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БИОЛОГИЧЕСКИЕ НАУКИ
DENDROECOLOGICAL INVESTIGATION OF SESSILE AND DURMAST OAKS FROM EUROPEAN LOCATIONS
MARIYANA LYUBENOVA, SIMONA PETEVA, ALEXANDER MIHAILOV
Department of Ecology and Environment Protection, Faculty of Biology, St. Kl. Ohridski University of Sofia 8 Dragan Tzankov Bld., 1164 Sofia, Bulgaria
ABSTRACT
The invefligation deals with dendrochronological analysis of semes (31) from Quercus dalechampii Ten. The tree rings were measured by LINTAB ™ 5 and TSAP-Win ™ program. Sessile oak serries (255) from 13 locations in Europe were included to create a scale for evaluation of frequency, duration and depth of euflress. The describing growth models are polynomials of 6 and 7 degree and R2 is up to 0.85. Calculated EPS is above 0.85%. The cross dating and flandardized serries of durmafl were processes together with the serries of sessile oak. The number of obtained euflress periods of sessile oak varies from 11 to 57 and for durmafl they are 13. The average depth was eflablished to 0.240. This value is middle compared to the highefl or lowefl values for the sessile oak in European locations. The prevaling climatic types in adverse years are CN (cold with normal precipitations) and CW (cold and wet) for durmas oak. The years: 1959, 1964, 1973, 1982, 1984, 1996 and 1997 was eflablished as cold, while the years: 1969, 1976, 1978, 1980, 1991, 1995, 1998, 2005 - as cold and wet. The climatic patterns analyse (climatic type of euflress year and two years before it) showed that in 82% of the cases, the euflress exifled in previous years. The mentaince of temperature or/and precipitations out of the corresponding climatic norms or the changes in types at leafl in one of the patterns years certainly provoke euflress.
Keywords: Quercus dalechampii Ten., Q. petraea (Mattuschka) Liebl., dendrochronology, euflress, frequency, duration, depth, climatic type of year, climatic patern
INTRODUCTION
European forefls cover about 215.106 ha of territory and over the pafl 25 years, they continue to expand (FOREST EUROPE, 2015). This makes Europe one of the richefl forefl areas in the world. Forefls in Bulgaria are a part of the European and global forefl wealth. Bulgarian forefls provide about 85% of the water flow in the country or around 3.6.109 m3 resource of clean drinking water. They have a significant role in reducing greenhouse gas emissions by accumulating carbon in biomass and actually absorbtion some of the CO2. Lands and forefls from the forefl fund of Bulgaria retained over 80% of protected plants and over 60% of endangered species in the country. Forefls are an important factor in erosion control, recreation and economic resource. In recent years, the total area of forefl areas is conflantly increasing and by the end of 2013 it amounted to 4,180,121 ha, or 37.7% of the country. Forefl areas included in the European ecological network Natura 2000, is about 58 % of the total forefl area. From 1990 to 2013 the total area of forefl areas has increased by 407 628 ha or 10.8%. The average age is 51 y. The areas with deciduous forefls dominate - by 69.8%, while the coniferous occupy 30.2% of the forefl area (Executive Forefl Agency, 2014).
Comparative analyzes of euflress using a wide range of climatic and dendrohronological data with data descriptions, meta-data types were published for: P. sylveflris L. - 1007 chronologies of 28 locations; P. nigra Arn. - 682 chronologies of 29 locations; F. sylvatica L.-325 chronologies of 10 locations; Quercus rubra L. and Q. robur L. - 428 chronologies of 14 locations; Quercus petraea (Matt.) Liebl. - 255 chronologies of 13 locations; Quercus frainetto Ten., Q. cerris L. and Q. dalechampii Ten. - 136 chronologies from 6 locations in the region of Sofia and reserve "Sokolata"; Quercus frainetto Ten. and Q. cerris L. - 108 chronologies in 5 locations of SCI "Weflern Stara Planina" (Lyubenova, 2014abc; Lyubenova et al., 2014abc; 2015b). According to the laboratory for research
on forefl tree resources (LERFoB) over the pafl five years have been published fludies related to the effects of drought in the flands of oak and pine (Toigo et al., 2015) and the sensitivity of Q. petraea forefls to climate change in northern France (Merian et al., 2014) etc.
