CC BY
109
UDC 57.045
FLUCTUATING ASYMMETRY OF BETULA PENDULA LEAVES AS A BIOINDICATOR OF AEROTECHNOGENIC POLLUTION OF AGROLANDSCAPES
Lobkov V.T., Doctor of Agricultural Sciences, Professor Vetrova J.V., Post-graduate student Orel State Agrarian University, Orel City, Russia E-mail: [email protected]
ABSTRACT
The main goal of our research was to determine the variability model and fluctuating asymmetry indices of the metric signs of Betula pendula as a typical species which grow uniformly in the Orel region and Orel.The following problems were solved:to collect material in the planting of silver birch in two areas;to determine the parameters of Betula pendula leaf blade and the level of its asymmetry; to explore the basic statistical properties of the asymmetry parameters of the individual features characterizing the asymmetry of the whole object;to substantiate the use of Betula pendula in urban ecosystems for gardening and landscaping. The estimation of the changes of developmental stability Betula pendula in biotopes with different levels of anthropogenic impact is carried out. The character of the fluctuating asymmetry of Betula pendula place in the Orel region and Orel, in areas with weak and strong anthropogenic impact, has been studied. Found that the deterioration of the ecological state of urban environment does not determine the reduction of the population development stability of Betula pendula and can testify to its tolerance to environmental contamination.
KEY WORDS
Betula pendula; Industrial pollution; Development stability; Fluctuating asymmetry.
Currently, the dominant factor causing soil degradation and air pollution in agricultural landscapes is technogenic contamination from industry, transport and other forms of human activity [1].The most dangerous and intense source of urban air pollution is road transport [2], in the emissions of which about 300 harmful substances is found, including particularly dangerous carbon oxides, hydrocarbons (carcinogenic benzopyrene and benzanthracene, formaldehyde, benzene), nitrogen oxides, soot, lead, mercury, sulfur dioxide, aldehydes [3,4]. In this connection special importance have researches, aimed at studying the effects of environmental pollution on the plant component of ecosystems.For this purpose, the methods of phytoindicationtechnogenic pollution are widely used.One of these methods, which have gained wide popularity, is the definition of fluctuating asymmetry as an integral indicator of environmental quality [5]. Under the fluctuating asymmetry (FA) understand the independent change of bilateral characteristics of the organism.Found that the phenomenon of fluctuating asymmetry is connected with violation of organism development stability as a result of external factors, first of all - anthropogenic [6].The degree of FA expressiveness depends on the force of factor impact, the greater the factor impact, the greater the deviation from the norm has an index of FA [7], this dependence allowing at the macroscopic level to use it as a measure in evaluating the stability of organism development [8].Consequently, the stability of development, estimated by the level of FA is a sensitive indicator of the state of natural populations [9, 10].
Thus, the determination of the environmental contamination impact on the rate of fluctuating asymmetry of Betula pendula leaf lamina was the purpose of our study.
MATERIALS AND METHODS
The objects of the study were birch trees (Betula pendula) which growing in s. Ivanovka of Orel region, located at a considerable distance from technogenic sources of pollution,
which allowed us to identify this habitat as a conventional control.Roadside population of Betula pendula which grows on the Gostinnaya str. and characterized by high load road transport was used as an experimental variant [11].Material for the study was collected in June after stopping the growth of leaves.In each biotope, from the short shoots of lower crown from 10 trees, about one generative age, 10-15 leaves, approximately the same size, were collected.Very different in size or damaged leaves were culled.From each biotope not less than 100 leaves were investigated.To estimate the rate of fluctuating asymmetry of birch leaf lamina the standard set of five morphological traits [9], which characterize the stability of leaf formation in ontogenesis was used: 1 - The width of the left and right halves of leaf (from the border of the central vein to leaf margin); 2 - The length of the second-order vein, the second from the base of leaf; 3 - The distance between the bases of the first and second veins of second order; 4 - The distance between the ends of these veins; 5 - The angle between the main vein and the vein of the second order.
Figure 1 - Calculating integral index of fluctuating asymmetry of the morphological traits complex of leaf lamina has been produced using normalized difference algorithm [5]
where Lij and Revalue of the j-th character in the i-th leaf to the left and right side of the plane of symmetry and convolution of the functions, respectively, that in the form of finite sums can be represented by the following formula [12]:
m
— 1 “ 2 XL-*R»
A7= 1 - — * 2 —t~
- mi=iz(Il+R)
j=l
Statistical processing of the experimental data was performed by N.A. Plohinskiy methods [13] using the software package Microsoft Excel.
RESULTS AND DISCUSSION
Value determination of the integral indicator of developmental stability Betula pendula, growing in biotopes with varying degrees of anthropogenic pollution, showed that
investigated populations, in terms of the FA, significant differences had not.In control biotope, average value of the integral index was 0.0250; for trees growing on the Gostinnaya str. -
0.0350. No statistically significant differences with the control sample by Student's test (p>
0.05) indicates the absence of instability development of Betula pendula population in experimental biotope. (Fig. 2)
Figure 2 - Comparative indicators of the rate of fluctuating asymmetry (FA) of the assimilation apparatus in Betula pendula populations, growing in biotopes with different levels of anthropogenic
impact
Comparative analysis of FA rates for each of the five studied morphological features that characterize the stability of forming leaf lamina of Betula pendula during ontogenesis showed that in the investigated samples statistically significant were differences on only two parameters: distance between the ends of the first and second veins of second order; angle between the main vein and the vein of the second order (Table 1).
