ECOLOGICAL AND FLORISTIC CHARACTERISTICS OF NEW MONTPELLIER MAPLE (ACER MONSPESSULANUM L.) SITE IN THE LOCALITY GLOGOVITA KOSA ON MT. BORANJA

: A new motpellier maple ( Acer monspessulanum L.) site was described in this paper, located on mountain Boranja, in forest management unit „Istočna Boranja“, above Roguljski potok, on Glogovita kosa ridge. Montpellier maple occurs on elevations between 460 and 480 m a.s.l., on southwestern and western aspect, on very steep slopes with inclination 45° tо 50°. The site area is 874 m 2 , аnd coordinates of site centre are: λ=19°13’49.0” and φ=44°25’21.33”. In this site, Montpellier maple occurs in a plant community of hop-hornbeam and manna ash, and considering that Montpellier maple was recorded in all three layers, and that it oc curs abundantly in shrub and ground layers, a subassotiation with montpellier maple was set apart ( Оstryo carpinifoliae-Fraxinetum orni subass. аceretosum monspessulanii ). According to floristic composition, most plant species belong to the submediterranean floral type, so this community represents an enclave of submediterranean vegetation in the belt of continental beech forests. The community is of azonal character, orographically-edaphically conditioned, and occurs in warmer aspects, on shallow and skeletal rendzina on oolithic limestones.

У флористичком саставу ове заједнице већина врста припада субмедитеранском флорном елементу, па наведена заједница представља енклаву субмедитеранске вегетације у појасу континенталних шума букве на Борањи. Заједница црног граба и црног јасена са макленом (Оstryo carpinifoliae-Fraxinetum orni Aichinger 1933 subass. аceretosum monspessulanii) је азоналног карактера и условљена јe орографско-едафски, јер се појављује на топлим експозицијама, на плиткој и скелетној рендзини образованој на геолошкој подлози коју чине оолитски кречњаци. In this site, Montpellier maple occurs in a plant community of hop-hornbeam and manna ash, and considering that Montpellier maple was recorded in all three layers, and that it occurs abundantly in shrub and ground layers, a subassotiation with montpellier maple was set apart (Оstryo carpinifoliae-Fraxinetum orni subass. аceretosum monspessulanii). According to floristic composition, most plant species belong to the submediterranean floral type, so this community represents an enclave of submediterranean vegetation in the belt of continental beech forests. The community is of azonal character, orographically-edaphically conditioned, and occurs in warmer aspects, on shallow and skeletal rendzina on oolithic limestones. The new montpellier maple site in western Serbia, in the locality Glogovita kosa on Boranja mountain was described in this paper, which belongs to the UTM zone 34 Е 359125 and N 4920334 ( Figure 1). The orographic and edaphic site conditions were presented for this site, the plant community was defined, its floristic composition was described and comparison of ecological conditions of this montpellier maple site with those in the two previously known sites on Boranja was made. The results of this research will contribute to a better knowledge of montpellier maple distribution and its ecological and coenological characteristics, considering that it was insufficiently researched in western Serbia.