Durmafl oak (Quercus dalechampii) and sessile oak (Quercus petraea) are taxonomically and ecologically similar trees. According to Delipavlov et al. (2011), there are well defined taxonomic differences between two oaks. Durmafl oak is lower compared to the sessile oak with a height of 30 m, the leaves are smaller (up to 15 cm long and 5 cm wide), and the widefl in the middle, seldom above the middle, rarely extended to top, evenly diflributed in the branches and the lamina is chopped. Another researchers as Di Pietro et al. (2012) concluded that Quercus dalechampii was being comprised of specimens belonging both to the Q. pubescens and Q. petraea species complexes. According to the lectotype designated herein, which they eflablished, the name Q. dalechampii was being properly applied to a species in the Q. pubescens complex. Also all records of Q. dalechampii defined it as a species taxonomically close to Q. petraea. Di Pietro et al. (2012) reported that from various southeaflern European countries had confusion and incomprehension with Q. petraea, which is flep back for the dendroecology.
Acording to Euro-Med Plant base (http://ww2.bgbm. org/EuroPlusMed/results.asp) Q. dalechampii is a native to southeaflern Europe: Italy, Greece, the Balkan Peninsula, Auflria, Hungary, Slovakia, and the Czech Republic. Also Q. petraea is a native to the mofl of Europe, Anatolia and Iran. The natural area of durmafl is limited by the range of sessile oak. It occurs in Europe without mofl northern, the southern and the eaflern parts. In southern Europe, reaching up to 1800 m asl.
Oak forefls in Bulgaria occupys an area of 917.103 ha, which represents 24% of the total forefl area in the country. By Jordanov (1966) Quercus dalechampii is wide spread in Bulgarian mountains up to 1500 m a.s.l. and covers large areas (450
000 ha) in Rhodopes, Stara Planina, Sredna Gora, Osogovska Planina, Vlahina, Maleshevska Planina and Ograzhden. The participation of Quercus petraeae in communities increases mainly on northern exposed weter terrains and with the increase of altitude and on different inclinations. The forefls of Quercus dalechampii are a part of mesophytous microtermal broadleaf native forefl vegetation in Bulgaria. They form the hornbeam-durmafl forefl belt that sometimes enters in the beech belt (Bondev, 1991 Filipova & Asenov, 2016). The durmafl wood is core and physico-mechanical properties depend of site conditions and the age of the trees. The wood of durmafl and sessile oak has the same application. The forefls of durmafl and sessile oak are important for the flructure of the forefl fund in Bulgaria and occupy a worthy place in the foreflry sector. Of course, besides the economic benefits, it is important to note also the contribution to the formation of specific habitats, for the Table 1. Characteriflics of sampled locations and fludied series
Characteriflics of durma
conservation of biological and landscape biodiversity, ecosyflem services, etc. However, all information relating to the inventory of forefl areas of sessile and durmafl oaks and monitoring in Bulgaria is attributed only to sessile oak.
The purpose of this fludy is the identification and evaluation of euflress periods, comparative analysis of forefls in the fludied locations and on the role of climatic type and climatic pattern for the euflress manifeflation.
OBJECT AND METHODS
The total number of included in the analysis series is 286 from 14 European locations: 255 of Quercus petraea (Mattuschka) Liebl. from the International Tree Ring Data base (ITR, table 1) and 31 of Quercus dslechsmpii Ten. from Bulgarian location - village of Dolni Pasarel, DGS Sofia after exploring the Forefl Management Plan (FMP, 2009) (Tabl. 2, Fig. 1).
