rajko.milosevic@sfb.rs Faculty of Forestry, University of Belgrade
Transcription
rajko.milosevic@sfb.rs Faculty of Forestry, University of Belgrade
THE TYPES OF MONODOMINANT MONTANE BEECH FORESTS WITH THE HIGHEST PERCENTAGE IN SERBIA AND THEIR ECOLOGICAL - PRODUCTION CHARACTERISTICS Rajko Milošević, Vladan Živadinović rajko.milosevic@sfb.rs Faculty of Forestry, University of Belgrade, Serbia, Kneza Višeslava 1 Abstract : Montane beech forests in Serbia form and clearly differentiated and distinguished spatial and ecological entity – a climate - regional belt - on all mountainous massifs. They were formed under the synerctic effect of a complex of factors. Consequently, they are characterised by high ecological diversity, expressed by petrographic - edaphic, orographic, microclimate and coenological characteristics. This belt is characterised by a specific microclimate, which is favourably reflected to the ecological and coeno-ecological optimum for beech forests in the greatest number of forest types: more rainfall, higher relative humidity, lower temperatures (which is especially important during summer droughts) and lower temperature fluctuations. The highest percentage in this climate-regional belt is that of monodominant montane beech forests. The following most represented types of these forests are differentiated by typological classification: - Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep acid brown soils; - Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils. The above forest types have been identified on all mountainous massifs in Serbia. The percentage of stands of the former type is greater, with a wider and more mesophilous ecology and with a significantly higher potential productivity. Key words: Montane monodominant beech forests, the most represented types, ecology, Serbia. 421 1. Introduction Thanks to its specific bioecology, beech is a tree species with the greatest spatial and ecological distribution. For this reason, beech forms the highest number of coeno-ecological entities and forms the highest number of forest types. Beech is the dominant species in the total growing stock in Serbia with the percentage of 40.5 % in total volume and with 30.6% in volume increment (Banković et al., 2009.). The coeno-ecological group of forest types – the montane beech forests cover the greatest area and forms a clearly differentiated and homogeneous spatial-ecological entity – climate - regional belt - on all mountainous massifs in Serbia. They were formed under the synerctic effect of a complex of factors. Consequently, they are characterised by high ecological diversity, expressed by petrographicedaphic, orographic, microclimate and coenological characteristics and typology. This belt is characterised by a specific microclimate, which is favourably reflected to the ecological and coenoecological optimum for beech in the greatest number of forest types: more rainfall, higher relative humidity, lower temperatures (which is especially important during summer droughts) and lower temperature fluctuations. Within the basic typological coordinate system of forests, and based on the bioecological characteristics of the principal species and the interaction of the complex of ecological factors, montane beech forests are classified in the complex (belt) of mesophilous beech and beechconiferous forest types. They form a special group within this complex – Coeno - ecological group of forest types of montane beech forests (Fagenion moesiacae montanum) on different brown soils (Jović, et al., (1996.). Based on the ecological studies, this coeno-ecological group of forest types is characterised by high ecological diversity, i.e. there is a great number of ecologically different parts – ecological units (Jović, et al., 1996.). However, they are typologically significantly more homogeneous regarding their ecological characteristics (Medarević, Milošević, 2005.; Jović, Banković, Medarević, 1991.; Milošević, 2006.; Banković, et al., 2003., etc.). Monodominant beech forests occupy the highest percentage in the total area of montane beech forests. They represent a special entity from the aspect of typological composition and typological characteristics. Considering the percentage of these stands (types) in the total area of montane beech forests on the one hand, and their priority function zones, and finally the economic effects, these forests are the most significant part of the total growing stock of montane beech forests. As for their typological composition, and taking into account the typological definition of these forests, the following two most represented types of these forests are characteristic: 1. Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep humus acid brown soils and diluvium; 2. Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils. This paper presents the above types with typological characteristics and elements which constitute the starting points for silvicultural and management modelling and modern plan conceptions. 2. Material and Method This paper is based on the typological studies and typological classification of montane beech forests (Jović, et al., 1996.; Jović, et al. 1991.; Banković et al. 2003.; Medarević, Milošević, 2005.; Medarević, Milošević, 2005.; Milošević, 2006.; Milošević, 2009.), special forest management plans, and the Code Manual for the Information System on Forests of the Republic of Serbia (Banković, Medarević, 2003.). 422 3. Results The belt of montane beech in Serbia, by its characteristics in the sense of typology, and based on the present typological classification system of forests in Serbia, is defined in the following typological classification categories: Complex of mesophilous beech and beech-coniferous forest types; Coeno - ecological group of montane beech forests (Fagenion moesiacae montanum) on acid brown soils, Jović, et al., (1996.). Forest types: The two most represented types of forests within the ecological category of montane beech forests, were defined based on the typological classification of beech forests, characterised by ecological conditions. Their ecological diversity is reflected on their potential productivity, structure and dynamism and the course of the main indicators, i.e. on the relevant silvicultural and management procedures. Table 1. Production characteristics per forest types - locality Veliki Jastrebac (Milošević, 2006.). Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep acid brown soils Species t(yr) n(trees) gm2/ha dg(cm) dgmax(cm) hg(m) hgmax(m) V(m3/ha) Ivtm3/ha Beech 80 542 40.70 29.41 42.25 27.05 30.85 587.56 16.71 Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils Species t(yr) n(trees) gm2/ha dg(cm) dgmax(cm) hg(m) hgmax(m) V(m3/ha) Ivtm3/ha Beech 85 464 31.5 28.7 43.6 24.4 28.8 415.2 9.60 Table 2. Statistical indicators of diameter structure per forest types Forest type Tree species Beech Foresr type Tree species Beech Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep acid brown soils Mean Coef. Coef. Min. Max. Stand. Stand. Coef. diametar of of var. Median Mod diameter diameter deviation error (ds) skew. kurtos (α3) . (α4) cm cm % 29.41 29.0 31.5 10.5 54.0 9.46 0.66 0.36 -0.31 32.19 Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils Mean Coef. Coef. Min. Max. Stand. Stand. Coef. diametar of of var. Median Mod diameter diameter deviation error (ds) skew. kurtos (α3) . (α4) cm cm % 28.73 28.0 17.5 12.0 77.5 10.49 0.74 0.95 1.62 35.52 423 Table 3.: Statistical indicators of height structure of forest types Forest type Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep (humus) acid brown soils on diluviums Mean Coef. Coef. Min. Max. Stand. Stand. Coef. diametar Tree of of var. Median Mod height height deviation error (ds) species skew. kurtos. (α3) (α4) cm cm % Beech 27.05 28.10 30.0 12.00 33.10 4.19 0.29 -1.45 1.83 15.5 Foresrt Forest type montane beech with fescue grass (Fagetum moesiacae montanum type drymetosum) on medium deep and sometimes skeletal acid brown soils Mean Coef. Coef. Min. Max. Stand. Stand. Coef. diametar Tree of of height height deviation error var. Median Mod (ds) species skew. kurtos. (α4) (α3) cm cm % Beech 24.38 25.10 20.0 11.00 33.00 4.48 0.36 -0.37 0.37 18.38 1. Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep (humus) acid brown soils on diluviums The stands of this forest type cover the greatest part of the area of monodominant beech forests and in general of the climate-regional belt of beech forests. This forest type includes several ecological entities of beech forests, primarily depending on the orographic and soil factors. Most often in the natural conditions they are: typical montane beech forest (Fagetum moesiacae montanum typicum) on deep acid brown soils, montane beech forest with broadleaved garlic (Fagetum moesiacae montanum alliosum) on deep and very deep (humus) acid brown soils, and typical montane beech forest (Fagetum moesiacae montanum typicum) on diluviums. The stands of this forest type cover most frequently the central parts of the montane beech belt, altitude 700 – 900 metres, on somewhat less steep slopes in more mesophilous conditions, mainly on cooler aspects. Edaphic conditions are very favourable, with the soils of high ecological and production potential – acid brown soils, deep, with very favourable physical-chemical properties. In