**Version 3.0 - nov 2000**

The ULM computer program (Legendre & Clobert 1995; Ferrière *et
al.* 1996) was designed to study population dynamics models, and, more generally,
discrete dynamical systems.

WINDOWS

Biologists, Ecologists, Mathematicians, either for research or teaching purposes in the following domains:

- management, conservation biology (Ferrière
*et al.*1996), - evolutionary demography,
- general deterministic or stochastic dynamical systems.

ULM is distributed free of charge. Users are under their own responsibility.

Click here to download autoulm.exe
self-extracting file

- create directory
*c:\ulm*in which you will install ULM, - move
*autoulm.exe*to the ULM directory, - double-click on
*autoulm.exe*.

**ULM directory should now contain:**

- the ULM program
*ulm.exe*, - example model files
**.ulm*, - user's information
*readme.txt*, - reference manual
*ulmref.rtf.*

The complete list of files contained in *autoulm.exe* may be found in *readme.txt*.

- Double-click on any model file
**.ulm*, and select program*c:\ulm\ulm.exe*to open the file, - ULM will then be run with files
**.ulm*as input. - For detailed informations, consult
*readme.txt*and*ulmref.rtf*.

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 simulation.

- any species life cycle graph (matrix models) (Caswell 1989, 2000),
- inter- and intra-specific competition, density dependence (non linear systems),
- 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,
- fitness landscape,
- probability of extinction, of quasi-extinction, extinction times,
- statistics on population trajectories,
- lyapunov exponents, bifurcation diagrams.

Caswell, H. 1989. Matrix Population Models. Sinauer Associates Inc., Sunderland, MA, USA.

Caswell, H. 2000. Matrix Population Models. Second edition.

Ferrière, R., F. Sarrazin, S. Legendre, and J.-P. Baron. 1996. Matrix population models applied to viability analysis and conservation: Theory and practice with ULM software. Acta OEcologica 17:629-656.

Legendre, S., and J. Clobert. 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.

**Stéphane Legendre**

Laboratoire d'Ecologie, Ecole Normale Supérieure, 46 rue d'Ulm, 75230
Paris Cedex 05, France.

Tel: (33) 1 44 32 37 01 - Fax: (33) 1 44 32 38 85 - Email: legendre@ens.fr

Jean Clobert, Régis Ferrière, Frédéric Gosselin, Jean-Dominique Lebreton, François Sarrazin.