Carlos A. Rivera Rondón

Pontificia Universidad Javeriana · Department of Biology

The objective of this investigation is to evaluate the recent changes in the accumulation of organic matter and carbon on the Yahuarcaca lake system, by means of a multiproxy Paleolimnological study. The methodology based on lithological descriptions of 210Pb/137Cs-dated cores allowed us to infer the centennial sedimentation processes and carbon a...

In tropical regions there are a large number of species of diatoms that have not been identified yet. This research aimed to study the composition of epilithic diatom flora found in samples collected in Dagua River a tropical Andean hydrographical basin located to the southwest of Colombia. Samplings were performed in three stations with their resp...

A survey of 60 high mountain lakes of Colombia’s Eastern Range was performed to evaluate the response of surface-sediment diatoms to environmental variables. In each one of these lakes, water samples were taken for physical and chemical characterization, and diatoms were collected from the superficial bottom sediment at the deepest part. Multivaria...

Functional traits play a key role in driving plant community effects on ecosystem function. We examined nine functional traits in various palm (Arecaceae) species and their relationships with moisture, tree-fall gaps, slope, and forest type at 29 transects (500×5 m) in the northeastern region of the Colombian Amazon. Redundancy analysis of mean tra...

Quantification of multivariate trait spectra (or axes of specialization) make the definition of plant strategies more operational, which promotes trait-based theory of community assembly and the understanding of dynamics and functioning of ecosystems. We used field-quantified soil data to explore trait-environment relationships across palm communit...

The rivers of the neotropical region of the Andes present a seasonality in the water flow that intensifies during extreme climatic events. Climate change projections suggest that droughts will be much more intense in the coming decades. The Cauca River is one of the most critical ecosystems in Colombia, running through the country from south to nor...

The páramo lakes, Colombia, situated in the neotropical region, are of great value both as natural heritage and as water source to the most populated areas of the Andes, but are threatened by expanding agriculture, livestock, mining, and landscape fragmentation. Nonetheless, a general assessment of the lakes’ distribution and biogeochemical charact...

A new species, Nupela eremica sp. nov. is described from a high mountain lake located in the Eastern Range of Colombian Andes. The new taxon was studied from sediment and epiphyton samples and under light and scanning electron microscope. Comparison with morphologically similar taxa is showed. N. giluwensis, N. carolina, N. gomphosphenioides, N. en...

For five decades Olduvai Gorge has been a key site to reconstruct and understand the relationship between environmental and landscape conditions and use of affordances by early African hominin populations. Following the first Olduvai Gorge Coring project (OGCP) during 2014, a multiproxy microbiological analysis, which includes phytoliths, pollen, d...

Las floraciones de cianobacterias pueden causar problemas en la calidad del agua por su rápido crecimiento y abundancia. Además de generar biomasa en exceso, causan cambios físicos, químicos y biológicos en el ecosistema. Asimismo, las cianobacterias producen neurotoxinas, hepatotoxinas y dermatotoxinas, entre otras. Los problemas asociados con las...

Bioindication is a method to assess environmental conditions using indicator organisms. In Colombia, water quality evaluation is mostly performed following the Biological Monitoring Working Party/Colombia method (BMWP/Col), which uses aquatic macroinvertebrates at the taxonomic family level. Studies on potential bioindicators are important to produ...

Diatom assemblages are used widely as indicators of environmental conditions. They have been particularly useful in the assessment of some acute environmental problems such as water acidification, eutrophication and salinisation. High mountain lakes are currently a research focus as sentinels of global change, predominantly of long-distance atmosph...

La vegetación riparia es primordial para el funcionamiento de los ecosistemas acuáticos al aportar materia orgánica. Dado que el perifiton juega un rol indispensable en la dinámica de estos ecosistemas y existen pocos trabajos sobre su ecología en el Neotrópico, se planteó la pregunta: ¿Cómo afecta el tipo de cobertura vegetal de la zona riparia, l...

Palaeolandscape studies are an essential tool for understanding adaptation and use of plant- and water-related affordances by hominins. A number of high-resolution palaeolandscape analyses have been carried out at Olduvai Gorge (northern Tanzania) over the last two decades but none have focused on the Tuff ID-IE stratigraphic interval (1.83–1.84 Ma...

Tropical high mountain lakes show unique environmental conditions where chironomids play an important role in ecosystem functioning. The characteristics of these environments could favor diet overlap and therefore a high interspecific competition. This study described the dietary habits of chironomid genera, identified whether the dietary habits we...

This paper reports the results of renewed fieldwork at the HWK EE site (Olduvai Gorge, Tanzania). HWK EE is positioned across the boundary between Lower and Middle Bed II, a crucial interval for studying the emergence of the Acheulean at Olduvai Gorge. Our excavations at HWK EE have produced one of the largest collections of fossils and artefacts f...

Environmental assessments and palaeoreconstructions can take advantage of the high diatom diversity present in mountain lakes. There are only a few studies dealing with the diatom flora of the Pyrenees and research on species taxonomy, distribution and ecology are still at an initial stage. With the aim of updating the list of species present and p...

