Bachelor thesis deals with the issue of the variability of the growth characteristics, the growth potential of natural populations alder gray in the selected area of the mountain range Čergov. Measurements were made provisionally on the three research areas. For each of these areas is chosen three level trees, each other in crown aroused layer and represent the middle strain of a particular crop with its own dendrometricks characteristics.From the individuals were collected holes in the two to each other perpendicular directions using Pressler borer in the amount of d1,3m. To prevent systematic errors, the direction of the first bore continuously changing. Holes dry and then glued into a wooden stencil. After drying of the samples we fine sandpaper regrind. The samples taken are digitized in scanner Epson Expression 10000 XL with a resolution of 1200 DPI and processed in the program WinDendro™ 2009b.The width of rings was measured with an accuracy of 0,001 mm. Taken holes were pre-sampled to determine the age of the studied individuals and to determine the average radial increment for a given area. When the radial increments of the individuals and comparing their values alder of gray on the plots, we see a synchronized oscillation increments. It follows that this is a similar micro-climatic sites and individuals, which are found on these surfaces respond to the changing conditions of the environment very much.When assessing the extent of similarity of time series nonparametric (GI) the test can be observed in both cases, the relatively high similarity of the individual time series. For all individuals have been using the program Arstan calculated descriptively statistics and for all the surfaces created in the standard chronology.