Abstrakt 2003/4/6

Prace Inst. Bad. Leœ. 2003/4: 91–106.

Wskaźniki i znaczenie wypadu drzew w drzewostanach

Indicators and importance of tree mortality in stands

Grigorij V. ÈIRKOV, Nikolaj A. PIROGOV
Sankt-Peterburgskij nauèno-issledovatel’skij, instutut lesnogo chozjajstva, Rossija, 194021, St. Peterburg, Institutskij pr., 21

Abstract. The dynamic of the spruce stands of Leningrad region was studied by addressing the following questions: (1) How does mortality rate vary according to the stem size? (2) How long can the snags stand before they fall down? The observation was carried out on the 8 permanent sample plots that were established in the unmanaged spruce stands about 40 years ago. The significance of tree mortality for forest management is showed. Annual mortality rate decreases consistently with the stem size in all sample plots. The lowest rate (1% per year and less) is in the dead trees with diameter at breast height (DBH) 20 cm and more. The average period of snags standing is 9.6 years and their number decreases with the stem size.

Key words: mortality rate, snags, logs, period of snag standing, permanent sample plots