Soil geochemistry and constraint of tree seedlings immediately after germination on Macrotermes termite mounds in the Kruger National Park, South Africa

Eighty composite samples (0-2 cm) were taken from treeless mounds and within adjacent savannas at a site ~20 km southwest of Skukuza Rest Camp (40 samples) and a site ~15 km northeast of Phalaborwa Gate in the Kruger National Park (40 samples) with permission from South African National Parks. Each composite sample comprised 8-10 sub-samples taken from ~100 cm² within a plot of ~100 m². The samples in savannas were taken outside of tree canopies. The distance between a mound and its paired adjacent savanna sampling area was a maximum of 20 m.

Soil samples were air-dried and sieved to <2 mm. pH was determined using a 1:2.5 soil:1M KCl solution. Inductively coupled plasma mass spectrometry was used to analyse: i) K, Ca, Mg and Na (1% citric acid extract); ii) P (1% citric acid extract); iii) S (calcium phosphate extract); iv) B (hot water extract); and v) Mn, Cu and Zn (0.02M di-ammonium ethylenediaminetetraacetic acid extract). Organic C (SOC, %) was determined using the Walkley-Black method.

`termite-mound-savanna-soil-data.csv` contains soil chemical measurements of Macrotermes termite mound and savanna soil samples from the Phalaborwa and Skukuza areas of the Kruger National Park, South Africa, with the following 18 columns:

1: 'Site' (whether the sample was from the Phalaborwa or Skukuza study site)

2: 'Habitat' (identifying whether a sample is derived from termite mound or savanna soil)

3: 'Pair' (labelling each sample pair, e.g. both rows labelled '01' form a pair)

4-5: 'Latitude', 'Longitude' (the coordinates, in decimal degrees, of each sample location)

6: 'Elevation' (the elevation above sea level, in metres, of each sample location)

7-12: 'Na', 'Mg', 'K', 'Ca', 'P', 'S' (soil chemical concentrations, all in mg per kg soil, i.e. ppm)

13: 'SOC' (soil organic carbon, in %)

14-17: 'B', 'Mn', 'Cu', 'Zn' (soil chemical concentrations, all in mg per kg soil, i.e. ppm)

18: 'pH'

`termite-mound-savanna-soil-analyses.R` contains the R code used to describe (means and standard deviations) and analyse (two-sided paired t-tests) the data.

`termite-mound-savanna-soil-t-test-results.csv` is a summary of the t-tests, generated by the analysis script.

`termite-mound-savanna-soil-figure.R` used both the raw data and the results of the t-tests to produce the graph in the manuscript.19687