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Displaying 16 - 29 of 29 records found.
Title
Type

Subtle global bifurcation with dramatic ecological consequences in a simple population model

Model
This model presents an example of a global bifurcation (a heteroclinic connection). The model is a three-dimensional system with two resources and a single consumer, where one of the resources is fixed and the other is reproductive. By assuming that, for all values of resource consumers (C) below its carrying capacity (K), the fixed resource facilitates the consumption of the reproductive resource, the system can be reduced to a two-dimensional system. The reference article, Vandermeer and King...
09 Aug 2016

The inevitability of surprise in agroecosystems

Model
This is a simple model of competition between noxious and benigne weeds in an agroecosystem based on predator-prey dynamics. The interesting aspect of this model is that it demonstrates the inevitability of surprises in system behavior - meaning that for some systems, early warning signals (e.g, increased variance or autocorrelatin) are almost non-existent prior to critical transitions in systems. The reference article, Vandermeer (2011), gives the following overview. "Many critical...
09 Aug 2016

The Tsembaga Maring swidden agriculture and animal husbandry, Simbai River Valley, Papua New Guinea

Case
Tsembaga Maring are a group of horticulturists who live in the highlands of New Guinea. The main resource upon which they relied on is swidden agriculture. The Tsembaga also practiced animal husbandry - the main domesticated animal being pigs. The Tsembaga derived little energetic value from pigs. Pigs did, however, play an important role in Kaiko, an important cultural ritual practiced by the Tsembaga people. Kaiko is a 5-25 year long ritual cycle that is coupled with pig husbandry and...
09 Aug 2016

The Hohokam Cultural Sequence (Irrigation and Foraging), Sonoran Desert, greater Phoenix basin, Arizona, USA

Case
The Hohokam is a Native American cilivilization that emerged and occupied the present day Phoenix Basin area and its outer bounds for a thousand years. The archeological records indicate that the Hohokam society evolved into a complex irrigation society and reached its peak in levels of population, social institutions, and irrigation infrastructure by the 11th century.Perplexingly though, the Hohokam society subsequently declined and collapsed by the mid 14th century. As they declined, the...
09 Aug 2016

Agave Cultivation in the Arid Pre-Hispanic, Villanueva Municipality, state of Zacatecas, northern Mexico

Case
Agave is a perennial plant that can be used for multiple purposes: as edible materials for yielding caloric values and as fiber materials for producing items like clothing, ropes, and baskets. Historical records indicate that the cultivation of agave was a common practice in pre-Hispanic Northern Mexico and the American Southwest. It is generally accepted among archeologists that the agave cultivation was linked to the strategy of ensuring food supply when maize cropping failed from droughts....
09 Aug 2016

Robustness and Resilience across Scales: Migration and Resource Degradation in the Prehistoric U.S. Southwest

Case
Migration is arguably one of the most important processes that link ecological and social systems across scales. Humans (and other organisms) tend to move in pursuit of better resources (both social and environmental). Such mobility may serve as a coping mechanism for short-term local-scale dilemmas and as a means of distributing organisms in relation to resources. Movement also may be viewed as a shift to a larger scale; that is, while it may solve short-term local problems, it may...
09 Aug 2016

The Evolution of Social Norms in Common Property Resource Use

Case
The problem of extracting commonly owned renewable resources is examined within an evolutionary-game-theoretic framework. It is shown that cooperative behavior guided by norms of restraint and punishment may be stable in a well-defined sense against invasion by narrowly self-interested behavior. The resource-stock dynamics are integrated with the evolutionary-game dynamics. Effects of changes in prices, technology, and social cohesion on extraction behavior and the long-run stock are analyzed....
09 Aug 2016

Paradox of marine protected areas: suppression of fishing may cause species loss

Case
This is a placeholder case for the model for the same name. Please revise case information to reflect the case study represented in the model.
09 Aug 2016

Regime shifts in a socio-ecological model of farmland abandonment

Case
Figueiredo & Pereira (2011) developed a mathematical model with two-way linked socio-ecological dynamics to study farmland abandonment and to understand the regimes shifts of this socio-ecological system. The model considers that migration is a collective behavior socio-economically driven and that the ecosystem is dynamic. The model identifies equilibria that vary from mass migration, farmland abandonment, and forest regeneration, to no migration and forest eradication; partial migration...
09 Aug 2016

The coupled dynamics of human socio-economic choice and lake water system: the interaction of two sources of nonlinearity

Case
Suzuki & Iwasa (2009) study a mathematical model for the coupled dynamics of human socio-economic choice and lake water system. In the model, many players choose one of the two options: a cooperative and costly option with low phosphorus discharge, and an economical option with high phosphorus discharge. The choice is affected by an economic cost, a social concern about water pollution, and a conformist tendency. The pollution level in the lake is determined by total phosphorus discharge by...
09 Aug 2016

Conflict between groups of players in coupled socio-economic and ecological dynamics

Case
Conflict among multiple groups is a major source of difficulty in environmental conservation. People are often divided into various groups that have different social factors, sometimes leading to differences in the degree to which they cooperate in environmental conservation. This obstructs the social consensus needed to solve the environmental problems. Here we study the coupled dynamics of human socio-economic choice and lake water pollution, and examine the magnitude of the difference in...
09 Aug 2016

Tourists and traditional divers in a common fishing ground

Case
Lee & Iwasa (2011) study socio-ecological models for a fishing ground open to tourists. On Jeju Island, Korea, women traditional divers called “Haenyeo” harvest resources in a common fishing ground. To investigate the impact of introducing tourists on the benefit to the fishing association and the resource level, we examine two models that differ in the way the number of tourists is controlled. In the first model, the fishing association charges an entrance fee to tourists and the level of...
09 Aug 2016

Subtle global bifurcation with dramatic ecological consequences in a simple population model

Case
Numerous situations exist in which a consumer uses two different kinds of resources, one fixed, the other renewable, e.g., nesting resources and food resources. With an elementary modification of the basic Lotka–Volterra consumer resource equations, we investigate the population dynamics of a consumer dependent on two resources, one fixed, the other renewable. Emerging from this structure is a situation of alternative attractors that remain qualitatively robust over a significant range of...
09 Aug 2016

The inevitability of surprise in agroecosystems

Case
Many critical transformations of ecosystems contain advanced signals of their imminence, but it is also true that many critical transformations can be shown to contain no such signal, at least with the sorts of data normally available to field workers. This paper explores some generalized theoretical structures and distinguishes between those that may provide a signal that could be used to predict a critical transformation and those that, by their very nature, do not provide such a clue. I...
09 Aug 2016