the upper storey, beech is the only species, with varying percentages of mainly individual valuable broadleaves, depending on the spatial and ecological position of the stands. The shrub layer is almost absent, with individual occurrences of black elder (Sambucus nigra) and broadleaved spindle tree (Evonimus latifoliae). In the ground flora layer, the dominant species is broadleaved garlic (Allium ursinum) in stands of the forest type (Fagetum moesiacae montanum alliosum) on deep and very deep acid brown soils. This forest type includes the most productive stands of montane beech forests. Their potential productivity expressed by stand taxation indicators is very high. Volume at the stand age of 85 years is 580 m3, current volume increment varies about 16 m3/ha. (localities of Goč, V. Jastrebac, Željin, etc.). The high potential is illustrated also by other forest estimation indicators, especially mean maximal and mean stand height as the most indicative indicators (Table 1). Also, the high potential of this forest type is illustrated by the time of culmination of diameter and height increment, as well as the culmination values (Diagram 1 and Diagram 2). Diameter increment culminates in the period between 20 and 30 years, and height increment about the age of 30 years, with very high culmination values (id = 7.3 mm; ih = 0.58 m). 424 Diagram 1.: Current diameter increment of beech trees per forest types Diagram 2.: Current height increment of beech trees per forest types The stands are characterised by pronounced even-agedness with a very small positive skewness (almost symmetrical form) (Diagram 3., Table 2.). 425 Diagram 3.: Diameter and height structure of forest type 1 40 22 20 35 18 30 16 25 12 N (%) N (%) 14 10 20 15 8 6 10 4 5 2 0 0 5 10 15 20 25 30 35 40 45 50 55 d (cm) 60 65 70 75 80 85 90 95 100 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 h (m) 2. Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils on granodiorites These stands are also distributed over vast areas, but their percentage in the total area of montane beech forests is somewhat lower. Also, their ecology is significantly different from the previously described type of monodominant beech forests. They often occupy the altitudes between 750 and 850 m, in more xerothermic conditions, i.e. in more difficult edaphic conditions (shallower and more skeletal soils), on mainly warmer – southern aspects and steeper slopes. From the ecologicalcoenological aspect, they are homogeneous, making one ecological entity – ecological unit (ecological type) which is simultaneously a forest type. In the tree layer, beech is the only edifying species. The shrub layer is sparse. In ground flora layer, fescue grass (Festuca drymeia)is the dominant species from the aspects of abundance and degree of coverage. Potential productivity of the stands of this forest type is significantly lower compared to the previous type of monodominant beech forests. The volume of stands at the age of 85 years ranges from 350 to 400 m3/ha, and volume increment is 9.6 m3/ha (localities of Goč, V. Jastrebac, Željin, etc.). The potential level is also illustrated by other forest estimation indicators, especially mean stand height and mean maximal height, as the most indicative indicators of forest productivity (Table 1.). The lines of diameter increment and height increment are completely different compared to forest type 1 (Diagrams 2. and 3.). Diameter increment and height increment culminate twice: in the period between 30 and 40 years - the first and at 70 years - the second, i.e. between 30 and 40 years - the first, i.e. between 50 and 60 years - the second, and with considerably lower culmination values. Diameter structure is characteristic for even-aged stands, with a somewhat wider distribution, its slow change and strong left skewness, i.e. the slower establishment of the symmetrical form (Table 2., Diagram 4.). 426 Diagram 4.: Diameter structure of forest type 2 25 35 30 20 25 15 N (%) N (%) 20 15 10 10 5 5 0 0 5 10 15 20 25 30 35 40 45 50 55 d (cm) 60 65 70 75 80 85 90 95 100 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 h (m) 4. Discussion The defined two forest types constitute two completely separate ecological and production entities. This is manifested by their ecology, potential productivity, structure and the dynamism of current diameter increment and height increment. The largest area of monodominant beech forests are covered by the stands classified as the type of montane beech forests (Fagetum moesiacae montanum – typicum) on deep and very deep (humus) acid brown soils and diluvium. They are characterised by very diverse ecology which is