Project name: Improvement of the management of forest vegetation special reserves threatened by the effects of climate change
Client: Medvednica Nature Park
Period: 6/2024 – 10/2025
Location: Croatia
Public Institution “Medvednica Nature Park” contracted Oikon Ltd – Institute of Applied Ecology to implement the project “Improving the Management of Forest Vegetation Special Reserves Threatened by the Consequences of Climate Change.”
The project was carried out in cooperation with subcontractor Pro Silva Ltd and included the preparation of a professional basis, study documentation, and project-technical documentation for the establishment of a monitoring system of natural habitats and their components within the Medvednica Nature Park area.
The project’s objective was to establish a scientifically grounded and methodologically consistent system for monitoring the condition of forest ecosystems in three Special Forest Vegetation Reserves: Bliznec – Šumarev grob, Gračec – Lukovica – Rebar, and Tusti vrh – Kremenjak. These are the most valuable forest complexes of Medvednica, selected as representative examples for long-term monitoring of the impacts of climate change on forest ecosystems due to their natural diversity, structure, and ecological importance.
In the first phase of the project, a professional basis was prepared, providing an initial analysis of forest habitats, forest communities, and related ecosystem components. Field surveys were carried out for all research groups defined in the document, including forest habitat types, vascular flora, entomofauna, bats, aquatic ecosystems, and abiotic environmental factors. This ensured a comprehensive and interdisciplinary foundation for the development of the monitoring system.
The field data collected during this phase enabled the determination of basic biotic and abiotic parameters and the identification of key indicators for future monitoring. This professional basis thus served as the foundation for the development of a detailed monitoring methodology in the study documentation.
The second phase resulted in the preparation of the study documentation, which included a comprehensive analysis of the condition of forest stands, flora, forest and non-forest habitat types, entomofauna, aquatic habitats, and bats. The documentation elaborated a detailed methodology for monitoring all defined components (target habitat types and target species).
In addition to monitoring biotic elements, the study documentation also identified the main pressures and threats to forest ecosystems – from extreme weather events and successional changes to the occurrence of invasive species. For each component, conservation guidelines and recommendations were developed, and the results were consolidated into a comprehensive methodological framework that will serve as a reference for future monitoring and adaptive management.
The project-technical documentation represented the final and most operational phase of the process, following the preparation of the professional basis and study documentation. While the initial phases focused on analysis and methodology development, this phase consolidated and expanded existing knowledge, enabling the systematic implementation of monitoring of target species and habitat types, as well as the execution and planning of management measures. Collectively, these activities contributed to nature conservation in Medvednica Nature Park.
The documentation established the technical, methodological, and organisational framework for monitoring the status of habitats and species – including forest, grassland, and aquatic ecosystems – and for developing educational and communication activities that strengthened the capacities of the Park’s Public Institution and the local community. At the core of the approach was an integrated monitoring system, linking scientific data with practical management and decision-making for the protection of natural values. This created a dynamic tool for long-term ecosystem monitoring and timely responses to environmental and social pressures.
An important indicator of the condition of forest stands was the measurement of stand structure in the Special Forest Vegetation Reserves. It showed deviations from the optimal structure that ensures stability and future development. Competent authorities at the time did not find it necessary to apply silvicultural interventions, so such measures were not included in the final report. Management in other forests within the Natura 2000 ecological network continued according to approved Forest Management Programmes, which incorporated many habitat conservation elements, including the recording and preservation of target species and habitat types.
Parallel to the stand-structure analysis, tree health status and deadwood volume were assessed along selected transects. These results provided reliable indicators of stand condition and needs for potential interventions to improve stability and guide management towards maintaining resilient forest ecosystems.
The flora and vegetation of Medvednica are highly representative of the hilly regions of central Croatia, especially regarding the distribution and vertical stratification of forest vegetation. The rich flora was partially inventoried during the project, and key species were categorised as typical, strictly protected, or threatened. Typical species of a habitat type served as indicators of its naturalness and conservation status, while the presence of strictly protected and threatened species reflected the positive condition of forest ecosystems and centuries-long ecologically sustainable forest use.
