Scope
The fieldwork focus on the vascular plants (Tracheophyta). Algae and mosses (Bryophyta) are excluded from the current study. The primary emphasis are native species, yet introduced, naturalized species, and occasional escapes from cultivation are also recorded and reported. Their inclusion is justified by the long history of human presence in the region, dating back to antiquity. Anthropogenic influence influence has significantly shaped the region’s ecology and contributes to its current floristic diversity.
Objectives
The primary objective of the fieldwork is to document and assess the taxonomic diversity of vascular plants (Tracheophyta) in the Osogovo region. Key aims include:
– Compiling reliable floristic records.
– Recording and evaluating the diversity of vascular plants under natural field conditions.
– Contributing to a comprehensive and updated flora of the Osogovo Mountains.
– Identifying and verifying taxa using classical morphological taxonomy.
– Documenting the occurrence of both native and naturalized species.
– Identifying and monitoring of stable hybrid forms based on morphological traits.
Study area
The fieldwork is conducted in the Osogovo Mountain Massif located in the Balkan Peninsula, on the border between northeastern North Macedonia and southwestern Bulgaria. The study area lies in the Macedonian part of the range, encompassing a wide range of elevations, habitats, and levels of human influence.
Osogovo features a complex topography, with elevations ranging from approximately 400 meters to 2,252 meters above sea level (Ruen Peak). This altitudinal gradient supports a diverse array of habitats, including: lowland hill pastures and orchards, ruderal zones and disturbed sites near settlements, mixed oak forests and European beech forests, various stages of forest degradation in the ruderal areas, artificial conifer plantation, subalpine pastures, rocky terrains, riparian forest and other moist/ wet habitats such as hydrophilous tall herb vegetation on river banks and springs and spring mires in the highest parts of the range.
While parts of the Osogovo region retain relatively intact natural habitats, much of the landscape — especially at lower and mid elevations — has been shaped by centuries of human activity. Agriculture, forestry, grazing, and settlement have created a mosaic of semi-natural and modified habitats. As a result, a clear distinction between “natural” and “anthropogenic” ecosystems is often difficult to draw. This blend of natural and human-influenced environments contributes significantly to the floristic diversity of the region.
Fieldwork sites were selected to represent this ecological and elevational variation. A list of surveyed localities (as of 2025), along with dates, elevation, and habitat types, is provided in Anex 1.
Methodology
The fieldwork studies are conducted across a range of localities in the Osogovo Mountains, selected to represent the region’s elevational and habitat diversity, and include both natural and human-influenced environments. Field visits are carried out regularly during the growing season, and visited on a number of occasions depending on the plants grown cycle. Sites are visited multiple times within a season when needed, particularly during flowering and fruiting periods, and repeatedly visited during the years. For example, if a plant is recorded in flower, but the fruit is needed for correct identification, the locality is visited in the fruiting season and the same population is examined again to record the fruit and collect samples for correct identification.
At each site, vascular plants are identified in the field if possible, and sampled for further study. They are photographed in situ, documenting both habit and diagnostic traits. Plant samples are taken for further study for the process of identification using verified botanical keys and literature. Many of the recorded plants are herbarized and labeled according to standard procedures, and stored in a private herbarium collection for future reference and comparative study.
During the fieldwork, plants are examined and photographed in detail under natural field conditions. In situ photographs are an essential part of the process, providing visual records that support taxonomic identification and morphological assessment.
Each plant is photographed in its natural environment, capturing: the general habit of the plant within its habitat; key morphological structures: inflorescences, flowers, fruits, leaves, stems, branches, woody parts (including trunks if present), roots, when their diagnostic value justifies limited excavation; close-up images of diagnostic features such as adaxial and abaxial surface of leaves, ligules, indumentum (hairiness) and other surface structures.
Field data includes locality and location within Osogovo, elevation, habitat description, and date of collection. This systematic approach ensures reliable identification and supports the development of a verifiable flora of the Osogovo region. GPS coordinates of examined localities are recorded using Google Maps and a mobile location application. Photographs are geotagged using location data to ensure precise spatial reference and facilitate future verification or revisits.
This photographic documentation supports transparency, allows for further verification, and contributes to the creation of a high-quality, image-based flora of the Osogovo region.
