Forest Resources and Their Ecological Functions in Bulgaria

Christo Bojinov

Summary

The paper is divided into seven parts.

1) Management, ownership, and general characteristics of the forestland area

All forests in Bulgaria are managed and exploited according to the Forest Law and forest management projects. The organizational structure for management of the forests consists of three levels: the Committee of Forests, 16 Regional Forestry Boards, and 164 Forest Enterprises. Until recently, all forests in the country were owned by the state, having been nationalized in 1947. The restoration of ownership rights on municipal forestland (57% of the forests prior to 1947) and private forestland (19% before 1947) is expected soon. In 1990 the total forestland area comprised 3871.4 thousand hectares. The stands of natural origin covered 2295.0 th. ha, or 59.3% of the total. The stands of artificial origin covered 1032.1 th. ha (26.7%). Dwarf pine stands covered 20,900 ha (0.5%). The afforested area was 3348.0 th. ha, or 86.5% of the total forestland area. This is 30.16% of the total area of the country (or 0.372 ha of forest per citizen).

The first part of this report describes the distribution of the afforested area by type of forest and age class, site index, and densities. The forest species composition consists of Scots pine (17.0% of the woody area), Norway spruce (4.7%), Austrian pine (3.5%), and other conifers, and by beech (16.5%), oaks (23.8%), Turkey oak (7.8%), and other deciduous species. In 1990 the total forest growing stock volume of Bulgaria was 404,872 th. m3 (121.7 m3/ha). The average annual increment was 9,600 m3 or 2.9 m3/ha.

2) Forest sites, territorial distribution, and characteristics of the wood resources

The Forest Sites Classification Scheme, published in 1983, classified Bulgaria's forests into 147 forest sites. For the purposes of this paper, these were aggregated into 55 eco-units. Detailed information for the area and growing stock volume distribution of the tree species in the framework of the eco-units is presented in 7 tables.

3) Forest health

Dramatic changes in ecological conditions, combined with physiological instability in some forests, are the major factors behind the present decline in forest health. In 1992, 62.8% of the country's forests were affected by air pollution. In 1992, 62.8% of the forests were affected by air pollution. For 34.3% of the forest ecosystems, the degree of the damage (discoloration and defoliation) was rated as moderate or severe. The young conifer stands were more strongly affected. There is also great danger, however, for the survival of fir and oak stands in the country.

4) Ecological functions of the forests

By "ecological functions," we mean the aggregate of infrastructural material and non-material services that conserve and improve the living environment as a condition for the comfortable, wholesome, and spiritually complete life of man, and that conserve and improve the nation's stability and the economic potential of the environment as the basis for society's production within and beyond the forestry sector. A general impression of the ecological functions of the forests can be drawn from information on the growing stock of the forests and the distribution of the forests by area, which is presented here in terms of the forests dedicated to special purposes.

5) Level of economic importance of tree species, endemism, and fragility under human activities

The tree species (135 in number) are separated into 3 levels according to their economic importance. The most important are those of autochthonous origin. The tree species of endemic origin and those that have been introduced into Bulgaria from other parts of the world are also presented. The fragility of the tree species under different human activities is expressed in terms of the resistance of the species to air pollutants.

6) Human activities in the forests

Afforestation, management of young forest stands, forest protection, and the tending of forests through thinning and final cutting are the main human activities in the forests. In recent years, about 40-45,000 ha have been afforested annually. Forest protection is realized through pest and disease control, forest fire control, and protection against infringement. The results of thinning, clear-cutting of low productivity stands, and final cutting are discussed in this section. The total timber yield in 1990 was 4755 m3. This was 71.45% of the total volume provided for in the forest management plans, and 1.17% of the total growing stock volume of the forests in the same year.

7) Economic analyses and analyses of the development of the Bulgarian forests

The expenditures in the forestry sector that are not met through cash inflow from direct commercial exchange are compensated for through governmental subsidies. Expenditures for implementation of some forest activities in the period 1980-1989, and expenditures for labor and construction investments, are presented in a table.

The value of the forests' ecological functions are determined on the basis of the social expenditures made for the production of environmental benefits and goods from the forests. It is logical to accept that the capital value of the ecological functions of the forests in Bulgaria is about twice as high as the value of the forestland and tree resources, and amounts to approximately 33% of the total value of the country's tangible assets.

