Reintroduction of Curly Birch

Abstract

The paper offers a systematic overview of the results of research regarding reintroduction of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti published by Russian and foreign authors over the past few decades. We briefly outline the current situation with its resources and the key causes of their decline in the late 20th – early 21st centuries, such as mass-scope illegal logging, vanishing or substantial alteration of typical curly birch habitats, as well as some biological features (fragmented distribution, low competitive capacity, etc.). The main outcomes of the curly birch introduction activities in the areas lying far beyond its natural distribution (mainly to the south-east from it) are reported. It is shown that the experience of curly birch reintroduction in Russia is mostly based on planting of forests and establishment of specially protected areas. The results of curly birch reintroduction in Finland, Sweden, Norway, Germany, Belarus and other countries are observed. Although reintroduction is not equally effective in all countries (its success depends on many factors), it has made and is making a significant contribution to the preservation and augmentation of the resources of this unique member of the European forest tree flora. Importantly, the curly birch from the reintroductions performed in different years and different edaphic and climatic conditions steadily retains its key biological features, such as figured grain and diversity of growth forms and trunk surface characteristics, which once again confirms the authors’ previously expressed opinion that there are grounds for classifying the curly birch as a separate biological species. Proceeding from the analysis of the data amassed by now, it is suggested that that the efficiency of curly birch reintroduction to its natural habitats can be promoted by mainly using the stocking material of local provenance (when restoring populations) or by transferring it from other populations (for repatriation cases). An important role in the preservation and reproduction of curly birch belongs to the micropropagation technique.