Anex 1. List of sampled localities
| Locality | Municipality | Elevation | Habitat type | Year |
| Hills near Kochani | Kochani | 400 – 600 m | Hill pastures, pine plantations, shrubland | 2020, 2021, 2022, 2024 |
| Kochani region | Kochani | 400 m | Ruderal areas | 2021, 2022, 2023, 2024, 2025 |
| Gorge of Kochanska River | Kochani | 400-600 m | Rocky terrains, hill pastures, shrubland, pine plantation, oak forests, orchards, riparian forests (degraded), ruderal areas | 2020, 2021, 2022, 2024, 2025 |
| Lake Gradche, including Golema River waterfall | Kochani | 500 m | Oak forests, aquatic, riparian forest, ruderal areas | 2020, 2021, 2022, 2023 |
| Ridge between Mala and Golema River (Gradche) | Kochani | 500-700 m | Rocky terrains, oak forests | 2020, 2022, |
| Ridge east of lake Gradche region between Gorno (Gradche), Varaninci and Pripor | Kochani | 600-900 m | Hill pastures, oak forests, shrubland, pine plantations, ruderal areas | 2020, 2021, 2022, 2023, 2024 |
| Village of Krushka to Valavici | Kochani | 800-900 m | Pastures, oak forests, ruderal sites | 2020, 2022, |
| Leshki region | Kochani | 950-1000 m | Pastures, oak forests, rideral areas | 2023, 2024 |
| Village of Beli region | Kochani | 450-600 m | Hill pastures, ruderal areas, orchards | 2020, 2021, 2022, 2023, 2024, 2025 |
| Village of Nivichani region | Kochani | 700 m | Ruderal area | 2023 |
| Hills between Beli and Nivichani | Kochani | 500-550 m | Hill pastures, shrubland, ruderal area | 2020, 2021, 2022 |
| Village of Pantelej region | Kochani | 800-1000 m | Oak forests, ruderal areas, orchards | 2021, 2024, 2025 |
| Region between pantelej and Rajchani | Kochani | 700-800 m | Ruderal areas, oak forests, hill pastures | 2021, 2023, 2024, 2025 |
| Rajchani and Svilanovo region | Kochani | 500-700 m | Ruderal areas, oak forests, rocky terrains, hill pastures | 2023, 2024, 2025 |
| Region between Svilanovo and village of Spanchevo | Kochani | 400-500 m | Ruderal area | 2023 |
| Village of Orizari region | Kochani | 600-800 | Oak forests, rocky terrains | 2024 |
| Preseka region | Kochani | 1000-1100 m | Oak forests, scrub, ruderal areas, pastures | 2022, 2024 |
| Leshki region | Kochani | 950-1000 m | Pastures, oak forests | 2023 |
| Region between Ponikva and Jastrebnik (Gorna maala) | Kochani | 1250-1500 m | European beech forets, oak forests, ruderal areas | 2024 |
| Shtalkovichka River (Tursko rudari, shtalkocixa, mangov kamen to the waterfalls) | Probishtip | 550-900 m | Rocky terrains, oak forests, european beech forets, riparian forest, ruderal areas | 2021, 2022, 2023, 2024, 2025 |
| Shtalkovica- Kpchanski dol | Probishtip | 800-950 m | Oak and European beech forests | 2025 |
| Village of Ratkovica and ratkova Skala region | Probishtip | 900-1350 | Oak forest, european beech forests, rocky terrains, Pteridium aquilinium fields | 2022, 2023 |
| Ponikva, including Visoka Chuka and springs of Shtalkovicka river | Probishtip/ Kochani | 1450-1580 m | Pastures, European beech forest, rocky terrains, Pteridium aquilinium fields, hydrophilous tall herb finge cominities, ruderal areas | 2021, 2022, 2023, 2024, 2025 |
| Ponikva – panagjur peak | Probishtip | 1550-1640 m | Pastures, rocky terrains | 2023 |
| Venechka river | Probishtip | 1300-1400 m | European beech forests | 2025 |
| Emirichka river | Kratovo | 1100-1200 m | European beech forests, hydrophilous tall herb finge communities | 2025 |
| Kormina | Kratovo | 1450-1500 m | European beech forests, pastures | 2022, 2023, 2024 |
| Retki Buki | Kochani | 1650-1700 m | Subalpine pastures | 2024 |
| Mrtvica-Mrtvicki rid | Kochani | 1700-1750 m | Subapline pastures, subalpine heath and scrub | 2023, 2024 |
| Carev vrv peak | Kochani, Kriva Palanka, Makedonska Kamenica | 1800-2085 m | Subapline pastures, subalpine heath and scrub | 2023, 2024 |
| Carev vrv – markova stupka | Kochani | 1700-1800 m | Subapline pastures, subalpine heath and scrub, | 2024 |
| Carev vrv – springs of Bela River | Kochani | 1750-1850 m | Subalpine pastures, hydrophilous tall herb finge cominities | 2024 |
| Carev vrv- springs of Durachka river | Kriva Palanka | 1700-1800 | Subapline pastures, spring mires, hydrophilous tall herb finge comminities | 2024 |
| Hills between Village of Istibanja and Manilovo (bezikovo) | Vinica, Kochani | 400-850 | Oak forests | 2024 |