martes, 3 de noviembre de 2009

Allan Berryman: Population Analysis System (PAS)

The Population Analysis System (PAS) consists of a series of microcomputer programs designed to help you construct models and analyze the dynamics of populations of organisms inhabiting variable environments.


One-species Analysis
Pressing [2] in the PAS Main Menu will access programs for modeling and analysis of populations consisting of a single species. All other species are relegated to the environment of the subject population. The programs are:
  • P1a - Analyzes and models population census (time series) data.
  • P1b - Builds logistic population models and simulates dynamics.

Two-species Analysis
Pressing [3] in the PAS Main Menu will access programs for modeling and analysis of the interaction between two covarying populations such as predators and their prey, competitors or cooperators. The programs are:
  • P2a - Analyzes census data collected at equal time intervals on two coexisting species.
  • P2b - Models and simulates the dynamics of two interacting populations.

Applications
Pressing [4] in the PAS Main Menu will access programs that use models created by other PAS routines. They are mainly self-explanatory and no user manuals are provided. Clicking on the programs below show examples of them in action:
  • P1i - Interprets the biological meaning of model parameters in P1a or P1b.
  • P1s - Evaluates the sensitivity and stability of single-species models.
  • P2p - Forecasts future population densities and probabilities of outbreak or extinction.
  • P2m - Plays management games and tests harvesting or pest control strategies.

Lessons
Pressing [5] in the Main Menu will access programs for learning the theory of population dynamics and how it can be applied to real-life data. They are mainly self-explanatory and no user manuals are provided. Clicking on the programs below show examples of them in action:
  • PL1 - Exponential growth and the limits to growth.
  • PL2 - Predator-prey interactions in time and space.
  • PL3 - Competition between species.
  • PL4 - Interaction between plants and herbivores and pest management.
  • PL5 - Predator-prey cycles and pest management.

Games
Pressing [6] in the Main Menu will access programs for studying simple artificial life systems, like cellular automata. They are mainly self-explanatory and no user manuals are provided. Clicking on the programs below show examples of them in action:
  • PG1 - The Game of Life.
  • PG2 - Logistic growth of cellular automata.
  • PG3 - Predator-prey automata.

System