Los pequeños ríos de los Andes tropicales se han estudiado escasamente y poco se conoce sobre la composición, diversidad y estructura de sus comunidades de macrófitas. En esta investigación se estudiaron las comunidades de plantas acuáticas de 18 pequeños ríos andinos pertenecientes a las cuencas de los ríos La Vieja (Quindío) y Otún (Risaralda) en...

The ratio between chrysophycean cysts and diatom valves (CD ratio) in lake sediments has been suggested as a useful indicator of changing trophic state conditions in oligotrophic lakes. Other environmental factors, however, may influence the CD ratio because chrysophycean cysts usually reflect conditions in the planktonic environment and diatoms re...

Incluye bibliografía e índice

Se comparó la abundancia relativa de Grundulus bogotensis entre dos cuencas y la dieta entre poblaciones de tres cuencas del altiplano Cundiboyacense. Entre marzo y junio de 2006 se realizaron muestreos en 10 localidades utilizando un equipo de electropesca. Laabundancia relativa de cada localidad se expresó como el número deindividuos capturado po...

To compare the relative abundance of Grundulus bogotensis in two river basins and the diet of the populations of three basins in the Cundiboyacense plateau, we sampled 10 localities using electrofishing equipment between March and June 2006. The relative abundance in each locality was expressed as the number of fish caught per hour on a 100m stretc...

Hydraulic dynamics is one of the primary factors determining the structural and temporal changes in phytoplankton communities in reservoirs. There is little information on the factors that explain the temporal changes in biotic communities in the high-mountain reservoirs that provide water to the city of Bogotá (Colombia). Our objective was to iden...

Aquatic systems and their biodiversity are probably the environments that have received the least research attention in the tropical Andes. Current knowledge is limited and derived from studies that are relatively narrow in scope and restricted to specific systems and taxonomic groups of aquatic organisms. Thus, the information available to describ...

Morphometric characteristics of the Lake Guatavita were investigated in order to disclose possible connections with its ecological functioning and discuss some hypotheses that exist about the origin of this lake. The lake has a basin with a conical shape, low perimeter development, maximum depth of 30 m and relative depth of 7.9%. The hypsographic...

span style="font-size: 12pt; font-family: ";Times New Roman";; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: ES-MX; mso-fareast-language: ES; mso-bidi-language: AR-SA;" lang="ES-MX">En este estudio se desarrolló una caracterización física y química de los principales ríos, quebradas y humedales de la región aledaña a la ciudad de P...

We carried out a physical and chemical characterization of the major rivers, streams and wetlands of the surrounding area of the town of Puerto Carreño (Vichada, Colombia) in the flooding and dry seasons, as well as a biological characterization in the dry season. Most of the studied systems showed an acid pH and low ion and nutrient concentrations...

G. bogotensis has a geographic distribution restricted to the Colombian Cundiboyacense plateau, it is listed as near threatened, and research on its autoecology is scarce. Three collections were made in 2006 in the Fúquene Lake, Cundinamarca, Colombia (5° 27' 55" N, 75° 46' 19" W) to describe the habitats occupied by G. bogotensis and to determine...

Minimum (F0), maximum (Fm), and variable (Fv = Fm - F0) fluorescence and photosynthetic efficiency (Fv/Fm) of phytoplankton were measured for several depths and under laboratory conditions during two seasons (June and October of 2000) in Lake Guatavita, Colombia. When the lake was stratified (June) the surface algae were photoinhibited and photosyn...

Guatavita Lake is a small, sheltered tropical high mountain lake located in the Colombian Andes, with a closed watershed and a maximum depth of 25 m. It is the freshwater source for human consumption in nearby small towns, as well as being a site of cultural value for the country, as it was a sacred place to indigenous peoples until about five cent...

In four mountain aquatic ecosystems of altiplano Cundiboyacense, Colombia, we compared through analysis regression data set of chlorophyll-a obtained with spectoropho-tometric (tricromatic formula) and fluorometric (Welschmeyer) methods. The analysis showed that the spectrophotometric method overestimated the chlorophyll-a concen-tration, but it co...

En cuatro ecosistemas acuáticos de montaña del altiplano Cundiboyacense, Colom- bia, se compararon mediante un análisis de regresión los datos de clorofila-a obteni- dos a partir de los métodos espectrofotométrico (fórmula tricromática) y fluorométri- co (método de Welschmeyer). El análisis demostró que el método espectrofotométrico sobreestimó la...

RESUMEN En veinte ríos de la cuenca alta y media del Río Bogotá (Cundinamarca, Colombia) se estudió la relación entre algunas variables físicas, químicas e hidrológicas con la comunidad de diatomeas perifíticas. A partir de un Análisis de Componentes Principales se estableció que la conductividad, el pH, el amonio, la turbidez, el fósforo total, el...

Minimum (F 0 ), maximum (F m ), and variable (F v = F m - F 0 ) fluorescence and photosynthetic efficiency (F v /F m ) of phytoplankton were measured for several depths and under laboratory conditions during two seasons (June and October of 2000) in Lake Guatavita, Colombia. When the lake was stratified (June) the surface algae were photoinhibited...

In 16 sampling points, which were located in 14 streams of the middle and high basin of the Bogotá River (2.617 - 2.988 m), we analyzed some physical, chemical and hydrological variables and the benthic algae community (taxonomic classes). By means of Principal Component Analysis, we concluded that the rivers respond to a basin area gradient and mi...