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Displaying 1 - 15 of 16 records found.
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A model of robustness tradeoffs in social-ecological system

Model
Feedback control systems in general exhibit inherent robustness-fragility tradeoffs. That is, by becoming very robust to a given set of disturbances for maintaining stability, feedback systems necessarily introduce hidden fragilities to disturbances outside this set. Even a small unanticipated disturbance can initiate cascading system-wide failures as a result. The model presented here demonstrates this phenomenon. In Anderies et al. (2012), an agricultural production system is illustrated as...
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

Analyzing the Impact of Agave Cultivation on Famine Risk in Arid Pre-Hispanic Northern Mexico

Model
Here, a simple model of a subsistence economy based solely on the cultivation of maize and agave is presented. While maize is an annual plant that humans can eat and store, agave is a perennial plant that can be used for multiple purposes: as edible materials yielding caloric values and as fiber materials for producing items like clothing, ropes, and baskets.  This model tries to capture the essence of a cultivation strategy of a portfolio of plants that have differing levels of sensitivity...
09 Aug 2016

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

Model
This is a model for the coupled dynamics of conflict between two different user groups regarding their socioeconomic choice (between cooperative and non-cooperative collective action) and nutrient loading input level into a lake water system. Suzuki and Iwasa (2009),gives the following overview of the model. "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  ...
09 Aug 2016

Culture and Human Agro-ecosystem Dynamics: the Tsembaga of New Guinea

Model
The model of Tsembaga agro-ecology explores the coupled dynamics involving population growth, renewable resource base, resource consumption by humans, and the self-regulating effect of cultural ritual. The model demonstrates that the cultural ritual of Tsembaga (Kaiko) can stabilize the Tsembaga population and its resource level. This is achieved by attenuating wildly fluctuating limit cycles of population and resource levels down to desirable small-amplitude cycles. Anderies (1998) describes...
09 Aug 2016

Non-linear dynamics of population and natural resources: The emergence of different patterns of development

Model
This model explores the long-term dynamic interaction between the exploitation of natural resources and population growth. This is a variant of Brander and Taylor (1998). The reference article, D'Alessandro (2007), gives the following description of the model. "Two new assumptions are introduced: i) the disaggregation of the ecological complex into two different resources; ii) irreversibility —namely, an inexorable tendency to exhaustion when the renewable resource stock is below a certain...
09 Aug 2016

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

Model
This is a simple model of a prey–predator system in two areas, one of which receives fishing activity (fishing ground) and another that does not (MPA: marine protected area). Takashina et al. 2012 gives the following description of the model. "A number of fish and invertebrate stocks have been depleted by overexploitation in recent years. To address this, marine protected areas (MPAs) are often established to protect biodiversity and recover stocks. We analyzed the potential impact of...
09 Aug 2016

Regime shifts in a socio-ecological model of farmland abandonment

Model
This is a simple model with reciprocal feedbacks between social and ecological dynamics of farmland abandonment. With the rising urbanization, human migration to urban centers have increased significantly around the globe. One notable consequence of this migration pattern is that mountainous forests that had been traditionally cleared for farming are increasingly becoming abandoned. As a result, such lands likely become forests again through natural regeneration. These trends may induce two...
09 Aug 2016

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

Model
This is a simple model that integrates 1) resource-population dynamics, 2) population migration, and 3) spatial heterogeneity in biophysical conditions (i.e., soi fertility). The reference article, Anderies and Hegmon (2011), gives the following abstract of the model. "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 ...
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

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 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

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 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 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