Table S1. Short description of the case studies and the calibration of the outcome Conflict type Cases summary Outcome score Location Main stakeholders Case 1: Human- The conflicts were related to brown bears’ ‘1’ Vrancea, Parties in conflict: wildlife conflicts (Ursus arctos arctos) presence within Although collaboration between Covasna and Representatives of inhabited areas where they had become a parties led to an agreement Harghita hunters, farmers and threat to farmers’ livestock and people concerning the methods to be Counties local citizens ≠ (i.e., bodily harm). Thus, the Romanian used for brown bear conservation (which environmentalists; government increased the quota for (materialized in The Guide to include local environmental hunting brown bears for reasons of safety, Brown Bear Population Estimates several protection agencies which incited reactions from and The Practical Guide For Natura 2000 (EPAs); environmentalists. This triggered the Preventing Brown Bears’ Habitat sites for large environmental NGOs development and implementation of an Degradation and Fragmentation and carnivores’ EU-LIFE project which made possible the for Ensuring the Connectivity of the conservation) collaboration between parties in order to Natura 2000 Sites), the Ministry of reduce human-bear conflicts, enhance the the Environment did not make the bears’ conservation status and develop proposed methods mandatory; it innovative methods for management of only recommended them. the bear population. Case 2: Human- The development of the management plan ‘1’ Oltul Parties in conflict: wildlife conflicts for two Natura 2000 sites has created The approved management plan Superior and Agricultural opportunities for negotiating solutions to includes the possibility of asking Raul Negru landowners; the damage caused to agricultural lands for compensation when damage is Natura 2000 Romanian water and forestry sites by beavers (Castor fiber). caused by beavers. However, sites, Covasna national Requests to include compensation schemes unlicensed culling practices and Brasov administration; for beaver-related damage in the continue to conflict with the Counties Covasna Forestry management plans have been made, as no conservation of beavers, which Division ≠ the such subsidies are currently in place. benefit from a strict protection management agency status. of the Natura 2000 sites Case 3: Human- The legislative framework of the Iron ‘2’ Iron Gates Parties in conflict: wildlife conflicts Gates Natural Park does not allow for The collaboration process Natural Park, Nose-horned viper nose-horned viper (Vipera ammodytes) involving the affected parties Caras Severin farmers ≠ the local farms, as the species carries the ‘rare’ came to the unanimous decision and municipalities; the protection status. The conflicts were that the farms were not legal, this Mehedinti scientific council and ignited by the existence of a few farms (for prohibiting such activities. Counties the management the collection of venom) and applications agency of the park for other licenses. Case 4: Human The conflicts started when a few American ‘2’ Feldioara Parties in conflict: wildlife conflicts minks (Neovison vison) (considered as an The collaboration process Municipality, Owners of the invasive species) escaped from a farm. involving the affected parties led Brasov Feldioara American This incident led to the discovery that the to the decision to issue County Mink Farm ≠ the local farm was operating without environmental authorization for EPA; the local environmental authorization. The request the farm. environmental guard; for the farm extension and environmental the management authorization, as well as controls to be agency of the carried out by the local environmental Dumbravita-Rotbav guard, opened up the possibility for Natura 2000 site; collaboration. While some parties Sercaia American highlighted the negative environmental Mink Farm impacts that can be caused by the escaped minks, other parties denied that such an incident in fact happened and accused a competing mink farm of sabotage. Currently, the farm is operating with environmental authorization, and it has not been possible to prove whether or not the minks escaped. Case 5: Human- The conflicts were triggered by the ‘1’ Harghita Parties in conflict: wildlife conflicts problems (i.e., damage to agricultural As a result of the collaboration County Agricultural lands; bodily harm) caused by large process, hunting a specific landowners; part of carnivores (especially bears and wolves) number of bears was approved the local population; which encouraged the county council to through a legislative act in areas hunting agency ≠ establish hunting quotas. A collaboration where the most damage was county council; part process was initiated to understand the caused. However, the conflict of the local problems and their main causes (i.e., bears’ remains unresolved as new population habitat loss; logging; bears’ strict damage can occur at any time in protection status; the real number of areas not covered by the bears). Two divergent perspectives approved hunting quota. emerged: (i) conservationists believe that the bears must be protected and not