especially reflected by orographic – edaphic conditions. Simultaneously they are the most productive stands, with a very high production potential. The high production potential is reflected on the structure and dynamics of diameter increment. The structure is distinguished by an almost symmetric form of distribution, i.e. by a faster change of distribution and establishment of almost symmetric form already at the stand age of 85 years. Also, the very high production potential is illustrated by the culmination of diameter increment and height increment which occur already between the ages of 20 and 30, i.e. at the age of 30 years. The stands of the forest type Fagetum moesiacae montanum drymetosum on medium deep and sometimes skeletal acid brown soils are distributed over a great part of this belt (by the area of distribution they are directly following the stands of the previous type). Ecology, productivity, structure and the courses of development of beech in this forest type are significantly different compared to forest type 1. This forest type is characterised by a significantly lower production potential which is reflected on the significantly different structure and dynamics of diameter increment and height increment compared to forest type 1. At the stand age of 85 years, the distribution is characterised by strong left skewness and a slower change of distribution compared to forest type 1. The dynamics of diameter increment is completely different from the previous forest type. The course of diameter increment is characterised by two culminations (the first at the age of 40 years, and the second (with lower values) at the age of 70 years) The culminations of height increment occur about the age of 30 years - the first, i.e. between 50 and 60 – the second 5. Conclusion The typological definition of monodominant beech forests is based on the typological system of forests in Serbia the current classification of typological categories. The two types of monodominant montane beech forests with the highest percentage in Serbia were determined based on the typological classification of forest categories and their typological definition. Taking into account the character of 427 their constituting elements which are the base and the starting point of the guidelines for the selection of forest management goals and silvicultural measures, the defined types are simultaneously also the management entities. The most represented typological – management entities of monodominant beech forests in Serbia are: 1. Forest type montane beech (Fagetum moesiacae montanum typicum) on deep and very deep acid brown soils on granodiorite; 2. Forest type montane beech with fescue grass (Fagetum moesiacae montanum drymetosum) on medium deep and sometimes skeletal acid brown soils on granodiorites. 428 References Aleksić, P. (1994): Istraživanje uticaja ekološko – proizvodnih osobina bukovih sastojina mešovitog porekla na način gazdovanja na Malom Jastrepcu. Doktorska disertacija, Beograd. Banković, S., Medarević, M., Knežević, M., Milošević, R. (2003): Tipovi bukovih šuma Srbije. Šumarstvo 1 – 2, Beograd, str. 197 – 204. Banković, S., Medarević, M. (2003): Kodni priručnik za informacioni sistem o šumama republike Srbije Banković,S., Medarević,M., Pantić, D., Petrović, N., Šljukić, B., Obradović,S. (2009): Šumski fond Republike Srbije - tanje i problemi, Glasnik Šumarskog fakulteta, br. 100, Šumarski fakultet Univerziteta u Beogradu, Beograd. Jović, D., Banković, S., Medarević, M. (1991): Proučavanje razvojno-proizvodnih karakteristika ekoloških jedinica bukovih šuma na Željinu i njihovo proizvodno diferenciranje. Glasnik Šumarskog fakulteta, br. 73, Šumarski fakultet Univerziteta u Beogradu, Beograd. Jović, D., Banković, S., Medarević, M. (1985): Proučavanje strukturnih karakteristika bukovih šuma na Željinu, Godišnji izveštaj RZN Srbije, Beograd. Jović, N., Tomić, Z., Jović, D. (1996): Tipologija šuma, Udžbenik, Šumarski fakultet Medarević, M., Milošević, R. (2005): Tipovi bukovih šuma Srbije. Rad u monografiji „Bukva u Srbiji“, Udruženje šumarskih inženjera i tehničara Srbije i Šumarski fakultet Univerziteta u Beogradu, Beograd, str. 365 – 370. Medarević, M., Milošević, R. (2005): Tip šume osnovna gazdinska kategorija – metodika diferenciranja – Monografija „Tipovi šuma N.P.Đerdap“, str. 84-90. Milošević, R. (2006): Definisanje tipova bukovih i bukovo-jelovih šuma na Velikom Jastrepcu, Doktorska disertacija, Šumarski fakultet Univerziteta u Beogradu, Beograd. Milošević, R., (2009): “ Tipovi monodominantnih šuma planinske bukve na Velikom Jastrepcu“, Šumarstvo,3-4. Udruženje šumarskih inženjera i tehničara. Beograd, str.81-90. 429