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| Titel |
Pollen dispersal over complex terrain: How does anisotropic airborne pollen transport affect interpretation of fossil pollen records? A case study in Northern Patagonia. |
| VerfasserIn |
Claudio Pérez, María Martha Bianchi, Marisa Gassmann, Ignacio Pisso |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250100204
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| Publikation (Nr.) |
 EGU/EGU2014-16097.pdf |
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| Zusammenfassung |
| Accumulated pollen in stratified fossil reservoirs is used to infer temporal changes in
vegetation composition. Transport and dispersal by winds are known to introduce large biases
in the interpretation of polynic records. In order to calibrate the models used to infer
information about past species distributions, human activities and climate, contemporary time
series of polynic records are assessed and modelled. In this study we analyse measurements
collected hourly in Bariloche, Argentina (41° 10’ S, 71° 15’ W, 850 masl) of the
species Weinmannia trichosperma, a characteristic forest tree which grows only the
western (Chilean) slopes of the Andes, but not on the eastern (Argentinian) slopes
where the measurements were collected. Instead of the simplistic Gaussian plume
mixing model that is usually employed by the palynological community, we apply a
full 3D Lagrangian dispersion model to interpret the observations and assess the
impact of long-range transport over the Andean mountain range. The Lagrangian
calculation of the origins of the air masses (the "backward footprint") is consistent
not only with the Chilean Weinmania pollen measurements but also with a set of
species only found on the dryer steppe located to the east of the measurement site in
Argentina. The agreement of the modelling results indicates that significant interpretation
mistakes may arise from inconsistent transport treatment. We also discuss the further
application of inverse trajectory modelling to the estimation of source intensity. |
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