Spreading walnut (Juglans regia) into the wild in the basin Bystrytsia Solotvynska river (Ciscarpathia, Ukraine)


  • Ihor Kucherko Vasyl Stefanyk Precarpathian National University
  • Viktor Shparyk Vasyl Stefanyk Precarpathian National University
  • Andrew Vasyl Stefanyk Precarpathian National University




walnut, Juglans regia, biological invasions, Carpathian region, Bystrytsia Solotvynska


The problem of walnut (Juglans regia) invasion is new not only in Ukraine, but also in all of Central Europe. Its invasion is well documented in Austria, Slovakia and Poland. Information about walnut invasion in Ukraine is still insufficient. In this study, we presented the results of a study of walnut invasion in the Bystrytsia Solotvynska river basin, including its mountain and lowland parts. In the mountainous part, the walnut is absent, and in the foothills, it forms two clear centers of invasion: in the cities of Ivano-Frankivsk and Bohorodchany, as well as their closest vicinities. Outside the cities, the intensity of invasion is much lower and the number of trees per unit area decreases in proportion to the distance from large settlements. We consider the reason for this invasion to be the presence of permanent colonies of crows (Corvus frugilegus) in both cities, which are the main vectors of the spread of walnut seeds. In addition, we noted the influence of a complex altitudinal gradient on the intensity of invasion: with a decrease in altitudes, the intensity of invasion increases. The greatest intensity of invasion is observed in the height range of 250-350 m above sea level; at heights of 350-450 m, it is much lower; above 450 m invader is completely absent. It is obvious that the invasion of walnut into the natural and semi-natural ecosystems of the region depends on many factors, including both biotic and abiotic. We found that the main habitats invaded by walnut are willow and willow-alder forests along rivers. However, walnut in the willow and willow-alder forests of the Bystrytsia Solotvynska basin still plays a minor role and does not form a separate type of forest. The transformation of willow and willow-alder forests under the walnut invasion is slow. To date, almost everywhere, walnut constitutes the understory, gradually reaching the second layer of the willow forests. The further development of the walnut invasion in the Bystrytsia Solotvynska basin is generally predictable. This includes the transition from primary to secondary invasion and the gradual transformation of walnut into an edifier. We also proposed a prognosis of the possible ecological and economic consequences of the walnut invasion in the Bystrytsia Solotvynska basin.


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How to Cite

Spreading walnut (Juglans regia) into the wild in the basin Bystrytsia Solotvynska river (Ciscarpathia, Ukraine). (2023). Notes in Current Biology, 4(2). https://doi.org/10.29038/2617-4723-2022-2-3