Academic Staff
Prof. dr. Rike Wagner-Cremer
Rike is a professor in 'Palaeophysiology of plants in the context of environmental change', with a strong background in palaeoecology and palaeobotany. Rike is involved in teaching Biology and Geosciences courses, experimental work in the UU phytotron and botanical gardens, and a variety of research projects focusing on reconstructing environmental change through time, using pollen, diatoms and stomata. Her research particularly focuses on plant responses to changing CO2 concentrations in the past and present. By studying modern plant-environment interactions in the field as well as in experimental set-ups, her research provides calibration data for palaeoecological proxies. As such, she can reconstruct past environmental conditions and climate change.
Prof. dr. Rike Wagner-Cremer
Rike is a professor in 'Palaeophysiology of plants in the context of environmental change', with a strong background in palaeoecology and palaeobotany. Rike is involved in teaching Biology and Geosciences courses, experimental work in the UU phytotron and botanical gardens, and a variety of research projects focusing on reconstructing environmental change through time, using pollen, diatoms and stomata. Her research particularly focuses on plant responses to changing CO2 concentrations in the past and present. By studying modern plant-environment interactions in the field as well as in experimental set-ups, her research provides calibration data for palaeoecological proxies. As such, she can reconstruct past environmental conditions and climate change.
dr. Timme Donders
Timme is an experienced palaeoecologist and assistant professor at Utrecht University. Timme is involved in research, laboratory operations and teaching Biology and Geosciences courses. His current research focuses on land-sea correlations in warm climates, long Quaternary records, and the use of annual-scale signals in high-resolution pollen. He has worked on interdisciplinary palaeo-projects all over the world, ranging from the Netherlands to Macedonia, and from the USA (Florida) to Australia and Ecuador.
Timme is an experienced palaeoecologist and assistant professor at Utrecht University. Timme is involved in research, laboratory operations and teaching Biology and Geosciences courses. His current research focuses on land-sea correlations in warm climates, long Quaternary records, and the use of annual-scale signals in high-resolution pollen. He has worked on interdisciplinary palaeo-projects all over the world, ranging from the Netherlands to Macedonia, and from the USA (Florida) to Australia and Ecuador.
Postdoctoral researchers
Dr. Aleksandra Cvetkoska
As expert in freshwater diatoms, Aleksandra’s research focuses on ancient Lake Ohrid (Macedonia/Albania). Lake Ohrid is an UNESCO World Heritage Site since 1979; and it is the oldest and most diverse lake in Europe with more than 300 endemic species. An International Continental Deep Drilling (ICDP) campaign was conducted at Lake Ohrid in the spring 2013 and ca. 600 m long sediment sequence was recovered at water depth of ca. 245 m. As a science team member of a major international project, Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO, http://www.ohrid-drilling.org), Aleksandra is involved as one of the experts studying the diatoms in this sediment record. The preliminary results from the ~1.2 million years old sediment sequence showed evidence for evolutionary events in the diatom record. A major group of international scientists is now focusing on detailed analysis of this core in order to understand the link between the environment and the evolution.
Dr. Aleksandra Cvetkoska
As expert in freshwater diatoms, Aleksandra’s research focuses on ancient Lake Ohrid (Macedonia/Albania). Lake Ohrid is an UNESCO World Heritage Site since 1979; and it is the oldest and most diverse lake in Europe with more than 300 endemic species. An International Continental Deep Drilling (ICDP) campaign was conducted at Lake Ohrid in the spring 2013 and ca. 600 m long sediment sequence was recovered at water depth of ca. 245 m. As a science team member of a major international project, Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO, http://www.ohrid-drilling.org), Aleksandra is involved as one of the experts studying the diatoms in this sediment record. The preliminary results from the ~1.2 million years old sediment sequence showed evidence for evolutionary events in the diatom record. A major group of international scientists is now focusing on detailed analysis of this core in order to understand the link between the environment and the evolution.
Dr. Alejandra Goldenberg
Alejandra is an ecologist and palaeoecologist currently developing diatom based models to infer salinity, tidal height and nutrient concentrations for environmental and sea level reconstructions in the Wadden Sea during the Holocene. Specifically, she is interested in exploring diatom functional groups, known as ecological guilds, in marine and brackish environments. These groups are especially sensitive to environmental changes and habitat conditions, which make them a valuable tool for ecological monitoring and climate reconstructions. Other advantages of the use of ecological guilds is that they are universal to all diatom species, so they can be applied to different ecosystems and geographical areas. In addition, it is easier to identify diatoms to functional group level than to individual species and therefore also time and cost-effective.