hunted, and that people should accept losses when they are in the bears’ habitat; (ii) some people believe that the bears should be hunted not for economic gains, but agree that the damage they cause should be reduced. Case 6: Forest Forest exploitation restrictions were ‘1’ Putna- Parties in conflict: exploitation- imposed on owners where the forest area Although the parties agreed to Vrancea Forest Owners’ related conflicts had been designated as a strict protection some compromises, the Natural Park, Association ≠ the area within a natural park. The conflicts representatives of the Forest Vrancea management agency started when no compensation could be Owners’ Association remained County of the park; local guaranteed for the owners due to the intransigent. Currently, the park’s EPAs inexistence of a management plan for the administration comes between the park at that time. The collaboration efforts forest owners and forest initiated by representatives of the forest exploitation, but this balance is owners and the park’s management fragile. agency succeeded in avoiding forest exploitation and conserving the area’s richness. Case 7: Forest The local forestry division asked for ‘1’ Putna- Parties in conflict: exploitation- permission to remove wind-damaged trees The management agency of the Vrancea The local forestry related conflicts attacked by bark beetles from a special natural park agreed to wood Natural Park, division ≠ the conservation area located within a natural exploitation in the special Vrancea scientific council and park. The conflict was ignited by the conservation area. However, the County the management concerns that a larger amount of wood conflict could be reignited if the agency of the park than necessary would be exploited and forestry division exploits more that the forest plan did not correlate with wood than what was permitted. the management plan of the natural park. The collaboration process led to improved information regarding the negative effects of wind-damaged trees on healthy ones. Case 8: Forest The conflict was triggered by ‘0’ Semenic- Parties in conflict: exploitation- unauthorized logging by the Romanian Although the collaboration Cheile The management related conflicts forest management company within the process made clear that such Carasului agency of the natural full protection area of a natural park where logging is illegal, forest Natural Park, park; Caras-Severin no exploitation of natural resources is exploitation within the park Caras-Severin Forestry Division ≠ permitted according to Romanian continues. This reflects the county local EPA; local legislation. The local environmental NGOs political will that supports forest environmental guard; submitted a complaint regarding such exploitation as well as the environmental NGOs destructive logging. A collaboration interests of the Romanian Forest process attempted to create awareness of Management Company in the need to stop logging in the full exploiting wood resources. protection area. Case 9: A protected forest, which is also an ‘0’ Gradistea- Parties in conflict: Transportation- important habitat for migratory and The agreement was not Caldarusani- The State Road related conflict endangered birds, has been affected by a implemented because the parties Dridu Natura Company ≠ local massive transportation project (a had barely collaborated. The 2000 site, EPAs; environmental highway). A collaboration process has agreement was completely Ilfov County NGOs been initiated to negotiate possible violated by the state road building solutions to both protect the biodiversity company. For this reason, another and still build the highway. Although conflict began, where the compensatory measures (i.e., tunnels, European Commission green bridges for bats, sound-absorbing intervened, but no solution has panels for the protection of the migratory emerged until now. and endangered birds, as well as compensating the proposed area for deforestation sixfold) were agreed upon, none of them was implemented. Case 10: The national EPA requested the revision of ‘2’ Fegernic Parties in conflict: Transportation- the environmental authorization for a As a result of the collaboration Meadow, The State Road related conflicts highway section (Suplacu de Barcau-Bors efforts, the parties concerned Bihor County Company; local and section). This was triggered by the agreed to the construction of the county agencies ≠ intention to build a viaduct close to a highway viaduct and approved national EPA, local Natura 2000 site, an important habitat for the environmental authorization, environmental guard the European ground squirrel which includes solutions to (Spermophilus citellus). A collaboration protect the species. process was organized in order to issue a new environmental authorization, including solutions to protect the species (i.e., ecoducts for species migration). Case 11: A group of NGOs advocating for the ‘2’ Pitesti-Sibiu Parties in conflict: Transportation- protection of the Natura 2000 sites brought A final decision resulted from the highway, The State Road related conflicts a complaint regarding the omission of collaborative efforts, where the Sibiu, Valcea Company; local