BCB Faculty Candidate for Math Dept. - Ying (Joy) Zhou

January 21, 2016

Ying (Joy) Zhou visits this week as a part of the BCB faculty cluster hire the College of LAS has granted to our program. The Mathematics Department will be the home department for this faculty position.

Dr. Zhou is a Postdoctoral Fellow at the Mathematical Biosciences Institute (MBI) at The Ohio State University. Her PhD work was conducted at the Department of Applied Mathematics at University of Washington, Seattle.

She will present a seminar for the ISU community on Thursday, January 28 in 1213 Hoover Hall at 4:10.  There will be a reception at 3:45 in 404 Carver Hall prior to the seminar.  Details of the seminar:

Spatiotemporal Dynamics of a Population Under Environmental Changes

Abstract: We live in an environment that is constantly changing. On a large time scale, climate change has a global effect on the dynamics of plant populations. On a smaller scale, there are seasonal changes of local habitats, for example, flooding and drying of wetland habitats. In this talk, I will present a spatial perspective of the effects of environmental changes. What happens when the suitable habitat of a population changes its location, or its size over time? Are there limits of the population’s ability to cope with these spatial changes? How does the life history of plant species affect their persistence in the presence of environmental change? I will present a set of mathematical models aiming at answering these questions.

Dr. Zhou's website is at: https://yingzhou.weebly.com/.  Excerpts from it are below:

My research aims at utilizing and advancing mathematics in an applied setting. The applications involve pressing issues such as climate change, and medical applications such as interpretation of human skin-microbe interactions. I collaborate with many mathematicians and biologists, and contribute to the collaborations by developing mathematical models and analyzing them with tools in dynamical systems and stochastic processes. Click on the tabs above to learn more!

Movement of living creatures

The world is a dynamic place that is full of traffic. For example, everyday, millions of seeds disperse in the wind, in the river, inside animal guts, or on animal fur, from their birth places to other locations. (Here is a video about the "what, why, and how" of seed dispersal). Every year, migratory species such as the Monarch butterfly and whooping cranes travel thousands of miles in the pursuit of suitable habitats. On a much smaller scale, microbes such as bacteria are also mobile. The movement of living creatures, from microbes to plants and animals, are connected with fascinating questions such as the impact of climate change on the geographic distribution of plants and animals. 


Precipitation variability and wetland ecosystems

Wetland ecosystems are strongly influenced by precipitation. For example, in the Everglades in Florida, water levels in aquatic habitats vary widely between the rainy season from May to October and the dry season from November to April. The aquatic habitats therefore expand and contract seasonally, creating seasonal cycles in the population dynamics of small fish species. Using a mathematical model, I found that precipitation variability on the seasonal or annual time scale has negative impacts on the fish population. Moreover, conflicting trends in precipitation variability on different time scales may have mixed effects on the fish population. Since trends of precipitation changes depend on the time scale, we need to take time scales into consideration when discussing impacts of precipitation variability.


Climate extremes and tropical forests

What happens when there is a severe drought in a rain forest? During the strong El Niño event from 1982 to 1983, rain forests in Panama and East Borneo experienced droughts so severe that forest fires broke out. Another extremely strong El Niño event during 1997-1998 brought a drought to the forests of Sarawak, Malaysia, which typically experience no clear dry season. Climate extremes such as droughts in tropical forests are commonly associated with El Niño Southern Oscillation (ENSO), which may be strengthened or weakened because of climate change. In my research, I am using stochastic processes to study the effect of climate extremes, such as droughts, on tropical forests. (Photo credit: Noelle Beckman)

Publications: research articles in preparation

  • Ying Zhou, Sharon Bewick, William Fagan, A race for survival: a branching random walk model with a discretely-jumping absorbing wall, in preparation. 
  • Ying Zhou, Noelle Beckman, Ilya Timofeyev, Climate extremes: a tipping point for frequency, in preparation.
  • Ying Zhou, Range-shifts under accelerated climate warming, in preparation.

Publications: submitted research articles

  • Ying Zhou, William Fagan, A discrete-time model for population persistence in habitats with time- varying sizes, submitted. 
  • Henry C. Tuckwell, Ying Zhou, Nicholas J. Penington, Simplified models of pacemaker spiking in raphe and locus coeruleus neurons, submitted.

Publications: peer-reviewed research articles

  • Melanie A. Harsch, Ying Zhou, Janneke Hille Ris Lambers and Mark Kot, Keeping pace with climate change: stage-structured moving-habitat models, The American Naturalist (2014) 184.1: 25-37.
  • Ying Zhou and Mark Kot (2013), Life on the Move: Modeling the Effects of Climate-Driven Range Shifts with Integrodifference Equations. In: Dispersal, Individual Movement and Spatial Ecology: A Mathematical Perspective (eds: M. Lewis, P. Maini and S. Petrovskii), 263–292.
  • Ying Zhou and Mark Kot, Discrete-time growth-dispersal models with shifting species ranges, Theoretical Ecology (2011) 4:13–25. 

Publications: perspective articles

  • Melanie A. Harsch, Austin Phillips, Ying Zhou, Margaret-Rose Leung, D. Scott Rinnan, Mark Kot, Moving forward: Insights and applications of moving-habitat models for climate change research, in preparation. 
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