The development of the Bulgarian forests in the period 1955-2035 is analyzed in this paper. The future development of the forest is determined through the computerized Model of Forest Lands (Bojinov, 1988). In the model the forests' natural processes are simulated and concepts about a future management of these forests are expressed in numbers. Changes in certain important forest characteristics - total afforested area, species composition, growing stock volume, mean annual increment, yield from thinnings and final fellings, etc. - are analyzed. The growing stock volume is expected to exceed 500 million m3, and the future annual cut is predicted to be about 10 million m3 of standing timber.

The characteristics of our forests reveal the need for an enormous investment of work in tending the young, mainly coniferous stands; in converting coppice stands, suitable for such purposes, into high-stem stands over an area of 784,000 ha; and in reconstructing stands of low value and productivity over an area of 608,000 ha, and replacing them with high-stem stands of suitable composition. The general approach to solving these problems involves investments of credit for building forest roads and facilities; for converting undersized stands of oak (mainly Turkey oak) and poplar; for increasing the production of seedlings in nurseries; and for improving the effectiveness of afforestation and reforestation work.

Management, Ownership, and General Characteristics of the Forestland Area

The forests in Bulgaria occupy one third of the country's territory and are extremely important as for its socio-economic development, and for the state of the environment in the Balkan Peninsula and Europe. The forests, with their productive, protective, and environmental functions, comprise an environmental element that is irreplaceable in the man/nature relationship. They also underlie, to a great extent, the development of society.

All forests in Bulgaria are managed and exploited according to forest management plans. Until recently, the forests and lands foreseen for forest purposes were included in the total figure for forestland area. The Law for Ownership and Use of Agricultural Lands, enacted in 1991, permits forests to be classified as agricultural lands also. This problem, along with many others associated with the forests and arising from the new trends in the development of society toward democracy and a market-oriented economy, will be addressed through a new forest law.

In the Forest Law Project, a three-level organizational structure for the management of the country's forests is offered.

The Forest Enterprises are independent corporate bodies. Their main function is to direct growth and reproduction, management, and logging on the state forestland area. All forests in the country are owned by the state. This is due to the fact that in 1947 the forests were nationalized. The restoration of ownership rights on the municipal forests (57% of the forests prior to 1947) and on private forests (19% before 1947) is expected soon. It will be realized through a law that is now being developed, and that will be submitted to Parliament for passage simultaneously with the new Forest Law.

The total area of forestland in Bulgarian in 1990 was 3871.4 th. ha. This area is distributed according to the categories of lands presented in Table 1.

Stands of natural origin covered 2295.0 th. ha, or 59.3% of the total area. Stands of artificial origin totalled 1032.1 th. ha (26.7%), and dwarf pine stands 20.9 th. ha (0.5%). The afforested area was 3341.6 th. ha (0.5%). The afforested area was 3348.0 th. ha, or 86.5% of the total forestland area. This is 30.16% of the total area of the country, or 0.372 ha of forest per citizen of the country.

Table 1. Distribution of the total forestland area according to type of land

  Thousands hectares %
Forest land Stands Dwarf pine Afforested area Bare ground to be aforested Other bare ground Forest pasture ground
Total 3327.1 20.9 3348.0 132.6 281.7 109.1 3871.4 100.0
% 86.0 0.5 86.5 3.4 7.3 2.8 100.0  
Includes:                
Forests managed by the state 3236.8 20.9 3257.7 128.0 277.8 109.0 3772.5 97.5
Forests managed by the agro-industrial complexes 78.7 - 78.7 4.5 3.3 - 86.5 2.2
Forests managed by the Higher Institute of Forestry 11.6 - 11.6 0.1 0.6 0.1 12.4 0.3

The distribution of the high-stem and low forests area according to age classes is presented in Table 2.

Coniferous forests cover 1107.0 th. ha, or 33.3% of the afforested portion (not including dwarf pine forests) of the forestland area. Broad-leaved high-stem forests cover 710.5 th. ha (21.4%). The percentage of low-productivity and non-valuable stands is high. The species composition of these stands is to be reconstructed using tree species with higher productivity and higher quality timber. The area of these stands is 608,100 ha, or 18.3%. The coppices that can grow into high-stem stands by applying higher rotation ages cover 388,400 ha (11.6%); those that can be converted into high-stem stands by applying shorter rotation ages cover 395,600 ha (11.9%). The low-stem forests, consisting mainly of black locust stands, cover 3.5% of the afforested portion (excluding dwarf pine) of the forestland area, or 117,000 ha.