and conservation solutions for bats within the highway project was blocked by and Arges regional public environmental statement for a highway. means of cancelling its Counties agencies; the highway The request for a new environmental environmental authorization. engineers ≠ permit led to a collaboration process, environmental NGOs which made clear the mandatory inclusion of wildlife management solutions (i.e., ecoducts), as well as the ecological implications of the bats’ habitat fragmentation. Case 12: Human The development of the management plan ‘1’ Lower Siret Parties in conflict: pressures on for a Natura 2000 site (a river valley and Most of the parties’ concerns have Meadow And Owners of residences protected areas associated protected areas) has created been included in the management the and guesthouses ≠ opportunities to resolve disagreements plan, which resulted from the overlapping Association for over the management of natural resources collaborative efforts. Some issues protected Biodiversity and the shift from resource exploitation remained unresolved, but the areas, Braila, Conservation (i.e., mineral exploitation, inadequate leader of the project has sufficient Galati and grazing and forestry practices) to capacity to implement the plan. Vrancea biodiversity conservation. Moreover, the parties that were Counties involved in the conflict have begun to view the protected area as a good way to commence collaborations on other projects. Case 13: Due to the high level of tourist interest in a ‘0’ Iron Gates Parties in conflict: Investments in rock sculpture located within a natural The local municipality has made Natural Park, Local municipalities ≠ protected areas park, the local municipalities want to some investments (i.e., lighting for Caras Severin the scientific council invest in tourist infrastructure (such as the rock sculpture) without and and the management toilets, parking areas, commercial areas). receiving the approval of the Mehedinti agency of the natural The negotiations between the scientific council of the park. Counties park municipalities, the scientific council and the management agency of the park have established specific conditions for the construction of the infrastructure. However, such conditions have not been met. Case 14: The designation of an area as a national ‘1’ Defileul Jiului Parties in conflict: Investments in park required new environmental As part of the collaboration, National The main state protected areas authorization for the works needed to decisions were made to stop the Park, Gorj company that uses create an artificial lake to store water. The project by cancelling the County hydropower to main state company that uses hydropower environmental authorization. produce electricity; to produce electricity supported the However, the works continue. The the Romanian realization of the project, claiming that conflict has been escalated to the government ≠ there was no need for new environmental European Commission, as environmental authorization given the advanced status of Romania has been sued for NGOs; local the works. The NGOs argued that the violating European legislation environmental guard; project would impact the ecosystems of related to biodiversity local EPA the river basins to be drained to fill the conservation. lake. Case 15: Environmental NGOs submitted a ‘1’ Fagaras Parties in conflict: Investments in complaint regarding the illegality of the Decisions were made to stop the Mountains, The companies protected areas environmental authorization for the construction of the SHPs. Sibiu County owning the SHPs ≠ construction of hydro-power plants in the However, the constructions exist, environmental alpine and subalpine area of the Fagaras which may cause conflicts in the NGOs; the local Mountains. Collaborative efforts were future. environmental guard initiated to make clear the construction progress of the SHPs and their environmental impact. Case 16: Environmental NGOs made a complaint ‘0’ Hațeg Parties in conflict: Investments in regarding the illegality of the As no compromise could be Country The management protected areas environmental permit issued to two SHPs reached, the conflict was escalated Dinosaurs agency of the within the special conservation zone of a to the court. Currently, the SHPs Geopark, protected area ≠ local protected area. Subsequently, the local continue to operate. Hunedoara EPA; environmental EPA canceled the environmental permit, County NGOs; the Ministry finding the management agency of the of the Environment; protected area guilty of approving such the Anticorruption activities. Collaborative efforts were Agency; local initiated to make clear the necessity to environmental guard; cancel all the environmental permits local police issued for such projects. Case 17: Human The conflicts were triggered by the ‘1’ Nerei Valley, Parties in conflict: interventions in complaints submitted by NGOs regarding The decision resulted from the Caras-Severin SHPs’ investors; the protected areas the negative impact of a few SHPs. A collaborative efforts, leading to County author of the EIA ≠ collaboration process shed light on the the cancellation of the SHPs’ environmental