Life
The flora of the Central Balkan national park is extremely rich and varied, with approximately 1900 species and sub-species of higher plants found growing in the region. These include 67 Balkan endemics, 10 Bulgarian endemics, and 10 local endemics that are unique to this part of the Stara Planina. The latter include three species of lady’s mantle Alchemilla achtarowii, Alchemilla jumrukczalica and Alchemilla asteroantha, as well as Ognyanov’s knapweed (Centaurea ognianoffi), Urumov’s hawkweed (Hieraceum urumoffii), Bulgarian seseli (Seseli bulgaricum), two catchflies Silene balcanica and Silene trojanensis, the mullein Verbascum boevae and the beautiful little primrose Primula frondosa.
While walking through the Central Balkan national park you will pass through six distinct vegetation zones. Around the lowest edge of the national park, between about 550m and 900m, there are patches of oak forest. Typically these comprise Turkey oak (Quercus cerris), Hungarian oak (Quercus frainetto) or downy oak (Quercus pubescens), and also include secondary associations of eastern hornbeam (Carpinus orientalis), prickly juniper (Juniperus oxycedrus), hop-hornbeam (Ostrya carpinifolia), manna ash (Fraxinus ornus) and Tartar maple (Acer tartaricum). Many of the trees in this zone are stunted by decades of cutting and grazing, and resemble thickets rather than mature woodland.
Central Balkan endemic flora: Balkan primrose (Priumla frondosa) (Walk 2)
The oak zone is found exclusively on the southern flank of the mountains. Here too, and again reaching up to altitudes of about 900m, there is also a somewhat similar oak-hornbeam zone. This is dominated by communities of the Balkan durmast oak (Quercus dalechampii) in conjunction with hornbeam (Carpinus betulus) and eastern hornbeam (Carpinus orientalis). Manna ash (Fraxinus ornus) and hop-hornbeam (Ostrya carpinifolia) again both also often occur in this zone, as well as silver lime (Tilia tomentosa), hazel (Corylus avellana) and blackthorn (Prunus spinosa).
Between about 800m and 1600m, on both sides of the ridge, it is beech forests that dominate the national park, covering over 40 per cent of its total area. Indeed, about 70 per cent of all trees growing within the national park are beech (Fagus sylvatica), and these have an average age of 135 years. Not only do they play a fundamental role in terms of local climate, hydrology and biodiversity, they also make up the most extensive and least degraded block of beech forest in Europe. Within this zone one also frequently finds examples of sycamore (Acer pseudoplatanus), hornbeam (Carpinus betulus), Balkan maple (Acer heldreichii), Norway maple (Acer platanoides) and silver fir (Abies alba), as well as the occasional common ash (Fraxinus excelsior), rowan (Sorbus aucuparia) and hazel (Corylus avellana).
Within the Central Balkan national park, coniferous forests are highly fragmented and do not form a distinct zone as they do in the Rila and Pirin mountains. Isolated blocks of Norway spruce (Picea abies) are found in and around the Boatin, Tsarichina, Stara Reka and Dzhendema reserves, with the average age of trees being 120 years. Of particular interest is the occurrence of Macedonian pine (Pinus peuce) within the national park. Not only is the region of the Tsarichina Reserve the sole location of this Balkan endemic species in the Stara Planina, it also represents the most extreme northerly outpost of its worldwide geographical distribution.
As the beech or coniferous forests finally give way, somewhere between 1500m and 1850m, you enter into the sub-alpine zone. Here the vegetation is dominated by low scrubby formations of Siberian juniper (Juniperus sibirica), whortleberry (Vaccinium myrtillus) and Balkan spike-heath (Bruckenthalia spiculifolia). In places you can also find patches of dwarf mountain pine (Pinus mugo), but the occurrence of this species within the Central Balkan national park is far more restricted than it is in the Rila or Pirin mountains.
