T2 — Konferencijos pranešimo tezės

Fediajevaitė, Julija ; Juzėnas, Sigitas

Smart Bio : 2nd international conference, 3-5 May 2018, Kaunas, Lithuania : abstract book, 2018, p. 57

Anglų

Vilniaus universitetas

(eLABa ID)28253156

N 013 - Botanika (100 %)

The aim of this research was to analyze the horizontal structure of L. clavatum and L. annotinum clones and to determine how their initiation was related to disturbances. The research was carried out in Nemenčinės and Aukštagirio scots pine stands of dry sites (Vaccinio-myrtillosa type), in 2017 august-September. The ecological conditions, such as canopy closure and type of habitats, for all clones of both species were similar (coefficient of variation 13%). The age of tree stands varied between 67-127 years. Fifty-two clones of L. clavatum and L. annotinum were studied, however 26 were selected after two procedures: firstly, the verification of the tree stand age was carried out using 1944-1950 ortophotos and topografic maps, and secondly, the circularity of the clones was estimated. Clone was considered as circular, if its lenght/width ratio was less than 1.5. The selected clones were considered as primary, i.e. developed after the sexual reproduction. 53.8 % of selected clones were located on the tracks and paths or were not further than 2 m from them. Assuming, that there is a linear relationship between the size of the clone and the time after the disturbance, we examined, whether the size of the clone is related to the age of the tree stand. However, no significant correlation was found (rs, p>0.05). This suggests that the settlement of selected clones was not related with the establishment of pine stands. Next, we determined the probable age of clones. The spread of potential ages was 45 years for L. annotinum and 40 years for L. clavatum. Hence, the studied clones formed asynchronously in the pine stands. Following the presumption of club moss biology, we suppose that the studied clones of both species developed from spores when the age of the pine stands reached the pole phase and the settlement continued as the stands were reaching mature phase. The distribution of the frequency of the hypothetical time of establishment was invariable among the tree stands age classes, though L. annotinum showed greater preference (38.9 % of studied clones) to emerge when the age of tree stands were 61-70 years. Besides, the establishment of studied clones did not coincide with the stands initiation phase. A time lag of more than 27 years was determined in this research. Consequently, the emergence of studied clones could be explained by small-scale disturbances rather than the large-scale event, i.e. reforestation. Forestry activities such as thinning of pole sized stands and arise of paths and tracks could be favorable factors for studied clones to appear in plant communities. Finally, the emergence of studied sporophyte clones from gametophytes was a steady process, which occurred during the development of pine stands.

Lycopodium clavatum; Lycopodium annotinum; clones; horizontal structure; disturbances; Scots Pine forest;