Пожары как фактор утраты биоразнообразия и функций лесных экосистем

Abstract

Due to ever-increasing anthropogenic impact and global climate change, wildfires are becoming more frequent and intense all over the world. The wildfire factor is turning into an acute problem for forested countries that requires prompt solutions as the areas of forest ecosystems are reducing catastrophically, which results in an irreparable loss of biodiversity that provides all ecosystem functions and forest services. Many biologists consider wildfires a factor destructive to biota that results in permanent loss of some species and groups of living organisms; even if it is possible for them to recover after a wildfire, they may need a lot of time to do so. However, some studies argue that not only do wildfires reduce the biodiversity in forest ecosystems, but they also increase it, thus contributing to species conservation and sustainable functioning of forests. This article is aimed at analyzing the works that study how wildfires impact the main components, biodiversity, and functions of forest ecosystems. The authors answer the question why wildfires, while being an obvious destruction factor, are sometimes considered a factor for increase in biodiversity. The “positive” influence wildfires have on biodiversity can mostly be reduced to mosaic patterns, that is, forest canopy gaps that occur after a wildfire. However, reference analysis shows that the persistent opinion found in a number of works that a certain frequency of wildfires is necessary to maintain forest communities may be associated with ignored or misunderstood importance of biotic factors in the functioning of forests. In contemporary forest ecosystems, populations of key large mammal species disappeared or are greatly reduced; therefore, there are no microsites they usually form, including large forest canopy leaps (gaps, glades) that provide both opportunities for photophilous flora and pollinating insects to develop and generally sufficient conditions for multi-aged polydominant forest ecosystems with high biodiversity. In the forestry practice, measures are known to maintain mosaics. They include special types of felling, supporting populations of key animal species, etc., and are both significantly less catastrophic in comparison with the wildfire factor and substantiated biologically. The authors provide recommendations for the conservation and maintenance of biodiversity and ecosystem functions in contemporary forests.