This project is my Ph.D. thesis and I am currently working on it under the supervision of Stefan Haar and Franck Pommereau, and with a collaboration of Cédric Gaucherel to discuss topics in ecology. My doctoral contract started on 1st of October 2020 and goes until 30th of September 2023.

EcoSystem Causal Analysis Using PEtri Net Unfoldings (ESCAPE) brings together the causal analysis of discrete processes via Petri Net unfolding, and the reasoning about interactions in ecological systems under a network perspective. New discrete models have recently been proposed for capturing influences and interactions, linking ecosystemic graph models - extended by encompassing hypergraphs - to reaction rules reflecting influences between species, abiotic components, artefacts etc. The project aims at these approaches fruitful for prediction, causal explanation, and control of system models, via the development of partial order unfolding methods that have arisen in fault diagnosis, attractor analysis, and control, giving a full sight of the causal relations that determine these processes.

For the time being, I have been able to reproduce unfoldings using read and reset semantics which go beyond the literature using ordinary Petri Nets. Place replication encoding (from Baldan et al. 2012) and reset complement were used to enable us an adequate representation of ecosystem dynamics. I have released a software called Ecofolder which opens a door for more research! Here below I present a net to model a termite colony (right) based on a rule system (left, Gaucherel & Pommereau, 2019):

  1. Rp+ Ec+, Rp+

  2. Rp+, Ec+ Wk+, Rp+, Ec+

  3. Wk+ Wd+, Te+, Fg+, Ec+, Wk+

  4. Wk+, Wd+ Sd+, Rp+, Wk+, Wd+

  5. Wk+, Te+ Wd-, Wk+, Te+

  6. Wd- Wk-, Te-, Wd-

  7. Wk- Fg-, Sd-, Te-, Wk-

  8. Wk-, Rp- Ec-, Wk-, Rp-

  9. Ac+, Sd- Wk-, Rp-, Ac+, Sd-

Rp: termites reproductives, the queen, the king, the eggs and the nymphs.

Wk: termites workers, all termites able to work.

Sd: termites soldiers.

Te: termitomyces are fungi grown by termites.

Fg: fungal gardens are chambers in the termite mound set by growing fungi.

Ec: egg chambers are built in the mound to serve as a nursery.

Wd: wood is used by termites to build their mound and to grow fungi.

Ac: ant competitors that may attack the colony.