Table 1 - Leaf lamina of Betula pendula during ontogenesis
№ Investigation variant Morphological traits
1 2 3 4 5
1 Orlovskiy district 0,018±0,006 0,02±0,007 0,018±0,025 0,66±0,014 0,001±0,0001
2 Orel, Gostinnaya str. 0,021±0,005 0,02±0,008 0,081±0,022 0,09±0,014 0,03±0,012
The data obtained allow concluding that the birch is a culture of tolerance to environmental contamination, as evidenced by the lowest rates of FA, indicating no violation of the stability of its ontogenetic development. Plant resistance to the action of aero toxicants associated with their ability to withstand high concentrations of toxic gases without decreasing growth and development [14, 15]. This fact allows us to recommend Betula pendula for use in landscaping urban ecosystems with high levels of environmental contamination.
CONCLUSIONS
1. The study did not found a significant dependence of fluctuating asymmetry Betula pendula on the level of anthropogenic load.
2. No statistically significant difference in fluctuating asymmetry of trees growing in urban areas, compared with controls, indicating their tolerance to environmental contamination.
3. Recommended use Betula pendula for landscaping urban ecosystems as culture tolerant to environmental contamination.
REFERENCES
1. Titova V.I. Some approaches to environmental assessment of pollution of land / V.I.Titova, M.V.Dabagh, E.V. Dabahova // Eurasian Soil Science. - 2004. - № 10. - p. 1264-1267.
2. Bocharov V.L. Ecological and geochemical methods for assessing contamination of the atmosphere of small towns / V.L. Bocharov, V. Ivanov // Vestnik of VSU. Series: Geology
- 1997. - № 4. - p. 137 - 145.
3. Bagrova L.A. Crimea Geography: Textbook for students of secondary schools / L.A. Bagrova, V.A. Bokov, N.V. Bagrov - K. : Lybid, 2001. - 304 p.
4. Melnikov N.N. Organic chlorine compounds in the environment / N.N. Melnikov, S.R. Belan // Agrochemicals. - 1998. - № 10. - p. 83 - 93.
5. Zakharov V.M. Environmental Health: the practice of evaluation. Russian Environmental Policy Center / V.M. Zakharov, A.T. Chubinishvili, S.G. Dmitriev [and others]. - M., 2000.
- 318 p.
6. Kozlov M.V. Fluctuation asymmetry of birch leaves increases under pollution impact / M.V. Kozlov, B.J. Wilsey, J. Koricheva, E. Haukioja // J. Appl. Ecology. - 1996. - № 33. -p. 1489 - 1495.
7. Zorin A.A. Characteristics of fluctuating asymmetry of the two species of birch leaf in Karelia / A.A. Zorin, A.V. Korosov // Ecology. Experimental genetics and physiology. Proceedings of the Karelian Research Center. - Issue 11. - 2007. - p. 28 - 36.
8. Zakharov V.M. Ontogenesis and population (stable development and population variability) / V.M. Zakharov // Ecology. - 2001. - № 3. - p. 177 - 191.
9. Guidelines for the implementation of quality assessment environment as living beings (stability assessment development of living organisms on the level of asymmetry of morphological structures) / Ministry of Natural Resources; Introduced. 16.10.03. - № 460-R. - M., 2003. - 24 p.
10. Soldatov V.Y. Fluctuating asymmetry of birch (Betula platyphylla Sukacz.) as a criterion for the quality of the urban environment and areas prone to anthropogenic influence (for example, Yakutia): Author. dis. ... PhD of biol. sciences: 03.00.16 / V.Y. Soldatov -Yakutia, 2006. - 18 p.
11. Asanova U.B. Accounting load of road transport on urban ecosystems / U.B. Asanova, L.A. Useinov // The key to their future profession. Issue 4. - Simferopol: CEPU SIC 2009.
- p. 137 - 139.
12. Gelashvili D.B. Structural and bioindicativeaspects of fluctuating asymmetry bilaterally symmetrical organisms / D.B. Gelashvili, E.V. Chuprunov, D.I. Iudin // Journal of General Biology. - 2004. - Vol. 65, № 5. - p. 433 - 441.
13. Plohinsky N.A.Biometrics / N.A. Plohinsky. - Moscow: Moscow State University, 1970. -367 p.
14. Kagarmanov I.R. Poplar plantations in Ufa: Biological features and prospects / I.R. Kagarmanov, R.V. Urazgildin // Geoecology in the Ural-Caspian region: Reports theses of Intern. scientific-practical conf., Ufa, Sep., 1996. - Part 2. - Ufa, 1996. - p. 18-20.
15. Zharko L.E. Growth and development of silver birch in urban environments / L. Zharko // Botanical Studies in Siberia. - 1995. - № 4. - p. 27 - 28, 99.
