ASSESSMENT OF THE CURRENT AGROBIOLOGICAL STATE OF THE PROTECTED FOREST STRIPS OF THE RIGHT BANK FOREST STEPPE
Authors: Tkachuk O. P. , Viter N. G. 
Published: March 2024

The significant age of field-protective forest strips, measures of intensive agriculture and global warming lead to deterioration of their functioning conditions and oppression. The purpose of the research is to analyze the modern agrobiological features of the forest protection strips of the Right-Bank Forest Steppe under conditions of intensive agriculture and global warming.

The research was conducted within 25 forest strips on designated test sites 100 m long in four repetitions. The number of rows of trees in each forest strip, the distance of trees between rows and within rows, the width and height of the forest strip, the girth of the tree trunk at a height of 1.3 m, the spread of diseases and pests on tree leaves were determined.

Observations of the metric parameters of the protective forest strips of the right-bank forest-steppe in the section of blown, openwork and dense structures showed that the most rows of trees were found in dense forest strips - 9. There were 7 rows of trees in the openwork main forest strip, and 3 rows in the additional one, and this was the smallest of of all investigated forest strips. The blowing main field protective forest strip had 5 rows of trees, and the additional one had 4 rows.

Observations of the distance between the rows of trees of the field protection forest strips showed that the projected distances coincide with the actual ones. That is, rows of trees can be seen completely. In particular, the distance between the rows of trees in the main blowing forest strips was the smallest compared to all the studied types of field protection forest strips and was 1.0 m. While in the blowing additional field protection forest strips, the distance between the rows of trees was much larger and amounted to 3.0 m.

Openwork main field protection forest strips had a distance of trees between rows of 2.2 m, and additional ones - 3.5 m. This distance of rows was the largest among all the studied forest strips. In a dense field protection forest strip, the distance between rows of trees was 2.5 m.

The distance of trees in the rows of field protection forest strips during the period of creation and in fact had significant differences. In particular, the projected distance of trees in the rows was 2.0 m, but in fact it is 5.0 m in the main field protection forest strip, which means that only two of the five planted trees survived. This is 60% thinning of the trees in the row. In the blowing additional field protection forest strips, the projected distance between the trees in the rows was 2.0 m, and the actual distance was 4.0 m. That is, only 2.5 trees survived out of five planted trees. The percentage of thinning of trees was 50%.

In openwork main and additional field protection forest strips, the projected and actual spacing of trees in rows was the same and amounted to 1.5 m and 3.0 m, respectively. The thinning of trees was also 50%. In the dense field protection forest strip, the projected distance of trees in the rows was 1.0 m, and the actual distance was 3.0 m. That is, only 3 were preserved for every 10 planted trees. The thinning of trees in the rows of dense field protection forest strips is 70%.

Thus, our research established that the greatest thinning of trees in the rows of field protection forest strips was found in the dense main forest strip - 70% and the blowing main forest strip - 60%. In the remaining forest strips, thinning of trees in rows was also significant and amounted to 50%.

The width of the blown main field protective forest strip was the smallest of all the studied and was 7 m. The width of the additional blown field protective forest strip was 5 m larger and was 12 m. The main openwork field protective forest strip was 15 m wide, and the additional one was 9 m wide. The dense forest strip was the widest. - 20 m.

The height of all investigated field protection forest strips was approximately the same and amounted to 14-15 m. The trees of the main blowing and openwork field protection forest strips had the largest trunk girth - 1.7 m each. The trunk girth of the blowing additional forest strip was 1.5 m, of the additional openwork - 1.3 m and was the smallest, and the densest - 1.4 m.

We determined the distribution of diseases and pests in the plantings of field protection forest strips. In particular, among leaf diseases, we found the spread of powdery mildew on common maple in the main dense forest strip with damage to 30% of the leaf blade surface. Also, powdery mildew was detected on the leaves of the ordinary maple of the main blown forest strip with damage to 6% of the leaf plate.

Most common maple trees were affected by powdery mildew in the main forest strip - 60%. In the dense main field protection forest strip, 25% of ordinary maple trees, mostly of young age, were affected.

Manifestation of pests was manifested in the form of continuous rough and marginal eating of the leaf plate. In this way, about 45% of the leaf plate of the maple of the ordinary dense forest strip was damaged; 12% of the sheet plate of ordinary hornbeam with additional tracery; 10% of the leaf plate of the edge eating of the common ash of the main openwork and 8% of the leaf plate of the common ash of the additional blowing forest strip. It was also found that the leaves of common ash were damaged by aphids in the form of corrugated leaves with a damage percentage of 5% of the main blown forest strip.

The number of rows of trees in the field protection forest strips varied from three to nine. The main forest strips had 5-9 rows of trees, and additional - 3-4 rows; blowing - 4-5 rows, and dense - 9 rows. The distance of trees between rows in different field protection forest strips was 1.0-3.5 m. Additional field protection forest strips had a greater width between rows, compared to the main ones, by 1.5-3 times. Trees were planted in the rows of field protection forest strips at a distance of 1.0-2.0 m. Blowing forest strips were created more sparsely, and dense ones were created more densely. There was no difference between the distance of trees from the main and additional field protection forest strips of the same structures. The greatest thinning of trees in the rows of the field protection forest strips, compared to the planned planting, was found in the dense main forest strip - 70% and the blowing main forest strip - 60%. In the remaining forest strips, thinning of trees in rows was also significant and amounted to 50%. The width of the field protection forest strips varied from 7 to 20 m. The widest were the dense field protection forest strips, and the narrowest were the blowing ones. The greatest number of diseases and pests was detected on the ordinary maple of the dense forest belt. Powdery mildew disease developed on 30% of the leaves, and rough eating of 45% of the leaf surface was detected. The largest number of trees with drying tops and side branches was found in the main blowing forest strip: 20% of common ash trees and 37% of common maple trees, as well as in 15% of common ash trees in the main openwork forest strip.