Pollen/climate calibration based on a near-annual peat sequence from the Swiss Alps.

摘要: The objective of this study was to develop a high-resolution pollen-based climate inference model (using ‘calibration in time’) for the mire Mauntschas (SE Swiss Alps, 1818 m above sea level). We focused on 11 types pollen and spores (referred as simplicity) which we produced 150 year (a) time series accumulation rates percentages. Dating these based 29 14C dates from pure Sphagnum, spheroidal carbonaceous particles, larch bud moth events, an age–depth that took into account probabilities calibrated ages, degree curvature line changes concentrations all major types. Time resolution 1–5 a. first smoothed using 3 triangular filter, thus removing time-resolution dependent variability, minimising effects potential dating uncertainties. Using redundancy analysis, then studied simultaneous response selected 288 different combinations monthly temperature or precipitation data measured at Sils Maria (1798 level), located 9 km Mauntschas. From AD 1954 2002, mean May–August air same explained most (18.1%) variation rates. amount dropped 9.9% after detrending with 50 high-pass possibly removed non-climatic trends. Temperature more among PAR than percentages; however, during verification period (AD 1864–1953) former were potentially affected by uncertainties could not be used. For developing model, tested ordinary least squares regression, ridge principal components partial regression. During well-dated calibration 1954–2002), regression percentages six turned out parsimonious having cross-validated root square error prediction 0.23°C April–November temperature. A comparison reconstructed showed best reflected long-term (at decadal-scale) changes. Copyright © 2009 John Wiley & Sons, Ltd.