34G3

G. Forests

Norway spruce (Picea abies) forests

Relationships with habitat classifications. EUNIS: G3.1E Southern European [Picea abies] forests; PAL. CLASS.: 42.24 Southern European Norway spruce forests; HD 92/43: 9410 Acidophillous Picea forests of the montane to alpine levels (Vaccinio-Piceetea); Bondev (1991): 12 Spruce (Piceeta abietis) forests, partly mixed with scrub (Pineta mugi) communities, 13 Mixed spruce (Picea abies) and Balkan pine (Pinus peuce) forests, 14 Mixed spruce (Picea abies) and Silver pine (Pinus sylvestris) forests, 15 Mixed spruce (Picea abies) and White fir (Abies alba) forests; 16 Mixed spruce (Picea abies), White fir (Abies alba) and Silver pine (Pinus sylvestris) forests, 17 Mixed spruce (Picea abies) and ordinary beech (Fagus sylvatica) forests.

Conservation status. LBD, HD, BC.

Category. Nearly Threatened [NT - A1, 2 B1 C3 D1 E1 F1 G1 H1 I L3].

General characteristics. Norway spruce forests dominate the coniferous belt in the mountains of Bulgaria with largest areas in Rhodopi, Rila, and Pirin Mts., and smaller territories in West and Central Balkan Range, Vitosha and Ossogovo Mts. They occur mainly from 1500–1600 up to 1900–2100 m alt. In closed kettles and deep river valleys with temperature inversions, mainly in Rhodopi Mts., the Norway spruce phytocoenoses can exist also at 1200 m alt. Although altitude, relief, exposure, basic rock and soil type are not of crucial importance for the development of the Norway spruce phytocoenoses they have impact on their floristic composition and productivity. Spruce forests prefer northern slopes, flat areas or slopes with moderate tilt, acidic bed rock and soils. Close to the timberline the soils are Mollic Cambisols, while at lower altitudes they are Eutric Cambisols. Seldom, (mainly in Central Rhodopi Mts.) the Norway spruce forests are monodominant, while polydominant forests occur on calcareous Rendzic Leptosols.

In the upper range of its distribution (1700–2100 m alt.) the Norway spruce forests are mostly monodominant with participation of Macedonian pne (Pinus peuce) and Scots pine (Pinus sylvestris). They form the upper timberline, but in some areas of Rila and Pirin Mts. and the Balkan Range they are replaced by the forests of Macedonian pine (Pinus peuce). In mixed, Norway spruce – Macedonian pine forests the spruce predominates. They are distributed mainly on stony places at the upper timberline. The mixed Scots pine – Norway spruce forests are very typical for Rhodopi Mts. and occur at lower altitudes. They cover elevations with northern exposure and slope foothills and relief depressions in areas with southern exposure. In these places, very often they are of primary origin while in places with different exposure or relief shapes the Norway spruce forests represent mainly the transitional stage in the recovery of primary spruce forests, destroyed by different factors. In lower altitudes (1200–1800 m alt.) the Norway spruce forests are mixed with Silver fir (Abies alba), Scots pine (Pinus sylvestris) and the Common beech (Fagus sylvatica).

As a result of the high canopy layer almost no shrub and herbaceous layers develop in the spruce forests. In some high-mountain spruce forests the shrub layer is formed by Pinus mugo. Other typical shrubs for the spruce forests are Daphne mezereum, Lonicera coerulea, L. nigra, Ribes alpinum. The herbaceous synusium is dominated by species, diagnostic for the northern coniferous forests: Calamagrostis arundinacea, Deschampsia flexuosa, Juniperus sibirica, Luzula luzuloides, L. sylvatica, Myosotis sylvatica, Oxalis acetosella, Vaccinium myrtillus, V. vitis-idaea.Constant species are Campanula sparsa, Hieracium murorum gr., Homogyne alpina, Melampyrum sylvaticum, Moehringia pendula, Orthilia secunda, Pyrola minor, Soldanella rhodopaea.