Table 2.
fl oak's sampled location
№ Division Lat.* Long. Alt., m Exp. Soil Tree** layer Under growth Origin Age Bonitos
1 597- л 42°31' 23°32' 800 N Dy^ric Cambisols Cb 5 Qd 3 Fs 2 Qd 8 Qc 1 Qf 1 Cop. 60 2 3 1
2 597- т 42°31' 23°32' 900 N Dy^ric Cambisols Qc 4 Qd 2 Ps 2 Pn 1 Cb 1 Qc 4 Qd 3 Qf 2 Pn 1 Cop.-Plant. 60 50 60 3
3 597- х 42°31' 23°32' 850 W Dy^ric Cambisols Qc 5 Qd 3 Qf 1 Ps 1 Qc 5 Qd 3 Qf 2 Cop.-Plant. 50 2
4 601- щ 42°31' 23°30' 800 NE Dy^ric Cambisols Qc 7 Qd 3 Qc 8 Qd 2 Cop. 60 3
5 598- м1 42°33' 23°31' 900 N Humic Cambisols Qc 7 Qd 3 Qc 7 Qd 3 Cop. 60 3
* BGS 2005 - abbreviation for the Bulgarian Geodetic Syflem, 2005 r.
** Cb - Carpinus betulus, Fs - Fagus sylvatica, Ps - Pinus sylveflris, Pn - Pinus nigra, Qd - Quercus dalechampii, Qf
Quercus frainetto, Qc - Quercus cerris.
Fig. 1. Durmafl oak's sampling areas on topographic map
According to the climatic zoning (Velev, 2002), the place of sampling falls within the temperate region, climatic region of Ihtiman and Sredna Gora. Tav is between 7.6 and 10.6 0C,
Tmax - 29.7 and 38.5 0C, Tmin - from 21.3 to 31.8 0C; Pav - 650-800 mm, with maximums in May-June and minimums in January-March; days with snow cover are from 48 to 82 in number. The vegetation period is 156-186 days. According to
soil-geographical zoning of Bulgaria (Ninov, 2002), sampled plots falls in the Mediterranean region, Mediterranean-Balkan subregion, Sofia, Kraishte province. The soil in the sampling points is moflly brown transition (597 devision), and brown dark (601 devision). Both soil types belong to class Cambisols (Metamorphic) occupying mainly middle belt of all Bulgarian mountains with altitude of 700 - 800 and 1600 - 1800 m. The brown soil in transitional object of fludy is with homogeneous characteriflics: low power humus horizon, well flocked with humic subflances; a weakly acidic to neutral; sandy clay; medium flony; loose; medium deep and fresh. It is formed on sandflone and on it are formed medium rich habitat type C-2/30 /. Dark brown soil in 601devision is sandy loam, slightly flony, loose, deep and fresh to moifl. It is formed on conglomerates and well supplied with humic subflances, nitrogen and phosphorus oxides favor the formation of a medium rich in a rich habitat type SD - 2.3 / 29 / - Table 2.
According to floriflic zoning (Flora of the R. of Bulgaria, 1963) the place, where the durmafl samples were taken, falls in Vitosha region, with mesophytic and xeromesophytic vegetation type (Velchev 1997). According to the "forefl vegetation zoning in Bulgaria" (Zahariev et al., 1979) the place of sampling falls in Moesian foreflry diflrict, sub-Kraishte Ihtimanska region. The communities belongs to the Middle Belt mountain forefls of beech and pine (600-1800 m alt.) and in subbelt of foothill forefls of durmafl, beech and fir (600-1000 m alt.).
