Wildfires as a Factor of the Loss of Biodiversity and Functions of Forest Ecosystems

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.

Wildfires’ Effect on Soil Properties and Bacterial Biodiversity of Postpyrogenic Histic Podzols (Middle Taiga, Komi Republic)

“…The necessity to change the classification (to include soils disturbed by pyrogenesis) has been discussed by several researchers, including Yu. N. Krasnoshchekov [10,14,16,17,21]. The effect of the fire on the soil macromorphology was pronounced only in the topsoil or superficial soil horizons.…”

“…Pyrogenesis is one of the main natural or anthropogenic factors that changes the soil properties [10][11][12]. As a result of the pyrogenesis impact, the pH and morphological soil properties change [13][14][15][16][17]. The fire's influence on tree vegetation and its subsequent post-pyrogenic change have been studied in sufficient detail.…”

“…The fire's influence on tree vegetation and its subsequent post-pyrogenic change have been studied in sufficient detail. A literature analysis reveals that most studies aimed at pyrogenic changes in forests characterize the territory of Siberia [14][15][16]. Modern research describing soil changes during fires in the European North is rare, with a predominance of publications on the vegetation dynamics during post-pyrogenic successions.…”

Observations of Climate Change Impacts on Terrestrial Ecosystems in Russia

“…Changes in temperature and precipitation patterns varies signifi cantly over the country with a general trend to warming and increasing of heat waves by number. Draughts and fl oods happen every year, sometimes at the same place during one season million hectares (an average 3.662 million hectares per year) [47]. According to satellite data, the fi gures are higher.…”

“…According to satellite data, the fi gures are higher. Between 2001 and 2016 annually in Russia from 5 to 20 thousand forest fi res were recorded, which damaged forests on an area from 5 to 20 million hectares per year [47,48]. About 10% of natural fi res occur annually in Russia due to thunderstorms.…”