Alejandra is an ecologist and palaeoecologist currently developing diatom based models to infer salinity, tidal height and nutrient concentrations for environmental and sea level reconstructions in the Wadden Sea during the Holocene. Specifically, she is interested in exploring diatom functional groups, known as ecological guilds, in marine and brackish environments. These groups are especially sensitive to environmental changes and habitat conditions, which make them a valuable tool for ecological monitoring and climate reconstructions. Other advantages of the use of ecological guilds is that they are universal to all diatom species, so they can be applied to different ecosystems and geographical areas. In addition, it is easier to identify diatoms to functional group level than to individual species and therefore also time and cost-effective.
PhD-students
Kimberley Hagemans MSc
Kimberley is an ecologist and palaeoecologist studying El Niño variability in Southern America during the Holocene. To do this, she is reconstructing past vegetation dynamics and environmental conditions in Cajas National Park, Ecuador. In the tropics the link between ENSO activity and precipitation patterns is so strong that individual El Niño/La Niña events directly influence plant growth. So, by looking at pollen records preserved in annually laminated sediments from lakes in the high Ecuadorian Andes she can obtain a high resolution record of past temperature and precipitation. Combined with data on diatoms, chemistry and sedimentation in the lakes she can get a unique direct measure of past ENSO dynamics.
Kimberley Hagemans MSc
Kimberley is an ecologist and palaeoecologist studying El Niño variability in Southern America during the Holocene. To do this, she is reconstructing past vegetation dynamics and environmental conditions in Cajas National Park, Ecuador. In the tropics the link between ENSO activity and precipitation patterns is so strong that individual El Niño/La Niña events directly influence plant growth. So, by looking at pollen records preserved in annually laminated sediments from lakes in the high Ecuadorian Andes she can obtain a high resolution record of past temperature and precipitation. Combined with data on diatoms, chemistry and sedimentation in the lakes she can get a unique direct measure of past ENSO dynamics.
Alexandra Hincke MSc
Junior Researchers
Fabian Ercan MSc
Fabian is a biologist and palaeoecologist, specialized in stomata-based CO2 reconstructions and deep time palynology. He recently obtained a Master’s degree from the UU master program Environmental Biology, specializing in paleoecology, climatology and marine sciences. Fabian is currently working together with Benjamin on digitalization of the Utrecht University pollen reference collection with one of the Leica-DM6000B microscopes at the Palaeoecology research group. The Leica-DM6000B in combination with the LAS Core program is capable of automatically creating high-resolution 3 dimensional Mosaics scans of entire sides. This enables researchers to maneuver digitally in the picture like they normally would on a microscope. We aim to ultimately create an online high quality reference collection that enables the handling of viewing requests from all over the world, with easy and fast sharing, which will improve the use of reference material in research and education.
Fabian Ercan MSc
Fabian is a biologist and palaeoecologist, specialized in stomata-based CO2 reconstructions and deep time palynology. He recently obtained a Master’s degree from the UU master program Environmental Biology, specializing in paleoecology, climatology and marine sciences. Fabian is currently working together with Benjamin on digitalization of the Utrecht University pollen reference collection with one of the Leica-DM6000B microscopes at the Palaeoecology research group. The Leica-DM6000B in combination with the LAS Core program is capable of automatically creating high-resolution 3 dimensional Mosaics scans of entire sides. This enables researchers to maneuver digitally in the picture like they normally would on a microscope. We aim to ultimately create an online high quality reference collection that enables the handling of viewing requests from all over the world, with easy and fast sharing, which will improve the use of reference material in research and education.
Benjamin Hoogstraten MSc
Benjamin is an environmental biologist, specialized in palaeoecology, working (parttime) as a junior researcher at the department of Physical Geography. Together with Fabian Ercan, he digitizes the pollen and dinocysts reference collections of the palaeo-ecology and the marine palynology & palaeo-oceanography groups. He will focus mainly on digitizing the holotypes in dinocysts collection and any other specimens of important dinocysts species. The photos will be taken using the camera microscopes which allow for making stacked images. This function allows us to make photos of a single dinocyst on multiple focus levels, showing more details and making it possible to scroll through the stack of photos as if you were looking through the microscope yourself. The stacked images can also be turned in simples GIF files that automatically and continuously scroll through the photos and these GIF files are easily applicable for different purposes like PowerPoint presentations or consulting experts about classification.
Benjamin is an environmental biologist, specialized in palaeoecology, working (parttime) as a junior researcher at the department of Physical Geography. Together with Fabian Ercan, he digitizes the pollen and dinocysts reference collections of the palaeo-ecology and the marine palynology & palaeo-oceanography groups. He will focus mainly on digitizing the holotypes in dinocysts collection and any other specimens of important dinocysts species. The photos will be taken using the camera microscopes which allow for making stacked images. This function allows us to make photos of a single dinocyst on multiple focus levels, showing more details and making it possible to scroll through the stack of photos as if you were looking through the microscope yourself. The stacked images can also be turned in simples GIF files that automatically and continuously scroll through the photos and these GIF files are easily applicable for different purposes like PowerPoint presentations or consulting experts about classification.