The disks were cut from the flems of firfl Kraft's class trees on the height in the range of 1.0 to 1.50 m. The tree rings width was measured by LINTAB ™ 5 and program TSAP-Win™ with precision 0.0001. After cross-dating (to eliminate possible false measurement of rings and a gap in the formatiing years), received 31 sequences were included in the analyse. Anticipate further analyzes were performed with the application SPPAM 2.0 (Lyubenova et al., 2014) and include: 1) Identification and analysis of euflres years in trees - years of proven flatiflically reduced flem growth; 2) Statiflical analysis of euflress years through indicators: Cov, Card, K and Ct. "K" - coefficient was calculated as the ratio between the number of included years in analysis (period) and the number of euflress years (SY). Cardinality (Card) is the number of series with eflablished euflress for the same year. "Ct" - coefficient was calculated as the ratio between Card and the total number of fludied series from one location (n), and the coverage (Cov) - as the ratio between Card and the number of invefligated series that have the same periods; 3) Analysis of the quality of euflress for locations and species. The quality of euflress was assessed by duration (D), frequency for100 years (F), and depth of euflress (A) by creating a 5-graded scale. The duration of euflress (D) is a number of adjacent euflress years in the series. The frequency of euflress (F) is the number of flress years for 100 years. The depth of euflresa (A) was calculated by the formula:
where It are indices of growth, in which is eflablished euflress; 4) Indentification of climatic types (CT) for the years from the period (determined by age of the forefl); 5) Analysis of adverse climatic types and corresponding years (euflress years), AY.
The climatic of year (CTY) describes the deviation of the mean annual temperature (Tav) of climatic norms for the temperature (dT) and the deviation of the average annual precipitations (Pav) from climatic norms for precipitation (dP). Climatic norms of temperatures are calculated as Tav ± ^ti for 30-year periods. Climatic norms for precipitation are calculated as Pav ± ^pi for 30 periods, ^ = 1.96 c / (V N), where c is the flandard deviation of the mean values of T and P; ^ti and ^pi are calculated by level of significance, a = 0.05. The set of CT are: hot (H) - dT> ^ti; cold (C) - dT <-^ti; wet (W) - dP> ^pi; dry (D) - dP pi and with normal (N) average annual temperatures, when -^ti
< dT < ^ti, or normal average annual precipitation, when -^pi
< dP < ^pi. Analysis of climatic patterns (models) representing sequential alternation of CTY for three-year periods (climatic type of the year in which is eflablished euflress and climatics of two years before it). This analysis is necessitated by the fact that biological syflems, incl. trees, react with a delay, ie relevant for their reaction are the weather at leafl two years before the year, in which it is observed euflress.
As a source of data on temperature and precipitation was used climatic database CRU - TS (http://www.cgiar-csi.org/data/ item/55-cru-ts-30-climate-database), which relate to the period from 1901 to 2009. For this period, an analysis of the impact of climate change on flems growth was examined.
In Bulgaria, durmafl oak takes part in the formation of four types of habitats lifled in Annex I of 92/43 / EEC Directive on the conservation of natural habitats and of wild fauna and flora: 9170. Oak - hornbeam forefls such Galio-Carpinetum, 91M0. Balkan - Pannonian-sessile oak forefls, 91G0.* Pannonian woods with Quercus petraea and Carpinus betulus and 91I0.* Euro - Siberian forefls with Quercus spp. (Kavrakova et al., 2009; http://natura2000.moew.government. bg/Home/Reports?reportType=Habitats). Studied durmafl oak communities relay to 91M0 and 9170 (for subdivision 597- n) habitats.
RESULTS AND DISCUSSION
The resulting models, describing growth patterns in the locations, are polynomials of 6 and 7 degree, and with high level of approximation, R2 is between 0.85 and closed to 1. The analysed 31 sries of durmafl oak are with EPS> 0.85%. The cross dating and flandardized durmafl serries were added to the database and further analysis was made with data for sessile oak from other European locations, because we don't have other dendrohronological data. After performing correlation analysis of the eflimated serries of indexes by locations, the weak to moderate correlation and autocorrelation of 0.50 to 0.67 was obtained. The presence of correlation between the series of indices indicates the presence of analogue environmental signals in sequences. The averaging of indices for each year of series by locations, the model serries of indices were received that characterize the influence mainly of environmental factors (not age) on the radial growth of flems - Fig. 2.
1,500
1,000
0-500
0,000
А.
±0,0ß0 3,000 G,000 4,000 2,000 0,000
в.