MATERIAL AND METHODS
Locating of new montpellier maple on Boranja was done by handy GPS device Garmin GPSMAP 66st, with an accuracy of 2 m.
Soil research was done on the basis of one analysed soil profile. Analytical method treatments, according to which field and laboratory soil research was made, are described in guidebooks for soil research JDZP (1966,1997). The laboratory researches of the basic physical-chemical properties were done in laboratories of the Faculty of Forestry, University of Belgrade, by standard methodology. The analysed physical properties are: hygroscopic water content (drying in kiln on temperature 105°C during 6 tо 8 hours) and granulometric composition (treating of samples by sodium-pyrophosphate, soil fractioning by combining the pipette method and the elutration method using sieve by Aterberg, with determining the following percentage fraction contents: 2-0.2 mm, 0.2-0.06 mm, 0.06-0.02 mm, 0.02-0.006 mm, 0.006-0.002 mm and less than 0,002 mm). The determination of soil texture was done by the American soil survey triangle (Soil Survey, 1951).
The determined chemical properties were: active and substitutional acidity (pH in H 2 O and in 0.01M CaCl 2 , determined electrometrically by pH meter), hydrolitical acidity (Y 1 cm 3 , by the Kappen method), the sum of adsorbed alkali cations (S in cmol*kg -1 , the Kappen method), total capacity of adsorption for cations (T in cmol*kg -1 ), sum of acidic cations (T-S in cmol*kg -1 , calculated according to hydrolitical acidity), soil saturation level by alkalies (calculated after Hissink in %), the total sum of nitrogen (by the Kjeldahl method %), carbon to nitrogen ratio (C:N) and the content of accessible phosporus and potassium (mg/100 g of soil, calculated by the Al method). Soil type was determined using "Soil classification of Yugoslavia" by Škorić et al. (1985). The geological bedrock was determined by field research and "Basic soil map of Serbia", sheet "L34-123 -Zvornik", scale 1:100.000 (Мо ј s i l ovi ć et al. 1960-1968). For establishing coenological affliation one phytocoenological releve was produced in the field, according to the Braun-Blanquet method (B ra u n -B l a n q u e t , 1964). Plant species were determined by literature sources: "Flora of Serbia" (Јоsifović et al. 1972-1977S a r i ć et al. 1992;Stevanović et al. 2012), "Flora Europaea" (Tutin et al. 1964(Tutin et al. -1980 and "Ikonographie der flora des südöstlichen Mitteleuropa" (J avo r ka , C s a p o d y 1979). The coenological affliation of the community in which montpellier maple occurs, was determined after To mi ć (2006). The floral elements were determined after Gaj i ć (1980,1984).

RESULTS
Montpellier maple (Acer monspessulanum L.) was investigated in a new site in Serbia, on Boranja mountain in forest management unit "Istočna Boranja" near Radalj settlement, southeast from Donja Borina and southwest from Gornja Borina (Figure 2).
The new montpellier maple site is located above the Roguljski stream, on Glogovita kosa ridge, on an area of 874 m 2 , and elevation between 460 tо 480 m. Montpellier maple occurs in the soutwestern and western aspect, on very steep inclination of 45° tо 50°. The site is of elliptical shape WGS84, where the centre has coordinates λ=19°13'49.0" and φ=44°25'21.33", аnd according to Gauss-Krüger the projection belongs to zone 7 with coordinates y 7359515 and x 4921300 (Figure 3).
According to the "Basic geological map of Serbia" (Мојsilović et al. 1960-1968) and according to field research it is determined that the geological bedrock in the new site is layered and banked oolithic limestones ( Figure 4).
On the basis of the results of field and laboratory soil research, the soil type was defined as rendzina according to the Soil classification after Škorić еt аl. (1985) ( Figure 5).
The soil profile has a structure А -АC -R. The potency of horizon А is around 20 cm, rich in humus, the colour is brown-blackish (10YR 2/2 - Minsell colour atlas), silty, lax, without structure. The skeletal content is very high, up to 80% of soil volume. According to the granulometric composition, horizon A is silty-clayey loam (Table 1).
Silt dominates among granulometric fractions (55.80%). Sand content fraction is twice lower (27.60%), while the content of particles less than 0,02 mm -clay, is the lowest (16.60%). The soil is very skeletal, and a large number of moderately masive limestone pieces extrude to the ground. The soil contains free carbonates and it is weakly carbonatic ( Table 2).
The alkali saturation level is very high. The concretions of calcium carbonate are present in the soil profile, formed by substrate decomposition and react intensively by adding a solution of hydrochloric acid. The humus content is high (25.94%), which indicates organic character of the topsoil. Formed humus matters have characteristics of mul humus type. The soil is very rich in nitrogen (1.05%). It is very poorly supplied with readily available phosphorus, while it is well supplied with potassium. The research locality is situated on an altitude ranging from 460 tо 480 m a.s.l, the quality of duff is good, as well as the climatic conditions for transformation. The C/N ratio (14.33) indicates that humification processes of organic material are somewhat more pronounced compared to the process of humus mineralisation. High total nitrogen content, due to poor mineralisation, does not guarantee good supply of this micronutrient to plants. In line with the high humus content, hygroscopic water content is also high (7.55%).
On the basis of the field phytocoenological research (Table 3), it is ascertained that montpellier maple occurs in the plant community of hop-hornbeam and manna ash (Оstryo carpinifoliae-Fraxinetum orni Ai ch i n ger 1933). According to To m i ć (2006), the mentioned community belongs to the alliance of hop-hornbeam and manna ash forests (Fraxino orni-Оstryon carpinifoliae To m a ž i č 1940), to the order of thermophilous broadleaved forests (Quercetalia pubescentis Klika 1933) and the class of beech and oak forests (Querco-Fagetea Br.-Bl. et Vlieg. 1937).
The tree layer has a 0.6 canopy, the average tree height is 7 m, and the average diameter is 17 cm. The highest frequency and coverage in this In the shrub layer (Table 3), with a 0,7 canopy and an average height of 4 m, the most frequent species are manna ash (Fraxinus ornus 3.3) and montpellier maple (Acer monsspesulanum 2.2). The species which occur with a lower frequency are: warted spindle-tree (Euonymus verrucosus 1.2), common hawthorn (Crataegus monogyna 1.2), checker tree (Sorbus torminalis 1.2), com-mon ivy (Hedera helix +) and European bladdernut (Staphylea pinnata +).
The ground layer coverage is 0.6, the highest frequency have manna ash (Fraxinus ornus 3.3) and montpellier maple (Acer monsspesulanum 2.2), аnd other wood species present are: Rosa arvensis 2.

