Anthropogenic impact on stability of forest crops development of silver birch Betula pendula Roth in the green zone of Astana

Abstract

Recreational load affects the quality of the environment, which is confirmed by the change of fluctuating asymmetry of silver birch leaves. The deviation level of the environmental quality is minimal when the quality is normal. However, when the environmental quality level is declining it leads to decrease in stability and state of biome, which is observed by the sign of the magnitude of changes as the integral indicator of developmental stability. The purpose of the research was to study fluctuating asymmetry of leaves of silver birch ( Betula pendula Roth) in the green zone of Astana. The objects of research were 19-year-old artificial plantings of silver birch, some of which underwent intercropping practice simultaneously on the same field 7 years after planting. The planting site was conventionally divided into high and low latitudes due to the vertical elevation change in a landscape. All the studied forest plantings to some degree exhibited a weakening state. The condition of the trees is gradually declining, which constitutes 66.971.2 points on replanted plots and 72.372.4 points - on non-replanted trial plots in 2022. Prior to the creation of a recreational zone in transplanted crops at a high latitude, an initial stage of deviation from the conventional norm was observed. After the forest crop improvements were implemented, fluctuating leaf asymmetry indicator reached its highest magnitude in 2022 in all the studied crops, except for transplanted crops at a low latitude, which had a 3rd-4th score for all the years of observation. So far, in these forest plantings, the quality of the environment has not reached a critical level, but they also display a strong anthropogenic impact, because of compression of topsoil due to the settling of unorganized paths. Therefore, it is necessary to take silvicultural and other measures to increase sustainability and improve condition and state of artificial forest plantings. It is imperative to carry out plants trimming and utilize soil amendments, organize a regulated road and footpath network, and strengthen control over travelers.

Keywords

• fluctuating asymmetry
• recreational zone
• stability of development
• condition of trees