1. General Model Information
Name: Unified Life Models
Main medium: all
Main subject: populationdynamics
Organization level: population
Type of model: not specified
Main application: research, education
Keywords: life cycle, competition, parasitism, migrations, demographic process, metapopulation, discrete dynamic systems, stochastic model, Monte Carlo simulation, matrix population models
Laboratoire d'Ecologie, Ecole Normale Supérieure,
46 rue d'Ulm,
75230 Paris Cedex 05,
Phone: (33) 01 44 32 37 01
Fax : (33) 01 44 32 38 85
How does ULM work ?
Models are described in a text file according to a reduced declaration
language, close to the mathematical formulation. The program is run with the
model file as input and the system can be studied interactively by means of
simple commands producing convenient graphics and numerical results. The kernel
of ULM is a symbolic evaluator. Stochastic models are handled via Monte Carlo
What can be modeled ?
Which results ?
- any species life cycle graph (matrix models) (Caswell, 1989),
- inter- and intra-specific competition, parasitism, density dependence
- environmental stochasticity (Tuljapurkar, 1990) (random processes),
- demographic stochasticity (branching processes),
- metapopulations, migrations (coupled systems).
- population trajectories, distributions,
- growth rate, population structure,
- generation times, sensitivities to changes in parameters,
- probability of extinction, extinction times,
- lyapunov exponent, bifurcation diagrams,
- power spectrum, correlation,
- quasi-stationary distribution, statistics,
- fitness landscape.
Author of the abstract: Stéphane Legendre
II. Technical Information
Operating System(s): Windows 3.xx see section V.
ULM is distributed free of charge. Users are under their own responsibility.
Click here to download autoulm.exe (154 Ko) self-extracting file
III. Mathematical Information
Caswell, H., 1989. Matrix Population Models.
Sinauer Associates Inc.,Sunderland, MA, USA.
Ferrière, R., Sarrazin, F., Legendre, S., Baron, J-P., 1996. Matrix population models applied to viability analysis and conservation: Theory and practice with ULM software,
Acta OEcologica, 17.
Legendre, S., Clobert, J., 1995. ULM, a software for conservation and evolutionary biologists,
Journal of Applied Statistics, 22, 817-834.
Tuljapurkar, S., 1990. Population Dynamics in Variable Environments,
Lecture Notes in Biomathematics, Springer Verlag, Germany.
V. Further information in the World-Wide-Web
VI. Additional remarks
Last review of this document by: T. Gabele: Tue Oct 7 1997
Status of the document: - preliminary
last modified by
Tobias Gabele Wed Aug 21 21:44:51 CEST 2002