RESULTS: A distinctive new species of Pittosporum (P. peridoticola J.B.Sugau and Ent, sp. nov.) was discovered on Mount Tambuyukon in the north of Kinabalu Park during ecological fieldwork. The diagnostic morphological characters of this taxon are discussed and information about the habitat in which it grows is provided. The soil chemistry in the rooting zone of P. peridoticola has high magnesium to calcium quotients, high extractable nickel and manganese concentrations, but low potassium and phosphorus concentrations, as is typical for ultramafic soils. Analysis of foliar samples of various Pittosporum-species originating from ultramafic and non-ultramafic soils showed a comparable foliar elemental stoichiometry that is suggestive of 'Excluder-type' ecophysiology.
CONCLUSION: Pittosporum peridoticola is an ultramafic obligate species restricted to Kinabalu Park with only two known populations within the boundaries of the protected area. It is vulnerable to any future stochastic landscape disturbance events, such as forest fires or severe droughts, and therefore its conservation status is 'Near Threatened'.
RESULTS: Biochar+compost application resulted in 37% and 300% higher soil total organic carbon and available phosphorus content, respectively, during the first 3 years of experimentation compared to control. Similarly, trunk diameter and shoot number of apple trees increased 23-26% by the end of the first year. Nevertheless, there were no significant changes in fruitfulness, fruit weight or starch pattern index as productivity indices.
CONCLUSION: Biochar and compost were beneficial in improving soil quality, mainly by increasing soil nutrient content and decreasing soil bulk density, and in increasing plant growth at early growth stages of apple orchards. However, they failed to enhance overall yield and fruit quality, most likely due to their limited ability to suppress apple replant disease. © 2018 Society of Chemical Industry.