Quercus pubescens +
The phytocoenological releve shows that montpellier maple occurs in all three layers, and that it is abundant in the shrub and ground layers, so the subassociation with montpellier maple was set apart within the association of hop-hornbeam and manna ash (Оstryo carpinifoliae-Fraxinetum orni Ai ch i n ger 1933 subass. аceretosum monspessulanii) (Figure 6).
According to the floristic composition, most plants belong to submediterranean floral ele-

DISCUSSION
Jovanovi ć (1973) notes in "Flora of Serbia V" that montpellier maple is widespread in Serbia, and most of its localities were recorded by Mišić (1981) in gorges and canyons of eastern Serbia, where it always occurs on limestone bedrock.
Montpellier maple is less frequent in western and southwestern Serbia, and on all so far recorded localities: Gučevo (Vu ki ćevi ć, 1971), Boranja, Tara, near Priboj (То m i ć , 1980) and river Drina canyon (Мišić, 1981) it also occurs on limestones. Plant communities in which montpellier maple occurs form on soils of low level of evolutive-genetic development. In the Priboj area, Tomić (1980) recorded regosols, organic, intermediate and coluvial rendzinas, while on Boranja she determined only regosols. In the new site on Mt. Boranja, montpellier maple was recorded on organic rendzina. Considering ecological-productive characteristics, the most unfavourable conditions for montpellier maple development are on regosol, while they are somewhat more favourable on organic rendzina. Intermediate rendzina is at a little better stage of development compared to organic rendzina and is characterized by a slightly higher depth of around 30 cm, higher clay content (32-65%), and lower humus content (То mi ć, 1980).
The mountain massif of Boranja is located in western Serbia. Despite the high precipitation level in the Boranja area (above 1000 mm yearly), summer drought occurs, which is caused by the character of geological bedrock and relief, so its extreme forms manifest especially on limestone and warmer aspects with high inclinations. High inclinations, limestone bedrock, the occurence of erosion process and continual removal of soil material cause retarded genesis and forming of poorly developed and shallow soils, as regosols and rendzinas.
Montpellier maple in eastern Serbia is represented in various forest and shrub ommunities, and it occurs most frequently in degraded oak forests and shrublands with the dominance of oriental hornbeam (М i š i ć, 1981).
In contrast to eastern Serbia, where montpellier maple occurs in polidominant forests and shrublands dominated by oriental hornbeam (Carpinus orientalis), in western Serbia it mostly occurs in forests where hop-hornbeam (Ostrya carpinifolia) is the dominant species. In Gučevo, in the watershed of the Siga stream, Vu k i ć ev i ć (1976) recorded montpellier maple in the community of turkey and downy oaks (Оstryo carpinifoliae-Quercetum (B. Jovanović 67) Tomić 1980 Syn. Quercetum cerris subass. ostryetosum), in the ground layer, on elevation 720 m a.s.l, in southeastern aspect and an inclination of 10°.
In at an elevation of 850 m, in the northwestern aspect, at an inclination of 35°.
On Boranja mountain, montpellier maple was, so far, recorded in two localities -in the basin of the Borinska river and the Bučevo stream, in the plant community of oaks and hop-hornbeam (Оstryo carpinifoliae-Quercetum (B. J o va n o v i ć 1967) To m i ć 1980., syn. Helleboro-Ostryo-Quercetum To m i ć 1980). In both sites, Montpellier maple occurs only in the shrub layer, at an elevation of 400 m a.s.l. In the first site, it occurs in the southern aspect at an inclination of 60°, аnd in the second site in the southwestern aspect at an inclination of 30° (То mi ć, 1980).
In the new site on Mt. Boranja this species was recorded above the Roguljski stream at a higher elevation (460 tо 480 m). There, it is present in warmer aspects (southwestern and southeastern), similar to the first site recorded by To mi ć (1980), different from the second site, which is in the northern aspect. Montpellier maple in this new site is situated on very steep slopes (40° -50°), slightly higher than in the second site (30°), аnd slightly lower than in the first site, where the inclination is 60°. In contrast to both sites recorded by Tomić (1980) where montpellier maple occurs only in the shrub layer, in the new site on Mt. Boranja maple occurs abundantly in all three layers (tree, shrub and ground layers).
In both sites near Priboj (То mi ć, 1980), montpellier maple occurs at higher elevations than in the new site on Mt. Boranja, because it is recorded at an elevation of 1050 m a.s.l. in the first site, аnd 700 m a.s.l. in the second site. Montpellier maple in the new site on Mt. Boranja occurs in a warm aspect, like in first site near Priboj, but on higher inclinations (40°-50°), than in the site near Priboj (30°). Compared to the second site near Priboj, the inclinations are similar (40°-50°), but montpellier maple here occurs in the cold (northern) aspect. Although it belongs to the same community of hop-hornbeam and manna ash (Оstryo carpinifoli-ae-Fraxinetum orni A i c h i n ge r 1933., Syn. Orno-Ostryetum (A i c h i n g e r 1933) Erker 1970), the new montpellier site on Mt. Boranja differs from sites near Priboj by orographic conditions.

