Western Siberian Warming Shifts Larch into the Tundra and Reshapes Forest Boundaries
New observations from researchers affiliated with the Ural branches of the Russian Academy of Sciences and the Ural Federal University indicate that rising temperatures in Western Siberia are pushing the larch tree northward into tundra regions. This subtle shift is contributing to a visible change in the regional ecosystem as larch populations gradually move beyond their traditional limits. The process is slow because larch seeds lack a strong mechanism for long-distance dispersal, making the migration nearly imperceptible on short timescales.
Experts note that many northern forest areas are expanding into closed forest zones, defined by a crown density in excess of 20 percent. As the climate warms, the boundary between forest and tundra becomes more distinct. The warming is not simply smoothing a gradual transition; it appears to be redefining the landscape’s edge, with evergreen species playing a larger role in these frontier forests. In some cases, species better suited to warmer conditions, such as spruce, begin to replace older larch stands. What was a larch-dominated forest a century ago is increasingly becoming a spruce-dominated forest in many locales.
These observations build on long-standing dendrochronology studies conducted by a laboratory specializing in plant and animal ecology at the Ural Science Academy. By examining the annual growth rings of ancient trees from the Yamal region, researchers have reconstructed summer temperature patterns stretching back thousands of years. The data reveal that air temperatures gradually cooled over much of the last millennium. However, from the mid-19th century onward, a consistent warming trend emerged, accelerating into more recent decades and reaching peak values in the most recent period studied. This climatic turning point aligns with broader evidence of human-driven temperature increases and underscores the link between regional warming and ecosystem shifts in Western Siberia.