Growth characteristics of sessile oak (Quercus petraea (Matt.) Liebl., Fagaceae) young crop in conditions of small size regeneration areas

Abstract

In accordance with the biology of sessile oak that implies shade tolerance and the ability to regenerate in the closed stand canopy conditions in the monodominant sessile oak forests in Serbia, the natural regeneration of stands is mainly based on beforehand, spontaneously formed young crop and its gradual release from shade of the secondary species and mother trees by means of regeneration cuts on the areas of various size. In the conditions of small size regeneration areas on a site of a mesophilious variant of monodominant sessile oak forest (Quercetum petraeae Čer. et Jov. 1953. s.l) in the area of northeastern Serbia, a morphometric analysis was conducted on sessile oak young crop that was formed after successive mast years (2002, 2005, 2009 and 2011). In the oldest found young crop that was formed in the closed canopy conditions, the above-cotyledon-axis was on average 9.0 cm tall in the first year of its development while at age 15 years it was 55.0 cm with a root collar diameter of 6.3 mm. The morphology of the seedlings was typical of shade conditions (sciomorphic). The current annual height increment in the unchanged canopy conditions in the period from the 2nd to the 9th year of age was 1.0–2.6 cm. When the canopy conditions were changed, from 10th to 15th year, the current annual height increment was 1.4–10.9 cm. In the conditions of small size regeneration areas, the sessile oak young crop shows a specific norm of reaction of height growth in the first and in the following years of development and the main height growth type was one-flush growth.