negative environmental impact of the environmental authorization, NGOs; local SHPs, which was initially underestimated, which subsequently blocked the communities; local and on the fact that their construction projects. However, this may not EPA started without any environmental permit. be the final decision as the environmental institution has insufficient power to impose it. Case 18: Human The conflicts were related to the proposal ‘2’ Ceahlau Parties in conflict: interventions in to change the limits of a sustainable The decision to modify the limits National County council; local protected areas development zone in a national park to of the sustainable development Park, Neamt public agencies; part allow for the construction of a ski track. A area was institutionalized through County of the scientific collaborative process facilitated by a the management plan of the council of the park ≠ mediator aimed at clarifying, on the one protected area, which was part of the scientific hand, the economic advantages of the ski unanimously approved. council of the park; track for a semi-abandoned touristic area environmental NGOs located within the sustainable development zone of the park and, on the other, the potential impact on habitat fragmentation. Case 19: Built-up Owners of residences and guesthouses ‘0’ Iron Gates Parties in conflict: zones in complained about the activities of the No agreement could be reached as Natural Park, Owners of residences protected areas main state company which uses some parties (i.e., the owners of Caras Severin and guesthouses ≠ the hydropower to produce electricity. residences and guesthouses) and hydroelectric power According to the owners, the company’s withdrew from the meetings. The Mehedinti plant activities were exerting an influence on the conflict is difficult to resolve, Counties stability of their houses. They then claimed given the legal framework, which compensation for the damage caused. does not allow construction During the negotiation process, the within the protection area of the company’s representatives brought into accumulation lake. focus the fact that the construction of the houses (within the protection area of an accumulation lake) could not be justified from a legal point of view. This led the owners to give on up their claims. Case 20: Built-up The conflicts were triggered by the ‘2’ Putna- Parties in conflict: zones in requests made by a municipality to extend This collaboration process Vrancea Local municipality; protected areas its built-up area in the sustainable resolved the contested issues and Natural Park, private landowners ≠ management area of a natural park. A made possible the inclusion of the Vrancea the scientific council collaboration process was initiated to requests within the general urban County and the management understand what scattered built-up zones plan as well as the management agency of the park would mean in such an area and whether plan of the protected area. its designation as a sustainable management area was appropriate. Case 21: Built-up Private landowners expressed their ‘1’ Putna- Parties in conflict: zones in intention to build homes in an area located The decisions resulting from the Vrancea Private landowners; protected areas between two municipalities, which was collaborative efforts have been Natural Park, local municipality ≠ considered an important wildlife corridor included in the current urban plan Vrancea the scientific council within a natural park. Thus, the local which prohibits extensions to County and the management municipality asked for the area within the built-up zones. However, private agency of the park built-up zone to be included in the landowners have built fences proposal submitted to the scientific council around their land, impeding and management agency of the park. The wildlife’s access to water negotiation sessions indicated that the resources. contested area is located within a sustainable management area where the extension of built-up zones is not allowed. Case 22: Built-up The local municipality asked to extend its ‘0’ Iron Gates Parties in conflict: zones in built-up zone in an integral protection area As a result of the collaborative Natural Park, The local protected areas (Moldova Noua Isle) by modifying the efforts, decisions were taken to Caras Severin municipalities ≠ the limits of the protection area. The conflicts restrict the expansion of the built- and scientific council and were triggered by the rejection of the up area on Moldova Noua Isle. Mehedinti the management proposal by the scientific council of the However, the general urban plan Counties agency of the park park. The negotiation sessions assessed the of the municipality has not yet possibility of changing the limits of the been institutionally approved, protection area by involving a neutral which could cause the conflict to external consultant. The consultant’s ignite in the future. report highlighted that it would not be appropriate to change the limits of the protection area and to extend the urban area on Moldova Noua Isle. Case 23: Mining- The sterile dust (from a Romanian mining ‘1’ City of Parties in conflict: industry related company, located