsat satellites; Landscape; Logging; Ocean currents; Oil palm; Peatlands; Plantations; Proximity; Rainfall; Rainforests; Remote sensing; Satellite observation; Timber industry; Tropical environment; Tropical environments; Tropical forests; Vegetation
• ISSN: 0959-3780; 1872-9495
• DOI: 10.1016/j.gloenvcha.2017.10.001

[Display omitted] •Fire activity, land change and climate were modelled over El Niño events, 1982–2010.•Fire frequency strongly responded to oil palm establishment and proximity.•Fire frequency increases suddenly below 200mmmo−1 precipitation.•Migration of fire activity appears driven by smallholder-oil palm interactions.•Propensity for elevated fire activity in Borneo declined over 2000s from 1990s. Tropical rainforests, naturally resistant to fire when intact, are increasingly vulnerable to burning due to ongoing forest perturbation and, possibly, climatic changes. Industrial-scale forest degradation and conversion are increasing fire occurrence, and interactions with climate anomalies such as El Niño induced droughts can magnify the extent and severity of fire activity. The influences of these factors on fire frequency in tropical forests has not been widely studied at large spatio-temporal scales at which feedbacks between fire reoccurrence and forest degradation may develop. Linkages between fire activity, industrial land use, and El Niño rainfall deficits are acute in Borneo, where the greatest tropical fire events in recorded history have apparently occurred in recent decades. Here we investigate how fire frequency in Borneo has been influenced by industrial-scale agricultural development and logging during El Niño periods by integrating long-term satellite observations between 1982 and 2010 – a period encompassing the onset, development, and consolidation of its Borneo’s industrial forestry and agricultural operations as well as the full diversity of El Niño events. We record changes in fire frequency over this period by deriving the longest and most comprehensive spatio-temporal record of fire activity across Borneo using AVHRR Global Area Coverage (GAC) satellite data. Monthly fire frequency was derived from these data and modelled at 0.04° resolution via a random-forest model, which explained 56% of the monthly variation as a function of oil palm and timber plantation extent and proximity, logging intensity and proximity, human settlement, climate, forest and peatland condition, and time, observed using Landsat and similar satellite data. Oil-palm extent increased fire frequency until covering 20% of a grid cell, signalling the significant influence of early stages of plantation establishment. Heighted fire frequency was particularly acute within 10km of oil palm, where both expanding plantation and smallholder agriculture are believed to be con