Needle anatomy suggests hybridization between the relict turfosa form of Pinus sylvestris L. from the Gazwa peat bog and typical Scots pine

The aim of this study was to characterize the turfosa form of Pinus sylvestris from the Gazwa peat bog reserve in terms of 16 anatomical needle traits and to determine whether pines with a typical morphotype inhabiting the peat bog have been so successful thanks to hybridization with the unique tufosa ecotype. Investigations were conducted on three phenotypic groups of Scots pine growing in the peat bog. The first two groups consisted of 30 tufosa trees at the age of 117-217 years and 20 trees at the age of 30-85 years. The third group consisted of typical pines represented by 10 trees at the age of 20-55 years. In total 30 trees of typical pine, surrounding the peat bog, at the age of 100-150 years served as outgroup. Descriptive statistics, analysis of variance with the F test, Tukey's test, and a number of multivariate analyses were used to estimate differences between the studied groups of trees based on 16 anatomical needle characteristics. The old turfosa form from the Gazwa reserve proved to be a unique and relict peat bog pine, as it was shown by the differences in 10 analyzed needle traits in comparison to pine with a typical morphotype growing in the areas surrounding the peat bog. The young typical pines have adapted to conditions found in the peat bog owing to hybridization with the turfosa forms. The young turfosa trees differed from the old turfosa trees and also they have probably been of a hybrid origin. The old turfosa form from the Gazwa reserve is a threatened ecotype due to its hybridization with pines from the population surrounding the peat bog.