Rakhimov Tulkin Uktamovich Candidate of Biological Sciences, Department of Botany and Ecology, Karshi State University, Republic of Uzbekistan
*Corresponding author: Rakhimov TU, Rakhimov Tulkin Uktamovich Candidate of Biological Sciences, Department of Botany and Ecology, Karshi State University, Karshi, Republic of Uzbekistan
Submission: May 28, 2021; Published: December 09, 2021
ISSN 2578-0336 Volume9 Issue3
Phytoindication can be carried out by the response of plants in the species most sensitive to pollutants, or by the accumulation of harmful substances in the body of plants. Therefore, among plants, bioindicators with a high sensitivity to pollutants and storage bioindicators are distinguished. The dendrochronological method makes it possible to study changes in climatic conditions on the planet and the effect of various ecological and anthropogenic factors on woody plants of the ecosystem. A reliable correlation has been established between the levels of air pollution by pollutants and a decrease in radial annual growth in tree species. The article discusses the assessment of environmental pollution using phytoindication. One of the signs of phytoindication in the industrial zone is the annual growth of wood of these trees. According to the data obtained, under the influence of industrial waste, first of all, there is a decrease in the annual growth of wood of existing trees.
Keywords: Phytoindication; Resistance; Wood; Bark; Annual growth; Dendrochnology; pollutants
Changes in the ecological situation of the planet as a whole and many industrialized
countries in the second half of the 20th century led to a revision of ecological concepts of
nature protection, the search for new effective methods for assessing environmental pollution
and the condition of biota at all levels of its organization, the development of new ecological
standards for permissible anthropogenic loads on natural systems. Vegetation is the most
important component of biogeocenosis, providing the vital activity of other biotic components.
Changes in vegetation under the influence of various environmental factors influence to
the biogeocenosis condition as a whole and, as a result, can be used as diagnostic signs.
Phytoindication can be carried out by the response of plants in the species most sensitive
to pollutants, or by the accumulation of harmful substances in the body of plants. Therefore,
among plants, bioindicators with a high sensitivity to pollutants and storage bioindicators
are distinguished. The classification of the principles and levels of phytoindication can be
classified according to the generality of research methods phenological methods, morphoand
biometric, anatomical-cytological, physiological; biochemical, biophysical, floristic ,
genetical, biocenotic, ecosystem.
In this regard, phytoindication is singled out in the monitoring system - as one of the methods for assessing the quality of the environment.
Phytoindication methods are highly sensitive. They allow to:
i. To register air pollution 3-5 times lower than the sanitary and hygienic MPC (Maximum Permissible Concentration);
ii. Practically without physical and chemical analyzes of air samples or with their limited number to determine the levels of air pollution in large areas;
iii. To determine the level and danger of the impact of pollutants on ecosystems;
iv. To study the nature of anthropogenic digression of ecosystem components;
v. To identify the relative role of individual large sources of emissions and the environmental hazard of individual ingredients in the total pollution of the environment and their impact on ecosystems;
vi. To determine the permissible or critical loads of pollutants for biota, to develop environmental standards for anthropogenic impacts on ecosystems;
vii. To provide a scientific basis for forecasting the development of the ecological situation in the region and for the development of activities to improve the environmental condition.
The dendrochronological method allows it possible to study changes in climatic conditions on the planet and the effect of various ecological and anthropogenic factors on woody plants of an ecosystem. A reliable correlation has been established between the levels of air pollution by pollutants and a decrease in radial annual growth in tree species . Some methodological rules have been developed to improve the reliability of the dendrochronological method for the bioindication of air pollution. It is also perspective because it allows to calculate the decrease in the growth of wood per year and, therefore, the economic damage from air pollution, and at the same time to assess the state of forest ecosystems . In this regard, the purpose of our research was: a comprehensive assessment of the impact of industrial emissions from gas processing enterprises of the Kashkadarya region on the dendrological indicators of some tree species as the main link in the industrial ecosystem. Scientific substantiation and selection of criteria for the stability of tree species; scientific substantiation of phytoindication methods-identification of the most sensitive indicator tree species and selection of express methods for assessing industrial pollution.
We aimed to study the dynamics of changes in the nature of metabolic, photochemical disturbances in order to better understand the mechanism of photosynthesis disturbance. For this, we have chosen five landscaped trees (Ulmus pumila L. - Siberian elm, Acer negundo L. - Аsh-leaved maple, Fraxinus syriaca Boiss. - Syrian ash, Populus alba L. - White poplar, Morus alba L. - White mulberry tree species of different stability that grow on the territory of the Mubarek gas processing plant (1st experience), Shurtanneftgaz UDP (2nd experience), Shurtan gas chemical complex (3rd experience) under the influence of S02 and a relatively clean sanitary zone of the city of Karshi (Control). Besides, we investigated the agroclimatic production characteristics of the study areas (Table 1). As can be seen from (Table 1), the pollution level of industrial zones is relatively high concerning the sanitary zone. To assess the pollution level of the industrial zone, we used some anatomical features of annual shoots of tree species (diameter of annual shoots, bark thickness, annual growth of wood) (Table 2).
Table 1: Brief description of the study areas (average annual data for 2016-2017).
