Expansion of oil palm and other cash crops causes an increase of the land surface temperature in the Jambi province in Indonesia

Abstract

Abstract. Indonesia is currently one of the regions with the highest transformation rate of land surface worldwide related to the expansion of oil palm plantations and other cash crops replacing forests on large scales. Land cover changes, which modify land surface properties, have a direct effect on the land surface temperature (LST), a key driver for many ecological functions. Despite the large historic land transformation in Indonesia toward oil palm and other cash crops and governmental plans for future expansion, this is the first study so far to quantify the impacts of land transformation on the LST in Indonesia. We analyze LST from the thermal band of a Landsat image and produce a highresolution surface temperature map (30 m) for the lowlands of the Jambi province in Sumatra (Indonesia), a region which suffered large land transformation towards oil palm and other cash crops over the past decades. The comparison of LST, albedo, normalized differenced vegetation index (NDVI) and evapotranspiration (ET) between seven different land cover types (forest, urban areas, clear-cut land, young and mature oil palm plantations, acacia and rubber plantations) shows that forests have lower surface temperatures than the other land cover types, indicating a local warming effect after forest conversion. LST differences were up to 10.1 ± 2.6 • C (mean ± SD) between forest and clear-cut land. The differences in surface temperatures are explained by an evaporative cooling effect, which offsets the albedo warming effect.Our analysis of the LST trend of the past 16 years based on MODIS data shows that the average daytime surface temperature in the Jambi province increased by 1.05 • C, which followed the trend of observed land cover changes and exceeded the effects of climate warming. This study provides evidence that the expansion of oil palm plantations and other cash crops leads to changes in biophysical variables, warming the land surface and thus enhancing the increase of the air temperature because of climate change.

Prolonged tropical forest degradation due to compounding disturbances: Implications for CO2and H2O fluxes

“…In tropical regions, land cover change has dramatically altered surface energy and water balance at regional scales (Silvério et al, 2015). The similarity we observed between ET in a highly degraded forest and an undisturbed one agrees with other recent studies of fluxes in agroforests and natural forests (Sabajo et al, 2017). The similarity we observed between ET in a highly degraded forest and an undisturbed one agrees with other recent studies of fluxes in agroforests and natural forests (Sabajo et al, 2017).…”

Measured greenhouse gas budgets challenge emission savings from palm-oil biodiesel

“…The sustainability of palm-oil biodiesel remains actively debated 26 , not only with regard to GHG emissions but also considering other ecosystem properties and functions such as biodiversity 27 , microclimate 28,29 and C pools and fluxes 30,31 . Life cycle analyses (LCA) are a tool to quantify the climatic impacts of palm-oil-derived biofuels [32][33][34] .…”

Reconciling Canopy Interception Parameterization and Rainfall Forcing Frequency in the Community Land Model for Simulating Evapotranspiration of Rainforests and Oil Palm Plantations in Indonesia

“…Further land use change experiments are needed to isolate the effect of oil palm land cover on runoff from topographic/watershed effects at the regional scale. Nevertheless, the small drying effect on top soil moisture associated with oil palm's higher water use by our regional simulations indicates the risk of aridification after forest to oil palm conversion that would impact water supply to other ecosystems (Merten et al, ) and incur possible energy feedbacks (Meijide et al, ; Sabajo et al, ).…”

“…In particular, since the 1990s, the Indonesian regions of Sumatra and Kalimantan experienced the highest rate (average 450,000 ha/year) of oil palm expansion anywhere in the world (Austin et al, ; Carlson et al, ; Gaveau et al, ; Meijaard et al, ; Statistics Indonesia, ). In situ and remote sensing observations have found significant impacts of such land cover change on carbon emissions (Carlson et al, ; Guillaume et al, ), water and energy fluxes (Meijide et al, ; Merten et al, ), surface temperatures (Sabajo et al, ), and microclimates (Hardwick et al, ; Meijide et al, ). Oil palm plantations in Sumatra and Kalimantan span 8–11 × 10 6 ha (Mha), nearly 10% of total regional land area.…”