چکیده (انگلیسی):

The conventional theory of boreal forest dynamics recognizes two distinct disturbance regime types,
Small-scale gap dynamics and dynamics driven by large stand-replacing disturbances. We used satellite
imagery and extensive field measurements to examine the landscape-level pattern and impact of an
extensive disturbance episode that occurred in the early 2000s in primeval forest dominated by Picea
Abies in the Arkhangelsk region, Russia, due to drought and subsequent bark beetle (Ips typographus) outbreak. We also quantified forest age structures and deadwood characteristics at the landscape-level to
Study how such disturbances shape forest structures over larger scales. Satellite image analysis revealed
That disturbance patches covered about 16% of the land area in the 12 km _ 12 km landscape studied. The
size of the disturbance patches was strongly skewed toward small ones (median size 0.12 ha) and they
Were distributed across the landscape with some tendency of aggregation. The landscape forest matrix
Was dominated by old-growth forest. The dominant trees in the forest were established prior to 1850,
And approximately half of the forest had established prior to 1800. However, the patchy occurrence of
younger forest suggests that the landscape previously was subject to patchy disturbance similar to the
Recent one. This conclusion also gained support from historical records. We conclude that the structure
and dynamics of the studied primeval forest landscape was driven by the combined impact of small-scale
‘‘background’’ mortality (classical gap dynamics) and infrequent episodes of patchy intermediate severity
And scale disturbances.