Ecosystem Resistance and Resilience
Research in this area focuses on how systems respond to
disturbance. Every ecosystem is subject to perturbations such as climate,
nutrient fluctuation, loss of biodiversity, and introduction of exotic species,
that can alter ecosystem structure and function. The degree to which ecosystems
respond to perturbations depends their ability to withstand perturbation and
maintain normal function (resistance) and/or recover from disturbance
(resilience). These two components of stability, in essence, address how a
system responds to disturbances and knowledge about them is key to developing
ecosystem recovery and restoration efforts. As such, our research in this area
focuses both on the theoretical foundations of stability and on the management
implications of this theory for ecosystem restoration.
We are initiating a resistance research program to investigate
the response of multitrophic systems to perturbation. Specifically we aim to
evaluate how asymmetry, toplogical structure, and functional diversity
influence the degree of ecosystem resistance. We will investigate our research
questions using a multiyear field mesocosm experiment. We will place specific
emphasis on how these aspects of community structure influence resistance and
ultimately the implications this response has for ecosystem function. Research
in this area has both theoretical and applied relevance for environmental
policy as well as species management and conservation.
Our resilience research focuses on one possible ecosystem
response to perturbation -multiple stable states. If a system exhibits multiple
stable states, its recovery will require more than merely removing the
perturbation. Instead, environmental conditions must be altered beyond their
previous levels to overcome hysteresis and restore the system. The hysteresis
feature of this theory is critical to ecosystem restoration projects, and is of
particular interest when management goals are set to restore ecosystems to a
pre-disturbance state. Our research on ecosystem resilience asks whether
systems can recover their predisturbance states and seeks to inform management
how to best restore disturbed ecosystems.
Specific projects in this area include: