@article {2559,
	title = {Climatic and biotic thresholds of coral-reef~shutdown},
	journal = {Nature Climate Change},
	volume = {5},
	year = {2015},
	month = {Nov-02-2016},
	pages = {369 - 374},
	abstract = {Climate change is now the leading cause of coral-reef degradation and is altering the adaptive landscape of coral populations1, 2. Increasing sea temperatures and declining carbonate saturation states are inhibiting short-term rates of coral calcification, carbonate precipitation and submarine cementation3, 4, 5. A critical challenge to coral-reef conservation is understanding the mechanisms by which environmental perturbations scale up to influence long-term rates of reef-framework construction and ecosystem function6, 7. Here we reconstruct climatic and oceanographic variability using corals sampled from a 6,750-year core from Pacific Panam{\'a}. Simultaneous reconstructions of coral palaeophysiology and reef accretion allowed us to identify the climatic and biotic thresholds associated with a 2,500-year hiatus in vertical accretion beginning ~4,100 years ago8. Stronger upwelling, cooler sea temperatures and greater precipitation{\textemdash}indicators of La Ni{\~n}a-like conditions{\textemdash}were closely associated with abrupt reef shutdown. The physiological condition of the corals deteriorated at the onset of the hiatus, corroborating theoretical predictions that the tipping points of radical ecosystem transitions should be manifested sublethally in the biotic constituents9. Future climate change could cause similar threshold behaviours, leading to another shutdown in reef development in the tropical eastern Pacific.},
	keywords = {Climate-change ecology, Palaeoceanography, Palaeoclimate, Palaeoecology},
	issn = {1758-678X},
	doi = {10.1038/nclimate2541},
	url = {http://www.nature.com/doifinder/10.1038/nclimate2541},
	author = {Toth, Lauren T. and Aronson, Richard B. and Cobb, Kim M. and Cheng, Hai and Edwards, R. Lawrence and Grothe, Pamela R. and Sayani, Hussein R.}
}
@article {2558,
	title = {Holocene variability in the intensity of wind-gap upwelling in the tropical eastern Pacific},
	journal = {Paleoceanography},
	volume = {30},
	year = {2015},
	month = {Jan-08-2015},
	pages = {1113 - 1131},
	abstract = {Wind-driven upwelling in Pacific Panam{\'a} is a significant source of oceanographic variability in the tropical eastern Pacific. This upwelling system provides a critical teleconnection between the Atlantic and tropical Pacific that may impact climate variability on a global scale. Despite its importance to oceanographic circulation, ecology, and climate, little is known about the long-term stability of the Panamanian upwelling system or its interaction with climatic forcing on millennial time scales. Using a combination of radiocarbon and U-series dating of fossil corals collected in cores from five sites across Pacific Panam{\'a}, we reconstructed the local radiocarbon reservoir correction, ΔR, from ~6750 cal B.P. to present. Because the ΔR of shallow-water environments is elevated by upwelling, our data set represents a millennial-scale record of spatial and temporal variability of the Panamanian upwelling system. The general oceanographic gradient from relatively strong upwelling in the Gulf of Panam{\'a} to weak-to-absent upwelling in the Gulf of Chiriqu{\'\i} was present throughout our record; however, the intensity of upwelling in the Gulf of Panam{\'a} varied significantly through time. Our reconstructions suggest that upwelling in the Gulf of Panam{\'a} is weak at present; however, the middle Holocene was characterized by periods of enhanced upwelling, with the most intense upwelling occurring just after of a regional shutdown in the development of reefs at ~4100 cal B.P. Comparisons with regional climate proxies suggest that, whereas the Intertropical Convergence Zone is the primary control on modern upwelling in Pacific Panam{\'a}, the El Ni{\~n}o{\textendash}Southern Oscillation drove the millennial-scale variability of upwelling during the Holocene.},
	doi = {10.1002/2015PA002794},
	url = {http://doi.wiley.com/10.1002/2015PA002794},
	author = {Toth, Lauren T. and Aronson, Richard B. and Cheng, Hai and Edwards, R. Lawrence}
}
