Pett-Ridge,J.C.(2009): Contributions of dust to phosphorus cycling in tropical forests of the Luquillo Mountains, Puerto Rico. Biogeochemistry, 94, 63-80.

『プエルトリコのルキジョ山脈の熱帯林におけるリン循環に与える風塵の貢献』


Abstract
 The input of phosphorus (P) through mineral aerosol dust deposition may be an important component of nutrient dynamics in tropical forest ecosystems. A new dust deposition calculation is used to construct a broad analysis of the importance of dust-derived P to the P budget of a montane wet tropical forest in the Luquillo Mountains of Puerto Rico. The dust deposition calculation used here takes advantage of an internal geochemical signal (Sr isotope mass balance) to provide a spatially integrated longer-term average dust deposition flux. Dust inputs of P (0.23±0.08 kg ha-1 year-1) are compared with watershed-average inputs of P to the soil through the conversion of underlying saprolite into soil (between 0.07 and 0.19 kg ha-1 year-1), and with watershed-average losses of soil P through leaching (between 0.02 and 0.14 kg ha-1 year-1) and erosion (between 0.04 and 1.38 kg ha-1 year-1). The similar magnitude of dust-derived P inputs to that of other fluxes indicates that dust is an important component of the soil and biomass P budget in this ecosystem. Dust-derived inputs of P alone are capable of completely replacing the total soil and biomass P pool on a timescale of between 2.8 ka and 7.0 ka, less than both the average soil residence time (〜15 ka) and the average landslide recurrence interval (〜10 ka).

Keywords: Luquillo Mountains; Dust; Nutrient cycling; Phosphorus』

Introduction
Site description
Calculation of P mass balance for the Rio Icacos watershed in the Luquillo Mountains
 Dust-derived inputs of P
 Denudation-driven inputs of P to soils (conversion of saprolite to soil)
 Losses of P from soils
 Overall P budget and turnover time
 Availability of P in soil and dust
 Temporal and spatial variability of P fluxes
 Comparison with P cycling in the Amazon and Hawaii
 Conceptual models of P depletion
Conclusions
Acknowledgments
References


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