Pelkinės uolaskėlės (Saxifraga hirculus L.) populiacijų struktūros ir bendrijų pokyčiai po 10 metų

• Main Author: Petrauskaitė, Ieva
• Other Authors: Meškauskaitė, Edita
• Format: Bachelor Thesis
• Language: Lithuanian; English
• Published: Institutional Repository of Vilnius University 2017
• Subjects: Saxifraga hirculus
• Online Access: http://vu.lvb.lt/VU:ELABAETD35836234&prefLang=en_US

The aim of this bachelor‘s degree was to investigate how the structure of S. hirculus populations and its habitats have changed after 10 years. This research was conducted in nine investigation sites in which populations and habitats of S. hirculus were investigted by E. Meškauskaitė in 2006. The data was collected according to the same methodology used by E. Meškauskaitė, and then the resuslts were compared. The purpose was to determine the changes in populations of S. hirculus and its habitats within this period, as well as to examine how the intensity of nature management had influenced these investigated sites. Habitats of S. hirculus were investigated by using Elenberg indicator values of vascular plants. It was found that the ecological conditions of habitats with S. hirculus are similar to one another and haven‘t changed significantly in the past 10 years. Minimum data variation was caused by the following ecological factors: salinity, acidity and changes in humidity. However, no significant changes of these factors were found in the investigated sites. The analysis of the floristic composition of habitats with S. hirculus showed that the majority of the investigated sites haven‘t changed and belongs to as. Caricetum diandrae and as. Caricetum rostratae. The ecological density of S. hirculus populations have changed unevenly. In five investigates populations, ecological density had decreased from 3,4 to 19 times. Three investigated populations had increased from 1,3 to 3,2 times, while two populations had almost disappeared, as only few shoots of S. hirculus were found. Morphological features of generative shoots of S. hirculus (stem length, the longest sheet, the maximum sheet length and width ratio, and number of leaves and flowers) have changed significantly only in one investigated population, while in other populations only individual factors have changed significantly. The study revealed that between 2006 and 2016, regular nature management measurements were taken in two investigated habitats with S. hirculus, while nonregular measurements were taken in three. A statistically significant correlation was found between the intensity of nature management and the distribution area of S. hirculus population (p=0,0151).