MOSCOW, March 1. /TASS/ Scientists from the RAS Forest Institute, the Siberian Federal University (SFU) in collaboration with representatives from the Russian Center of Forest Protection and NASA's Goddard Space Flight Center discovered that the Siberian climate’s increased aridity and an explosion of predatory insects have resulted in the deterioration of Siberia’s fir, spruce, and cedar forests, the SFU press service reported, citing the recently published article in the journal, Forest Ecology and Management.
Cedar and fir are moisture-loving conifers, sensitive to any lack of moistness. "When attacked by bark beetles, a healthy tree responds by discharging resin, whereas trees debilitated by a lack of moisture become a very attractive target for predatory insects and root phytopathogens," explained the leader of the research, Vyacheslav Kharuk, who is also the Chief of the Chair of Geoinformation Systems at SFU and Head of Laboratory of Forest Monitoring at Sukachev Forest Institute.
At the same time, the rise in the climate’s aridity and the lengthened lifespan of plant growth helps insects endure the cycle faster, increase their population, broaden its geographical range, while advancing north and towards the high mountain ranges. Researchers note that climate change, in weakening dark coniferous forests, have stimulated a population boom of Polygraphys Proximus, a small bark beetle which inflicts the most distinct damage to Siberia’s fir populations. Such an population explosion of insect predators who ravish conifers in the Siberian taiga has been never observed before.
Krasnoyarsk biologists have pointed out that this problem does not exclusively affect Siberia. A similar situation is now being observed in South America. where an insect population explosion of tiny bark beetles known as Dendroctonus Ponderosae has already engulfed an area of more than 25 million of hectares causing the loss of billions of cubic meters of wood.
The rise in temperatures and the climate’s growing aridity have produced a negative impact on cedar and fir in the southern regions of their habitats, but in the middle and north taiga, as well as in the extreme mountainous regions, this sort of change in climate is favorable for these species. The main forest-forming species of Siberia, the larch, stands also to gain from this phenomenon.
According to scientists, reviving fir and cedar forests in the areas which have already become unsuitable due to climate change is not worth the effort. Instead, it would be better to replace them with more drought-resistant tree species such as the larch and pine.