Distribution and natural regeneration of Tilia cordata Mill. in Ukrainian plain forests in a changing climate

The aim of this study was to assess the current state of small-leaved lime stands under climate change, as well as to identify optimal conditions for the occurrence and further growth of natural lime regeneration under the stand canopy to grow productive and sustainable mixed stands. The areas of small-leaved lime (Tilia cordata Mill.) stands in plain Ukrainian forests and mixed stands with English oak (Quercus robur L.) were defined according to reference materials (as of 2016). Growth and liveability peculiarities of natural regeneration of lime under the canopy of oak-lime stands in climate change were identified. The main stand characteristics contributing to maximal appearance and further development of advance growth of lime, such as composition, age and relative density of stocking, were determined. It was found that the lime stands of vegetative origin occupy the largest part of the lime forests’ area, being less resilient and productive than those originated from seeds. Small-leaved lime is the best associated species in mixed oak stands. The presence of lime improves health, assortment composition, and productivity of oak stands and increases their resistance against pests and diseases. In the future, lime can play an important role in the adaptation of forests to climate change due to its biological and forest properties and adaptability to a sustainable existence in a relatively wide range of environmental conditions. A summary of the studies complements a system of knowledge about the current state of lime stands as well as peculiarities of their regeneration and growth. The data obtained can be used as a theoretical base for forest management to promote natural regeneration and maintain the sustainability of these forests.