Thanks Liz for finding that P info. In yet another (blatant) example of my forgetting to write down the URL of the source, here's a Wollemia soil characteristics document I copied onto my word processor some months ago. 6.2 Soil characteristics Soils are sandstone-derived boulder alluvium, with high organic matter, some shale component and a substantial basalt wash from the higher reaches of small tributary canyons (Jones et al. 1995). The soil is very shallow. In some areas there is little or no soil layer. Roots of the Wollemi Pine plants grow into rock fissures or extend for tens of metres away from the main groups of trunks. The soil has a poor structure and appears to have water-repelling qualities. Levels of nutrient are low and the soil is extremely acidic, often in the range 3-4 pH, with low levels of most elements although high in aluminium, sulphate and iron. There are patches of highly saline soil. Salt probably leaches from the parent material (Offord et al. 1996, C. Offord pers. comm.) (See Table 2). Senescent branches fall and contribute substantially to the litter layer (Hill 1995). Decomposition of these fallen branches may contribute to the low pH of the soil and this acidity and lack of nutrients may contribute to the slow growth of mature trees and seedlings (Offord et al.1996). Characteristic Range Interpretation pH(inH20) 3.8-4.6 strongly-extremely acidic pH(in CaC12) 2.9-4.2 strongly - extremely acidic Electrical Conductivity 0.1-1.9 mS/cm low-highly saline Sodium 0.0-0.14 meq% good Potassium 0.15-0.8 meq% low-good Calcium 0.3-2.9 meq% very low - marginally good Magnesium 0.5-2.24 meq% low-high Aluminium 0.1-4.9 meq% trace-very high Phosphorus 0-3.3 mg/kg none - low Ammonium 10-42 mg/kg low Nitrate 0.1-20.7 mg/kg low-good Iron 179-357 mg/kg high - good Sulphate 73-176 mg/kg high - good Zinc 1.6-2.6 mg/kg low Copper 0.6-2.3 mg/kg low Maganese 1.1-7.7 mg/kg low Table 2: Soil chemical characteristics of the Wollemi Pine at Site 1 6.3 Light intensity Field recordings show that light on the canyon floor at Site 1 is very low, with less than 10% ambient light. Due to their orientation both Wollemi Pine sites receive only limited light at most times of the year. The amount of available light is further reduced at Site 1 by shading from competing flowering trees. Site 2 receives even less light than Site 1 due to aspect and the narrowness of the canyon. Some areas of Site 1 receive direct light in the middle of the day for a very short time, possibly less than one hour (Offord et al. 1996). Note they spelled aluminum and manganese incorrectly. The statement "soil appears to have water-repelling qualities" interested me because our North Okanagan soil is very light; water seems to run off before it goes in.