The average age of the forest is 42 years. Table 2 presents data on the total area of the stands (excluding dwarf pine) according to forest type and age class. The table shows that the Bulgarian forest is relatively young. The most widely distributed stands are from the II (21-40 year) age class (31.9%) and the I (up to 20 years) age class (30.6%).

Table 2. Percentages of high-stem and low-stem forests

Kind of Forest Age Class Total %
1-20 21-40 41-60 61-80 81-100 101-120 121-140 141-60
Thousand hectares
Coniferous high-stem forests 590.1 199.3 78.2 107.6 77.4 34.9 11.6 7.9 1107.0 33.3
Broad-leaved high-stem forests 212.5 111.8 50.3 76.4 83.7 71.4 63.3 41.1 710.5 21.4
Broad-leaved forests for reconstruction of tree species composition 77.7 264.2 121.3 57.2 43.6 25.7 13.6 5.3 608.1 18.3
Coppice forests for growth into high-stem stands (long rotation) 25.1 215.4 132.1 15.8 - - - - 388.4 11.6
Coppice for conversion into high-stem stands (short rotation) 33.9 235.1 111.2 15.4 - - - - 395.6 11.9
Low Forests 77.5 35.4 3.5 0.6 - - - - 117.0 3.5
Total 1016.8 1061.2 496.6 273.0 204.7 132.0 88.5 54.3 3327.1 100.0
% 30.6 31.9 14.9 8.2 6.2 4.0 2.6 1.6 100.0  

Table 3. Distribution of the afforested area according to site index and stand density

Kind of Forest Thousands hectares Average site index Average density
Site Index Total site index
I II III IV V
Coniferous high-stem forests 101.3 262.2 384.5 402.5 33.3 1183.8 3.00 0.77
Broad-leaved high-stem forests 66.5 95.1 202.6 194.7 67.1 626.0 3.16 0.76
Broad-leaved forests for reconstruction of the tree species composition 1.0 2.3 8.6 86.9 467.3 566.1 4.13 0.60
Coppice forests for growth into high-stem stands (long rotation) 37.9 102.4 191.6 46.0 8.2 386.1 2.70 0.83
Coppice for conversion into high-stem stands (short rotation) 26.5 45.2 97.6 167.3 33.1 369.7 3.36 0.81
Low forests 7.9 14.4 34.7 27.4 20.7 105.1 3.38 0.84
Total 241.1 521.6 919.6 924.8 629.7 3236.8 3.37 0.75

Table 4. Tree species distribution (ha)

Tree Species Abbreviations Thousands hectares %
Pinus silvestris L. Ps 566.4 17.0
Picea abies L./Karst. Pa 155.7 4.7
Pinus nigra Arn.+ other conifers Pn 336.5 10.1
Abies alba Mill. Aa 31.8 1.0
Pinus peuce Grisb. + Pinus heldreichii Christ. Pp 16.6 0.5
Total coniferous   1107.0 33.3
Fagus sp. FA 549.9 16.5
Quercus petraea Liebl. Qp 425.3 12.8
Quercus trainetto Ten. + other Qt 502.8 15.1
Quercus cerris L. Qc 258.4 7.8
Carpinus betulus L. Cb 113.6 3.4
Fraxinus sp. F 13.7 0.4
Tilia sp. T 46.6 1.4
Populus tremula L. Pt 4.9 0.2
Betula sp. B 10.3 0.3
Carpinus orientalis Mill. Co 172.9 5.2
Robinia pseudoacatia L. R 98.4 2.9
Populus sp. P 23.3 0.7
Total broadleaved   2220.1 66.7
Total   3327.1 100.0

Table 3 presents data on the distribution of the afforested area (excluding dwarf pine) of the forests managed by the state, according to forest type, site index, and density. As can be seen in Table 3, the average site index of the forests is III (3.37). Coppices that are to grow into high-stem stands have the highest index: III (2.7). Forests that are to be reconstructed have the lowest: IV (4.13). The average stand density for the forests of national importance is 0.75. The highest stand density (0.84) is found in the low forests, and the lowest in forests for reconstruction (0.60).

The distribution of tree species in the Bulgarian forests is presented in Table 4. This table shows that the widely occurring coniferous tree species in the country are the Scots pine (Pinus silvestris L.), black pine (Pinus nigra Arn.) and spruce (Picea abies L./Karst.) and the most widely occurring broad-leaved trees are beeches (Fagus sp.) and oaks (Quercus petraea Liebl., Quercus trainetto Ten., Quercus cerris L.).

