Agrobiological problems of functioning of forest shelterbelts in conditions of intensive farming and climate change

Abstract

The significant life span of forest shelterbelts, climate change, and intensification of agriculture significantly worsen the conditions of their functioning and inhibit their growth and development. The purpose of the study is the analysis of the current agrobiological state of forest shelterbelts of the Right-Bank Forest-Steppe in the conditions of climate change and intensification of agriculture. The study was conducted within 28 forest shelterbelts on selected test plots of 100 m long in four repetitions. In order to conduct the investigation, the following aspects were determined: the number of the rows of the trees in each forest belt, the distance between the rows, the width and height of the forest belt, the girth of the tree trunk at a height of 1.3 m, the manifestation of the signs of the spread of the diseases and pests on the leaves of trees.

The number of trees in the shelterbelts varied from three to eight. The main forest belts had 5-8 rows of trees, and the auxiliary ones had 3-4 rows, the blowdown ones had 4-5 rows, and the dense ones had 8 rows. The distance between the trees in the rows in different shelterbelts was 1.0-3.5 m, respectively. The width of the rows was determined between the auxiliary shelterbelts, compared to the main ones, by 1.5-3 times. In the rows of the shelterbelts, the trees were planted at a distance of 1.0-2.0 m. Blowdown forest belts were planted more sparsely, and dense ones were planted more densely. The difference in the distance between the trees in the rows of the main and additional shelterbelts of the same structures was not determined. The greatest thinning of the trees in rows of shelterbelts, compared to the design planting, was determined in the dense main forest strip – 70% and the main blowndown forest strip – 60%. In the remaining forest strips, thinning of the trees in the rows was also significant and amounted to 50%. The width of the shelterbelts varied from 7 to 20 m. The widest were dense shelterbelts, the narrowest were blowndown ones. The greatest number of the diseases and pests was found on the sharp-leaved maple in the dense shelterbelt. Powdery mildew disease developed on 30% of the leaves, and rough gnawing was found on 45% of the leaf surface. The largest number of the trees with drying tops and lateral branches was in the main windbreak forest strip: 20% of lanceolate ash trees and 37% of sharp-leaved maple trees, as well as in 15% of lanceolate ash trees in the main open field shelterbelt.