Research Experiences for Undergraduates, NSF
Defining Ecosystem Health

Group Picture
Organizer: Caner Kazancı
Teaching Assistant: Leopold Matamba
Class: Driftmier Engineering Center, Room 314C.

Overview

Temperature, blood pressure and specific enzyme levels are typical health indicators for human beings. For a healthy person, the values of these indicators lie in specific intervals. Defining similar health indicators for ecological systems is a major question in ecosystems ecology. Over the years there have been many efforts in this direction, resulting in many formulas that claim to represent the health of an ecosystem. However most of these formulations are relative measures, and are not universal to all ecosystems. One such example is the cycling index: The higher the cycling in an ecosystem, the higher the utilisation of mass and energy within the system before it is lost due to respiration and other factors. Therefore cycling index is believed to represent ecosystem health. However, there is no specific interval for cycling index that identifies a healthy ecosystem.

Our objective is to come up with solid, universal, and non-relative ecosystem health indicators, such as body temperature. We tackle this problem by combining mathematical, computational and statistical approaches. We will use real ecological field data (gathered from over 40 ecosystems) and EcoNet to compare current ecological health indicators, and investigate new mathematical definitions of ecosystem health.

Projects

Dominance of indirect effects in ecological networks - Julia and Linda

How can we quantify the effect of nutrient flow that occur through indirect pathways in an ecosystem? We use an agent based approach (a discrete stochastic process compatible with the continuous representation) to re-investigate this question.

Throughflow and Storage Analysis - Priscilla and Michelle

In an ecosystem, what is the final destination of an environmental input in an ecosystem? How much of it is retained, how much of it is cycled back to the environment? How much activity (and where) is generated by environmental input? We formulate general answers to these questions using an agent based method.

Utility Analysis - David, Matt and Emily

It is easy to identify the relation between deer and trees, or wolf and deer. Can we quantify the same relationship in a complex ecosystem with many feedbacks and cycling? We will try to extend the boundaries of the current ecological utility theory.

Ecological Thermodynamics - Emily and Matt

Can we take a statistical approach in quantifying the temperature of an ecosystem? We use the path histroy distribution of individual energy-transferring agents in an ecosystem to quantify an "ecological temperature", and investigate its relation to other ecosystem properties, such as cycling and indirect effects.

Aquatic and terrestrial models built during the field trip to Lake Herrick.
Group Picture Group Picture
Aquatic model, by David, Julia, Linda and Michelle .
Terrestrial model, by Emily, Matt and Priscilla.

Announcements

  • 06/16 Group presentations are scheduled for today at 2:00pm at Driftmier Engineering center auditorium.
  • 06/09 Guest lecture by Bernard C. Patten and Stuart J. Whipple on integrating the aquatic and terrestrial models built during the field trip to Lake Herrick.
  • 06/03 Field trip to Lake Herrick is today at 1:30pm.
  • 06/30 Guest lecture by Bernard C. Patten and Stuart J. Whipple on utility analysis.
  • 05/28 Guest lecture by E. William Tollner on ecological thermodynamics.
  • 05/27 Guest lecture by Bernard C. Patten and Stuart J. Whipple on Network Environ Theory.

Documents & Materials

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