32G3
Silver fir (Abies alba subsp. alba) forests
Relationships with habitat classifications. EUNIS: G3.16 Moesian [Abies alba] forests; PAL. CLASS.: 42.16 Moesian Silver fir forests; HD 92/43: 91BA Moesian Silver fir forests; Bondev (1991): 36 White fir (Abies alba) forests, 37 Mixed White fir (Abies alba), Ordinary beech (Fagus sylvatica) and spruce (Picea abies) forests, 38 Mixed White fir (Abies alba), ordinary beech (Fagus sylvatica), Silver pine (Pinus sylvestris) and spruce (Picea abies) forests, 39 Mixed white fir (Abies alba), ordinary beech (Fagus sylvatica) and Silver pine (Pinus sylvestris) forests, 40 Mixed White fir (Abies alba) and ordinary beech (Fagus sylvatica) forests, 41 Mixed White fir (Abies alba), Black pine (Pinus nigra) and Ordinary beech (Fagus sylvatica) forests.
Conservation status. BDA, BC, HD.
Category. Endangered [EN - A1, 2 B1 C3 D2 E2 F2 G2 H1 I L3].
General characteristics. The forests of Abies alba subsp. alba have limited distribution in the mountains of Bulgaria. The altitude range is more than 1500 m (450–2000 m alt.). The optimal altitude is between 1000 and 1700 m alt. Most often they cover the northern slopes of relief depressions and deep ravines where the air and soil humidity is relatively high. The bedrock is usually silicate, more rarely limestone. The fir forests develop mainly on deep, humid, rich to very rich soils that are acidic to slightly acidic, well drained and aerated. They belong to the types of Cambisols and Mollic Cambisols. Apart from these optimal characteristics of the habitat, the fir can occur in various topographic, climatic, hydrological, petrographic and soil conditions that reflect in the great diversity of the floristic composition of the different coenoses.
The forests dominated by the Common fir, with few exceptions, belong to the autochthonous vegetation of Bulgaria. During the last glaciation period they have been preserved in single refugia and after the retreat of the glaciers the species distributed itself in the mountains of the Balkan Peninsula. The monodominant forests of the Silver fir are increasingly becoming relics threatened by extinction. More widely distributed are the mixed forests in which the spruce (Picea abies) and the Common beech (Fagus sylvatica) occur. The ratio between the three species changes at different stages of their syndynamics. Co-ediphicators to the fir, although much more rarely, can also be Pinus sylvestris and Pinus nigra subsp. pallasiana, Pinus peuce and Pinus heldreichii, Acer pseudoplatanus etc. The shrub layer is absent. Corylus avellana, Daphne mezereum, Lonicera nigra, L. xylosteum, Rosa pendulina, Rubus idaeus appear sporadically.
According to the ratio between the ediphicators, the ecological characteristics and the total floristic composition, the monodominant and mixed forests of the common fir that occur on acidic substrate can be categorised into different classes. The phytocoenoses in which the Silver fir prevails and the mixed coenoses in which the Common beech prevails but the fir still is abundant belong to class Querco-Fagetea, order Fagetalia sylvaticae, alliance Fagion, association Galio-Abietum and community Abies alba-Fagus sylvatica. The herbaceous layer is dominated by species typical for the European deciduous mesophilic forests: Aegopodium podagraria,Athyrium filix-femina, Cardamine pectinata,Dentaria bulbifera, Dryopteris filix-mas, Euphorbia amygdaloides, Galium odoratum, Glechoma hederacea, Lamiastrum galeobdolon, Mycelis muralis, Sanicula europaea and Soldanella chrysostricta.The forests in which the spruce and fir prevail and the participation of the beech is lower belong to class Vaccinio-Piceetea, order Piceetalia,alliance Piceion,sub-alliance Abieti-Piceenion and association Veronico urticifoiliae-Abietum. Species that are typical both for the European deciduous mesophilic forests and for the coniferous boreal forests occur in the herbaceous layer – Luzula luzuloides, L. sylvatica, Oxalis acetosella, Vaccinium myrtillus, Rhytidiadelphus triquetrus etc.