In contrast, non-forest (open) habitats showed signs of degradation due to the abandonment of traditional management, resulting in overgrowth. For this reason, interventions were planned on non-forest areas – reduction of woody vegetation, removal of invasive species, and regular mowing – to restore dry grasslands (6210) and hydrophilous tall-herb fringes (6430) along watercourses. Their success was tracked through ongoing monitoring.
Forest habitat types represent the core natural feature of Medvednica Nature Park and provide habitat for numerous target species of flora and fauna. They were especially well represented within the three reserves, where most of the research was carried out. Four target habitat types (five according to the National Habitat Classification) were identified, hosting over 100 typical, 16 strictly protected, and 6 threatened species. The state of these habitats was assessed as favourable, supported by data on deadwood volume and structure. Monitoring was conducted along 11 transects, with the methodology and protocols detailed in the study documentation. In addition to typical species, strictly protected and threatened plants, particularly orchids (Orchidaceae), were recorded.
Aquatic habitats were extremely important for maintaining biodiversity and target species. Although covering only 254 ha (1.37% of the Park), their inventory showed a good condition. Key target species Bombina variegata, Austropotamobius torrentium, and Barbus balcanicus – were found at numerous sites in satisfactory numbers, while the Italian crested newt (Triturus carnifex) was not recorded, requiring detailed monitoring to confirm its presence. As aquatic habitats faced pressures and threats, their conservation represented a particular challenge. The project included dredging of three major ponds (Tigrovo oko, Kraljičin zdenac, Mali potok), cleaning stream banks of vegetation and waste, and other interventions to ensure a constant inflow of clean water.
Bat fauna served as an important biodiversity indicator. The project recorded at least 21 bat species, including eight target species, five of which are primarily forest-associated. All target species were found within the reserves, and their status was rated favourable, owing to the age structure of forest stands. The project planned intensive three-phase bat monitoring, from distribution mapping to long-term population tracking. Observed pressures included traffic, waste, forest management, and pond neglect.
The saproxylic entomofauna utilised older stands with a higher share of deadwood. Recorded species included Morimus funereus, Cerambyx cerdo, Rosalia alpina, and Lucanus cervus, while Osmoderma eremita was not detected. A high presence of bark beetles was recorded (Xyloterus domesticus, X. lineatus, Tomicus minor, Xyleborinus saxesenii, etc.). A recommendation was made for systematic monitoring of other target entomofauna species on Medvednica that are not saproxylic and were not included in this project.
The project also included an initiative to establish the internationally recognised “Smart Forests” programme, aimed at automated monitoring of tree growth, carbon sequestration, water balance, microclimate, and other parameters relevant for assessing forest resilience to climate change.
The project-technical documentation also encompassed educational and communication activities, including 12 capacity-building workshops, field trainings, and interpretative materials, providing support for implementing conservation measures and stakeholder engagement.
Alongside condition analysis, the project assessed required human resources, implementation schedule, and indicative budget. At least eight experts participated in the two-year implementation, conducting inventories, measurements, and analyses, thus contributing to the conservation and improvement of target species and habitats. The project was fully aligned with the Medvednica Nature Park Management Plan 2024–2033 and relevant EU and national regulations.
In conclusion, the project documentation served as a key instrument for transitioning from planning to implementation, ensuring the sustainability of natural value management in Medvednica Nature Park and linking the scientific foundation with management practice. Its implementation improved understanding of ecological processes, enabled timely action, and supported informed decision-making for the benefit of nature and society. By the Official Handover Record dated 24 October 2025, the documentation prepared by Oikon Ltd was formally delivered to the Contracting Authority, marking the successful completion of the project. This stage concluded several months of multidisciplinary work and launched the systematic application of the developed monitoring model in practice, thereby establishing the preconditions for sustainable, science-based management of the forest reserves within Medvednica Nature Park.
Implementation of this Project contributes to the following Sustainable Development Goals:
