Forster, B.; Knizek, M.; Grodzk:i, W. (eds.) 1999: Methodology ofForest Insect and Disease Survey in Central Europe.
Proceedings ofthe Second Workshop ofthe IUFRO WP 7.03.10, Apri120-23, 1999, Sion-Chateauneuf, Switzerland.
Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 74-79.
FOREST PESTS OliTBREAKS PROGNOSIS ON THE BASE OF CLIMATIC FACTORS ANALYSIS
Valentina L. Meshkova
Ukrainian Research Institute ofForestry & Forest Melioration, Ukraine, 310024, Kharlcov-24, Pnsh)cinskaya 86, e-mail zabist@u-fri.kharlcov.com
Forests in Ukraine occupy 10 :tnilli.ons ofhectares (14.3% of territory). Spatial dissemination, growth and condition of forest depends considerably on climatic factors. In a whole the climate of Ukraine is tempomry continental, except of narrow band in the South bank of Crimea where it is subtropical. The continentality increases from west to east, and forest covemge of Ukraine is the most in the west (30-55%), it is equal to 10-20% in the central part of country and it is less than 100.4 in the south and east part.
From coniferous Pinus L. (35% of stands), Picea A. Dietr .(16%) and Abie.s MilL (3%) are dominant From hardleaves they are Quercus L . (22%), Fagus L. (13%), Carpinus L .(2%), and from softleaves Betula L ., Populus L ., Alnus Mill. and Tilia L.) are wide-spread
There are several natural zones in Ukraine with different climate, soils, relief and vegetation.
Coniferous forests prevail in the north - west (forest zone), deciduous species become more numerous in the central part of co1m.try (right-bank forest- steppe) and prevail in the natural stands and shelter belts of the left-bank forest steppe and steppe zones. Artificial plantations of the Scotch pine grow on the sandy soils of the forest-steppe and steppe.
Area of deciduous stands in Ukraine is 3234.8 thous. of hectares. The average area of foliage eating insects foci there is equal to 105,681.3 ha, which is 32.7 ha per every thousand hectares of deciduous stands. Area of Scotch pine which is one of the main forest fonning species is . equal to 2240.7 thous. ofhectares. The average area of needle eating pests foci is 48,179.2 ha, which is 21.5 ha per every thousand hectares of pine stands.
Among defoliators of oak, Tortrix viridana L. is the most prevalent species.
n
can form outbreaks alone (1948-1952, 1960-1%1, 1971-1975, 1982-1985, 1988, 1992) and in complex with Archips crataegana Hb. , other leafrollers and loopers.Lymantria dispar L. had its maximum in 1948-1952, rather low density in 1960-70, formed the outbreaks in 1978-1990 (with different peak years in different regions), the last wave was
observed in Crimea in 1993-19%. There are permanent local foci of different micropopulations of gypsy moth in the South of Ukraine.
Euproctis chrysorrhoea L. outbreaks were observed in 1951, 1954, 1957-59, 1969-1972,
1978-1985. Now population begins to increase in the East part ofUkraine ( Kharlcov, Lugansk, Poltava regions).
Among needle-eating pests the main are pine sawflies, their outbreaks are prolonged due to diapause of cocoons which endure for several years. Diprion pini L. formed outbreaks in 1947- 49, 1952, 1955-1%5, 1973, 1976, 1979, 1984-1990, 1993-1999. nhas 2 generations per year and in the South there is the third intermediate generation between 1 st and 2nd ones, if adults go out from diapausing cocoons in the litter. In the Kherson region the outbreaks are almost
permanent, they are observed rather often in the pine forests on the sands at the bank of Severskij Donets. The years of Neodiprion sertifer Geoffr. outbreaks often coincide with Diprion pini, but it has 1 generation per year.
Dendrolimus pini L. outbreak was observed in 1%3-1%5, 1972-1975, 1978, 1986-90, 1997- 1999.
Bupalus piniarius L. usually forms foci together with sawflies and Dendrolimus pini. The outbreaks with its dominance developed in 1949, 1963, 1969-1971, 1979, 1990, 1994-1997.
Outbreaks of Panolis jlanunea Schiff. are not duiable usually but bring severe damage to stands (1947-52, 1957-1964, 1976-1980, 1984-1986, 1994, 1997-1999).
Lymantria mOTliicha L. formed local foci in the forest zone in 1949, 1956-1958, 1964-1966, 1978-1983, 1993-1994.
Thaumetopoea processionea L . had an outbreak in the 70 th, the last increase of population was observed in 1993-1999 in the south -west of Ukraine.
The main pests infestation history for the last years is
presented
in the Table 1.Table 1- Pest infestation history in Ukraine (1993-1999)
Pest name Hectares Infested by Year
1993 1994 1995 1996 1997 1998 1999 Lymantria dispar 3832 3419 7439 15116 3576 1581 1835 Tortrix viridana 32520 32452 26810 22463 13257 12417 10109
Euproctis chrysorrhoea 400 500 400 400 300 233 700
Complex of leafrollers and 35600 40000 46000 43815 41746 36590 7070 loopers
Neodiprion sertifer 3041 5031 1161 2643 12278 31196 50073 Diprion pini 25370 40215 28924 25834 23317 38375 22820
Dendrolimus pini 400 400 450 0 9614 11804 16782
Bupalus piniarius 0 6580 14384 3109 2173 773 ·773
Panolis flammea 0 1290 32 0 219 155 48
Thaumetopoea 15406 18175 14382 18780 13439 7401 2025 processionea
We tried to develop the methods of climatic factors analysis which allow to determine the zones of different forest damage; to reveal the water and thermal regimes which promote the decrease of food plant resistance. For this we use the climatic classification of Ukrainian forests which was proposed by D.Vorobjov ( Vorobjov 1965) and then developed by D.Lavrinenko (Lavrinenk:o 1965). Validity of the Vorobjov forest typology zoning was confumed on the large arrays of real forest datasets.
V orobjov forest typology zoning is based on such climate indices:
- a) sum of mean monthly temperatures for months with positive mean monthly temperature ('J'O); the boundaries of heat zones are T o indices with intervals of20 °;
-b) Vorobjov index of climate humidity (W): W=RIT-0.0286T, where R is the precipitation sum for months with positive mean monthly temperature; the boundaries of zones are isolines with intervals of 1.4 units ofW;
-c) Continentality index (A) is the difference between mean monthly temperature of the most warm and the most hold months (July and Januacy).
The isolines of continentality intercept the zones of heat and humidity, they characterize the vegetation period and phenological events, which is important for forest growing and protection (Table 2).
To evaluate the impacts of climate, Vorobjov zone map of country was built by means of Maplnfo ™ 4.0 in complex with Surfer ™ 5.1. Current mean monthly temperature and precipitation data were interpolated with 0.25 o spatial resolution (approximately 20 km) and thus presented as uninterrupted climatic fields. It allowed
to
estimate different climate indices not only in the interpolation nodes but in any point of Ukraine territory withinterpolation precision. Estimated data sets were used to determine V orobjov zones distribution in Ukraine ( Sidorov A. et al., 1997).
Mapping of forest climates on the base of interpolated data shows that index T o is equal to 84- 124
o:R
and exceeds this value only in the south of Kherson region and in Crimea. Moist sites are noted in the west part of Ukraine, damp ones are near Carpatbians. There are fresh sites inthe Central part of country and dry ones in the south-east. Continentality index is equal to 22
oc
in the west and increases to the east (maximum 28 °C). There are following types of climate in Ukraine (later on we11 call them Vorobjov zones): 2d, 3d, 4d, le, 2e and Of An island of lf zone is observed in the northern part of Crimea (Ukraine ... 1998).
The map of Vorobjov zones of Ukraine was overlaid with pest foci contours. Mountain regions of Crimea and Carpathians as well as Lviv and Tshemivtsi regions were excluded from our examination because of lack: of data. Probabilities of outbreak occurence and mean annual foci area were evaluated for_leaves-eating and needles-eating pests for regions, natural zones and climatic Vorobjov zones (Tables 3-6).
Table 2- Forest typological climates after Vorobjov classification ( Vorobjov 1965)
re
Heat indexw
Humidity index84°-104 ° d-temperate (deciduous forest) -2.2-{ -0.8) 0 very dry 104°-124° e-relatively wam.t (steppe) -0.8-0.6 I dry
124°-144° f-warm (dry steppe) 0.6-2.0 2 fresh
2.0-3.4 3 moist Table 3 - Probability of defoliators outbreaks in different regions ofUkraine
Conifers eating pests Deciduous eating pests Voro- Natmalzone Probability Predicted Probability Predicted bjov of outbreak number of of outbreak number of
zone years of years of
outbreak outbreak:
from 10 from 10
years :years
1 2 3 4 5 6 7
Kherson Oe/le I steppe 1.00 10.00 1.00 10.00
Dnipropetrovsk le I steppe 1.00 10.00 0.59 5.50
7 • _ 1._ - • -
le 0.80 7.80 0.95 . 9.50
Lugansk le steppe 1.00 10.00 0.95 9.50
Mi!olaiv le 0.93 9.27 1.00 10.00
Odesa le 0.67 6.33 1.00 10.00
Donetsk le steppe 0.87 8.53 1.00 10.00
Kirovograd 2elle 0.80 7.80 0.86 8.50
Sumi 2d left bank forest- 0.47 4.13 0.95 9.50
ir{harlriv lel2d left bank forest- 1.00 10.00 1.00 10.00
!foltava 2dlle left bank forest- 0.93 9.27 0.95 9.50
fKhmelnitskij 3d/2d right bank forest- 0.27 1.93 0.77 7.50
2d right bank forest- 0.67 6.33 1.00 10.00
!iltenne
Temopil 3d/2d right bank forest- 0.27 1.93 0.91 9.00
!iltenne
Tsherkasi 2d/2e right bank forest- 0.80 7.80 0.86 8.50
Continue ofTable 3
1 2 3 4 5 6 7
Vinnitsa 2d/3d right bank forest- 0.27 1.93 1.00 10.00
Volin 2d/3d forest 0.20 1.20 0.55 5.00
Zhitomir 2dl3d forest 0.00 -1.00 0.68 6.50
[Rivne 2d/2d forest 0.13 0.47 0.18 1.00
Tshemigov . 2d forest 0.53 4.87 0.73 7.00
Table 4 - Mean probabilities of defoliators outbreaks in different natural zones of Ukraine Conifers eating pests Deciduous eating pests
Zone Probability Predicted Probability Predicted of outbreak number of of outbreak number of years
years of of outbreak
outbreak from 10 years from 10
:years
forest 0.22 1.38 0.53 4.88
right bank forest- 0.45 3.99 0.91 9.00
left bank forest- steppe 0.80 7.80 0.97 9.67
steppe 0.88 8.72 0.92 9.13
Humidity (digits) or heat (letters) indices (V orobjov classification)
0 1.00 10.00 1.00 10.00
1 0.89 8.78 0.92 9.17
2 0.49 4.36 0.80 7.85
3 0.19 1.08 0.68 ·- 6.50
d 0.46 4.07 0.80 7.79
e 0.89 8.80 0.93 9.18
Table 5-Mean annual area of the most important pests foci in Ubaine (by regions) Conifers eating pests Deciduous eating pests
Voro- Natural zone mean mean area of foci,
bjov annual foci ha per area annual foci ha per area
zone area of pine area of
stands deciduous
(thous. of stands
ha) (thous. of
ha)
Kherson Oe/le 21841.7 388.0 1099.2 49.1
Dnipropetrovsk le """VVC 681.3 40.3 1419.1 29.7
. .
le steppe 15.3 4.9 679.3 41.9L11gansk le steppe 3652.8 52.3 14232.6 132.4
Mikolaiv le 1403.9 136.3 1851.1 88.6
Odesa le steppe 238.2 62.7 11040.9 151.0
Donetsk le steppe 886.5 39.9 5464.2 82.5
Continue of Table 5
2e/1e 207.6 37.8 5078.1 78.1
Sumi 2d left bank forest- 397.3 3.6 6662.1 44.1
IKlurrlriv le/2d left bank forest- 12399.9 123.4 24119.8 129.2
Poltava 2d/1e left bank forest- 2492.5 46.6 3432.6 44.9
Khmelnitskij 3d/2d right bank forest- 18.6 0.4 224.4 2.0
Kiiv 2d right bank forest- 460.0 1.6 1654.9 12.0
Temopil 3d/2d right bank forest- 245.0 16.2 1565.8 13.0
Tsherkasi 2d/2e right bank forest- 2149.9 33.1 2640.2 20.1
Vinnitsa 2d/3d right bank forest- 7.6 1.0 11272.1 60.5
Volin 2d/3d forest 43.3 0.2 145.8 1.0
Zhitomir 2d/3d forest 0.0 0.0 1058.0 4.1
Rivne 2d/2d forest 267.5 0.7 106.8 0.6
lfshemigov 2d forest 460.4 2.1 946.2 7.4
Table 6- Mean annual area of the most important pests foci in Ukraine (by zones) Conifers eating pests Deciduous eating pests
Zone mean area of mean area of foci, ha
annual foci foci, ha per annual foci per area of area area of area deciduous
pine stands stands (thous.
(thous. of of ha)
ha)
forest 192.80 0.73 564.20 3.27
bank 576.23 10.47 3471.50 21.54
left bank forest- steppe 5096.56 57.87 11404.82 72.73
3615.94 95.27 5108.06 81.67
Humidity (digits) or heat (letters) indices (V orobjov classification)
0 21841.7 388.0 1099.2 49.1
1 4382.0 93.2 6841.7 82.7
2 1473.05 20.51 4531.29 32.1
3 97.0 3.0 2395 .0 14.0
d 1578.5 19.1 4485.7 28.2
e 4179.1 87.7 6459.7 77.1
AB we can see, the probability of defoliators outbreaks is rather high in the whole territory of U'kmine (Table 3 ). For pests of pine the probability of outbreaks is almost twice higher in the right-bank forest-steppe comparing to forest zone, and almost twice higher in the steppe zone comparing to right-bank forest steppe zone (Table 4 ). The probability of defoliators outbreaks
in deciduous stands is the lowest in the forest zone too, but the indices for forest-steppe and steppe vary insignificantly. As to humidity indices, we can see continuous decrease of pests outbreaks probability from very dry (0) to moist (3) regions both for coniferous and deciduous stands. It is connected not only with more favorable conditions for pests in the dry sites but with more poor stands composition there and worsening of 1ree resistance there. Probability of needle-eating pests outbreaks is twice higher in the regions with heat index 'e ' - which corresponds
ro·
steppe "climate. The probability of leaves-eating insects outbreaks is rather high in all regions, but it is lower in the sites with 'd' heat index (temperate climate).Aiea of outbreaks considerably varies in different regions (Table 5). Taking into account different forest coverage of the regions, we calculated the relative index of mean annual foci area (ha) per 1 thousand hectares of stands. One can see, for example, that foci of needles- eating pests in Kbarkov region occupy almost 12400 ha, and in Mikolaiv region they are 1404 ha, but after dividing per pine stands area we get almost equ8l number- 123.4 ha per 1
thous.ha of pine stands for Kbarkov and 136.3 ha per 1 thous.ha of pine stands for Mikolaiv.
As we can see from Table 6, the foci area increases from forest zone to the steppe zone, it is more obvious for the relative area of foci (ha per 1 thousand ha of pine or deciduous stands).
Change of this index by humidity index is more clear for conifers, but for leaves eating pests the foci area, both absolute and relative, is the largest in the sites with humidity index '1' ·-'dry sites'. It may be explained by the fact that only part of Kberson region is located in the zone with humidity index '0'. As to heat indices, the outbreak area in all cases are considerably largest in the sites with heat index 'e' - 'steppe climate'.
So, analysis of defoliators dynamics for several decades in Ukraine allowed to note that
occurrence and scale of outbreaks varies in different parts of the country. It may be explained in the considerable degree by the different climatic conditions which influence on the forest growth and resistance, on the foliage quality as a sort of insect nutrition and on the insect
phenology. Evaluated probabilities of outbreaks occurence for different pests and forest districts can help to organize in time the strategy of survey and control.
REFERENCES
Lavrinenko D.D. 1965. Interaction of forest species in the different forest types. Moscow.
Forest industry. 248 p. (In Russian).
Sidorov A, O.Radchenko, lBuksha., V.Meshk:ova. 1997. GIS in a study of potential climate changes Effects on Forests' /!Proceedings 18th ICA/ ACI International Cartographic Conference -IICC 97/Swedish Cartographic Society. Stockholm, Sweden 23-27, June 1997.v.3, p.l541- 1548.
Ukraine and global green-house effect 1998. I Book 2/ Vulnerability and adaptation of ecological and economical systems to climate changes II.F .Buksha, P .F. Gozhik,
J,L,Yemeljanova, I.V.Trofliilova, A,I,Sheresbevskiy, editor V.V.Vasilcbenko, M V.Raptsun, a, I.V.Trofliilova.- Kiiv.- 208 c. (In Ukminian)
V orobjov D. V. Forest typology classification of climates. 1965. /!In: Proc. of Kbarlmv Agricultlnst Kbarkov, V.:XXX, p.235-260 (In Russian).