in a municipality close The conflict is currently ongoing Moldova The administrators of conflicts to the border with Serbia) transported by and reactivated with every wind Noua, Caras- the sterile ≠ local wind led Serbia to denounce Romania intensification. The large area Severin municipalities; before the Court of Justice of the EU. As a concerned and the lack of County environmental consequence, Romania must align its financial, logistic and agencies; legislation with that of the EU and find administrative resources have environmental NGOs solutions to stabilize the tailing dumps made it difficult to implement the against wind erosion. Although some protective measures which were protective measures have been adopted agreed upon. (i.e., plantations, spraying water over 40% of the sterile dust), they have not successfully exerted a protective role. Case 24: Mining- The designation of the Lower Siret ‘0’ Lower Siret Parties in conflict: industry related Meadow as a Natura 2000 site blocked the No decision emerged as a result of Meadow The firms owning the conflicts riverbed mining projects for aggregate the collaborative efforts. The Natura 2000 mining activities; the minerals. The attempts to obtain mining projects were stopped site, Braila, municipalities’ town environmental authorization for such when an extension to the Galati and halls; Romanian activities led to a collaboration between environmental authorization was Vrancea National Water the main parties, which made clear the refused. Counties Administration ≠ the environmental impact of these activities management agency and the role of the area as a Natura 2000 of the protected area; site. local EPA; higher education institutions Case 25: Human The conflicts were related to the presence ‘1’ Piatra Parties in conflict: pressures in of all-terrain vehicles (ATVs) and other The final agreement prohibits the Craiului ATV owners; the protected areas vehicles in a national park and its use of ATVs in some areas of the National organizers of events sustainable conservation zone. national park. However, due to Park, Arges where ATVs are used; Collaborative efforts were initiated to find the lack of a legislative framework and Brasov the mayors of a solution (i.e., approval from the imposing clear sanctions, the Counties neighboring protected area management agency is interdictions to use ATVs were municipalities ≠ the necessary to use ATVs within the park) to difficult to implement. management agency such a problem and to understand the of the park; local consequences for the wildlife and the environmental guard quality of their habitat. Case 26: Human The conflicts were triggered by the bans on ‘1’ Danube Delta Parties in conflict: pressures in fishing for sturgeon imposed by the The final agreement prohibits Biosphere Local communities; protected areas management agency of the Danube Delta fishing for sturgeon and exporting Reservation, fishermen; fishing Biosphere Reservation and legislation. sturgeon products. However, Tulcea, economic agencies ≠ Several meetings involving the interested cases of sturgeon poaching exist. Constanta the management parties opened up the way to and Galati agency of the Danube collaboration. This led to an increased Counties Delta Biosphere awareness among local communities about Reservation; local the conservation of sturgeons, which are environmental guard; close to extinction, and the economic and environmental NGOs ecological consequences. Case 27: Human The conflicts were triggered by low water ‘1’ Lake Petea Parties in conflict: pressures in levels in Lake Petea because of the Decisions to limit the use of Natura 2000 Economic agents; protected areas disorganized use of its thermal waters. A thermal water were made. site, Bihor private individuals collaboration process made clear that However, they were not County who exploit thermal activities such as exploiting the thermal implemented because of the high water resources ≠ waters of the lake have a negative economic interest in exploiting local EPA; local environmental impact (i.e., extinction of such resources and the limited environmental guard; some species, such as the thermal lily, reaction from public institutions. the management Nymphaea lotus f. thermalis) and should not agency of the Natura be allowed close to a Natura 2000 site. 2000 site Table S2. Truth table for the analysis of the combinations of factors sufficient for effective collaboration

Principled Shared Joint Outcome Number Sufficiency Cases engagement motivation action of cases inclusion score (PE) (SM) (JA) 1 0 0 0 0 3 0.333 Case 8, Case 15, Case 16 2 0 0 1 ? 0 - 3 0 0 2 ? 0 - 4 0 1 0 ? 0 - 5 0 1 1 ? 0 - 6 0 1 2 ? 0 - 7 0 2 0 ? 0 - 8 0 2 1 ? 0 - 9 0 2 2 ? 0 - Case 9, Case 13, Case 14, 10 1 0 0 0 7 0.571 Case 21, Case 24, Case 25, Case 27 11 1 0 1 0 2 0.5 Case 22, Case 26 12 1 0 2 ? 0 - 13 1 1 0 0 1 0 Case 19 14 Case 2, Case 4, Case 6, 1 1 1 1 6 1 Case 11, Case 17, Case 23 15 1 1 2 1 1 1 Case 18 16 1 2 0 ? 0 - 17 1 2 1 1 1 1 Case 3 18 1 2 2 ? 0 - 19 2 0 0 ? 0 - 20 2 0 1 ? 0 - 21 2 0 2 ? 0 - 22 2 1 0 ? 0 - 23 Case 1, Case 5, Case 7, 2 1 1 1 4 1 Case 12 24 2 1 2 ? 0 - 25 2 2 0 ? 0 - 26 2 2 1 ? 0 - 27 2 2 2 1 2 1 Case 10, Case 20