Table 5. Growing stock distribution (m3)

Kind of Forest Thousand cubic meters %

Wood Reserves

(m3/ha)
Age Classes Total
1-20 21-40 41-60 61-80 81-100 101-120 121-140 141-160
Coniferous high-stem forest 27239 31692 18275 34943 27577 12031 4046 2731 158534 39.2 143.2
Broad-leaved high-stem forest 6219 142038 9753 17382 21122 18162 15887 12229 114957 28.4 161.8
Broad-leaved forests for reconstruction of tree species composition 1694 8816 5527 3672 3314 2149 1276 538 26986 6.6 44.4
Coppice forests for growth into high-stem stands (long rotation) 1593 27278 22172 3110 - - - - 54153 13.4 139.4
Coppice for conversion into high-stem stands (short rotation) 1477 24378 14936 2584 - - - - 43375 10.7 109.6
Low forests 3262 3250 333 22 - - - - 6867 1.7 58.7
Total 41484 109617 70996 61713 52013 32342 21209 15498 404872 100.0 121.7
% 10.3 27.1 17.5 15.2 12.8 8.0 5.2 3.2 100.0    

Forest Sites, Territorial Distribution, and Characteristics of the Wood Resources

The forest zonation of Bulgaria is based on climatic changes in both the horizontal and vertical directions. From a forestry perspective, the country is differentiated into 3 forest-climatic regions: northern Bulgaria, with a temperate continental climate (Mizia); southern Bulgaria, with a transitional Mediterranean climate (Trakia); and a southern marginal region with a climate more closely related to that of the northern Mediterranean region (South). The boundaries of the forest regions can be seen in Map 1.

The main divisions in the forest zonation reflect climatic changes that occur as a result of variations in elevation and that influence the species composition, dis-tribution, and productivity of woody vegetation (Zahariev et al., 1979) (see Table 6). Edaphic factors are the other main determinants in the development of woody vegetation. The most widely distributed soils under the forests are: black earth, alluvial, gray forest soils, maroon forest soils, yellow soils, humus carbonate soils, brown forest soils, and mountainous forest dark soils.

The Forest Sites Classification Scheme (1983) coordinates the division of forest-climatic zones in Bulgaria with edaphic conditions and identifies 147 forest site types. For the purposes of this paper, the sites with similar characteristics have been unified into 55 groups of site types, or (so to speak) "eco-units." Data regarding these units are presented in Table 7. The numbers of the forest site types that are included in the eco-units are indicated in Column 3. The fertility of the soil (Column 5) follows Pogrebniak's scheme. Species composition (given by abbreviations) and the productivity of present vegetation (given by site indexes) are presented in Columns 6 and 7 respectively.

Data on the area and growing stock volume distribution of the tree species in the framework of the forest-climatic regions are presented in Table 8. Data on the area and growing stock volume distribution of the tree species in the framework of the forest eco-units are presented in Tables 9 to 14.

Table 6. Main divisions of forest zones in Bulgaria

Forest zone and subzone Forest regions (altitude, meters a. s. l.
Mizia Trakia South

I. Low plain-hill and hill-foothill zone of the oak forests:

 

     
1.1 Subzone of the river plain forests, and      
1.2 Plain-hill subzone of the deciduous oak and xerothermic forests 0-400 0-500 0-600
1.3 Hill-foothill subzone of the mixed broad-leaved forests 400-600 500-700 600-800
II. Middle mountain zone of beech and coniferous species      
2.1 Low mountain subzone of the durmast,beech, and fir forests 600-1000 700-1200 800-1500
2.2 Middle mountain subzone of the beech, fir, and spruce forests 1000-1500 1200-1700 1500-1900
2.3 High mountain subzone of spruce forests 1500-1800 1700-2000 1900-2200
III. High mountain zone      
3.1 High mountain subzone of spruce and white fir forests 1800-2000 2000-2200 2200-2500
3.2 Subalpine subzone of single tree, dwarf pine, and bush formation 2000-2200 2200-2500 2500-2700

Table 7. Characteristics of the forest eco-units (Regions: M-Mizia, T-Trakia, S-South)

Note: * = These site types are included in different forest regions, zones, and subzones in different ecounits.

