{"type":"ScholarlyArticle","title":"Towards the 30 by 30 Kunming-Montreal Global Biodiversity Framework Target: Optimising Graph Connectivity in Constraint-Based Spatial Planning","authors":[{"name":"Sulian Le Bozec-Chiffoleau","slug":"sulian-le-bozec-chiffoleau","given":"Sulian","family":"Le Bozec-Chiffoleau","affiliation":""},{"name":"Dimitri Justeau-Allaire","slug":"dimitri-justeau-allaire","given":"Dimitri","family":"Justeau-Allaire","affiliation":""},{"name":"Xavier Lorca","slug":"xavier-lorca","given":"Xavier","family":"Lorca","affiliation":""},{"name":"Charles Prud'homme","slug":"charles-prud-homme","given":"Charles","family":"Prud'homme","affiliation":""},{"name":"Gilles Simonin","slug":"gilles-simonin","given":"Gilles","family":"Simonin","affiliation":""},{"name":"Philippe Vismara","slug":"philippe-vismara","given":"Philippe","family":"Vismara","affiliation":""},{"name":"Philippe Birnbaum","slug":"philippe-birnbaum","given":"Philippe","family":"Birnbaum","affiliation":""},{"name":"Nicolas Rinck","slug":"nicolas-rinck","given":"Nicolas","family":"Rinck","affiliation":""},{"name":"Nicolas Beldiceanu","slug":"nicolas-beldiceanu","given":"Nicolas","family":"Beldiceanu","affiliation":""}],"abstract":"The Kunming-Montreal Global Biodiversity Framework aims to protect 30% of terrestrial, inland water, marine, and coastal ecosystems worldwide, and ensuring that at least 30% of these areas are under effective restoration by 2030.\r\nMaintaining and restoring ecological connectivity between natural habitats and protected areas is a key feature of this target.\r\nAchieving it will require effective and inclusive spatial planning supported by appropriate decision-support tools.\r\nMost spatial planning models address budget as an objective and connectivity as a constraint, formulating problems with Steiner trees.\r\nIn many real-world cases, such as landscape-scale restoration planning, this formulation is inappropriate when environmental managers seek to optimise connectivity under a budget constraint.\r\nThis problem was previously addressed with Constraint Programming (CP) and graph variables, but the current approach is severely limited in terms of spatial resolution.\r\nIn this article, we formalise this problem as the budget-constrained graph connectivity optimisation problem. Based on a real case study: the restoration of forest connectivity in New Caledonia, we illustrate why ``naive'' CP approaches are inefficient.\r\nIn response, we provide a preprocessing method based on Hanan grids which preserves the existence of at least one optimal solution.\r\nFinally, we assess the efficiency of our approach in the New Caledonian case study.","doi":"10.24963/ijcai.2025/1086","url":"https://ijcai.org/proceedings/2025/1086","pdf":"https://ijcai.org/proceedings/2025/1086.pdf","markdown":"https://ijcai.org/proceedings/2025/1086.md","bibtex":"https://ijcai.org/proceedings/2025/bibtex/1086","volume":{"slug":"2025","title":"Proceedings of the Thirty-Fourth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2025","url":"https://ijcai.org/proceedings/2025/","year":2025,"location":"Montreal, Canada","dates":"16-22 August 2025","editors":"James Kwok","isbn":"978-1-956792-06-5","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2025"},"section":"AI and Social Good","track":"AI and Social Good","number":1086,"pages":{"first":9772,"last":9780},"keywords":["Multidisciplinary Topics and Applications: General","Constraint Satisfaction and Optimization: General","Planning and Scheduling: General"],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}