Reconstruction of the mid-Holocene paleoclimate of the Ecuadorian Andean páramo at Tres Lagunas, Ecuador

Frederick, Logan; Brunelle, Andrea; Morrison, Mathew; Crespo, Patricio

doi:10.1177/0959683618761547

Cited by 5 publications

(7 citation statements)

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“…Changes in the convective index point to two drier episodes at 2550 and 1300 cal yr BP (Figure 6). At about 500 km south of Papallacta and at 3800 m asl, two drier episodes, between 2700 and 2000 cal yr BP and between 1700 and 1000 cal yr BP, were also observed in the lacustrine record of Tres Lagunas (Frederick et al, 2018) and can be attributed to abrupt changes in SASM activity at centennial scale.…”

Section: Interpretation and Discussionmentioning

confidence: 97%

“…For instance, at Shatuca and Tigre Perdido, the long dry period that lasted ~200 years at about 2300 cal yr BP (Bustamante et al, 2016; van Breukelen et al, 2008) does not correspond to the driest period at Papallacta. The multi-decadal changes observed in the speleothem records, for instance, the increase in moisture between 3500 and 2900 cal yr BP, are not observed at Papallacta or in the lacustrine record of Tres Lagunas (Frederick et al, 2018), suggesting that the vegetation was not impacted and/or that the amplitude of the event was smaller at higher elevations. The influence of the intensity of the SASM on precipitation variability over the high summits of the Andes after 2500 years BP is also visible in the Ti/Ca sediment record of Mollier-Vogel et al (2013) from the Gulf of Guayaquil (4°S) (Figure 6).…”

Section: Interpretation and Discussionmentioning

confidence: 98%

“…14 km, running north-south. There, glaciers descend to approximately 4600 m (eastern side) and 4800 m (western side), while older moraines dated to the Younger Dryas cold event indicate (Haug et al, 2001), LC Lake La Cocha (González-Carranza et al, 2012), TL Tres Laguna (Frederick et al, 2018), S Shatuca (Bustamante et al, 2016), TP Tigre Perdido (van Breukelen et al, 2008), H Huagapo (Kanner et al, 2013)) and the main climatic features discussed in the text (ITCZw is the position of the InterTropical Convergence Zone in winter, ITCZs in summer, HC the Humboldt Current, SASM South American Summer Monsoon). (b) Climate information represented on a Walter diagram (Luteyn, 1999) glaciers about 1200 m lower on the eastern side (Clapperton et al, 1997;Hastenrath, 1981).…”

Section: Study Areamentioning

confidence: 99%

“…(a) Map of western South America showing the tropical Andes (in red), the location of Papallacta bog (white star), the location of some of the records cited in the text (C Cariaco (Haug et al, 2001), LC Lake La Cocha (González-Carranza et al, 2012), TL Tres Laguna (Frederick et al, 2018), S Shatuca (Bustamante et al, 2016), TP Tigre Perdido (van Breukelen et al, 2008), H Huagapo (Kanner et al, 2013)) and the main climatic features discussed in the text (ITCZw is the position of the InterTropical Convergence Zone in winter, ITCZs in summer, HC the Humboldt Current, SASM South American Summer Monsoon). (b) Climate information represented on a Walter diagram (Luteyn, 1999).…”

Section: Study Areamentioning

confidence: 99%

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Changes in the vegetation and water cycle of the Ecuadorian páramo during the last 5000 years

et al. 2022

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We analyzed changes in the long-term vegetation cover and in fire activity over the past 5000 years in the Ecuadorian páramo using a sediment core from Papallacta (Ecuador). The chronology is constrained by three tephra layers and 32 AMS 14C ages, and 168 samples yielded a high-resolution record of environmental changes. We estimated the upslope wind convectivity as the ratio between pollen transported from the Andean cloud forest and Poaceae pollen to distinguish changes in atmospheric moisture from changes in soil moisture. The record showed that the two sources of moisture, either from year-round adiabatic cloud dripping linked to SASM activity or to ENSO variability at decadal-scale, influenced vegetation-cover changes. Between 5000 and 2450 cal yr BP, both soil moisture and biomass burning were higher than after 2450 cal yr BP. The shift between the two states matches the zonal increase in summer insolation that drove the ITCZ to its southernmost position. Our results underline resilience to volcanic activity, the importance of the upslope convective dripping with the lowest convective index observed at ~4500 cal yr BP, the anomalous last century with the highest convective activity and the driest soil conditions recorded in the last 5000 years, the recent increase in fire activity and the link between soil moisture and the position of the ITCZ.

