Feb 11, 2010
Insight: climate change in the Republic of Tuva, Siberia
Wildfires are a normal and natural process in boreal Siberia, and small-to-medium fires are particularly frequent in Scots pine stands. However, under current climate-change scenarios, models predict that the growing season length will increase and that the fire season will become longer. The amount of area burnt will also increase and fires will become more severe.
Even more worrying: local inhabitants have reported that "relic" pine forests, which have existed since the last ice age, are disappearing. This disappearance is consistent with bio-climatic simulations, which suggest that the region with be a "hot spot" of climate change.
An international scientific research team from the Russian Academy of Scientists (Krasnoyarsk, Russia), Siberian State Technological University (Krasnoyarsk, Russia) and the National Institute of Aerospace (Hampton, US) is studying this region.
The team drew from several sources of expertise to investigate past and current fire patterns, as well as undertaking fieldwork. For example, tree-ring fire scars (dendrochronological analysis) were analysed. Historic and current fire data were also provided by the Krasnoyarsk Forest Protection Airbase and Balgazin forestry division.
Based on monthly and annual wildfire occurrence and areas burnt, the researchers found that the frequency of fires has not changed significantly in the Scots pine stands over the past 300 years. This is in contrast to the fact that more fires are occurring in central Siberian boreal forests.
Tuva has been inhabited since the 12th century, starting with the expansion of the Mongolian empire, but because of changes in weather and climate (increasing drought, growing and fire seasons), the severity of fires and areas burnt have increased since 1990. At the same time, protecting the area against future fires is becoming more difficult. This might be because large portions of the forest are being converted to a steppe-type ecosystem after fires have occurred, which further inhibits post-fire forest regeneration. Such a conversion is precisely what models predict will be an initial indicator of climate-induced ecosystem change. In addition, annual fire carbon emissions have been estimated for the Balgazyn forest of Tuva with regard to ground fuel loading and fire severity. This is important because the dryer the fuels, the more severe the fires and the greater the greenhouse-gas emissions. And, forests are not always able to regenerate on severely burnt or repeatedly burnt regions.
The team now plans to continue to focus on changes in fire patterns in forest-steppe ecosystems in central Siberia (Krasnoyrskii krai), particularly the changes that influence and are influenced by climate and humans.
The researchers reported their work in Environmental Research Letters.