Horizontal structure of forest stands on permanent research plots in the Krkonoše Mts. and its development

Abstract

Horizontal structure on 38 permanent research plots is described for juvenile growth and developmental phases (natural seeding, advance growth, plantations) and tree layer of a parent stand. Hopkins-Skellam index, Pielou-Mountford index, Clark-Evans index and Ripley's K-function were computed. The results are presented separately for beech stands, mixed stands, spruce stands, stands in the timberline ecotone and relict pinewood. The numbers and distribution of natural and combined regeneration recruits are mostly sufficient from the aspect of ecological, environmental and production functions of forest. The horizontal structure of juvenile growth and developmental phases of natural and combined regeneration shows mostly clustering; it is random or moderately regular at places with a single dominant proportion of artificial regeneration. In the tree layer the horizontal structure of forest stands is mostly random to moderately regular. In the future silvicultural measures should be aimed to support the structure of homogeneous stands of younger growth phases that have originated on a large scale after the air-pollution disaster.