The species richness of plants and fungi in Bulgaria is considerable compared with the relatively small territory of the country. A big part of it, e.g. 20.5% of the vascular plants (Petrova & Vladimirov 2009), is threatened with extinction under the pressure of different negative factors – deterioration, fragmentation and loss of habitats, direct destruction of individuals due to trampling, grazing, infrastructure development and stone-pitting, competition with invasive alien species, etc. One of the effective means for species conservation is the compilation and periodic up-dating of Red Lists and Red Data Books. They inform the society and decision-makers about the contemporary state of and threats to biological diversity and appeal for urgent action for its protection. This volume is an important contribution of the Bulgarian botanical and mycological scientific community towards conservation of the plant and fungal diversity in the country. It presents up-to-date information and assessment of the risk of extinction of the vascular plants in Bulgaria 27 years after the publication of the first edition of the Red Data Book of People's Republic of Bulgaria (Velchev 1984) and includes for the first time algae, bryophytes and fungi.
The national IUCN categories of threat have been assessed under the project "Red Lists of Higher Plants and Fungi in Bulgaria" (2003-2005), funded by the Ministry of Environment and Water. The internationally adopted categories and criteria of IUCN (2001, 2003a, b) have been used. The results have been published in three articles (Gyosheva et al. 2006; Natcheva et al. 2006; Petrova & Vladimirov 2009). The current volume includes all Extinct, Regionally Extinct, Critically Endangered and Endangered species of plants and fungi. Due to the limited volume of this edition only selected species (ca. 20%) assessed as 'Vulnerable' have been presented. A few species assessed as 'Critically Endangered' (Achillea ochroleuca, Epipactis greuteri, Plantago maxima) or 'Endangered' (Epipactis exilis, E. pontica) after the accomplishment of the Red Lists project have not been considered here (Nedelcheva & Tzonev 2006; Tzonev & Karakiev 2007; Petrova & Venkova 2006, 2008).
The text is organised in the following order – algae, bryophytes, vascular plants and fungi. Within each major taxonomic group the species are arranged by category of threat (Extinct – EX, Regionally Extinct – RE, Critically Endangered – CR, Endangered – EN and Vulnerable – VU) and within each category the species are arranged in alphabetical order by Latin name. Altogether 808 species are included (Table 1).
Table 1. Distribution of the taxa with a threat-category by taxonomic groups.
* Due to volume limitations only a selection of the species with category VU have been included in this edition.
For each species the information is presented in the following order:
Fig. 1. Distribution of the plant and fungal species with a threat category on the territory of Bulgaria
Each species is illustrated by a colour drawing or photo and is accompanied by a map showing the distribution of the taxon in Bulgaria. The maps have been generated in the GIS Laboratory of the former Institute of Botany, Bulgarian Academy of Sciences. The software package ESRI® ArcGIS™ 9.2 Master LabKit was used. For storage and processing of data a special database in "ESRI personal geodatabase" format has been created using Microsoft® Access™ 2003. The distribution data have been provided by the authors as Microsoft® Excel™ 2003 files in a format specially designed for this purpose for all three volumes of this edition of the Red Data Book of Bulgaria and described in the software 'MapSoftV1' (Lubenov & Biserkov 2005). The maps include 10 × 10 km UTM squares. The known localities of the species are indicated as follows: red dots represent all currently known existing or possibly existing occurrences of the species whereas with black dots indicate only the localities in which the particular taxon was present but is now extinct. In a few cases the precise localization of some occurrences of the species was not possible (mainly for localities mentioned in old botanical literature from the first half of the 20th century). Therefore, in these cases, the particular floristic region is mentioned in the text but no dot is presented on the map.
The localities of all species included in this volume have been presented on a common map in order to demonstrate the distribution and concentration of the species of conservation concern in the country (Fig. 1). This allowed us to clearly show the regions with a high number of species with a threat category, such as the Black Sea Coast, high mountainous parts of Central Balkan Range, Mt Vitosha, Rila Mts, Pirin Mts, Mt Slavyanka and Western Rhodopi Mts. Most of these territories fall within protected areas. On the other hand, in the zones where more settlements are concentrated and human activities are most intensive, the species of conservation concern are few or lacking. When present they are under very strong anthropogenic pressures. Therefore, such territories also need to be studied, monitored and protected.
Under the subtitle 'Conservation measures taken' we provide information for the occurrence of the species in sites of the European ecological network Natura 2000 in Bulgaria. This is not a true conservation measure for most of the species included in the Red Data Book except only for the taxa included in Annex 2 of the Biological Diversity Act, respectively in Annex II of Habitats Directive, and which are subject to conservation in the particular Natura 2000 site. This information, however, can be useful for the management of the Natura 2000 sites, e.g. in cases when the species is typical or characteristic for a specific habitat, then it is subject to conservation in that site.
The richness of the Bulgarian flora and Mycota and the dynamic development of the country require high attention and great responsibility for protection of this biodiversity. We hope that the Red Data Book is a significant contribution for halting the loss of species and habitats and for the conservation and management of the biological diversity in the country.