Diatom-inferred ecological responses of an oceanic lake system to volcanism and anthropogenic perturbations since 1290 CE

Vázquez‐Loureiro, David; Gonçalves, Vítor; Sáez, Alberto; Hernández, Armand; Raposeiro, Pedro M.; Giralt, Santiago; Rubio-Inglés, María J.; Rull, Valentı́; Bao, Roberto

doi:10.1016/j.palaeo.2019.109285

Cited by 13 publications

(12 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lakes are natural traps in drainage basins, and their sedimentary records are potentially continuous on time scales of several millennia. Depending on the age of the lake basin and the sediments, as well as on sedimentation rates, lakes may host crucial information to reconstruct climatic, ecological, and tectonic histories of volcanic regions (e.g., Björck et al, 2006;Sáez et al, 2007;Giralt et al, 2008;Stockhecke et al, 2014;Hernández et al, 2017;Vázquez-Loureiro et al, 2019). In these regions, lacustrine sequences are usually rich in tephra layers, which constitute one of the best means to investigate the frequency, size, and style of eruptions affecting that region, often with a detail that cannot be achieved using terrestrial deposits alone (e.g., Wulf et al, 2004;Stern 2008;Van Daele et al, 2014;Kutterolf et al, 2016;McNamara et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Unraveling the Holocene Eruptive History of Flores Island (Azores) Through the Analysis of Lacustrine Sedimentary Records

et al. 2021

Self Cite

View full text Add to dashboard Cite

Lacustrine sequences from active volcanic settings usually hold a rich and continuous record of tephra layers, providing a critical source of information to reconstruct a most complete eruptive history of a region. Lake sedimentary records on volcanic islands are particularly useful as the typical small size of these islands and their steep subaerial and submarine slopes lead to a lower preservation of potential erodible pyroclastic deposits. Here we explore the lacustrine sedimentary record of Lagoa da Lomba, a crater lake in the central upland area of Flores Island (Azores), to gain insight into the recent eruptive history of this island. The strategic location of Lagoa da Lomba, half distance between the two clusters of recent volcanic activity of the island, together with its long-lasting record, back to 23.52 cal kyr BP, makes this lake a privileged site to investigate the Holocene volcanic history of Flores. Based on a detailed stratigraphic characterization of sediments from a lake transect of three cores, supported by glass shard geochemistry and radiocarbon dating, we recognized four Holocene eruptive events taking place between 6.28 and 2.36 cal kyr BP, demonstrating that the Holocene volcanic activity at Flores Island may have lasted longer than previously reported. Glass shard geochemistry from the different tephra layers suggests three populations, basaltic to trachybasaltic in composition, where the last eruption is the least evolved endmember. Two of the four eruptive events correlate with subaerially-exposed pyroclastic sequences, in terms of stratigraphy and geochemistry. The most recent event recorded at Lagoa da Lomba was constrained to 3.66 – 2.36 cal kyr BP and linked to an eruption sourced from Lagoa Comprida Volcanic System. The second most recent eruptive event was sourced from Lagoa Funda Volcanic System and dated at 3.66 cal kyr BP. Our observations show that Flores experienced vigorous volcanic activity during the Late Holocene. Therefore, contrary to what is assumed, the possibility of future eruptions should be properly considered, and the volcanic hazard here should not be underestimated. Moreover, we highlight the importance of tephrostratigraphy in recent lake sediments to reconstruct past volcanic activity, especially at small volcanic islands, such as Flores, where exposure is poor due to erosion within the limited subaerial area and the dense vegetation.

show abstract

Section: Introductionmentioning

confidence: 99%

Unraveling the Holocene Eruptive History of Flores Island (Azores) Through the Analysis of Lacustrine Sedimentary Records

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…To overcome the scarcity and incomplete historical records in the Azorean islands, environmental reconstructions based on long continuous sequences of natural archives (sediments older than 1450 AD) were used to establish species presence in pristine conditions before human settlement. Data from recent paleolimnological studies in the Azores (São Miguel, Pico, and Flores islands) that have been focused on climatic and environmental reconstruction using biological proxies, e.g., pollen, plant remains, frustules of diatoms, water fleas, and chironomids (van Leeuwen et al, 2005;Connor et al, 2012;Raposeiro et al, 2017;Rull et al, 2017;Vázquez-Loureiro et al, 2019) were considered for this new approach. For example, van Leeuwen et al (2005) unequivocally confirm the status of Selaginella kraussiana (Kunze) A. Braun as native on the Azores islands.…”

