Christopher Stieha


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Who am I?

I am an ecologist whose research interests revolve around understanding how individual-level interactions, such as competition or herbivory, scale up to affect dynamics at the population, metapopulation, and landscape levels. To answer my questions, I use mathematical models, computer simulations, laboratory experiments, and field biology to develop, test, and refine predictions. I am currently developing mathematical models to understand the effects of various plant defenses on herbivore population dynamics and the feedback between the two systems as an attempt to use bottom-up processes to mitigate pest outbreaks. I also use mathematical models and field experiments to quantify the effects of spatial arrangement of populations on the maintenance of the sexes. Please see my research page for more information

I am currently in the Abbott Lab at Case Western Reserve University.

I collaborate with the Poveda Lab at Cornell University.

Some things I am responsible for:

QPot: An R package for stochastic differential equation quasi-potential analysis
QPot examples, explanations, and ephemera
LogTHIS: A low-powered datalogger for Temperature, Humidity and Irradiance Sensors
bag of tricks: A collection of R functions as I need them and write them


News, or things that I think:

The first half of 2016 in review

4 August 2016
It’s always good to pause and take stock of what has happened. I usually do this personally, but figured I could also post about it as news to catch up on my backlog of things that have happened.

In February, our paper on the effects of plant compensatory regrowth on herbivore population dynamics was published in The American Naturalist. http://www.journals.uchicago.edu/doi/full/10.1086/684522 Long story short, plant compensatory regrowth, by themselves, can cause herbivore populations to cycle and can interact with plant resistance to produce non-intuitive effects on herbivore dynamics.

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QPot v1.1 The R Package for SDEs

19 April 2016
We’ve released QPot v1.1 into the wild!

QPot, the R software package for analyzing stochastic differential equations using the quasipotential, has been updated to version 1.1. The help files have been updated. The function Model2String has been updated to replace parameter names with parameter values for both simple strings as well as the function format used by deSolve.
QPot is available on the Comprehensive R Archive Network (CRAN) at http://CRAN.R-project.org/package=QPot. Our paper demonstrating applications of QPot has been resubmitted to the R Journal. A preprint version can be downloaded at http://arxiv.org/abs/1510.07992

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QPot The R Package for SDEs

23 October 2015
We’ve released QPot into the wild!

From Ben’s press release:
Researchers in Dr. Karen Abbott’s theoretical ecology lab in the Department of Biology at Case Western Reserve University have recently released a software package that will help scientists studying stochastic dynamical systems. The package, written for the programming language R, is called QPot (short for quasi-potential, which is one of the its primary analytic tools). Professor Karen Abbott’s lab, which includes research associates Christopher Moore, Christopher Stieha, and Ben Nolting, collaborated with Professor Maria Cameron from the University of Maryland to create QPot, which they hope will be useful to researchers in a wide variety of scientific disciplines, ranging from ecology to physics. QPot is available on the Comprehensive R Archive Network (CRAN) at http://CRAN.R-project.org/package=QPot. A paper demonstrating applications of QPot has been submitted to the R Journal and can be downloaded at (to be filled shortly).

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