Table 2: Indicators of anatomical features of annual shoots of the studied tree species.
As can be seen from (Table 2), we traced the change in the
anatomical features of the growth of annual wood in some tree
species and obtained the following results. The highest growth
of annual wood was observed in trees growing in the sanitary
zone of the city of Karshi. It is noteworthy that in this area we
have identified the minimum content of pollutants in the air
(Table 1). Slightly lower growth of annual timber was observed
in shurtan GCC. A similar relationship was typical for MGPP and
Shurtanneftgaz but note that the difference between these three
areas is statistically insignificant (Table 2). The smallest increase
in wood and bark thickness was observed at MGPP and was
2.0±0.11 and 1.2±0.03 mm for maple, respectively, and the content
of atmospheric emissions at these industrial facilities was the
highest. It is noted that the difference between these two points
is statistically insignificant. The difference in the length of the
annual growth of wood of the studied species between all the other
regions of the study is statistically significant. As can be seen from
(Table 2), for mulberry, elm and ash, the difference in the growth of
wood is insignificant, which indicates their resistance to industrial
Thus, considering the change in the diameter of the shoot, the annual growth of wood, in the studied species, we see a relatively clear inverse dependence of this parameter on the concentration of harmful substances in the air. According to literature data , it is known that SO2 has an inhibitory effect on growth processes, given that one of the main emissions of the studied enterprises is SO2, therefore, we observe a weakening of the apical and lateral growth of shoots of the studied breeds. These changes are manifested not only in a weakening of the annual growth of wood, but also in a decrease in the formation of latewood [4,5].
There are 21 possible types of growing conditions, or types of
ecological and plant complexes (ERCs), as a combination of types
of ecological conditions and types of vegetation in the world. The
distribution of ecological and plant complexes of the world is shown
in Figure 1. On the basis of vegetation ordination, an ecological
and plant map of the Earth is compiled (Figure 1). The types of
ecological and plant complexes shown in the ordination scheme are
shown on this map. The contours of the complexes themselves are
elongated mainly in the latitudinal direction, which indicates the
predominant role of heat supply in the distribution of vegetation,
reflecting mainly zonal botanical and geographical relations. As a
result of the analysis of the ecological and plant map of the world,
the main botanical and geographical relations of the planetary
level, the ecological conjugacy of environmental factors and
vegetation were identified, which largely determine the structural
and functional organization of forest vegetation at other structural
levels of vegetation: regional, landscape. Maps of ecological and
plant complexes make it possible to directly assess the ecological
stability of plant taxa, their changes in various combinations of heat
and moisture availability. Such maps, in essence, are a cartographic
model of possible changes in the structure under various variants
of environmental changes. Vegetation with a high level, an
indicator of ecological compliance occupies ecological optima and
is the most environmentally sustainable. At the global level of the
structural organization of vegetation, changes in the structure and,
consequently, in its productivity in ecotone areas are most likely.
Here the vegetation is most sensitive to the changes taking place. In this regard, such areas are the most vulnerable, they are characterized by increased indication properties. Therefore, the organization of biosphere stations for monitoring the natural environment, primarily vegetation cover in such places is most preferable. The map of ecological and plant complexes of the Earth) clearly reveals the patterns of spatial distribution of vegetation. Each level of heat supply, characterized by a sum interval of 400°, corresponds to a specific subzone of vegetation. Another pattern, called Buks II  provincial, reflects the dependence of the typological composition on the radiation index of dryness under equal conditions of heat supply. The quantitative relationships between the combination of gradation of the leading environmental factors and syntaxons can be used in predicting the structure of the vegetation cover structure in the course of environmental monitoring. In addition, as the experience of our research has shown, the identified botanical-geographical relations at the planetary level of vegetation cover can be used to identify dynamic processes in the combination of climate change and anthropogenic impact, through restoration (modeling) the structure and productivity of the original, or indigenous, vegetation cover and comparison with the modern one will allow us to assess the size and trend of these transformations of the plant world. The combined influence of heat and moisture supply determines forest vegetation conditions, which is used for geobotanical, forest vegetation, botanical and geographical zoning, making classifications of forest communities on an ecological and phytocenotic basis, climatic ordination of high-altitude forest vegetation belts, and allocation of high-altitude forest cover divisions.
The method was used in the preparation of maps of ecological and plant complexes that are adequate to correlation geobotanical maps. These results are used in the study of the forest formation process, cartographic modeling of the areas of the original taxa of vegetation cover, optimal places of growth of forest-forming rocks. The obtained research results allow us to draw up multi-level ecological and phytocenotic complexes that combine structural divisions of vegetation cover and higher levels, which are in many respects conceptually similar to the classification of multi-level forest types, They can be used for monitoring tasks not only of vegetation cover, but also in the field of ecological geography, as well as for other tasks. These research results can be used for a wide class of applied problems - in forestry practice (production of forest crops, reconstruction of low-value plantings, etc.), to predict the most environmentally sustainable forest vegetation and its dynamic processes in connection with different scenarios of climate change, and for other environmental monitoring tasks [11,12].
© 2021 © Rakhimov TU. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and build upon your work non-commercially.