Rapid conversions and avoided deforestation: examining four decades of industrial plantation expansion in Borneo

Abstract

New plantations can either cause deforestation by replacing natural forests or avoid this by using previously cleared areas. The extent of these two situations is contested in tropical biodiversity hotspots where objective data are limited. Here, we explore delays between deforestation and the establishment of industrial tree plantations on Borneo using satellite imagery. Between 1973 and 2015 an estimated 18.7 Mha of Borneo's old-growth forest were cleared (14.4 Mha and 4.2 Mha in Indonesian and Malaysian Borneo). Industrial plantations expanded by 9.1 Mha (7.8 Mha oil-palm; 1.3 Mha pulpwood). Approximately 7.0 Mha of the total plantation area in 2015 (9.2 Mha) were old-growth forest in 1973, of which 4.5-4.8 Mha (24-26% of Borneo-wide deforestation) were planted within five years of forest clearance (3.7-3.9 Mha oil-palm; 0.8-0.9 Mha pulpwood). This rapid within-five-year conversion has been greater in Malaysia than in Indonesia (57-60% versus 15-16%). In Indonesia, a higher proportion of oil-palm plantations was developed on already cleared degraded lands (a legacy of recurrent forest fires). However, rapid conversion of Indonesian forests to industrial plantations has increased steeply since 2005. We conclude that plantation industries have been the principle driver of deforestation in Malaysian Borneo over the last four decades. In contrast, their role in deforestation in Indonesian Borneo was less marked, but has been growing recently. We note caveats in interpreting these results and highlight the need for greater accountability in plantation development.

Figure 1. Land use and land cover change in Borneo (1973–2015).

(A) Total deforestation (18.7 Mha) and remaining old-growth and selectively logged forest in December 2015; (B) The expansion of industrial oil-palm plantations (7.8 Mha); (C) The expansion of industrial pulpwood plantations (1.3 Mha). Maps created using ArcMap v10.2.2 geospatial processing program http://www.esri.com/software/arcgis/arcgis-for-desktop.

Figure 2

The expanding area (9.1 Mha; yellow blocks) of industrial plantations (oil-palm and pulpwood) in six time periods from 1973 to 2015 in Borneo (A), Indonesian Borneo (B), and Malaysian Borneo (C). The decline in forest area (dark green) since 1973, and prior to plantation establishment (yellow) is shown to the left of each yellow block in each time period. The changes reveal when the land was forest (green), non-forest (light brown) or had been cleared (red and orange) prior to plantation development (yellow). Areas cleared more than five years prior to plantation establishment are shown as red blocks. Areas where forest was cleared less than five years or more than five years, but less than ten years before plantation establishment are shown as orange blocks. The areas where the dark green blocks (forest) touch the yellow blocks are areas where forest was cleared less than five years prior to plantation establishment (rapid conversion). The blue blocks indicate areas of uncertainty, where we could not define clear land cover transitions, because of either cloud cover or lack of imagery.

Figure 3

The expanding area (9.1 Mha) of industrial plantations (oil-palm and pulpwood) in six time periods from 1973 to 2015 with vegetation cover of the land just before observed conversion to plantations in Borneo (A), Indonesian Borneo (B), and Malaysian Borneo (C). Intact Forest: pristine old-growth forests. Logged Forest: old-growth forests that have lost their original structure and canopy cover through industrial-scale selective timber harvest at some point since 1973, indicated principally by the construction of logging roads. Scrub: old-growth forests impacted by drought and fire; these burn/drought scars tend to recover slowly. They are vulnerable to further burning and conversion to short vegetation follows; hence they appear as “deforested” in satellite assessments (see also methods). Non Forest since 1973: areas that have been cleared before 1973. Other Non-Forest: areas that have been cleared after 1973, but not converted to scrubs. We recognize that Non Forest since 1973 and Other Non-Forest may include secondary forests: young-growth, forest fallow or agro-forest.

Figure 4

Role of industrial plantations (oil-palm and pulpwood) in deforestation by period for Borneo (A), Indonesian Borneo (B) and Malaysian Borneo (C). On the primary axis (left Y axis), the grey solid line indicates the area of forest rapidly converted to industrial plantations (i.e. within five years of clearance), while the black solid line indicates the total area of deforestation by time period on Borneo (see also Fig. 1A). On the secondary axis (right Y axis), the dashed line represents the share of rapid conversion in total deforestation, expressed in percentage terms.

Figure 5

Proportion (in area terms) of industrial plantation (oil palm and pulpwood) established on land that lacked forest cover for at least five years (solid line) or at least ten years (dashed line) prior to planting, for Borneo (A), Indonesian Borneo (B) and Malaysian Borneo (C).

Figure 6

Proportion (in area terms) of industrial oil-palm (solid lines) and pulpwood (dashed lines) plantations established (A) on land that had forest less than five years before planting (rapid conversion), (B) on land that lacked forest cover for at least five years, or (C) for at least ten years prior to planting in Indonesian Borneo. (D–F) is for Malaysian Borneo.