The study site is located in a commercial oil palm plantation (1°41''35.0” S, 103°23''29.0” E, 76 m a.s.l.) in the tropical lowlands of Jambi province on Sumatra (Indonesia), approx. 25 km west-southwest of Jambi City. The landscape is flat with small elevation variations of approx. ±15 m. Average mean annual air temperature during the period 1991–2011 was 26.7 °C (±0.2 °C standard deviation) and mean precipitation for the same period was 2235 mm yr-1 (±381 mm SD), with a dry season from June to September and two peak rainy seasons around March and December (Drescher et al., 2016, doi:10.1098/rstb.2015.0275). The plantation is owned by Perseroan Terbatas Perkebunan Nusantara VI, Batang Hari Unit (PTPN6). The oil palm plantation covers 2186 ha and the palm seedlings were planted in the years 1999, 2002 and 2004. Our measurements are located in the section where the palms were planted in 2002. Palms are planted in a triangular array, with 9 m x 9 m horizontal density and 142 palms per ha. Canopy height is about 13 m. In 2015, 144 kg ha-1 of magnesium nitrate, 575 kg ha-1 of nitrogen–phosphorus–potassium (NPK) granular, and 251 kg ha-1 of dolomite fertilisers were applied in top-dress application. Stumps of pruned oil palm leaves are densely covered with epiphytes, e.g. ferns (Polypodiophyta) or flowering plants (Melastomataceae, Orchidaceae), while understory vegetation is scarce due to regular application of herbicides and occasional mowing. Highly weathered Loam Acrisols soils dominate in the area (Allen et al., 2015, doi:10.1371/journal.pone.0133325) and mean soil carbon and nitrogen content in the plantation reach 1.12% (±0.34% SD) and 0.08% (±0:02% SD) (Meijide et al., 2017, doi:10.1016/j.agrformet.2017.02.034).
