Plant Systematics, Conservation Biology, and Ethnobotany

10

Iván Jiménez, Ph.D.

posted on
Iván Jiménez, Ph.D.

Scientist
Center for Conservation and Sustainable Development

Research Interests

• Species concepts and delimitations
• Spatial patterns of species diversity and distributions
• Ecological computer modeling

Interactive, probabilistic key for the Espeletia species from páramo de Sumapaz. Jiménez is an Associate Scientist in the Center for Conservation and Sustainable Development. His research program seeks to determine the factors that determine the abundance and distribution of species at various spatial scales. The objective of this project is to produce an interactive, probabilistic key for the identification of Espeletia species from the páramo de Sumapaz. Espeletia is a genus of plants endemic to the northern Andes, largely restricted to high elevation ecosystems known as “páramos.” Páramos are considered strategic ecosystems because they are the main water source for major cities and agricultural centers in the tropical Andes. Espeletia plants are thought to play an important role in the functioning of the páramos, including water yield and regulation, because they are dominant plants in these ecosystems. Thus, governmental institutions in tropical Andean countries have interest in monitoring Espeletia plants at the species level. Unfortunately, species identification can be difficult in Espeletia, in part because these species diverged recently and hybridize frequently (1). To further complicate matters, the species taxa described in monograph of the group (2) do not seem to correspond to species in nature (3) and, therefore, are not useful to monitor Espeletia at the species level. To begin solving this problem, the student working on this project will develop an interactive, probabilistic key for the Espeletia species from páramo de Sumapaz, which is the largest páramo in the tropical Andes, located just south of Bogotá, Colombia. The key will be based on measurements of 13 diagnostic phenotypic characters, obtained previously (3). It will be interactive (sensu 4) because any combination of the 13 characters may be used to try to determine the species to which a particular specimen belongs. This would be useful for cases in which not all 13 characters are available in a particular specimen. They key will also be probabilistic because it will assign specimens to species via maximum likelihood, and will calculate the uncertainty of the assignment, based on the application of normal mixture models to the description and delimitation of species (5,6). The key will be intended primarily for those currently working on monitoring Espeletia species as part of biodiversity management programs in Sumapaz. The student participating in this project will use the R environment (http://www.r-project.org/) to manipulate data, write the key and perform computer simulation experiments to test the key. No previous experience with statistics or the R environment is needed; but if the student is not familiar with the R language or basic statistics, strong disposition to learn a computer language and statistics is required. 

References:

• Pouchon, C., Fernández, A., Nassar, J.M., Boyer, F., Aubert, S., Lavergne, S. and Mavárez, J., 2018. Phylogenomic analysis of the explosive adaptive radiation of the Espeletia complex (Asteraceae) in the tropical Andes. Syst. Biol. 67: 1041–1060.
• Cuatrecasas, J. 2013. A systematic study of the subtribe Espeletiinae (Heliantheae, Asteraceae). New York Botanical Garden Press.
• Pineda, Y.M., Cortes, A.J., Madrinan, S. and Jimenez, I. 2020. The Nature of Espeletia Species. bioRxiv. doi: https://doi.org/10.1101/2020.09.29.318865
• Dallwitz, Mike J., T. A. Paine, and E. J. Zurcher. 2000. Principles of interactive keys. Web-based document https://www.delta-intkey.com/www/interactivekeys.pdf.
• Zapata, F. & Jiménez, I. 2012. Species Delimitation: Inferring Gaps in Morphology across Geography. Syst. Biol. 61: 179–194.
• Cadena, C.D., Zapata, F. and Jiménez, I. 2018. Issues and perspectives in species delimitation using phenotypic data: Atlantean evolution in Darwin’s finches. Syst. Biol. 67: 181–194.

| Categories: | Tags: Species Concepts and Delimitations, Ecological Computer Modeling | Return