Crystal is an Assistant Professor at the University of Amsterdam, in the  Department of Ecosystem and Landscape Dynamics within the  Institute of Biodiversity & Ecosystem Dynamics (IBED). Her research is mainly focused on exploring how disturbances, including past human activity and fires, affect modern ecosystems. Most of her work is focused in the tropics, although she does have projects in other geographic regions and on other topics (see Research Focus tab).

Crystal coordinates the Tropical Ecology module (BSc Biology, Year 3), and teaches in the Palaeoecology (BSc Biology, Year 3), Global Ecology and Biodiversity (MSc Biology, Ecology & Evolution track) and Envrionments Through Time (MSc Earth Sciences, Geo-ecosystem dynamics track) modules. 

Crystal is also active in several scientific organizations. She is the Vice President of Conferences for the International Biogeography Society, and is also active in the British Ecological Society (BES). Crystal is an Associate Editor at the Journal of Ecology, which is a journal of the British Ecological Society, and is also an Associate Editor at Plants, People, Planet, a journal of the New Phytologist Trust.

Crystal is also part of the LandUse6k working group, and the National Institute for Mathematical and Biological Synthesis Climate Proxies working group. 

More details of her current research can be found on the 'Research Focus' tab

https://orcid.org/0000-0002-1064-1499

• Distributions of ancient people (archaeological sites) in tropical forests
• Human impacts in tropical forests
• Human-environmnet interactions 
• Pollen distribution mapping
• Using remote sensing to detect archaeological features under forest canopies
• Timing and transition to maize agriculture in the Michigan/Great Lakes region

My primary research focus involves spatial and temporal analyses of past people (both ancient and during the historical period) in tropical forests, particularly the Amazonian rain forest. For years it was thought that Amazonia had been a ‘pristine forest’ until Europeans arrived to the American continent in 1492 A.D. However, archaeologists have recently uncovered evidence of large and sedentary occupation sites in several regions of the Basin. My research uses soil charcoal, phytoliths, and ecological modeling, and remote sensing to predict when, where, and at what intensity the Amazon rainforest was modified or transformed prior to European contact. New and upcoming research will also include examining whether pre-Columbian or post-Columbian settlement patterns are associated with specific forest types  or species abundance distributions within Amazonia, or whether the forest types are legacies of pre-Columbian civilizations.

I am also working on parallel projects in Central and South America involving high-resolution reconstructions of paleo-climate and vegetation change using pollen and charcoal analyses. To fully analyze past climate and vegetation patterns, an understanding of modern climate-vegetation relationships is needed. The major limitation in calibrating the modern dataset with paleo-datasets is pollen identification, which is currently possible only to the family or genus level. I am involved with a collaborative effort to improve pollen taxonomy using microscopy and chemical techniques. We will use this improved taxonomic resolution for detecting decadal-scale responses of vegetation to drought events and other natural disturbances. We will also use these methodological improvements to create transfer functions that quantitatively predict temperature and precipitation regimes for the last 2000 years across Central and South America.

I am also involved in projects that involve modeling archaeological and paleoecological data within the United States. One project involves examining the timing and spread of maize agriculture in the Midwest/Great Lakes region of the US. This is an interdisciplinary project with a team of archaeologists and remote sensing experts from the University of New Hampshire and Florida Institute of Technology. We are predicting the timing and spatial patterns of pre-Columbian maize agriculture and earthwork formation across the region based on existing archaeological and paleoecological datasets and remotely sensed data. We will then test the predictive models with field-collected paleoecological and archaeological data.