No. region, zone, subzone Forest site type Soil Vegetation
Type Fertility Tree species Site index
1 2 3 4 5 6
1. M-I-2 10,11,12 black earth, gray forest D Qt,Qc,Qp,Cb,T,F,Pn,Ps,Pa I-II
2. M-I-2 13,14,15,121* black earth, gray forest CD,C Qt,Qc,Qp,T,Cb,Co,Pn,Ps, Pa III
3. M-I-2 138,122*,123*,131*,132* gray forest, hum. carbonate B Qt,Qc,Co,Qp,T,Cb,Pn,Ps IV-V
4. M-I-3 16,17,22 gray forest, brown forest, maroon forest D,CD Qp,Qt,Qc,F,Cb,T II-III
5. M-I-3 18,19,20,24,121* gray forest, maroon forest C Qc,Qp,Qt,Cb,T,Co,F,B,PnPs,Pa III-IV
6. M-I-3 21,23,139,122*,123*131*132* gray forest, maroon forest, hum. Carbonate B Qt,Qc,Co,Cb,T,Qp,Pn,Ps IV-V
7. M-II-1 29,30 brown forest D,CD FA,Qp,Cb,Qc,T,Pt,Ps,Pn Pa,Aa,Pp II-III
8. M-II-1 27,32,124* gray forest, maroon forest C Qp,FA,Cb,Qc,Qt,T,Co,B, Pt,Ps,Pn,Pa,Aa,Pp III-IV
9. M-II-1 28,31,33,125*,126*,133*134*,136,137,145* gray forest, hum. carbonate, maroon forest, brown forest B FA,Qt,Qc,Co,Cb,Qp,T,Ps,Pn,Pp IV-V
10. M-II-2 (lower part) 34 brown forest D,CD FA,Pt,Ps,Pp,Aa,Pa II-III
11. M-II-2 36,143* brown forest C PA,Qp,Qc,Qt,Co,B,Ps,Pp,Aa,Pa III-IV
12. M-II-2 lower part) 38 part,126*,133*,134* 145* brown forest hum. carbonate B FA,Qp,Qc,Qt,Co,Ps,Pp IV-V
13. M-II-2 upper part) 35 brown forest CD FA,Ps,Pa,Aa,Pp II-III
14. M-II-2 upper part) 37,143* brown forest C FA,Pa,Ps,Aa,Pp III-IV
15. M-II-2 upper part) 38 part,126*,133*,134*, 145* brown forest, hum. carbonate B FA,Ps,Pa,Pp IV-V
16. M-II-3 39,40,41,42,44 brown forest, mount. dark CD,C FA,Ps,Pa,Pp III
17. M-II-3 43,45,126*,133* 134* brown forest, mount. dark, hum. carbonate B FA,Ps,Pa,Pp IV-V
18. T-I-2 55,58,60,140,141 147 maroon forest, black earth D,CD Qt,Qc,Qp,T,Cb,F,Pn,Ps II-III
19. T-I-2 57,61,122*,123* 131*,132* maroon forest C Qt,Qc,Qp,Cb,Co,T,F,Pn,Ps III-IV
20. T-I-2 57,61,122*,123*,131* 132* maroon forest, hum. carbonate, gray forest D,CD Qt,Qc,Qp,Co,Qb,T,Pn,Ps IV-V
21. T-I-3 62 maroon forest D,CD Qt,Qp,Cb,Qc,T,F,Pt,Pn,Ps II-III
22. T-I-3 63,121* maroon forest C Qp,Qt,Qc,Cb,T,Co,Pn,Ps III-IV
23. T-I-3 64,122*,123*,131*,132* maroon forest, hum. carbonate B Qt,Qp,Qc,Co,Cb,T,Pn,Ps IV-V
24. T-II-1 67,70 brown forest, maroon forest D,CD FA,Qp,Cb,Qc,Qt,Pt,F,T,PsPn,Aa,Pa II-III
25. T-II-1 71,142,124* brown forest, maroon forest, hum. carbonate C FA,Qp,Cb,Qc,Qt,T,Co,B Ps,Pn,Aa,Pa III-IV
26. T-II-1 68,69,72,125*,126*,133*134* brown forest, hum. carbonate, maroon forest B,BC Qt,Qp,FA,Qc,Co,Cb,T,Ps Pn,Aa,Pa IV-V
