Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Discussion papers
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 22 Nov 2018

Research article | 22 Nov 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Biogeosciences (BG).

Silicon cycled by tropical forest trees: effects of species, elevation and bedrock on Mount Kinabalu, Malaysia

Ryosuke Nakamura1, Hidehiro Ishizawa2,3, Rota Wagai4, Shizuo Suzuki1,5, Kanehiro Kitayama1, and Kaoru Kitajima1 Ryosuke Nakamura et al.
  • 1Graduate School of Agriculture, Kyoto University, Kyoto, Japan
  • 2Faculty of Agriculture, Kyoto University, Kyoto, Japan
  • 3Graduate School of Engineering, Osaka University, Osaka, Japan
  • 4National Agriculture and Food Research Organization, Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki, Japan
  • 5National Institute of Technology, Numazu College, Numazu, Shizuoka, Japan

Abstract. Plant species differ in degrees of silicon (Si) uptake and accumulation, and may differentially influence biogeochemical cycles of Si, possibly in interaction with other environmental factors. Here, we report how patterns of Si cycling by vegetation differ with species composition, elevation and bedrock types for species-rich tropical forests on Mt. Kinabalu, Borneo. We used eight forest monitoring plots established in 1995 at four altitudes (700, 1700, 2700 and 3100m above sea level) on two geological substrates (Si-rich acidic sedimentary and less Si-rich ultrabasic igneous rock), where tree species composition, abundance, biomass and litterfall had been monitored. For live leaves of 71 dominant tree species (total relative basal area>60% in each plot) and leaf litter collected in traps, Si concentration was determined after alkaline extraction. Si availability in the upper 10cm of mineral soil was determined as Si dissolved to water after shaking overnight. Tree species with high leaf Si concentrations occurred mostly in the lowest elevation plots. The community-mean Si concentration in live leaves, as well as Si concentration in leaf litter, decreased with increasing elevation. The estimated annual flux of leaf litter mass and Si also decreased with increasing elevation. Leaf and litter Si concentrations showed no difference between the two bedrock types without interaction with elevation. Due to large turnovers of species composition with elevation and bedrock types, most species occurred only in one plot. For 11 species that occurred at two or three plots, only one species showed a weakly significant difference in leaf Si concentration between bedrock types. Surface soil Si availability was greater at lower elevation plots and differed with bedrock types only at 1700m. This pattern was consistent with a hypothesis that Si input via litter in the form of plant opal, rather than bedrock types, should influence the soluble Si in the upper soil horizons. These results suggest that Si cycling by vegetation is more active in lower elevation forests regardless of bedrock types, most likely because Si accumulating species are more abundant in lowland tropical forests.

Ryosuke Nakamura et al.
Interactive discussion
Status: open (until 03 Jan 2019)
Status: open (until 03 Jan 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Ryosuke Nakamura et al.
Ryosuke Nakamura et al.
Total article views: 285 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
246 36 3 285 7 2 4
  • HTML: 246
  • PDF: 36
  • XML: 3
  • Total: 285
  • Supplement: 7
  • BibTeX: 2
  • EndNote: 4
Views and downloads (calculated since 22 Nov 2018)
Cumulative views and downloads (calculated since 22 Nov 2018)
Viewed (geographical distribution)  
Total article views: 284 (including HTML, PDF, and XML) Thereof 284 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 18 Dec 2018
Publications Copernicus
Short summary
Silicon (Si) accumulation by plants should affect biogeochemical cycling of Si, but its geographical patterns are unknown for tropical forests. Comparing forests from 700–3100 m a.s.l. on Mt. Kinabalu, we demonstrate for the first time that lowland forests include more trees with high Si concentrations and have greater annual Si flux via leaf litter, regardless of the bedrock types. Our data of 71 tree species strongly suggest the importance of plant traits in modulating ecosystem Si cycling.
Silicon (Si) accumulation by plants should affect biogeochemical cycling of Si, but its...