A5103275162- Geology and Paleoclimatology Research
- Geological and Tectonic Studies in Latin America
- Geological formations and processes
- Geological and Geophysical Studies Worldwide
- Paleontology and Stratigraphy of Fossils
- Environmental and Cultural Studies in Latin America and Beyond
- Diatoms and Algae Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Fish Ecology and Management Studies
- Isotope Analysis in Ecology
- Pleistocene-Era Hominins and Archaeology
- Coastal wetland ecosystem dynamics
- Land Use and Ecosystem Services
- Hydrology and Watershed Management Studies
- Archaeology and ancient environmental studies
- Pacific and Southeast Asian Studies
- Marine and coastal ecosystems
- Groundwater and Isotope Geochemistry
- Aquatic Invertebrate Ecology and Behavior
- Coastal and Marine Management
- Hydrology and Sediment Transport Processes
- Coastal and Marine Dynamics
- Water resources management and optimization
- Flood Risk Assessment and Management
- Soil erosion and sediment transport
University of Regina
2015-2024
Universidad del Norte
2018
Smithsonian Tropical Research Institute
2018
Institut National de la Recherche Scientifique
2017
University of Massachusetts Boston
2015
University of Amsterdam
2001-2006
University of Edinburgh
2003
Amsterdam University of the Arts
2001
The early history of crustaceans is obscured by strong biases in fossil preservation, but a previously overlooked taphonomic mode yields important complementary insights. Here we describe diverse crustacean appendages Middle and Late Cambrian age from shallow-marine mudstones the Deadwood Formation western Canada. fossils occur as flattened fragmentary carbonaceous cuticles provide suite phylogenetic ecological data virtue their detailed preservation. In addition to an unprecedented range...
Lakes and their topological distribution across Earth's surface impose ecological evolutionary constraints on aquatic metacommunities. In this study, we group similar lake ecosystems as metacommunity units influencing diatom community structure. We assembled a database of 195 lakes from the tropical Andes adjacent lowlands (8°N-30°S 58-79°W) with associated environmental predictors to examine patterns at two different levels: taxon functional (deconstructed species matrix by guilds). also...
The Lateglacial and Holocene vegetation history from the Amazonian flank of south Colombian Andes has been studied in a 12 m long sediment core Lake La Cocha (2780 altitude). 18 AMS 14 C ages 550 pollen samples yielded ~25 yr resolution. Montane forest extended up to 2200 during shifted 10,000 period with millennial-scale centennial-scale variability superimposed, its present-day limit at 3550 m. We hypothesise that Intertropical Convergence Zone (ITCZ)-modulated trans-Amazonian moisture...
Abstract The Magdalena River in Colombia is one of the world's largest (discharge = 7100 m 3 s −1 ) tropical rivers, hosting > 170 aquatic vertebrate species. However, concise synthesis current ecological and environmental status lacking. By documenting anthropogenic stressors impacting river on time scales ranging from centuries to decades, we found that system subject compounding impacts climate change, impoundment, invasive alien species (IAS), catchment deforestation, water pollution....
Macrophyte invasive species spreading is one of the most pressing threats to tropical shallow lakes. Yet, studies addressing full extent biotic and abiotic changes that may occur in response are poorly documented. Less known how other human-induced stressors such as eutrophication lake draining interact over time with macrophytes jointly influence biodiversity loss. We combined ecological limnological observations paleoecological data from a eutrophic Neotropical lake, Fúquene Lake,...
Achieving water security for humans and ecosystems is a pervasive challenge globally. Extensive areas of the Americas are at significant risk insecurity, resulting from global-change processes coupled with regional local impacts. Drought, flooding, quality challenges pose threats, while same time, rapid urban expansion, competing demands, river modifications, expanding global markets water-intensive agricultural products drive insecurity. This paper takes social-ecological systems...
Abstract We inferred the late Holocene environmental history of Guatemala highlands from multiple lines evidence in a sediment core Lake Amatitlán. Inferred changes are generally synchronous with archaeologically documented highland Maya cultural shifts. Population increases Middle Preclassic, Early Classic, and Late Postclassic associated deforestation soil erosion. Land abandonment is for reforestation stabilization. Diatoms indicate relatively lower lake level greater trophic status at...
We analyzed diatoms, lithology, and stable isotopes in a sediment core from the Ciénaga Grande de Santa Marta lagoon to reveal history of late Holocene relative sea level rise ontogeny on Caribbean coast Colombia. At ~5300 cal. yr BP, area was characterized by shallow, freshwater ponds that were prone seasonal flooding. From ~4250 ~2060 these became brackish as began rise, since marine conditions have prevailed. In addition tracking we also investigated periods greater lesser precipitation...
Droughts constitute natural hazards that affect water supply for ecosystems and human livelihoods. In 2013–2016, the Caribbean experienced worst drought since 1950s, climate projections southern predict less rainfall by end of 21st century. We assessed streamflow response to a watershed in Colombian analyzing effects length land cover on recovery. generated calibrated SWAT model created annual monthly scenarios from records. used our yield selected covers (wet forest, shade coffee, shrub,...
Tota is an Andean lake located in the Altiplano of Eastern Andes Colombia where socio-politically hierarchical societies Herrera and Muisca, flourished for millennia. To them, surrounding forest were places used diverse activities including religious rituals. In this study we produced a multi-proxy paleolimnological reconstruction using diatoms, isotopes, geochemistry, to try understand lake’s pathways change response natural climatic variations anthropogenic activities. The diatom record...
Analyses of pollen, diatoms, XRF geochemistry, and pigments provide a unique window into how an insular ecosystem in Mauritius responded to extreme drought event 4200 years ago. We reconstruction regional vegetation change local wetland development under influence sea level rise inferred climate between 4400 4100 cal. yr BP. Our multi-proxy data evidence severe 4190 4130 BP, which ultimately led mass mortality larger vertebrates, including two species giant tortoises dodos <2-ha region....
Abstract The late Pleistocene–Holocene ecological and limnological history of Lake Fúquene (2580 m a.s.l.), in the Colombian Andes, is reconstructed on basis diatom, pollen sediment analyses upper 7 core Fúquene‐7. Time control provided by 11 accelerator mass spectrometry (AMS) 14 C dates ranging from 19 670 ± 240 to 6040 60 yr BP. In this paper we present evolution lake its surroundings. Glacial times were cold dry, lake‐levels low area was surrounded paramo subparamo vegetation....
We investigated middle- and late-Holocene hydroclimate patterns in the Colombian Andes using indicators of watershed erosion (lithic abundance), precipitation intensity (% silt), lake-level variability (organic carbon nitrogen, % sand, diatoms), fire frequency (fossil charcoal) from a ~4700-year-long sediment archive Laguna de Ubaque, small sub-alpine lake on eastern flank Andes. Our results indicate reduced precipitation, low levels, increased occurrence at Ubaque between 4700 3500 cal. yr...
ABSTRACT Modern changes in regional climates will result high ecosystem turnover and substantial biodiversity rearrangements. Understanding these requires palaeoecological studies at temporal resolutions comparable to the time window which modern climate change is occurring. Here we present a multi‐proxy, high‐resolution record of forest lake that occurred during last 1100 years middle elevations Panama. From ∼900 1400 CE, ecosystems were characterized by seasonality, probably associated...