Thresholds and Regime Shifts in Ecological and
A Resilience Alliance / Santa Fe Institute database
Below is a list of the fields and definitions of terms used in each of the threshold examples. It may be useful to have this window open when adding your own examples to the database.
Title of Example: The location of the example with a brief summary of the regime shift (e.g. Lake eutrophication; Lake Washington, USA).
Certainty of Shift: Has the change of state been observed or not?
Demonstrated or Proposed
Location: The location of the example from broad to local scale. Include ocean or continent name, region, country, town or local feature,
(e.g. North America, USA, Washington State, Lake Washington).
System Type: Which system does the threshold occur in?
Social-Ecological, Ecological, Physical, Other
Regime Shift Category: The attached diagram illustrates all of the possible interactions between social (S) and ecological (E) systems in relation to threshold shifts. Choose the category that your example best fits into. Click here for regime shift descriptions and diagram.
In summary, these categories are:
1a: Externally driven shift in ecological system; no interaction with society.
2a: Internally driven shift in ecological system; no interaction with society.
3a: Society drives a shift in ecological system; no feedback to society.
3b: Shift in ecological system impacts on society (but no shift).
3d: Ecological system drives a shift in social system (no feedback to ecosystem).
4a: 2-way interaction between ecology and society; shift in ecological system only.
4b: 2-way interaction between ecology and society; shift in social system only.
5: 2-way interaction between ecology and society; shifts in ecological and social systems.
Ecosystem Type: The most appropriate ecosystem type that the shift has occurred in;
Not applicable, Agriculture, Arid zone, Grassland/Savanna, Shrubland, Forest/Woodland, Tundra, Island, Urban, Coastal, Lake, River/Stream, Wetland, Algal/Sea grass beds, Coral reef, Estuary, Mangroves, Continental shelf waters, Open ocean, Upwelling zone, Other
Type of Resource Use: The primary use of the resource;
Conservation, Dryland Agriculture, Fisheries, Forestry, Irrigation, Livestock Production, Mixed Farming, Subsistence Agriculture, Other, Unknown.
Ecosystem Services: The benefits that people derive from the ecosystem;
Provisioning services: food and fibre, fresh water, fuel, genetic resources, biochemicals, natural medicines and pharmaceuticals and ornamental resources.
Regulating services: air quality maintenance, climate regulation, water regulation, erosion control, water purification and waste treatment, regulation of human diseases, biological control, pollination and storm protection.
Cultural services: cultural diversity, spiritual and religious values, knowledge systems (traditional and formal), educational values, inspiration, aesthetic values, social relations, sense of place, cultural heritage values, recreation and ecotourism.
Resource Users: The agents who use the ecosystem services,
e.g. Commercial and recreational fishers or subsistence farmers.
Ownership and User Rights: The type of ownership of the resource, or the rights of the users,
e.g. ‘Sole owner of a private property’ or ‘the right to graze cattle on a common property’.
Spatial Scale: The scale at which the regime shift has occurred:
Landscape / Local, (e.g. lake, catchment, community)
Sub-continental / Sub-regional, (e.g. Northern Australia, Central America, Amazon Basin)
Continental / Regional, (e.g. Africa, Asia)
Number of Possible Regimes: The number of alternate regimes in the example;
Time Scale of Change: The time taken for the shift to occur;
Not applicable, Instantaneous, Days, Weeks, Months, Years, Decades, Centuries, Unknown
Reversibility: The most appropriate term to describe the reversibility of the shift;
Reversible – Regime 2 can return to Regime 1.
Possibly reversible – Regime 2 may return to Regime 1 given the right conditions, but this has not yet been exhibited.
Reversible with hysteresis – Regime 2 can return to Regime 1, but along a different pathway.
Alternating – The system periodically alternates between Regime 1 and Regime 2.
Conditional – The shift is conditional upon management or other factors; there can be more than two possible regimes.
Irreversible – The system cannot return to Regime 1 from Regime 2.
Background: Information relevant to the example, such as historical information or a description of the study site.
Rules: Any laws, regulations, norms or taboos that have led to the regime shift.
Alternate Regimes: The alternate regimes of the system, or if the alternate regimes are rules, list them.
(e.g. “Regime 1: Clear water, macrophytes, diversity of fish species
Regime 2: Turbid water, phytoplankton, anoxic fish species only”)
Fast or Dependent Variable(s): The variables of concern that are radically altered during the shift,
(e.g. species composition, agricultural productivity).
Slower or Independent Variable(s): The variables that lead to the shift and define the position of the threshold,
(e.g. phosphorus and nitrogen, climate change, soil loss).
Disturbance or Threshold Trigger(s): The variables that trigger the changes in the Slower or Independent Variable(s),
(e.g. climate, market forces, successional shift, level of resource use, social changes).
External / Internal Trigger(s): Are the Triggers external drivers or internal processes?
External, Internal, Unresolved.
Mechanism: The process by which the Trigger(s), Fast/Dependent Variable(s) and Slower/Independent Variable(s) interact to effect the shift.
Management Decisions in Each Regime: Any relevant management or policy decisions, including incentives, subsidies, sanctions, and monitoring of the resource and resource users.
Reference(s): Full reference(s) and code(s) for the type of evidence;
(D=Descriptive, C=Conceptual/Diagrammatic, M=Quantitative model, E=Empirical data),
e.g., Gunderson, L. H. 2001. Managing Surprising Ecosystems in Southern Florida. Ecological Economics 37, no. 3: 371-78. (D).
Keywords: Keywords or phrases to assist in searching for the example.