User's Contributions

Displaying 1 - 15 of 29 records found.
Titlesort ascending
Type

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

Tourists and traditional divers in a common fishing ground

Model
A social-ecological model of a fishing ground open to eco-tourism is presented here. To assess the impact of introducing eco-tourism on the welfare of the fishing association and on the resource level, Lee and Iwasa (2011) constructs a model in which the fishing association charges an entrance fee to tourists. The level of the fee is chosen to regulate tourist number as well as maximing benefits accrued to the fishing association (combined revenue from tourism and conventional fishing by...
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 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

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 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

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

The Evolution of Social Norms in Common Property Resource Use

Model
This is a simple evolutionary game model (based on replicator equations) that couples evolution of users' social norms and renewable resource dynamics. The reference article, Sethi and Somanathan (1996), provides the following overview of the model. "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...
09 Aug 2016

The effect of scaling and connection on the sustainability of a socio-economic resource system

Model
Most modeling exercises on resource-population dynamics of a socio-economic system assume that many growth-related phenomena are linearly related to population size. The model presented here departs from this linear thinking by exploring potential non-linear relationships, or power-law scaling behaviors, with population size. For example, twice as many people do not mean that twice as much resources are required to maintain existing population. Similarly, twice as many people do not necessarily...
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

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

Model
Here, we present a model of the coupled dynamics between human socioeconomic choice (between cooperative and non-cooperative collective action) and nutrient loading input level into a lake water system. Suzuki and Iwasa (2008) explains the model as the following. "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...
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

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

Robustness, institutions, and large-scale change in social-ecological systems: the Hohokam of the Phoenix Basin

Model
This is a model that illustrates the relationship among levels of (1) population, (2) human-made capital, (3) natural capital , and (4) resource consumption. The key insight to be gained from the model is that as the ratio of capitalization in human-made infrastructure over human population is varied in the parameter space, the dynamics of natural capital changes and becomes vulnerable to different disturbance regimes. That is, as humans grow in population and over-invest in capitalization/...
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