Karst fields, as the largest surface forms of karst, are most numerous in our Dinaric system, which is unique on planet Earth. In Bosnia and Herzegovina, especially in the outer Dinarides, a large number of the largest and highest karst fields have developed, including Dabarsko and Fatničko poljes.
Karst fields represent complex structures where various hydrological and hydrogeological forms can be found, such as permanent and temporary springs, permanent open watercourses, as well as those that dry up and disappear underground.
In order to utilize precipitation for energy purposes in the eastern part of the watershed, the construction of hydroelectric power facilities is planned within the “Upper Horizons” project (HE Nevesinje, HE Dabar, and HE Bileća). This project plans to divert water from Nevesinje, Dabarsko, and Fatničko poljes into the Bileća Lake accumulation, and further to the HE Dubrovnik. This would reduce the inflow of water into the Buna, Bunica, and Bregava rivers, and indirectly, through the sinkholes in Popovo polje, into all the springs in the lower Neretva course and the Dubrovnik coastline. The goal of the project is to release the “excess water” in poljes that are naturally flooded and which nourished the underground streams.
However, rapid and unnatural drainage from karst fields can have far-reaching consequences.
To raise awareness of the richness and diversity of karst fields in Bosnia and Herzegovina and to highlight the harmful consequences of the Upper Horizons project, the Center for Environment, in partnership with the international organization CEPF (Critical Ecosystem Partnership Fund), supported research on several groups of organisms in the Dabarsko and Fatničko polje areas during 2024.
The key results of this research are:
Karst fields also represent complex structures where various hydrological and hydrogeological forms are found, such as permanent and temporary springs, permanent open watercourses, as well as those that dry up and disappear underground.
In order to energetically utilize precipitation in the eastern part of the watershed, the construction of hydroelectric power plants is planned as part of the “Upper Horizons” project (HE Nevesinje, HE Dabar, and HE Bileća). This project aims to divert water from Nevesinje, Dabarsko, and Fatničko poljes into the Bileća Lake reservoir, and further to the HE Dubrovnik. This would reduce the inflow of water into the Buna, Bunica, and Bregava rivers, and indirectly, through the sinkholes in Popovo polje, into all the springs in the lower Neretva course and the Dubrovnik coast. The goal of the project is to release the “excess water” in poljes that are naturally flooded, which nourished underground flows.
However, rapid and unnatural drainage from karst fields can have far-reaching consequences.
To raise awareness about the richness and diversity of karst fields in Bosnia and Herzegovina and to highlight the harmful consequences of the Upper Horizons project, the Center for Environment, in partnership with the international organization CEPF (Critical Ecosystem Partnership Fund), supported research on several groups of organisms in the Dabarsko and Fatničko polje areas during 2024.
The key results of these studies are:
- A total of 231 vascular plant taxa were registered, identified to the subspecies level, including two taxa endemic to the Balkan Peninsula. In the RS, 12 taxa are strictly protected, and 25 taxa are protected. Two taxa are listed in Annex II of the European Habitats Directive (Eleocharis carniolica W. D. J. Koch and Scilla litardierei Breistr.), and an equal number are in Annex II of the CITES Convention.
- According to the collected data, this unique area represents one of the most significant and richest areas for damselflies in Bosnia and Herzegovina. A total of 43 species of these insects have been registered in this region, which is more than two-thirds of the species present in Bosnia and Herzegovina. From a conservation perspective, the most significant species are Coenagrion ornatum and Sympetrum flaveolum. The first species is protected under the European Union’s Habitats Directive, while the second is classified as an endangered (EN) species according to the European Red List of Dragonflies. Additionally, 35 species are listed on the Red List of the Republic of Srpska. For comparison, this is more than the 42 species recorded in the Livanjsko polje and the 40 species recorded in the Nevesinje polje, the only two poljes for which more detailed data exist.
- The bird fauna research in the Dabarsko and Fatničko poljes, conducted over just a few days, revealed the presence of at least 95 different bird species, a significant number of which are under permanent protection. Both poljes serve as important migratory stopovers, providing birds with the necessary conditions for resting and feeding during their migratory routes. This is particularly significant for migratory species that travel long distances between their breeding sites and wintering grounds.
- The results show that the watercourses in the Dabarsko polje area are home to the Gata chub (Telestes metohinsis) and the Dabar chub (Telestes dabar), while individuals of the Trebinje chub (Delminichtys ghetaldii) were found in the Fatničko polje area. All of these chub species are endemic and represent a significant genetic resource. Data on the biology of these species is particularly important as they are endemic species with a narrow range, whose habitat is being radically altered by anthropogenic impacts.
- During the cave system research in these poljes, the most significant finding was from the Radovići cave, where it was estimated that there were over 1,000 bat individuals. A quick observation recorded the presence of at least four bat species: Rhinolophus hipposideros, Rhinolophus ferrumequinum/euryale, Miniopterus schreibersii, and Myotis myotis/blythii. Additionally, in the cave systems, the presence of 17 troglobitic, 7 aquatic, and 10 terrestrial species has been confirmed so far.
It should certainly be noted that this is only a part of the published data, and we believe that the final number will be significantly higher after the completion of laboratory analyses.
We would like to take this opportunity to thank all the colleagues who were part of the research and who, with their knowledge and expertise, contributed to a better understanding of the flora and fauna of these truly fascinating fields.