Spatial and Temporal Variation in the Occurrence of Gremmeniella abietina in Scots Pine in Finland

Abstract

Spatial and temporal patterns in the occurrence of the infections caused by Gremmeniella abietina in Scots pine stands in Finland during the years 1985-2005 were described in this paper The study utilized data from forest health monitoring plots (Forest Focus Level I plots) and permanent and temporal plots of the National Forest Inventories. The National Forest Inventories showed that the disease was far more common in southern than in the northern parts of the country. The disease was also clearly spatially clustered. The proportion of diseased stands decreased between the 8th NFI (1986-1994) and 9th NFI (1996-2003). The forest health monitoring revealed a heavy outbreak of Gremmeniella in 1988-89, and smaller peaks in 1997 and 2001. Temporal and spatial distributions of the disease were obtained using the level I data. The usability of various datasets were also compared with each other.