INFLUENCE OF SOIL ON FORMATION OF OVERGROUND AND UNDERGROUND PARTS OF COMMON OAK

Анотація

The diversity of the environment encourages researchers to study the
expression of various properties of plant species in their ability to adapt to extreme
conditions habitat. Afforestation gets a special attention in complex terrain urban
ecosystems. In this respect, the study of influence of soil conditions on the
formation of aboveground and underground parts of the oak is quite important.
The purpose of research - setting depending on soil conditions influence the
formation of aboveground and underground parts of oak on sod-podzolic sandy
soils in dry pine site.
Analyzing the literature data, it should be noted that between the structure of
the root system and soil conditions are close relationship.
The conditions of dry pine trees are not peculiar to the spread of common
oak, therefore his appearance here is a unique phenomenon. Our research has
focused on setting depending on soil conditions influence the formation of
aboveground and underground parts of oak on sod-podzolic sandy soils in dry
pine site. Profile of the soil has no clear differentiation on the horizon. Humus
shallow is less than 15 cm and contain 0,6-1,3% of humus. Soil texture makes it
water-air properties. A small amount of clay fractions (5-10%) can not create at
least some structure that causes large water penetration and small humidity.
The excavation of soil samples were carried out in November 2014 (in
leafless condition). At the average aboveground parameters a prototype age of 13
and a height of 62cm was chosen among self-seeding of common oak in the
plantations pine of 50 ages.
The total phytomass of plants was 220,32 g in wet state; in a completely dry
– 179,48 g. The relative weight of roots in total root phytomass was 67%. Crown
was formed by five trunks, one of which eventually dropped. The shape of the
crown elongated in a north-south by 64 cm, east-west - 49 cm. Horizontal
projection of the crown area is 0.15 m2. The maximum diameter of the root collar in
the bark is 3,7 cm and transverse to it – 2,7 cm. The diameters of the root collar
without bark are 3,0 cm and 2,0 cm, respectively. Maximum annual rings were 13.

The volume of aboveground parts specified by xylem method is 730 cm3, which is
39,4% of the total plant. The weight of aboveground parts in a raw state was 73,65
g and in dry – 60,12 g, the moisture of wood wass 18,4%.
The depth of penetration of taproot is 44 cm, while its length reaches 53 cm.
The maximum southward horizontal roots stretched by 96 centimeters, to the north
- 131 cm, east - 38 cm, west - 20 cm. Horizontal projection area of the root system
is 0,62 m2. The tested specimen of common oak has a special (incomplete) root
system in which the five selected in the classification, there are three subsystems:
subsystem taproot; subsystem horizontal roots, placed in the top 30 cm of soil and
copies the form of relief, extends to a distance of 2,27 m in the north-south
direction; subsystem oblique-vertical roots. It should be noted that the ratio of
active roots and leading indicators on the weight and volume consists for leading
and surface parameters and length indicate the advantage of leading active roots.
Despite the fact that the mass of roots leading dominated (84% of the total mass
of roots) almost 5 times, but the active surface roots, which is in direct contact with
the soil, is greater by 1.6 times.
In order to assess good adaptation of studied plant to these oak extreme
sites of growth we analyzed the comparative silviculture-morphological
characteristics of oak trees that grow in optimal conditions. Shallow penetration of
the root system, small weight and its small area of nutrition led to significant
differences in the amount of ground power prototype. Self-seed of oak on sod-
podzolic sandy soil, which corresponds to a dry pine site has extremely strict
conditions for their growth and development. The development of oak in extreme
conditions affected on all morphological parameters as above-ground parts of the
plant and its root system. Aboveground part formed in a bush, and the root system
is superficial. The most silviculture-morphological parameters of root systems were
in ten times lower than in the model tree. However, due to adaptation to extreme
growing conditions, the relative weight of roots in the total phytomass of
experimental plants appeared in double. This confirms the high plasticity of oak in
adapting to soil conditions, the ability to detect ameliorative effect that can be used
to consolidate the affected urban areas with similar soil conditions.