Wildlife
Dragonflies
The dragonflies of the Central Balkan national park have not yet been studied in detail, with records only from one small region. So far nine species have been reported: robust spreadwing (Lestes dryas), common bluetail (Ischnura elegans), azure bluet (Coenagrion puella), blue featherleg (Platycnemis pennipes), blue hawker (Aeschna cyanea), sombre goldenring (Cordulegaster bidentatus), broad-bodied chaser (Libellula depressa), southern skimmer (Orthetrum brunneum) and ruddy darter (Sympetrum sanguineum). It is likely, however, that after further research, especially along the upper courses of some of the streams, more species will be discovered.
Butterflies
The butterflies of the Central Balkan national park have been the focus of scientific research for almost 100 years. So far almost 60 species have been recorded in the region, and it has recently been recognised as a Prime Butterfly Area. Important species found within the national park include Apollo (Parnassius apollo), clouded Apollo (Parnassius mnemosyne), large blue (Maculinea arion), false Eros blue (Polyommatus eroides), purple emperor (Apatura iris), eastern large heath (Coenonympha rhodopensis), lesser spotted fritillary (Melitaea trivia), bog fritillary (Boloria eunomia), and a variety of high mountain ringlets such as Bulgarian ringlet (Erebia orientalis), woodland ringlet (Erebia medusa), almond-eyed ringlet (Erebia alberganus), Nicholl’s ringlet (Erebia rhodopensis), water ringlet (Erebia pronoe) and black ringlet (Erebia melas).
Fish
Lacking lakes or other large areas of open water, the variety of fish found within the Central Balkan national park is rather limited, with only six species recorded in the region. Most typical are the brown trout (Salmo trutta fario) and the minnow (Phoxinus phoxinus), while the miller’s thumb (Cottus gobio), Balkan barbel (Barbus meridionalis petenyi) and rainbow trout (Oncorhynchus mykiss) have been reported in rivers at the periphery of the national park. There is also a record of brook trout (Salvelinus fontinalis) from the river Zavodna from the 1970s, but this species has not since been recorded in the region.
Amphibians
There are eight species of amphibian currently known to be present within the Central Balkan national park. These are fire salamander (Salamandra salamandra), yellow-bellied toad (Bombina variegata), green toad (Epidalea viridis), common toad (Bufo bufo), European tree frog (Hyla arborea), marsh frog (Pelophylax ridibundus), common frog (Rana temporaria) and agile frog (Rana dalmatina).
Fire salamander (Salamandra salamandra)
Reptiles
Reptiles are well represented, with 14 species having been recorded within the national park. Most often seen by walkers are the slow worm (Anguis fragilis), viviparous lizard (Zootoca vivipara) and common wall lizard (Podarcis muralis). However, if you are lucky you may also spot green lizard (Lacerta viridis) and sand lizard (Lacerta agilis), and there are old records of Balkan wall lizard (Podarcis tauricus) and snake-eyed skink (Ablepharus kitaibelii) from the Stara Reka Reserve above Karlovo.
The Central Balkan national park also has seven species of snake. These include the common viper (Vipera berus) and nose-horned viper (Vipera ammodytes), as well as the grass snake (Natrix natrix), dice snake (Natrix tessellata), Aesculapian snake (Zamenis longissimus) and smooth snake (Coronella austriaca). Most interesting of all is the large whip snake (Dolichophis caspius), which has been recorded in both the Boatin and Stara Reka reserves.
Birds
Over 220 species of bird have been recorded within the Central Balkan national park, of which over 120 are thought to breed. Not surprisingly, the region has been internationally recognised as an Important Bird Area. In the beech forests, chaffinch (Fringilla coelebs), robin (Erithacus rubecula), wren (Troglodytes troglodytes) and blackcap (Sylvia atricapilla) are dominant, with other typical species being song thrush (Turdus philomelos), blackbird (Turdus merula), chiffchaff (Phylloscopus collybita), coal tit (Parus ater),