CONCLUSION
Montpellier maple was recorded in a new site on Boranja mountain in forest management unit "Istočna Boranja", northeastern from settlement Radalj, southeastern from Donja Borina and southwestern from Gornja Borina, above the Roguljski stream, on Glogovita kosa ridge. It occurs at elevations ranging from 460 tо 480 m a.s.l, in the southwestern and western aspect, on a very high inclination from 45° tо 50°. The area of the new site is 874 m 2 . Its centre has coordinates λ=19°13'49.0" and φ=44°25'21.33".
The geological bedrock is made of oolithic limestones, and the soil type is rendzina. The soil profile has structure А -АC -R. The potency of horizon A is around 20 cm, and it is rich in humus. The skeletal fraction content is very high (up to 80% of soil volume), аnd according to the granulometric composition, this horizon is silty-clayey loam. The alkali saturation level is very high. The humus content is high and indicates organic character of the topsoil, which belongs to the ripe (mul) humus. The soil is rich in total nitrogen, well supplied with potassium, while it is poorly supplied with readily available phosphorus.
Montpellier maple was recorded in the community of hop-hornbeam and manna ash in the new site on Mt. Boranja. Considering that montpellier maple is present in all three layers, and that it is abundant in shrub and ground layers, a subasociation with montpellier maple was set apart in this association (Оstryo carpinifoliae-Fraxinetum orni Aichinger 1933 subass. аceretosum monspessulanii).
In the floristic composition of this community, most species belong to submediterannean floral elements, so this community represents an enclave of submediterranean vegetation in the belt of continental beech forests on Mt. Boranja. The community of hop-hornbeam and manna ash with montpellier maple (Оstryo carpinifoliae-Fraxinetum orni Aichinger 1933 subass. аcere-tosum monspessulanii) has azonal character and it is orographically-edaphically conditioned, because it occurs in warm aspects, on shallow and skeletal rendzina produced on oolithic limestone bedrock.
Remark: This paper was realized within the Agreement on finansing NIO scientific work in the year 2021, which the University of Belgrade -Faculty of Forestry concluded with the Ministry of education, science and technological development of Republic of Serbia. Record number of the project is 451-03-9/2021-14/2000169.