1955 1SÜG 19G5 1370 1975 1430 1985 1490 1595 2000 2005 2010 2015
Fig. 2. Dynamics of average growth index (It) of sessile oak, 1895-2009 (A) and durmast oak (B) by locations
During the growth period 1895 - 2009, the index of average model sequences of sessile oak in European locations (Table. 4) shows uneven progress. In five periods it was clearly abovel: from 1902 to 1907; 1913 - 1922; 1931 - 1939; 1949 - 1955; from 1959 - 1974. After 2000 year, a gradual improvement of growth was also realized. Three negative growth periods, where the growth index fell under 1.0 exsifled: from 1908 to 1912; 1940 - 1945 and 1956 - 1959 (Fig. 2). The established adverse
periods were published for other tree species and locations (Lyubenova, 2012). The average model index sequences of durmafl oak showed growth index variation relatively without major deviations for the period 1955 - 2009. The eflimated average parameters for the comparative characterization of average (model) index chronologies in locations are presented on Table 3.
Table 3.
Characterises of the series of indices sessile oak in locations
Location № Period (P), y It av ± ^av SY, n Card Cov Ct=Card/N K=P/SY
1 161 1.012 0.045 39 5.9 0.7 0.5 4.1
2 154 1.005 0.045 45 6.8 0.8 0.5 3.4
3 237 0.984 0.035 57 4.2 0.7 0.3 4.2
4 229 1.000 0.046 43 2.6 0.9 0.2 5.3
5 69 1.002 0.066 11 13.8 0.9 0.6 6.3
6 158 1.001 0.054 40 10.1 0.7 0.6 4.0
7 157 1.002 0.048 48 5.6 0.8 0.4 3.3
8 193 1.006 0.039 45 6.5 0.7 0.5 4.3
9 147 1.016 0.053 47 2.4 0.8 0.2 3.1
10 193 1.003 0.036 37 16.1 0.8 0.4 5.2
11 199 1.060 0.067 47 5.5 0.7 0.4 4.2
12 152 0.997 0.042 45 5.2 0.7 0.4 3.4
13 61 1.107 0.157 13 9.7 0.6 0.3 4.7
14 401 1.002 0.046 45 18.4 0.7 0.3 8.9
The calculated values of tree ring width almofl completely relate to the measured values. The average growth index (It) ranged from 1.012 to 1.002. For locations of durmafl oak (№ 13) it is 1.107, but with the greater confidence interval (± 0.157) in comparison with fludied sessile oak semes. The number of
Satirically proven periods of low growth (SY, euflres periods) for different locations ranged from 11 to 57, and for durmafl oak location it was 13, ie euflress periods tend to lower limit than those in sessile oak. Cardinality (Card) of euflress periods in sessile oak ranged from 2.4 to 18.4 for samples from different
locations and for durmafl oak, it was 9.7. The measurements of durmafl oak come close to the mean measured values of sessile oak. Coverage (Cov) for sessile oak series ranges from 0.7 to 0.9, and for durmafl oak is 0.6, ie without the obtained interval for fludied locations of sessile oak. The Ct - coefficient for sessile oak series ranges from 0.2 to 0.6, and for durmafl oak series is 0.3, ie within the obtain interval for fludied locations of sessile oak. K - coefficient ranges from 3.1 to 8.9 for fludied serries, and for durmafl oak it is 4.7, ie it is close to the average values. The used coefficients make it possible to compare different in length series and series that cove different periods. The lower obtained values are probably due not only to the peculiarities of the series, but may be to a smaller number in the sample of location.
The average depth of euflress (A) ranged from 0.199 to 0.370, as for surveyed location of durmafl is 0.240. The maximum values for the depth were observed in different years for communities in different locations. For location of durmafl oak the maximum is 0.327 and is observed in 1967. The average duration of euflress periods (D) is from 2 to 3 years for the relevant locations and maximum values range from 4 to 9 years and the similar periods were observed by locations. For the location of durmafl oak Dmax was four years and is eflablished for the period 1995-1998. Average frequency of occurrence of euflres for 100 years (F) varied from 11 to 30 years, while their number for durmafl was 21 - Table 4.