The monodominant fir forests and those mixed with Pinus nigra, P. peuce, P. heldreichii and Picea abies that occur on limestone belong to class Erico-Pinetea,order Erico-Pinetalia, allience Orno-Pinion,sub-alliance Orno-Pinenion pallasianae and association Haberleo rhodopensis-Abietum. They have limited distribution in Central Rhodopi Mts. and Slavyanka Mts. Aquilegia vulgaris, Corallorhiza trifida, Daphne laureola, D. oleoides, Epipogium aphyllum, Haberlea rhodopensis, Hepatica nobilis and Rubus saxatilis participate in the herbaceous synusium.
Characteristic taxa.
- Vascular plants: Abies alba subsp. alba, Aegopodium podagraria, Aquilegia vulgaris, Aremonia agrimonoides, Athyrium filix-femina, Corallorhiza trifida, Cruciata glabra, Daphne laureola, D. oleoides, Dentaria bulbifera, Deschampsia flexuosa, Dryopteris filix-mas, Epilobium montanum, Epipogium aphyllum, Euphorbia amygdaloides, Galium odoratum, G. pseudaristatum, G. rotundifolium, Glechoma hederacea, Haberlea rhodopensis, Hepatica nobilis, Luzula luzuloides, L. sylvatica, Melampyrum sylvaticum, Mercurialis perennis, Mycelis muralis, Oxalis acetosella, Petasites albus, Prenanthes purpurea, Pulmonaria rubra, Rubus saxatilis, Sanicula europaea, Vaccinium myrtillus, Viola reichenbachiana etc.
- Fungi: Macromycetes – Amanita porphyria, Bondarzewia mesenterica, Chroogomphus helveticus, Fomitopsis pinicola, Hericium flagellum, Heterobasidion annosum, Hydropus marginellus, Hymenochaete cruenta, Lactarius deterrimus, Phaeolus schweinitzii, Phellinus hartigii, P. nigrolimitatus, Podofomes trogii, Russula amethystina, Rutstroemia bulgaroides, Trichaptum abietinum, Tylopilus pseudoscaber; Micromyceyes – Chrysomyxa abietis, Lophodermium abietis, Melampsorella caryophyllacearum (on Abies alba), Peronospora calotheca, Septoria cruciatae (on Galium odoratum).
Distribution in Bulgaria. The forests of Abies alba occur in the Balkan Range, Rhodopi, Rila, Pirin, Osogovo, Slavyanka and Belasitsa Mts.; 450–2000 m alt.
Conservation importance. The natural forests of Abies alba cover about 20 000 ha in Bulgaria. In some of the coenoses the following plant species of conservation importance occur: Aquilegia vulgaris, Daphne laureola, D. oleoides, Goodyera repens, Haberlea rhodopensis, Lathraea rhodopaea, Listera cordata etc., as well as fungi of conservation importance: Amanita porphyria, Bondarzewia mesenterica, Hericium flagellum, Phellinus nigrolimitatus, Podofomes trogii, Russula amethystina, Rutstroemia bulgaroides, Tylopilus pseudoscaber.
Threats. Reduction in the areas covered by the fir forests as a result of withering due to climate aridisation, replacement of the fir by beech at lower altitudes, unregulated logging, infrastructure development (ski trucks, hotels, roads).
Conservation measures taken. The habitat in included in Annex № 1 of BDA. Parts of the localities of the habitat are within protected areas – Rila, Pirin and Central Balkan National Parks, Rilski Manastir Nature Park, Parangalitsa, Ibar, Gornata Koriya, Kozyata Stena, Konski Dol (Kazana). Tsaritchina, Mantaritsa, Ardatchlaka Strict Nature Reserves and in sites of the European Ecological Network NATURA 2000. Selective forestry systems are being applied in some of the fir forests; parts are within internationally certified forestry units.
Conservation measures needed. Mapping and monitoring of the habitat state. Wider application of the selective forestry systems that are in compliance with the nature-friendly management of biological resources and improvement of the forest protection.
References.Penev et al. 1969; Roussakova & Dimitrov 2005; Tzonev et al. 2006.
Authors: Marius Dimitrov, Veska Roussakova
