The Galápagos Islands are an important locale for studies of conservation, evolution, and ENSO dynamics. We have produced the first modern pollen trapping study in the islands that made use of climate dataloggers in order to calibrate climate change and tradewind strength in Holocene records, as well as outline the degradation of the Galápagos by exotic taxa (Collins and Bush, in review). Global climate models hypothesize Eastern Pacific Basin changes that could cause reductions in highland garúa, high elevation fog drip (Vecchi et al., 2006); a result that could cause unprecedented challenges to current conservation projects based in the garúa zones. We will now used the modern pollen and climate data within garúa zones in conjunction with a core from Paul’s Bog (Santa Cruz) spanning 8742 cal yrs BP to: (1) located periods of garúa loss and (2) determine the vegetation composition during these periods. The top 20 pollen taxa from modern pollen traps and core samples will be analyzed with DCA analysis to locate past periods that were climatically similar and contrasting to modern. Periods dissimilar from modern will have vegetation structure analyzed to elucidate future species range expansions and contractions.
Results/Conclusions
DCA analyses on the modern pollen traps have successfully separated trapping locations by pollen and climate (presence/absence of garúa). The modern data has been tuned, allowing a measure of modern conditions to compare pollen from paleoreords within the Galápagos. The Paul’s Bog core record has been sampled at ~80 yr resolution and pollen diagrams possess pronounced changes in community structure during the mid-Holocene. A DCA analysis of the top 20 taxa from this core and garúa zone traps will provide a method to observe if periods of the Paul’s Bog core deviate from modern data, outlining periods of garúa absence. Discrepancies in mid-Holocene flora will provide a measure of the possible degree of change to highland communities with reductions in garúa.