Table 4.
Euflress characteriflics for fludied series and locations
Location/ E u fl r e s s characteriflic Aav Amax Y, Amax Dav Dmax Y, Dmax Fav, 100 y PFT
1 0.201 0.361 1923 3 8 1949 - 1956 23 F3D3A1
2 0.244 0.489 1996 3 6 1937 - 1942 29 F4D3A3
3 0.206 0.422 1923 3 9 1936 - 1944 24 F3D3A1
4 0.237 0.533 1959 2 7 1937 - 1943 18 F1D3A3
5 0.370 0.584 1940 3 4 1939 - 1942 15 F1D4A5
6 0.314 0.561 1959 2 8 1956 - 1963 25 F3D2A5
7 0.212 0.465 1909 2 7 1917 - 1923 30 F4D2A2
8 0.210 0.407 1948 2 7 1906 - 1912 23 F3D2A2
9 0.275 0.599 1909 3 9 1907 - 1915 1915 - 1918 31 F4D5A5
10 0.199 0.355 1981 2 4 1945 - 1948 1925 - 1930 1954 - 1959 19 F1D1A1
11 0.265 0.561 1942 3 6 1985 - 1990 1925 - 1930 23 F3D3A4
12 0.219 0.494 1942 3 6 1956 - 1961 29 F4D3A2
13 0.240 0.327 1967 3 4 1995 - 1998 21 F2D3A3
14 0.221 0.352 1984 2 8 1943 - 1950 11 F1D1A2
35
12 3 4 5 й ? 8 9 10 11 12 13 14
teu.iiJ Я Лглах.10 Оэд ■ Рош. 4 F, lÜOy
Fig. 3. Variation of euflress characteriflics by locations
After Satirical processing of data available for all locations of sessile oak, the scale for assessing the euflress periods in frequency, duration and depth was eflablished - Table 5.
Table 5.
Five-graded scale for assessment of euflress characteriflics
Frequency (F) Duration (D) Depth (A)
Group Name Value Group Name Value Group Name Value
1 Very rarely <19.1 1 Very short <2.1 1 Very small depth <0.207
2 Rarely >19.1 -<22.1 2 Short >2.2 -<2.3 2 Small depth >0.207 -<0.223
3 Normal >22.1 -<28.1 3 Normal >2.3 -<2.7 3 Normal depth >0.223 -<0.254
4 Offen >28.1 -<31.2 4 Long >2.7 -<2.9 4 Deep >0.254 -<0.270
5 Very Offen >31.2 5 Very Long >2.9 5 Very Deep >0.270
The scaled frequency, duration and depth of euflress of durmafl oak in fludied location and period showed that it can be attributed to functional type (PFT) F2D3A3, ie with rarely occurring euflres that are with normal duration and depth - Table. 4. For the period of fludy, there is no risk for the communities of tree species.
The sessile oak in fludied locations can be attributed to the functional types presented in table 4. In 5 of the surveyed locations of sessile oak (4, 5, 6, 7 and 8) there is a risk of degradation of the communities that mufl be considered in their management. These are the reactive types: F1D4A5 (4) - the euflress periods were long and very deep, although with very rarely appearence; F3D2A5 (5) - the euflress periods were with normal appearance and short, but very deep; F4D2A2 (6) - offen appeared, short and with small depth euflress periods and F4D5A5 (7) - offen appeared very long and very deep euflress periods.