Section: Paleolimnology Recordsmentioning

confidence: 99%

“…In the Azores, isolation, small island area, young geology, and numerous volcanic eruptions have acted as strong biogeographical filters, resulting in low diversity of native biotic assemblages and a high percentage of freshwater faunal endemism (11% - Raposeiro et al, 2012), when compared to continental systems (Hughes, 2006). Since the establishment of the first human settlements in the islands (official Portuguese colonization in 1432 CE), pressure on the ecosystems has increased exponentially, mainly associated with landscape disturbance due to changes in land use which have resulted in habitat degradation and fragmentation and the introduction of nonindigenous species (Triantis et al, 2010;Connor et al, 2012;Ferreira et al, 2017;Raposeiro et al, 2017;Rull et al, 2017;Vázquez-Loureiro et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Non-indigenous and Invasive Freshwater Species on the Atlantic Islands of the Azores Archipelago

et al. 2021

Self Cite

View full text Add to dashboard Cite

Freshwater systems on remote oceanic islands are particularly vulnerable to biological invasions. The case of freshwater ecosystems in the Azores Archipelago is especially relevant considering the islands’ youth and remoteness, and low natural connectivity. This study presents a review of the introduction and presence of non-indigenous freshwater species in the Azores, retrieved from various historical records, paleoenvironmental reconstructions, published records, and field data from two decades of the Water Framework Directive (WFD) monitoring programs. At least 132 non-indigenous freshwater species have successfully established in the Azores, belonging to several taxonomic groups: cyanobacteria (10), synurophytes (1), desmids (1), diatoms (20), plants (41), invertebrates (45), amphibia (2), and fishes (12). Intentional and accidental introductions have been occurring since the establishment of the first human settlers on the archipelago, impacting freshwater ecosystems. The first reported introductions in the Azores were intentional fish stocking in some lakes. Non-deliberate introductions have recently increased through transport-contaminants (51%) associated with the aquarium trade or agricultural products. In the Azores, the highest number of non-indigenous species occur on the largest and most populated island, São Miguel Island (116), followed by Flores (68). Plants constitute the most representative group of introduced species on all islands, but invertebrates, diatoms, and fishes are also well established on most islands. Among invertebrates, non-indigenous arthropods are the most well-established group on all islands except on the smallest Corvo Island. Many non-indigenous species will likely benefit from climate change and magnified by globalization that increases the probability of the movement of tropical and subtropical species to the Azores. Present trends in international trade, importations, and enhanced connectivity of the archipelago by increasing flights and shipping will probably promote the arrival of new species. Augmented connectivity among islands is likely to improve non-indigenous species dispersal within the archipelago as accidental transportation seems to be an essential pathway for non-indigenous freshwater species already present in the Azores.

show abstract

“…Apart from their ecological importance, peatlands are, together with lakes (e.g. Hernández et al 2017 , Raposeiro et al 2017 , Vázquez-Loureiro et al 2019 ), the best paleoecological archives available in the Azores. Due to the existence of active volcanoes, São Miguel Island is particularly rich in hydrothermal vent fields ( Gaspar et al 2015 ).…”

Section: Project Descriptionmentioning

confidence: 99%

Distribution of testate amoebae in bryophyte communities in São Miguel Island (Azores Archipelago)

Souto¹,

Gonçalves²,

Pontevedra-Pombal³

et al. 2021

BDJ

Self Cite

View full text Add to dashboard Cite

Testate amoebae are a polyphyletic group of protists living preferentially in soils, freshwaters and wetlands. These Protozoa have a worldwide distribution, but their presence and diversity in the Azores (a remote oceanic archipelago) is poorly known, with only twelve taxa recorded so far. The published information reflects occasional collections from sporadic field visits from naturalists to São Miguel Island, mainly in the nineteenth century. To overcome this limitation, a standardised survey was carried out on the Island, sampling different types of habitats from several localities to provide the distribution and information on species ecology of testate amoebae. In this study, 43 species of testate amoebae were recorded (within a total of 499 occurrences), belonging to two orders of Protista (26 Arcellinida and 17 Euglyphida). The most frequently occurring testate amoebae were Euglypha strigosa, Trinema lineare, Euglypha rotunda, Assulina muscorum and Cyclopyxis eurystoma. The most diverse genus was Euglypha (six species). A total of 38 species are new records for the Azores Archipelago. These data help to improve knowledge of the geographical distribution of testate amoebae in the northern hemisphere and their diversity in the Azores Archipelago.

show abstract

Diatom-inferred ecological responses of an oceanic lake system to volcanism and anthropogenic perturbations since 1290 CE

Abstract: Diatom-inferred ecological responses of an oceanic lake system to volcanism and anthropogenic perturbations since 1290 CE.

Cited by 13 publications

References 79 publications

Unraveling the Holocene Eruptive History of Flores Island (Azores) Through the Analysis of Lacustrine Sedimentary Records

Unraveling the Holocene Eruptive History of Flores Island (Azores) Through the Analysis of Lacustrine Sedimentary Records

Non-indigenous and Invasive Freshwater Species on the Atlantic Islands of the Azores Archipelago

Distribution of testate amoebae in bryophyte communities in São Miguel Island (Azores Archipelago)

Contact Info

Product

Resources

About