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This study focuses on the problem of irregular diameter structure in a silver fir-beech selection (plenter) forest with a ''surplus'' of large diameter trees and a lack of natural regeneration and small diameter trees. We sampled 274 plots (900 m 2 each) in the Belevine research site (266.24 ha) in the mountain region Gorski Kotar (Croatia), where diameter (dbh) distribution, diameter increment, and natural regeneration were analyzed in detail. A low density of natural regeneration, weak annual recruitment of small (10 cm dbh) diameter trees (only five trees per hectare), delayed diameter growth of trees, and a low annual rate of trees reaching the next dbh class were attributed to the current irregular dbh structure. The stand development prediction for the next 50 years is based on a simulation model, which considers the current diameter structure, increment, recruitment, and future cutting regime. Intensive cutting in the first of five 10-year cutting cycles (intensity higher of 25%) is needed to initiate natural regeneration and to accelerate growth of young silver fir trees. In the next 50 years, the irregular diameter structure will be gradually improved.

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The relative abundance and the population development of small rodents were investigated on 17 sites in Croatian forests from September 1999 through June 2003. Common snap traps were set for two or three nights along transect lines in different forest types. In 27,598 trap-nights, 2,151 specimens were trapped. Small rodents were present in up to 45% of the traps in pedunculate oak forests dominated by Quercus robur L. In common beech forests with a predominance of Fagus sylvatica L., the percentage of occupied traps reached 59%. At most sites the following species were dominant:Clethrionomys glareolus Schr., Apodemus agrarius Pall. and A. flavicollis Melch. Additionally, in a forest community of Carpino betuli-Quercetum roboris typicum R., the absolute number of small rodents was calculated by means of the standard minimum method. The minimum rodent density was observed in April 2003 with 11.63 n/ha (number of specimens per hectare). The maximum was reached in March 2001 with 82.03 n/ha. Near the same site, the absolute number of the small rodent population was estimated using the ''Y method'' in spring 2001 as approximately 101.34 n/ha. In general, the abundance of small rodents was dependent on the forest seed crop.