Birds of forest ecosystems of Southern Baikal in the conditions of modern climate warming: Dynamics of population density and structure in summer

Abstract

On the basis of long-term works (2010-2022), the materials of studying the influence of climate warming on the bird population of forest ecosystems in the summer period are presented. The main indicators of the bird population were studied: population density and species composition. The dynamics of these indicators of the bird population structure and the features of their structure depending on the level of climate change on the ascending branch of the heat-dry phase of the centuries-old climate cycle, close to completion, are considered. The intensity of bird eviction is associated with the localization of very severe, prolonged and extensive droughts. It is the intensity of evictions that determines the new species composition of birds of the studied territories. They are characterized by very low numbers and therefore there is no clear link between the population density of birds and their species richness. At the same time, the general tendency to preserve this pattern (with an increase in the number of species, the population density of birds increases) is noted in some of their main categories. The obtained materials allow us to find out the peculiarities of the dynamics of the biodiversity of birds in Eastern Siberia during periods of severe climatic anomalies. Such materials are extremely important, as they allow us to find out the real role of natural and climatic factors in the evolution of natural ecosystems and the maintenance of the overall biodiversity of large zoogeographic regions of the Earth.