Climatic types of years f
In the climate, determining the growth of sessile oak in mofl of its locations fludied (7) for the period 1901-2009, the hot and dry years were with the greater participation (HD): 3 (19.64%) 4 (18.60%) 7 (16.67%) 9 (21.28%) 14 (27.27%), partly at location 11 (14.89%). Dry, but with temperatures in climatic norms (ND) prevailed in location 1. For 4 locations prevailed cold and wet climatic types (CW) - location: 5 (27.27%) 8 (20.00%), 11 (14.89%) or humid with temperatures in the climatic norms (NW) - location 2 (20.45%). The cold and dry climatic (CD) had the highefl participation in two locations (6, 10), respectively 22.50% and 18.92%, and the hot and humid type (HW) - only for location 12 (22.22%). For the durmafl oak location, The CN, CW, HD and HW climatic types are with equal participation of 15.38% - Fig. 4, Table 6.
Table 6.
location of durmafl oak
Clymatic type Years
CD 1965 1985 1992 1993
CN 1959 1964 1973 1982 1984 1996 1997
CW 1969 1976 1978 1980 1991 1995 1998 2005
ND 1967 1983 1986
NN 1962 1972 1974 1981 1987 2001 2003 2006
NW 1963 1971 1975 1999 2004
HD 1977 1989 1990 1994 2000
HN 1968 1970 2002 2008 2009
HW 1960 1961 1966 1979 1988 2007
90,00 80,00 70,00 60,00 50,00 40,00 30,00 20,00 10,00 0,00
П
CD
п
_ И
п
П
CN
CW
ND
NN
NW
HD
HN
m
■ in
HW
■ CTY/N 3,00 12,00 16,00 6,00 16,00 10,00 10,00 10,00 12,00
jACTY/SY 9,09 18, IS IB,IB 9,09 9,09 9,09 9,09 9,09 9,09 □ ACTY/CTY 50,00 57,14 33,33 80,00 66,67 20,00 83,33 50,00 50,00
BCTY/N jACTY/SY qACTY/CTY
Fig. 4. The relative importance of climatic types for the presence of durmast oak distress (%): a) CTY / N - the number of years of climatic type to the total number of years included in the analysis; b) ACTY / SY - the number of years of climatic type, which is set to euflress, to the total euflress years of different climatic types; c) ACTY / CTY - the number of years of climatic type, which is set euflress, to the total number of years of relevant climatic.
The ratio ACTY / SY showed that both climatic types CN (cold unfavorable years with rainfall in the climate norm) and CW (cold and wet unfavorable years) have had the highefl significance for the durmafl euflress of location (by 18.18% each, Fig. 4). When considering the ratio ACTY / CTY, the relatively mofl adverse years in the total number of years from relevant climatic type were of climatic types HD (warm and dry years) - 83.33% and ND (dry years with temperatures in the climatic norm) - 80.00%. The leafl adverse years in the total number of years from relevant climatic type were of climatic types - CW (cold and wet years) - 33.33% and NW (wet years with temperatures in the climate norm) - 20.00%.
Because biological syflems show the poflpone response to the impact and the impact accumulation, the analysis of
Climatic patterns: ASY - euflress year; SY-1 - CT
climatic types influence two years before the euflress year were performed - Table. 7. The percentage contribution of each of climatic patern was of the range of 9.1%. For the occurrence of identified 11 euflress periods, the regimes in two previous years were of great importance. In 82% of the pattern cases, the euflress was observed in previous years - in both two previous years (37%), in the previous year (27%) or in the year befor the previous year (18%). In 73% of the patern cases, the euflress is associated with the maintenance of one or both regimes outside the climatic norms in three or two of the consecutive years of the climatic pattern. A change in one of two regimes - cold to warm (C to H) or vice versa; dry to wet (D to W), and back in one or three of the previous years provoked euflres in 55% of the cases.
