# SoilPhosphorous.csv
# Soil phosphorous is important for the invasion of native vegatation by exotic weeds.
# Clements (1983) studied the soil phosphorous in the Sydney region (Australia) to determine
# how soil phosphorous varied with topographical location and soil type.
# Bushland sites were chosen in Brisbane Waters National Park, Ku-ring-gai Chase National
# Park and Royal National Park.  These areas were relatively unaffected by suburban development,
# were free from immediate roadside or track effects, and had not been burned for at least
# two years.  Shale-derived and sandstone-derived soils in four topographic locations were
# examined with three 250 m^2 quadrats in each of eight combinations of soil type and
# topography.  Cores of soil of 75 mm depth and 25 m dameter, free from surface litter, were
# collected from each of five randomly selected points in each quadrat.  The five soil
# samples were pooled and the total soil phosphorous (ppm) was determined for each pooled
# sample.
# data from aaerg.canberra.edu.au/envirostats/bm/L5/SASBook_5_we2.pdf
# soil: soil type (shale or sandstone)
# topo: topographic location (valley, north, south, or hilltop)
# phos: soil phosphorous level (ppm)