[M-IS19] [JJ] Biogeochemistry

[MIS19-10] Climate and geochemical controls on soil phosphorus in Bornean tropical rainforest soils

*Rota Wagai¹, Yohey Hashimoto², Kosuke Ikeya¹, Shuntaro Hiradate¹, Taiki Yokoyama³, Kanehiro Kitayama³ (1.NARO, Institute for Agro-Environmental Sciences, 2.Tokyo University of Agriculture and Technology, 3.Kyoto University)

Keywords:Phosphorus, 31P liquid-state NMR spectroscopy, Tropical forest ecosystems, Biogeochemical cycling, Ultramafic rock

Phosphorus (P) is a major limiting nutrient controlling primary productivity in terrestrial ecosystems especially on highly-weathered soils. It was recently suggested that P depletion during soil weathering may also control long-term ecosystem evolution and plant species diversity. However, the connection between soil P forms and availability, forest productivity, and other ecosystem properties remains uncertain. The stock and chemical forms of soil P in ecosystem development is a fundamental issue because it affects plant and microbial strategies for acquiring P.

Here we examined how climate and parent materials control soil P in tropical rainforest ecosystems on Mt. Kinabalu, northeastern Borneo. We selected the sites developed on two chemically-contrasting rock types (ultramafic igneous and acidic sedimentary rocks) along an elevation gradients. We will present the results of soil P concentration (relative to C and N) as well as P forms assessed by liquid-state 31P NMR spectroscopy using NaOH/EDTA extracts.