Black pine (Pinus nigra Arn.) resources in Albania[35] (M.Dida[36], F. Ducci[37] and G. Zeneli²)

INTRODUCTION

The forest resource of Albania covers an area of about 1 025 000 ha, 34% of the total surface, with a stock of 84 000 000 cubic meters. The same area was 1 034 300 (36% of the national territory) before 1993 (Anonymous, 1998). Indeed, since that year, 300 - 400 ha were lost yearly because of forest fires and other man-induced causes. Reforestation activities had a stronger intensity during the period 1961 - 1990, when about 190 000 ha were planted. Since 1992 such activities have practically stopped.

Several forest ecosystems are present according to elevation and distance from the sea. Those are mainly dominated by the following forest tree species (Llubani and Habili, 1988):

Mediterranean pines including P. halepensis, P. pinaster, P. pinea, and P. nigra (< 5% of the total area)

P. heldreichii (11%)

Abies alba (2%)

Shrub and small tree ecosystems, Arbutus unedo, Erica sp., Carpinus sp., Corylus sp. and Ostrya carpinifolia (25%)

Oak forests, (32%)

Chestnut, Castanea sativa, (1%)

Mixed hardwood forests, Acer sp, Fraxinus sp. (8%)

Beech forests, Fagus sylvatica (17%)

TAXONOMY

According to Vidakovic (1992), the Black Pine populations of Albania belong to the ssp. pallasiana of Pinus nigra (Arn.). But stands naturally distributed in Albania are only partially homogeneous and, if judged by phenotypic variation, seem to belong to different subspecies. It should be noted that the Balkans is the region where several sub-species of Pinus nigra occur, as follows:

• ssp. nigra, in Austria, Carsick area, former Yugoslavia, Greece.
• ssp. dalmatica, central coasts of the Balkans, Dalmatian Island.
• ssp. pallasiana, southern Balkans, Carpatian range and Crimea.

In general, there is little scientific evidence of the presence of subspecies other than the “pallasiana”, since the taxonomy of these subspecies is not clear and the geographic borders between them have not been clearly defined. A survey of this variation is necessary, which will make the characterization of the best provenances of Pinus nigra easier and will be helpful for afforestation in Albania.

DISTRIBUTION OF BLACK PINE IN ALBANIA

Black Pine, Pinus nigra is among the most important species in Albania. It occupies an area of 110 520 ha, or 10.5% of the total forest area. At present, the natural area of the Black Pine is very scattered. Black Pine shows high variation in relation to altitudinal distribution. It can be found from 300 m to 1850 m above sea level, where it forms pure or mixed forests with other conifers or broadleaved species, depending on phytoclimatic zones. The optimum altitude is between 800-1500 m. The Black Pine natural populations of Albania show a wide variation in morphology and growth characteristics, which cannot be explained without reference to the possible genetic differentiation into subspecies or ecotypes.

The largest stands of Black Pines grow in the northern part of the Central Mountain zone, including Kukes (Surroj, Aren, Laku i Thive), Diber (Lure, Mali i Bardhe), Puka (Tuc, Kunore-Dardhe Livadhi i Kabashit), Mirdite (Orosh), Mat (Balgjaj), Kruje (Qafe Shtame). (See Figure 1). Black Pine is found in only small scattered populations in the northern and southern mountain zones of Albania, including Malesi e Madhe (Vukel -Niksh, Razem), Tropoje (Lugina e Valbones), Vlore, (Llogara), Erseke (Radat Germenje) and Gjirokaster (Pillua).

Figure 1: Map of Albania with information on Pinus nigra distribution

ECOLOGICAL CONDITIONS

Generally, Black Pine tolerates dry summers, snow in winter and a wide variation in temperature and rainfall. The Albanian Black Pine usually prefers dolomite serpentine soils, with some exceptions. In some part of the northern and southern mountain zones, stands growing on soils from limestone are found. In one case, a population was found to grow on soils derived from gypsum (Mali i Grames). Black Pine is thus a species with very high edaphic amplitude and is found on very different soils.

Table 1 - Main Environmental Features of Black Pine Stands (Pinus nigra Arn) in Albania

	Northern Mountain Zone	Central Mountain Zone	Southern Mountain Zone	Southern Mountain Zone
Bedrack	Limestone	Limestone, ultrabasic, sedimentar	Limestone, ultrabasic, sedimentar	Limestone, ultrabasic
Soil	Forestry grey-dark	MP.KM (browny)	MP.KM	MP.KM
Altitude (m)	1000 - 1200	900 - 1300	900 -1300	900 -1300
Climatic factor	IVa	IV bc	IV bc	IV-cd
Mean annual temperature	6.8°- 8.6° C	7.7° - 8.6°	7.7°- 8.6° C	10.6° - 11.3° C
Mean temperature of the hottest month	15.0° - 17.5° C	15.4° - 18.2° C	15.4° - 18.2° C	19.8° - 21.5° C
Mean temperature of the coolest month	- 2.2° - 1.1° C	- 0.2° - 2.9° C	- 0.2° - 2.9° C	1.9° - 3.2° C
Absolute Minimum temperature	-22.0° - -16.2 C	-17° - -14° C	17° - -14° C	-12° C
Humidity	50 ÷ 7 %	-	-	-
Annual rainfall (mm)	2500 - 2637	1120 - 2000	1120 - 2000	2000
Thickness of snow	150 cm	100 cm	100 cm	40 cm
Frost days	100 - 120	90 - 100	90 - 100

From a phytoclimatic point of view, the majority of pure Black Pine stands in Albania grow in the Fagetum zone. In competition with beech (Fagus sylvatica), Black Pine occupies the less productive soils. In the Supramediterranean zone, including the populations of Terbun, Livadhi i Hamtit, Kacinar and Orash to Qafe-Shtame (see Figure 1), Black Pine achieves its optimal productivity. These are mainly pure stands, but in some cases the stands are mixed with beech (Fagus sylvatica) or oak (Quercus spp.). The mixed stands grow in the lower limits of the region, and are well developed with high productivity. This had led to higher utilization pressures. In its upper limits Black Pine forms mixed stands with silver fir (Abies alba), Pinus peuce and Pinus heldreichii. Black Pine grows also in the Quercetum zone, in mixture with Quercus robur, Q. frainetto or maples (Acer spp). Even though Black Pine is not a typical species of that zone, it can be found in association with shrubs such as Erica arborea and Arbutus unedo.