27. T-II-2 (lower part) 73,78 brown forest, mount. dark D,CD FA,Cb,Qp,Qc,Pt,Ps,Aa,Pa II-III
28. T-II-2 (lower part) 75,143* brown forest, hum. carbonate C FA,Qp,Qc,Cb,B,Pt,Qt,Co,Ps,Aa,Pa III-IV
29. T-II-2 (lower part) 77,126*,133*,134*,145* brown forest, hum. carbonate B FA,Co,Qc,Qp,Qt,Cb,Ps,PaAa IV-V
30. T-II-2 (upper part) 74 brown forest, mount. dark C FA,Pp,Pa,Ps,Aa,Pp II-III
31. T-II-2 (upper part) 76,80,143* brown forest, mount. dark C FA,Pt,B,Pa,Ps,Aa,Pp III-IV
32. T-II-2 (upper part) 79,126*,133*,134*,145* brown forest, hum. carbonate, mount. dark B FA,Ps,Aa,Pa IV-V
33. T-II-3 81,82,84 brown forest, mount. dark CD,C FA,Pa,Ps,Pp II-III
34. T-II-3 83,85,126*,133*,134* brown forest, mount. dark, hum carbonate B FA,Pa,Ps,Pp IV-V
35. T-III-1 86 mount. Dark C Pa,Pp,Ps III-IV
36. T-III-1 87,88,130* mount. Dark B Pa,Pp,Ps IV-V
37. S-I-2 94,97,99 maroon forest, ?, ? D,CD Qt,Qp,FA,Qc,Cb,T,F,Pn Ps II-III
38. S-I-2 95,98,100,121* maroon forest, ?, ? C Qt,Qp,FA,Qc,Cb,T,Co,Ps Pn III-IV
39. S-I-2 96,122*,123*,131*,132* maroon forest, hum. carbonate B Qt,Qp,Co,Qc,Cb,FA,T,Pn Ps IV-V
40. S-I-3 101 maroon forest D,CD Qp,FA,Qt,Qc,Cb,T,Pn,Ps II-III
41. S-1-3 102,121* maroon forest C Qp,Qt,Qc,Cb,FA,Co,Pn,Ps III-IV
42. S-I-3 130,122*,123*,131*,132* maroon forest, hum. carbonate B Qt,Qc,Qp,Co,Cb,FA,T,Pn Ps IV-V
43. S-II-1 104,105 brown forest D,CD FA,Qp,Qt,Cb,Qc,Pt,Ps,Pn Pa,Aa II-III
44. S-II-1 107,108,124* brown forest, hum. carbonate C FA,Qp,Cb,Qt,Qc,B,Co,Ps Pn,Pa,Aa III-IV
45. S-II-1 106,106,125*,126*,133* 134*,145* brown forest, hum. carbonate B FA,Qt,Qp,Qc,Co,Cb,Ps,PnPa,Aa IV-V
46. S-II-2 (lower part) 110 brown forest D,CD FA,Pt,Ps,Pn,Aa,Pp II-III
47. S-II-2 (lower part) 112,143* brown forest, hum. carbonate C FA,B,Ps,Pa,Aa,Pp III-IV
48. S-II-2 (lower part) 113,126*,133*,134*,145* brown forest, hum. carbonate B Fa,Ps,Pa,Pp,Aa IV-V
49. S-II-2 (upper part) 111,114,143* brown forest, mount. dark, hum. Carbonate CD FA,Pa,Pp,Ps,Aa II-III
50. S-II-2 (upper part) 115,126*,133,134*,145* mount. dark, hum. carbonate, brown forest B FA,Pp,Pa,Ps,Aa IV-V
51. S-II-3 118 mount. Dark CD,C Pp,Pa,Ps III
52. S-II-3 119,126*,113*,134* mount. dark, hum. carbonate B Pp,Pa,Ps IV-V
53. S-III-1 120,130* mount. Dark BC Pp,Pa,Ps IV-V
54. M, T, S I-2, I-3 1-6,8,9 (M) 18-20 (T) 37-39 (S) black earth, gray forest, maroon forest, ? C,D,B Black locust III-IV
55. M, T, S I-1 1-9 (M) 51-54 (T) 90-93 (S) alluvial D,CD Poplar I-II

