@article {2715,
	title = {Four centuries of vegetation change in the mid-elevation Andean forests of Ecuador},
	journal = {Vegetation History and Archaeobotany},
	volume = {28},
	year = {2019},
	month = {Jan-11-2019},
	pages = {679 - 689},
	abstract = {Mid-elevation Andean ecosystems have immense species richness and endemism. Taxonomic composition is known to change through time on the eastern slopes of the Andes as a result of climatic change and disturbance events, both natural and by human actions. Fossil phytoliths can capture local scale vegetation changes, especially among monocotyledonous plants. Phytolith production is high in grasses and palms, plant groups that are particularly sensitive to climatic changes and disturbance events in Andean ecosystems. Here, we reconstruct four centuries of local-scale vegetation change and the corresponding fire history from lake sediment records retrieved from Lagunas Cormor{\'a}n and Chimerella, located at ca. 1,700 m a.s.l. in the mid-elevation Andean forests of eastern Ecuador. The charcoal analysis of the lake sediments showed no sign of past fires, and no evidence of cultivation was found at either lake. The phytolith assemblages indicated changes in the relative abundances of palms, grasses and trees over the last few centuries, suggesting that mid-elevation Andean phytolith assemblages are sensitive to local scale vegetation dynamics. The largest change in vegetation occurred at the end of the Little Ice Age, at which point the diversity of palm phytoliths decreases. These phytolith assemblages are probably responding to changes in the cloud base position through time, which strongly influences the distributions of many plants and animals.},
	issn = {0939-6314},
	doi = {10.1007/s00334-019-00715-8},
	url = {http://link.springer.com/10.1007/s00334-019-00715-8},
	author = {Huisman, Seringe N. and Bush, Mark B. and McMichael, Crystal N. H.}
}
@article {2714,
	title = {Vegetation responses to late Holocene climate changes in an Andean forest},
	journal = {Quaternary Research},
	volume = {89},
	year = {2018},
	month = {Jan-01-2018},
	pages = {60 - 74},
	abstract = {A paleoecological record from Lake Palotoa (1370 m elevation) in the Andean foothills of Peru spans the last 3800 years. Lake Palotoa lies near the modern cloud base in a location sensitive to changes in atmospheric moisture. In many areas, these forests have been destroyed, but Lake Palotoa shows no sign of human occupation today or in the past. The modern forest surrounding the lake is dominated by the Andean palm, Dictyocaryum lamarckianum, which is also the most abundant taxon in the fossil pollen record. Fossil pollen data show the vegetation assemblages have not experienced strong compositional changes in the late Holocene. Global-scale climatic events such as the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA) are identified within the record, though the vegetation responses are subtle. Hedyosmum and Sloanea pollen percentages increase near the onset of the MCA and may reflect decreased seasonality. The LIA coincides with increased Hedyosmum pollen percentages, and increases in Clethra and Begonia, two elements that tend to occupy forests now found at higher elevations. Our findings demonstrate the stability of montane forest systems to natural Holocene climate change.},
	keywords = {Cloud forest, Dictyocaryum, Fossil pollen, Little ice age, Medieval Climate Anomaly, seasonality, Tropical ecology},
	issn = {0033-5894},
	doi = {10.1017/qua.2017.64},
	url = {https://www.cambridge.org/core/product/identifier/S0033589417000643/type/journal_article},
	author = {Schiferl, Jacob D. and Bush, Mark B. and Silman, Miles R. and Urrego, Dunia H.}
}
@article {2717,
	title = {Tropical Pacific climate variability over the last 6000~years as recorded in Bainbridge Crater Lake, Gal{\'a}pagos},
	journal = {Paleoceanography},
	volume = {32},
	year = {2017},
	month = {Jan-08-2017},
	pages = {903 - 922},
	abstract = {Finely laminated sediments within Bainbridge Crater Lake, Gal{\'a}pagos, provide a record of El Ni{\~n}o{\textendash}Southern Oscillation (ENSO) events over the Holocene. Despite the importance of this sediment record, hypotheses for how climate variability is preserved in the lake sediments have not been tested. Here we present results of long-term monitoring of the local climate and limnology and a revised interpretation of the sediment record. Brown-green, organic-rich, siliciclastic laminae reflect warm, wet conditions typical of El Ni{\~n}o events, whereas carbonate and gypsum precipitate during cool, dry La Ni{\~n}a events and persistent dry periods, respectively. Applying this new interpretation, we find that ENSO events of both phases were generally less frequent during the mid-Holocene (~6100{\textendash}4000 calendar years B.P.) relative to the last ~1500 calendar years. Abundant carbonate laminations between 3500 and 3000 calendar years B.P. imply that conditions in the Gal{\'a}pagos region were cool and dry during this period when the tropical Pacific E-W sea surface temperature (SST) gradient likely strengthened. The frequency of El Ni{\~n}o and La Ni{\~n}a events then intensified dramatically around 1750{\textendash}2000 calendar years B.P., consistent with a weaker SST gradient and an increased frequency of ENSO events in other regional records. This strong interannual variability persisted until ~700 calendar years B.P., when ENSO-related variability at the lake decreased as the SST gradient strengthened. Persistent, dry conditions then dominated between 300 and 50 calendar years B.P. (A.D. 1650{\textendash}1900, {\textpm} ~100 years), whereas wetter conditions and frequent El Ni{\~n}o events dominated in the most recent century.},
	keywords = {Climate variability, El Ni{\~n}o{\textendash}Southern Oscillation(ENSO), Gal{\'a}pagos archipelago, mid-Holocene, monitoring, tropical Pacific Ocean},
	doi = {10.1002/palo.v32.810.1002/2017PA003089},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017PA003089},
	author = {Thompson, Diane M. and Conroy, Jessica L. and Collins, Aaron and Hlohowskyj, Stephan R. and Overpeck, Jonathan T. and Riedinger-Whitmore, Melanie and Cole, Julia E. and Bush, Mark B. and Whitney, H. and Corley, Timothy L. and Kannan, Miriam Steinitz}
}