The general situation of the Black Pine stands was relatively well known and documented in Albania prior to 1990. The uneven-aged, natural stands were in relatively good condition, with canopy ratios between 0.3 to 1.0 and mean diameter and height varying according to the site (Llubani., Habili, 1988). The best conditions were reported from the forest of Orosh Supramediterranean zone, with a canopy ratio of 0.7, an average diameter of 30 cm and height of 30 m. In Kukes Surroj and Diber Lure, Northern Mountain zone, diameters were 38 to 34 cm and height 18 m on average.

In Ersek Germenj, Southern Mountain zone, the Black Pine canopy ratio was lower than in the above-mentioned populations, but size ranges were larger.

PRODUCTIVITY OF BLACK PINE FORESTS AND PROBLEMS AFFECTING THE SPECIES

According to the Forest Map of Albania ((Llubani., Habili, 1988), the most productive areas for the Black Pine forests in Albania are in the northern zone, near the 42° parallel, where the mean increment per year and per ha is about 1.8 cubic meters. There, about 32% of the total wood production is of Black Pine. Other areas where the mean productivity is high are the mountain region near Lake Iohrit, with a mean annual increment at about 1.8 and 3.1 cubic meters per year and per ha. About 5% of the total production in this area is from Black Pine. Another productive region is the Ballabanove and Germanj stands, where the mean annual increment is in general, respectively, around 2.1 and 1.8 cubic meters. The Black Pine forests cover respectively 24% and 1% of the total production in this region.

The lowest mean productivity is found in the stands near the area of Lake Banjes: 1.1 cubic meters per year and ha. Here, Black Pine contributes 15% to the total production. In the stands near Korca productivity is 1.0 mc/y./ha, and Pinus nigra covers 20% of the total production.

During the last ten years, a total harvesting rate of about 3,000 - 4,000 ha per year has been estimated for Black Pine in Albania. At present, reforestation efforts do not match this figure. The forests of conifers, among which Black Pine, are also negatively influenced by an extremely high number of illegal cuttings for construction material, especially near villages and along roadsides (Anonymous, 1998). Damage is also imposed by over-grazing and fires. According to 6-year old information, forest fires burn between 250 and 400 ha per year (Anonymous. op. cit.).

In addition to these human pressure problems, Thaumetopea spp. (pine processionary) affected about 16% of the forest area. In 1994 this pest spread to about 70,000 ha, with intensities of attack from 5 to 95%.

CONCLUSION

The natural stands of Black Pine in Albania represent an important genetic resource which is still unexplored and still relatively well conserved. The distribution covers several ecological zones and, possibly, a number of ecotypes or subspecies.

The conservation of Black Pine in Albania in situ needs to be improved, and the stands need added protection against a number of threats, mainly those of human origin; these are especially heavy in areas where roads allow illegal cutting connected with urban expansion.

Harvesting can also be positive when well managed, and when it allows natural regeneration; however, cutting intensity should be strictly controlled.

The above issues need to be further studied. The State Forest Research Station in Tirana is planning to initiate a number of programmes for the conservation and improved management of Black Pine in Albania, including studies in silviculture, genetics and tree improvement.

REFERENCES[38]

Anonymous, 1998. The situation of Forests and Protected Areas. Found on Internet for Albania. [email protected]

Dano K., 1996. Studim mbi evidencimin e resurseve gjenetike te disa llojeve drunore kryesore te vendit tone dhe konservimi i tyre. Universiteti Bujqesor i Tiranes (Dizertacion) 131 fq.

Graudal, L, Kjaer, E., Thomsen, A. and Larsen, A.B. 1997. Planning National Programmes for Conservation of Forest Genetic Resources, Technical Note No. 48, December 1997, 58 pp.

Lako Th. 1994. Permiresimi gjenetik i pishes se zeze. Cikel leksinesh per studentet e Fakultetit te Pyjeve.

Llubani F., Habili D., 1988. Forest Map of PSR of Albania. Stacioni pyjeve dhe kulturave etherovajore, Tirane.

Mitrushi, I.1955. Druret dhe shkurret e Shqiperise. Instituti i Shkencave 604 Fq.

Balla R., Dermani.V. and Karadumi S., 1986.Pyllezimet.

Note from the Editor: A number of provenance trials of Pinus nigra have been established around the world, but it has not be possible to find any that contain provenances from Albania (see e.g. Miller J.T. and Thulin I.J. 1967. The early performance of Pinus nigra in New Zealand provenance trials. Research Leaflet No. 18, June 1967, Forest Research Institute Rotorua, (46 provenances, 8 countries); Wright J.W. and Bull, W.I. 1962. Geographic Variation in European Black Pine-Two Years Results, Forest Science, Vol. 8, No. 1; 33-42 (29 provenances, 6 countries)).

See also: FAO (1997) Directory of Seed Sources of the Mediterranean Conifers. Silva Mediterranea Network. FAO, Rome, Italy 118 pp.