The existing studies of the spruce communities based on the floristic method in Bulgaria are scanty. From a syntaxonomic point of view the Norway spruce forests belong to alliance Piceion excelsae.According to the altitude range and floristic composition two habitat subtypes belonging to suballiances Eu-Piceenion and Abieti-Piceenion occur in Bulgaria.

The high mountain spruce forests occur in the upper mountain and partly subalpine belts (1700–2100 m alt.). They are monodominant or mixed with other coniferous species, mainly Macedonian pne and Scots pine. Sometimes shrub layer with dwarf pine (Pinus mugo) and Siberian juniper (Juniperus sibirica) is formed. Species typical for the suballiance Eu-Piceenion – Dryopteris dilatata, Homogyne alpina, Luzula sylvatica, Melampyrum sylvaticum, Moehringia pendula participate in the herbaceous layer of these forests.Species typical for the subalpine herbaceous vegetation – Festuca nigrescens, F. valida, Vaccinium myrtillus, etc. enter the spruce forests that occur at the upper timberline, where the spruce canopy is less dense and the spruce  trees are organized in groups. In Rila and West Rhodopi Mts. the association Moehringio pendulae-Piceetum is widely distributed. In Central Balkan Range (Boatin Strict Nature Reserve) the association Piceetum excelsae balcanicum is described.

The mid-mountain spruce forests are pure or mixed with Silver fir and/or Common beech but still dominated by the spruce. They occur in the middle and upper mountain belt, at 1200 up to 1800 m alt. The herbaceous layer comprises both species typical for the European broad-leaved mesophytic and coniferous boreal forests – Dentaria bulbifera, Epilobium montanum, Festuca drymeja, Luzula luzuloides, L. sylvatica, Oxalis acetosella, Rhytidiadelphus triquetrus, Vaccinium myrtillus, Veronica urticifolia, Viola reichenbachiana. These forests belong to suballiance Abieti-Piceenion and association Veronico urticifoliae-Abietum.

Characteristic taxa.

Distribution in Bulgaria. Rila, Rhodopi, Pirin, Vitosha, Ossogovo Mts., Balkan Range, etc. at 1200 up to 210 m alt.

Conservation importance. The natural spruce forests in Bulgaria cover ca. 75 000 ha. Their conservation importance derives from the fact that they are in the southernmost border of the species area of distribution. The following species of conservation value status: Goodyera repens, Lathraea rhodopaea, Listera cordata, Pinus peuce, Pyrola media, P. rotundifolia, Rhynchocorys elephas, Streptopus amplexifolius, etc.

Threats. Replacement of spruce by beech at low altitudes, unregulated logging, infrastructure development (ski tracks, hotels, roads) as well as climate aridisation.

Conservation measures taken. The habitat is in Annex №1 of BDA. Part of the spruce forests are within the borders of protected areas: Rila, Pirin and Central Balkan National Parks, Rilski Manastir and Vitosha Nature Parks, Beglika, Soskovcheto, Doupkata, Parangalitsa, Bistrichko Branishte, Mantaritsa, Ibar, Central Rila, Chouprene, Gornata Koriya Strict Nature Reserves; Shabanica Managed Nature Reserve, Usketo, Uruchnik, Batashki Snezhnik (Karlaka), Arap Chal, Chairite, etc. Protected Sites, and in sites of the European Ecological Network NATURA 2000 in Bulgaria. Parts of the spruce forests (mainly these within the borders of protected areas) are floristically, syntaxonomically and faunistically studied. Selective forest-development management techniques have been applied in parts of the spruce forests. Some spruce forests are within internationally certified forest units.

Conservation measures needed. Elaboration of a forest typological scheme aimed at a more effective and nature-friendly management; elaboration of management plans and concepts for favourable conservation status of the spruce forests; mapping and monitoring; improvement of forest protection.

References. Dimitrov 2003; Penev et al. 1969; Roussakova & Dimitrov 2005.

Authors: Veska Roussakova, Marius Dimitrov


Norway spruce (Picea abies) forests (distribution map)