Topic - Ecological Resilience
These ecological resilience lessons are listed in recommended reading order.
Scale
Scale represents the physical dimensions of time and space and provides the necessary context for our observations of the world. Different disciplines associate with different scales and confronting the most pressing global issues will require integration of knowledge gained from multiple scales. In this lesson plan we discuss what scale is and how it helps us understand the natural world.
Heterogeneity
This entry discusses heterogeneity in the context of ecological landscapes and how the heterogeneity impacts the resilience of the system. Heterogeneity is closely linked to the scale of measurement, both spatially and temporally. We will walk through a simple example that highlights how the scale of observation can impact the heterogeneity of the system. The differences between functional and measured heterogeneity will also be explained. Finally, heterogeneity will be discussed in the context of its utility to management and how it can be used to understand the resilience of agro-ecosystems.
Ecological Resilience
This entry is an introduction to the concept of ecological resilience. Resilience is the amount of disturbance a system can withstand without transitioning to an alternative state characterized by fundamentally different structure and function. Disturbances include fire, flooding, grazing, and all kinds of modern human influences like pollution, and overharvesting of resources. Concepts of ecological resilience apply to complex systems such as the human body, ecosystems, societies, and economies. Overall, the concepts of ecological resilience can help us to better understand, conserve, and remediate Earth’s ecosystems in the face of historically unprecedented anthropogenic change while also understanding the dynamic processes at work within social systems of our own creation.
Alternative Stable State Theory and Regime Shifts
This lesson is an introduction to alternative stable state theory and regime shifts between these states, as well as a continuation of our education on ecological resilience. Complex systems are dynamic and when presented with a large enough disturbance or erosion of resilience through internal changes to stabilizing feedbacks may rapidly shift into a fundamentally different form of the system. We use the example of lakes, one clear-water lake and one with excess nutrients pollution from runoff causing the lake to become turbid and dominated by toxic cyanobacteria. These lakes are in the same location and exist under the same climatic conditions and yet they are fundamentally different. How? There has been a regime shift as one lake switched from a clear-water state to a turbid, cyanobacteria-dominated state, but how can such similar lakes end up in different states? To answer that question, we will visit the concepts of alternative stable states and regime shifts in depth.
Adaptive Cycle
This module covers the adaptive cycle, which is a conceptual model designed to help humans understand and manage how and why change occurs within common complex systems, such as ecosystems, societies, or economies. The adaptive cycle has four phases characterized by growth, stabilization, collapse, or reorganization. In this module we use the example of the Roman Empire and how its different periods can illustrate the phases of the adaptive cycle. Other examples of the adaptive cycle can be found in aquatic algal blooms, commodity crop markets, and other cultures and societies. The concept of the adaptive cycle is useful for management and decision making as an expansion on traditional ecological theory. Traditional ecological theory assumes that systems organize linearly into a single stable state that can be maintained in perpetuity despite unprecedented human change on local, regional, and global scales, which we now know is not the case in our dynamic world.
Panarchy
This module discusses panarchy theory, a framework for understanding how systems function and interact across scales. The key idea in panarchy theory is that adaptive cycles are nested together and interact with each other to form what are termed “panarchies.” Within a panarchy, broad scale adaptive cycles influence smaller scale cycles, and smaller scale cycles can influence broad scale ones. This is true of both social and ecological systems. Panarchy theory has been applied to examine regime shifts in ecology as well as company size distribution in economics.