Soil properties across primary forest, logged forest and oil palm plantation in Sabah, Malaysia

Eight 1-hectare plots were located across three sites representative of unlogged or logged tropical forest; Danum Valley Conservation Area (DVCA), Maliau Basin Conservation Area (MBCA) and SAFE project in Sabah, Malaysia (Riutta et al. 2018). A stratified sampling design was utilised. 1 Ha plots were first subdivided into twnety-five 20x20 m subplots with five of these randomly selected for sampling.

Soil nutrients data: at three locations within each subplot, four pairs of PRS™ ion exchange membranes (www.westernag.ca) (one pair = 1 cation & 1 anion) were buried vertically to approx 10cm depth. These were left in situ for two weeks, removed, washed with deionised water and shipped to the manufacturer (Western Ag, Canada) for analysis. The four probe pairs from each location were pooled prior to elution with 0.5M HCl for one hour. NO3- and NH4+ were measured colorimetrically using automated flow injection analysis (FIA). All other elements were analysed using inductively coupled plasma –optical emission spectroscopy (ICP-OES). Results are reported as supply rates over the burial period (µg/10cm2/14 days).

Soil properties data: Five samples were collected from each subplot using a gouge augur. The organic layer depth was measured and then horizons (organic and mineral soil) were separated and sealed in Ziploc bags. The five samples from each subplot were pooled prior to analysis to yield 20 organic and 20 mineral soil samples per forest type (Unlogged and logged forest). pH was measured on fresh soils in a 2.5:1 water suspension (Landon, 1984). Total C and N was measured using an elementar vario max CN analyser. Total P was extracted using a sulphuric-nitric-perchloric acid digest (Allen, 1989) whilst inorganic P was extracted using a Bray No. 1 solution (Bray and Kurtz. 1945). Concentration was measured on a spectrophotometer at 880nm (Anderson & Ingram, 1993). Sand silt and clay were determined using the pipette method. References available from supporting documentation.

This dataset is included in the following collections

NERC Human-modified Tropical Forest (HMTF) Programme