ForestNPP is a simple calculator that estimates forest net primary productivity, before and after climate change scenarios, using the Osnabruck Biosphere Model. Graduate-level environmental science teaching simulator. Flash 7.

New 2006-08.

Population Growth provides 2 plots to help compare the different basic population growth models of ecology. Multiple functions and parameterizations of those functions can be added to either plot. Java 1.3.

Revised 2005-03, orig 1998-9.

Density Dependence explores exponential population growth with and without density dependence. Java 1.3.

Revised 2005-03, orig 1998-8.

Diversity Metrics explores species diversity measures. There are 625 possible worlds to explore (four preset). The user samples the species landscape by positioning sample plots or transects one by one, or by using an autosample button. Diversity metrics include the species-area curve, the Shannon-Weaver index, the Simpson index, and beta diversity. Used in teaching Conservation Biology. Java 1.3.

Revised 2005-05, orig 2000-9.

Metapopulation Models are stochastic models of populations of populations (islands and mainland, with and without a rescue effect). Used in teaching Landscape Ecology and Conservation Biology. Java 1.3.

Revised 2005-04, orig 2000-11.

Derivatives is a review of some frequently-used functions, how their parameters change their shape, slope-taking and the functions' derivatives. Java 1.3.

Revised 2005-03, orig 1998-8.

Predator/Prey explores predator/prey coupled population equations. Starting from simple linear codependence, successive models add saturation to the predator, then logistic growth to the prey, then predator interference. Yale uses the functional response variant below instead, so this has minimal help files. Java 1.3.

Revised 2005-04, orig 1998-12.

Predator/Prey with Functional Response is Predator/Prey plus a first scenario to explore Types I, II, and III functional response, the function that relates predator consumption rate to prey abundance. This is the version of Predator/Prey we assign in class. Java 1.4.

Revised 2007-10, orig 1998-12.

Competition explores Lotka-Volterra Competition models on a time series. Same interface as Predator/Prey, but for a different two-species interaction. Java 1.3.

Revised 2005-04, orig 1998-11.

Exploitation Ecosystems is an introduction to classical theory on 3-trophic level food chains, across a gradient of plant carrying capacities, with two models controlling carnivore deathrate. Java 1.3.

Revised 2005-04, orig 1999-3.

Migrations and Sampling is an exploration of how sample sites scale up into an overall population, with and without population migration between the sites. Uses Predator/Prey populations at each sample site. Java 1.2.

Released 2000-6.

Density-Dependent Growth and Ricker Diagrams explores how chaos emerges in population ecology. No longer used - see Fracdyn for a more mathematical treatment. Java 1.2.

Released 2001-1.

Predator/Prey uses isocline and time series plots to explore predator/prey coupled population equations. Starting from simple linear codependence, successive models add saturation to the predator, then logistic growth to the prey, then predator interference. Trajectories can be added to the isoclines with a mouse click. This module has been retired in favor of a newer version without the isoclines - see newer Predator/Prey modules above. Java 1.2.

Released 1998-12.

Functional Response is similar to Predator/Prey, but adds a first scenario to explore Types I, II, and III functional response, the function that relates predator consumption rate to prey abundance. This module has been retired in favor of a newer version without the isoclines - see newer Predator/Prey modules above. Java 1.2.

Released 1998-12.

The Paradox of Enrichment is another Predator/Prey isoclines model, exploring how enriching the prey environment (raising carrying capacity) can depress the predator population. Java 1.2.

Released 1999-3.

Competition explores Lotka-Volterra Competition models, using twin plots, one displaying isoclines, and the other a time series. Trajectories can be added to the isoclines with a mouse click. This module has been retired in favor of a newer version without the isoclines - see newer Competition module above. Java 1.2.

Released 1998-11.