Table 8. Distribution of the afforested area and growing stock volume of the tree species within the framework of the forest-climatic regions

Tree species Mizia Trakia South Total
1000X ha. 1000X m3 1000X ha. 1000X m3 1000X ha. 1000X m3 1000X ha. 1000X m3
Pin.silvestris 100.3 9510 276.5 51388 189.6 24417 566.4 85315
Picea abies 21.9 1871 108.6 27876 25.2 5356 155.7 35103
Pinus nigra 84.0 6140 158.5 10838 94.0 6481 336.5 23459
Abies alba 3.0 825 24.9 8522 3.9 1103 31.8 10450
Pinus peuce 0.8 77 8.6 2410 7.2 1720 16.6 4207
Total coniferous 210.0 18423 577.1 101034 319.9 39077 1107.0 158534
Fagus sp. 248.0 55431 211.9 41718 90.0 14108 549.9 111257
Quer.petraea 133.8 9783 162.1 11835 129.4 8727 425.3 30345
Quer.trainetto 187.5 14374 175.6 18687 139.7 9353 502.8 42414
Quercus cerris 152.4 13862 90.7 10655 15.3 1295 258.4 25812
Carp. betulus 72.1 10305 36.4 7039 5.1 421 113.6 17765
Fraxinus sp. 8.9 699 4.6 1066 0.2 12 13.7 1777
Tilia sp. 37.0 5726 8.7 611 0.9 64 46.6 6401
Populus tremula 1.0 93 3.4 595 0.5 52 4.9 740
Betula sp. 3.6 248 4.1 200 2.6 88 10.3 536
Carp.orientalis 73.6 839 71.4 939 27.9 201 172.9 1979
R.pseudoacatia 77.2 4534 17.0 750 4.2 138 98.4 5422
Populus sp. 15.9 1286 5.2 410 2.2 194 23.3 1890
Total broadleaved 1011.0 117180 791.1 94505 418.0 34653 2220.1 246338
Total 1221.0 135603 1368.2 195539 737.9 73730 3327.1 404872

Table 9. Area (ha) of tree species distribution in the present species composition: Mizia region

No. of the ecounit Pinus peuce Picea abies Pinus sylvestris Abies alba Pinus nigra Fagus sp. Frax-inus sp. Populus trem. Betula sp. Quercus petraea Quercus trainetto Quercus ceris Carpinus betulus Tilia sp. Carpinus orientalis Total Black locust Populus sp.
Hectares
16 80 1806       13296                   19022    
17 50 447       3800                   6105    
 
13 100 2050   260   10100                   14548    
14 80 1240   200   8219                   12184    
15 80 823       10612                   16455    
 
10 50 1010   610   30566   260               35521    
11 80 3115   482   76435     850 7182 957 5300     750 110131    
12 80         8329       7654 1276 2539     3885 26783    
 
7 80 3630   650 7500 30900   310   9965   6219 10500 3800   86059    
8 85 5406   750 15010 41201   432 1500 44166 13835 38420 22473 6725 10180 232483 1233  
9 50       15005 14560       17627 9827 9644 7080 2755 13020 100818 3500  
 
4   505     7345   2150     2511 8375 8910 1300 750   32766 2000  
5   850     15606   4300   1254 17071 20342 24100 14200 8920 9592 118635 11800  
6         15352         8379 31611 8367 6160 1820 26500 100039 3933  
 
1   400     1824   2500     5308 27798 9040 3350 4360   55105 24060 15872
2   620     4306         10206 62836 34510 5200 6080 3520 128788 25074  
3         2030         3740 10817 5330 1800 1750 6120 32512 5600  
  815 21902 100281 2952 83978 248018 8950 1002 3604 133809 187674 152379 72063 36960 73567 1127954 77200 15872

Table 10. Area (ha) of tree species distribution in the present species composition: Trakia region

No. of the ecounit Pinus peuce Picea abies Pinus sylvestris Abies alba Pinus nigra Fagus sp Fraxinus sp Populus trem. Betula sp Quercus petraea Quercus trainetto Quercus ceris Carpinus betulus

Tila sp

 Carpinus orientalis Total Black locust Populus sp
Hectares
35 2600 6010 2549                         11159    
36 2050 22140 6976                         31166    
 
33 2681 44429 29727     12300                   89137    
34 919 12110 31455     7125                   51609    
 
30   8215 6800 2020   13820   420               31425    
31 150 8960 22261 3510   22320   330 535             58116    
32 200 1360 14543 1723   6210                   23836    
 
27   890 16360 2215   29565   650   762   1100 449     51991    
28   1625 30594 4421   49825   710 1050 7295 305 2210 1820   1015 100900    
29   250 23060 860   12200       945 804 2100 1040   4155 45414    
 
24   810 17600 2520 9900 21155   702   12798 3350 3615 3120 264   75834    
25   1509 37579 5731 17015 30199     2515 49970 7040 10850 5950 1650 7300 177308 173  
26   292 17625 1900 14120 7181       20151 9740 6450 2260 150 10920 90789 522  
 
