Oil palm plantation expansion into tropical forests may alter physical and biogeochemical inputs to streams, thereby changing hydrological function. In West Kalimantan, Indonesia, we assessed streams draining watersheds characterized by five land uses: intact forest, logged forest, mixed agroforest, and young (<3 years) and mature (>10 years) oil palm plantation. We quantified suspended sediments, stream temperature, and metabolism using high-frequency submersible sonde measurements during month-long intervals between 2009 and 2012. Streams draining oil palm plantations had markedly higher sediment concentrations and yields, and stream temperatures, compared to other streams. Mean sediment concentrations were fourfold to 550-fold greater in young oil palm than in all other streams and remained elevated even under base flow conditions. After controlling for precipitation, the mature oil palm stream exhibited significantly greater sediment yield than other streams. Young and mature oil palm streams were 3.9°C and 3.0°C warmer than the intact forest stream (25°C). Across all streams, base flow periods were significantly warmer than times of stormflow, and these differences were especially large in oil palm catchments. Ecosystem respiration rates were also influenced by low precipitation. During an El Niño-Southern Oscillation-associated drought, the mature oil palm stream consumed a maximum 21 g O2 m-2 d-1 in ecosystem respiration, in contrast with 2.8-±-3.1 g O2 m-2 d-1 during nondrought sampling. Given that 23% of Kalimantan's land area is occupied by watersheds similar to those studied here, our findings inform potential hydrologic outcomes of regional periodic drought coupled with continued oil palm plantation expansion.
|Original language||English (US)|
|Number of pages||19|
|Journal||Journal of Geophysical Research: Biogeosciences|
|State||Published - Jun 2014|
Bibliographical noteFunding Information:
The Young Persons Panel Survey is not the only innovation from the British Household Panel Survey (BHPS). The BHPS is particularly effective as a research instrument to monitor and measure social change as it tracks the circumstances of the same individuals over time, e.g. with respect to labour market participation (including various New Deal options), links between savings, benefits and earnings, short term labour market movement and learning attainment, and labour market histories (Rose, 1991). The potential thus afforded has not been lost upon the Scottish community of interest, and a campaign led by the Scottish Council Foundation (1998) was (partly) successful in canvassing for better household panel survey data for Scotland. While the case for a separate Scottish Household Panel Survey (SHPS) was lost, the BHPS is to undertake a Scottish booster which will generate a total sample of c. 2000 Scottish households per annum.
- oil palm