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Section: Interpretation and Discussionmentioning

confidence: 97%

Section: Interpretation and Discussionmentioning

confidence: 98%

Section: Study Areamentioning

confidence: 99%

Section: Study Areamentioning

confidence: 99%

See 2 more Smart Citations

Changes in the vegetation and water cycle of the Ecuadorian páramo during the last 5000 years

et al. 2022

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“…Mojanda and Mt. Fuya Fuya, Robin et al, 2009), and periodic burns during the Holocene (Frederick et al, 2018). Even though most genetic variation occurs within populations of Dyscolus alpinus , some among–population genetic differentiation was also revealed, particularly comparing Cashca Totoras (site 4) to other sites.…”

Section: Discussionmentioning

confidence: 99%

The role of dispersal for shaping phylogeographical structure of flightless beetles from the Andes

Muñoz-Tobar

Caterino

2019

PeerJ

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Background Páramo is a tropical alpine ecosystem present in the northern Andes. Its patchy distribution imposes limits and barriers to specialist inhabitants. We aim to assess the effects of this habitat distribution on divergence across two independently flightless ground beetle lineages, in the genera Dyscolus and Dercylus. Methods One nuclear and one mitochondrial gene from 110 individuals from 10 sites across the two lineages were sequenced and analyzed using a combination of phylogenetics, population genetic analyses, and niche modeling methods. Results The two lineages show different degrees of population subdivision. Low levels of gene flow were found in Dyscolus alpinus, where one dominant haplotype is found in four out of the six populations analyzed for both molecular markers. However, complete population isolation was revealed in species of the genus Dercylus, where high levels of differentiation exist at species and population level for both genes. Maximum entropy models of species in the Dercylus lineage show overlapping distributions. Still, species distributions appear to be restricted to small areas across the Andes. Conclusion Even though both beetle lineages are flightless, the dispersal ability of each beetle lineage appears to influence the genetic diversity across fragmented páramo populations, where Dyscolus alpinus appears to be a better disperser than species in the genus Dercylus.

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Paleolimnological responses of Ecuadorian páramo lakes to local and regional stressors over the last two millennia

et al. 2023

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Increasing surface air temperatures and human influences (e.g., agriculture, grazing, mining, urbanization, tourism) are altering lakes on the Andean páramo of South America, as illustrated by changes in diatom species composition in sediment cores from the region that span the last ~150 years. Previous studies were limited by their relatively short temporal scales and limited spatial coverage. We analyzed sediment cores from the northern (Laguna Piñan) and southern (Laguna Fondococha) Andean páramos of Ecuador. The deposits span the last two millennia and provide a longer-term perspective on past changes in lake ecological and geochemical dynamics.Both lakes show shifts in dominant diatoms through time. Dominant diatom taxa in Fondococha shifted between two Aulacoseira species, and there was a change in the planktic to benthic ratio, a proxy for open-water versus shallow-water habitats. Both changes are interpreted as evidence of fluctuating lake level. The inferred lake-level changes are corroborated by stratigraphic variations in the concentration of Ti, an erosional proxy, indicating changes in clastic input as a function of wetter or drier conditions. Piñan shows a directional shift in the diatom assemblage over the period of the record, from benthic diatoms tolerant of high dissolved organic carbon (DOC), low pH, and low nutrients, to an assemblage characteristic of lower DOC, higher pH, higher nutrients, and higher lake levels. Shifts in Piñan's diatoms are correlated with tephra layers in the sediment, suggesting that local volcanic ash deposition may have altered both the catchment and lake geochemistry. This is supported by relatively higher δ 13 C values in organic matter associated with tephra layers, which become more negative up-section. Our data suggest that remote lakes in spatially heterogenous montane regions are sentinels of environmental change, and the records from Piñan and Fondococha provide insights into Andean ecosystem responses to past environmental perturbations.

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Reconstruction of the mid-Holocene paleoclimate of the Ecuadorian Andean páramo at Tres Lagunas, Ecuador

Cited by 5 publications

References 49 publications

Changes in the vegetation and water cycle of the Ecuadorian páramo during the last 5000 years

Changes in the vegetation and water cycle of the Ecuadorian páramo during the last 5000 years

The role of dispersal for shaping phylogeographical structure of flightless beetles from the Andes

Paleolimnological responses of Ecuadorian páramo lakes to local and regional stressors over the last two millennia

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