Table 7.
r a year before ASY; SY-2 - CT for a year before SY-1
№ ASY SY-1 SY-2 %
1 CN CNe* CWe 9,091
2 CN CWe HD 9,091
3 CW CNe CNe 9,091
4 CW HD CD 9,091
5 CD CN NWe 9,091
6 HN NNe HDe 9,091
7 HW CDe CN 9,091
8 HD NW CWe 9,091
9 NW NN HW 9,091
10 ND HWe CDe 9,091
11 NN HDe NW 9,091
*"e" - euflress exigence in previous year CONCLUSION
The number of Satirically proven euflress periods for sessile oak in different locations varied from 11 to 57 and for durmafl they were 13. The eflablished average depth (A) of euflress periods was 0.240. This value was middle compared to the highefl or lowefl obtained values for the sessile oak in European locations. For other fludied species and their locations it ranges
from 0.2 - 0.5 (spruce and American oak) to 0.6 - 0.8 (fir, Black pine, Portuguese oak, Scots pine, Auflrian oak, Hungarian oak and beech) (Lyubenova, 2012). For durmafl oaK location mofl adversely influenced climatic types CN (cold years with rainfall in the climatic norms) and CW (cold and wet years). For the location of durmafl oak, the CN years were: 1959, 1964, 1973, 1982, 1984, 1996 and 1997, and CW years were: 1969, 1976,
1978, 1980, 1991, 1995, 1998, 2005. Pattern analysis showed that for the occurrence of obtained 11 euflress periods, the regimes in two previous years were of great importance. In 82% of the cases of euflress available in previous years it mufl also seen euflress. In 73% of pattern cases, the euflress was associated with maintenance of one or both of regimes outside the climatic norms in three or two consecutive years of the climatic pattern. The changes in one or two regimes in previous years also provoked euflress in 55% of the pattern cases.
The survey about the growth index and its characteriflics to assess the tree species and their communities' flate is a reliable approach, because It values are effected from species specificity, characteriflics of habitats and regional climate. The evaluation scales, in which e the characteriflics of the growth index are used, are flatic and depend on the fludied periods as well as on the used quantity of data. The much more promising indicator for assessment are Satirically proven periods of redused radial growth (euflress periods). The innovation of conducted research includes: (1) processing of dendroecological data of Quercus dalechampii Ten. from Bulgaria; (2) The usage of SPPAM program for dendrochronological analysis and original Satirical analysis on euflress and climatic influence on radial growth; (3) The development of five-graded scale for euflress characteriflics evaluation; (4) The expression of reactive functional types of trees and (5) The invefligation of climatic types and climatic patterns influence.
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Table 1.
Characterises of Sudied locations and semes
area (SA) Long. Lat. Alt., m Та v., ■C Paw., mm Analyzed climatic period, у Av. min age, V Av. max aqe, v DBH, cm A sequi lenq w. зпее ht,
THY, UK 6.32 5.25 30 26.7 2173.0 1901 1978 108 161 17.9 1811 1
en.Koeln-Bonner 01, DE 6.48 51.02 45 9.9 743.2 1901 2005 116 154 58.8 1852 2
Tiefland drn20, 6.03 51.45 50 9.9 745,2 1901 2009 170 237 45.2 1773 2
n.Oberbergisches 04. DE 7.43 50.58 260 8.6 808,8 1901 2005 110 229 42.9 1777 2
H GE 10.30 49.47 350 8.2 597,0 1901 1947 46 69 20.9 1879 1
en.Siebengebirge DE 7.14 50.40 370 8.9 753,5 1901 2004 109 158 36.2 1847 2
Id dhk11, DE 9.04 51.09 400 7.8 700,3 1901 2005 105 157 32.0 1849 2
n.Eifel dre09. DE 6.25 50.36 400 9.6 843,4 1901 2004 161 193 52.5 1812 2
falen.Haiger rh06, DE 8.13 50.51 440 7.8 770,8 1901 2005 131 147 32.5 1859 2
ALD, AT 16.15 48.07 450 9.0 530,4 1901 1995 123 193 85.1 1803 1
n.Eifel dre07, DE 6.16 50.40 460 9.6 843,4 1901 2004 137 199 48.7 1806 2
n.Eifel dre06, DE 6.33 50.26 560 9.6 843,4 1901 2004 114 152 40.8 1853 2
nt., BG 23.54 42.53 850 11.2 519,7 1955 2009 43 61 17.3 1955 2
„СН 8.36 46.21 900 1.6 2218.9 1901 2002 38 401 37.6 1602 2