21     2180   12420   503 550   3501 2552 4080 3610 810   30206    
22     4521   24334         35463 14712 13103 5400 1320 7360 106213 522  
23     3750   21180         13526 23750 8681 3520 715 15055 90174 174  
 
18     2264   13245   2162     3500 21123 6210 3162 1136   52802 4655 5200
19     3135   22000   1850     8120 53313 20145 4410 1945 8420 123338 9911  
20     3521   24286         6102 39004 12156 1629 710 17175 104583 1043  
  8600 108600 276500 24900 158500 211900 4515 3362 4100 162130 175693 90700 36400 8700 71400 1346000 17000 5200

Table 11. Area of tree species distribution in the present species composition: South region

No. of the ecounit Pinus peuce Picea abies Pinus sylvestris Abies alba Pinus nigra Fagus sp Fraxinus sp Populus trem. Betula sp Quercus petraea Quercus trainetto Quercus ceris Carpinus betulus

Tila sp

 Carpinus orientalis Total Black locust Populus sp
Hectares
53 1512 1008 277                         2797    
 
51 1150 987 380                         2517    
52 909 691 154                         1754    
 
49 1627 1918 510 325   225                   4605    
50 1083 958 150 240   150                   2581    
 
46 220 3800 3789 521   3831   220               12381    
47 405 5212 12521 1259   4140   420               23957    
48 265 1020 1887 221   2836                   6229    
 
43   3420 11050 385 4180 12886   239   2320 800 450 160     35890    
44   5140 81125 750 13220 22361     1080 10125 4500 1420 410   1120 141251    
45   1015 38085 195 10900 12603       10896 5120 1215 983   4850 85862 170  
 
40     2180   5011 4020       5520 950 1025 190 52   18948    
41     12840   11809 9820     981 12812 4901 2070 500 146 1650 57529 170  
42     6001   8000 2510       6807 6896 1620 1025 50 5150 38059    
 
37     1520   7850 3940 234     4965 7159 1840 234 120   27862 1228 2198
38     12095   20100 9197       57888 75406 3286 621 450 4120 183163 2416  
39     5075   13009 1514       18102 33953 2350 995 90 11050 86138 254  
  7171 25169 189639 3896 94079 90033 234 459 2481 129435 139685 15276 5118 908 27940 731523 4238 2198

Table 12. Volume (m3) of tree species growing stock in the present species composition: Mizia region

No. of the ecounit Pinus peuce Picea abies Pinus sylvestris Abies alba Pinus nigra Fagus sp Fraxinus sp Populus trem. Betula sp Quercus petraea Quercus trainetto Quercus ceris Carpinus betulus

Tila sp

 Carpinus orientalis Total Black locust Populus sp
1000m3
16 8 154 288     2781                   3231    
17 4 38 135     437                   614    
 
13 9 175 152 73   2112                   2521    
14 8 106 183 56   1719                   2072    
15 8 70 470     1220                   1768    
 
10 4 86 327 170   7124   24               7735    
11 8 266 1422 135   18955     35 598 76 517     9 22021    
12 8   326     958       378 63 146     44 1923    
 
7 8 310 1237 181 469 7163   29   785   607 1664 478   12931    
8 8 463 3219 210 1140 10617   40 111 3554 1097 3751 3562 1146 116 29034 72  
9 4   1142   1140 2345       1039 485 576 596 346 148 7821 205  
 
4   43 69   562   170     199 664 870 206 94   2877 118  
5   73 180   1169   336   102 1402 1618 2353 2251 1700 109 11293 693  
6     138   1158         413 1922 482 519 229 302 5163 231  
 
1   34 39   90   193     421 2209 883 531 548   4948 1414 1286
2   53 113   312         809 5706 3369 825 965 40 12192 1472  
3     70   100         185 534 308 151 220 71 1639 329  
  77 1871 9510 825 6140 55431   93   9783 14374 13862 10305 5726 839 129732 4534 1286

Table 13. Volume (m3) of tree species growing stock in the present species composition: Trakia region

No. of the ecounit Pinus peuce Picea abies Pinus sylvestris Abies alba Pinus nigra Fagus sp Fraxinus sp Populus trem. Betula sp Quercus petraea Quercus trainetto Quercus ceris Carpinus betulus

Tila sp

 Carpinus orientalis Total Black locust Populus sp
1000m3
35 792 1641 400                         2833    
36 603 5571 1300                         7474    
 
33 619 11515 5800     2416                   20350