کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4736730 1640908 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Merging chironomid training sets: implications for palaeoclimate reconstructions
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Merging chironomid training sets: implications for palaeoclimate reconstructions
چکیده انگلیسی

Icelandic and Norwegian chironomid calibration or training sets were merged to investigate whether a larger combined training set would be useful to apply to subfossil chironomid data from Iceland for periods such as the early Holocene, the Holocene Thermal Maximum and the Little Ice Age, when temperatures can be expected to be outside the current temperature range of the Icelandic training set. Following taxonomic harmonisation, the Icelandic and Norwegian data sets were compared before being merged to form a combined Norwegian-Icelandic training set. Analyses showed that it was biologically and statistically valid to merge the two data sets. The resulting combined inference model for mean July air temperature had improved performance statistics (r2jack = 0.87; RMSEPjack = 1.13) when compared to the best performing Icelandic model (r2jack = 0.61; RMSEPjack = 0.83), due to the longer environmental gradient covered (Icelandic 6–11 °C; combined 3.5–16 °C), and to the increased number of samples (Icelandic = 53 lakes; combined = 207 lakes) and taxa (Icelandic = 47 taxa; combined = 133 taxa) present within the combined training set. The inference models were applied to an early Holocene chironomid sequence from Vatnamýri, north Iceland, and a 450-year recent record from Myfluguvatn, north-west Iceland, to compare the reconstructions produced. The various inference models produced similar trends and patterns of temperature reconstruction, but the inference model based on the combined training set produced a larger range of reconstructed temperatures than the Icelandic model. It was found that different inference models produced more variation in the reconstruction than when different training sets were used. A comparison of the Myfluguvatn reconstructions with meteorological observations showed that the combined Norwegian–Icelandic inference model produced more reliable results than the Icelandic or Norwegian inference models alone.


► Icelandic and Norwegian chironomid training sets were compared and merged.
► Longer environmental gradients were covered by the merged training set.
► The merged training set was applied to Icelandic Holocene chironomid data.
► This led to improved accuracy and reliability of the chironomid reconstructions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 30, Issues 19–20, September 2011, Pages 2793–2804
نویسندگان
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