would like to acquaint you with the content of the research works that
have been made by students of Shelekhov Lyceum. We had gathered materials
for these researches during the summer practice that were processed
and analyzed later. The conclusions were done by the results of analyses
corresponding. Julia generalized the results of three research works
that had one general problem — the reaction of plants to the environmental
The principle of the researches in two works was the same: the birch
leaves and the mossy bodies had been gathered, dried up and then the
content of zinc and manganese was defined in samples. The principle
of the research in the third work is the definition of pine needles
suffering in percents. The samples for the experiences had been undertaken
in a pure ecological zone (Arshan). We called them "the background
samples", and some samples were gathered on several sites of Shelekhov.
All of these samples were compared to the laboratory samples. The method
used for calculation of the pine needles suffering was the most of the
simple. This method is a visual analysis. But it was more difficult
to definite the content of microelements because the special equipment
And why was that principle laid down in a basis of the researches?
Many biologists and chemists of the past researched living beings and
tried to find a special substance or “living force” tha
t causes the organism functioning. But no substance, even any instructions
on it were found. Scientists found out that organisms consist of the
same chemical elements that form the air, water, rock and soil minerals.
There are 80 chemical elements in the mixture of living organism. The
organism needs some elements in a big quantity (they are called macro-elements)
and other elements in a negligibly small quantity (they are called micro-elements).
It is important to know the role of each element in forming of a living
organism vital function.
Frey Basling had paid attention to the fact that chemical elements necessary
for the plants take a different position in periodic system. Further
researches showed that chemical element life need isn’t determined
only by the position in the periodic system but it determines by a whole
row of characteristics such as an ionization potential, ionic radius,
polarizability and ect. It is clear that element toxicity increases
according to the increase of its atomic mass. Content of these elements
is usually too little in the organism.
Microelements are the elements that content in living organisms doesn’t
exceed 10%. Microelements take part in breathing, photosynthesis, protein
synthesis, protein and lipid exchanges, humus synthesis and other processes.
On average content of Zn in the plant ashes is 10 and in the dry plant
is from 15 to 70 mg/kg. A number of elements in soil doesn’t exceed
65 mg/kg and assimilated by plants is from 0.03 to 20 mg/kg.
Biological absorption factor (BAF) of Zn is 10. A feature of this element
is its low chemical activity. That’s why it is partly involved
into the second circulation. Zinc takes part in the intracellular regulation
The average content of Mn in the plants is 10 mg/kg and BAF swings from
0.1 to 100. In the plant cell maximum of Mn can be find in its cytoplasm.
Manganese is a part of many ferments and chlorophyll.
And it stirs their formation to activity. Manganese takes an active
part in breathing, photosynthesis, synthesis, nitric and nuclein exchanges.
The activity of Mn in different physiological and biochemical processes
isn’t determined only by its quantity in the plant but it is determined
by the ratio of Mn to other chemical elements that take part in these
processes. The ratio of Mn to Fe and Cu is especially important.
Iron comes to the plant as a part of chelates. It is has a bivalence
condition. High concentrations of Fe (II) may influence on the plant
toxically. Iron acidified and precipitates over Mn. But this process
proceeds by a special ratio of these elements. If this ratio gets broken
the following things happen:
- A lack of the content of Mn in the plant brings to an excessive Fe
(II) concentration. This accumulation of Fe (II) can reach a toxic concentration.
- Fe (II) is transferred into Fe (III) with the help of Mn excess. Then
Fe (III) accumulates in the form of organic-phosphoric Fe and a plant
begins to suffer from the lack of Fe (II).
Copper influence on the content of manganese similarly. That cooperation
is visible not only in the plants but in the soil. Manganese takes part
in bud-formation. Soil horizons that are fortified by Fe are particularly
illuvial and they contain the increased quantity of Mn.
What is need for normal organism functioning?
1. At first, the determination of microelements concentration in habitat.
2. Secondly, definite ratio of absorbed elements
3. Thirdly, definite forms of compound where microelements in habitat
Non-observance of these demands brings to violation of different biochemical
processes. Increased or decreased concentration of microelements in
habitat may cause the endemics.
Why was maintenance of zinc and manganese exactly determined in samples
Zinc also plays an important role in a plant life, that’s why
increase or decrease of it causes different diseases of plants. Decrease
of Zn results in delay or stopping of many plants growth. Small-leaves,
rosette and defoliation are observed on trees. Chlorosis is observed
on maize, leaves pairing – on tomatoes, leaves mottling –
on citrus plants.
Shortage of Mn in soils brings down growth and development of the plant.
At the same time iodine assimilability of many plants is decreased.
Tannin formation of tanning plants is decreased, mottling and odor nuisance
of oats and spottiness of beans become apparent. Many plants amass iron
under the deficit of Mn and the content of Fe is decreased under the
excess of Mn (that brings to chlorosis).
In a couple of “plant-soil” is observed the dependence between
the content of chemical elements in the plants and in the soils. When
there is a little quantity of the element in the soil plant absorbs
all available quantities of this element forms in spite of the fact
that the quantity of the element in the plant is decreased.
Under the optimal content of the element chemical composition of the
plants mainly depends on the plant biological features and physiological
role of that element.
This way a geochemical surrounding isn’t the limitative factor.
So regulation machinery starts working in the plants. The content of
an absorbent element is determined by a need of the physiological processes
realization. It is clear that climatic conditions especially temperature
and moistening influence on the plant’s absorb of the elements
and therefore on the chemical composition. For example, in the northern
regions the plants contain more Cu, Mn, Zn than here.
A chemical composition of the plants depends on the technogenic processes
activity. A technogenic type of the elements migration appeared as a
result of human activity isn’t submitted to nature factors but
socio-economic laws and it presents a variety in accordance with its
origins. Also it includes the transference of products of natural raw
materials on long distances.
Fully unconsumed raw materials, solid and gaseous waste products of
industry come to the atmosphere and solid and liquid waste products
– to reservoirs. It begins to a sharp re-distribution of chemical
elements that is called on a violation of biogeochemical circulation
of such elements as C, B, P, Pb, Cu, Zn, Fe, Hg, Ag, Mn.
Distribution of chemical elements as a result of human economic activities
is uneven that bring to a high concentration of chemical elements in
local places with their following “diffusion” in more wide
natural habitats. In other words technogenic anomalies that are connected
with the work of industrial centres are formed.
Object & Metod