Upturned root systems are used by several species of birds as nesting sites. The primeval lowland temperate forests are the crucial the source of information with this respect. The aim of the study was to characterise the root plates as nesting sites in a forest covered by a reserve protection system for about 20 years. The research was conducted between 2016–2018 in south-eastern Poland. In the area examined, nests of the Eurasian Wren Troglodytes troglodytes and the European Robin Erithacus rubecula were found to occupy 19.9% and 2.1% of root plates in uprooted trees, respectively. Among root plates with wren nest, Scots Pine accounted 36.8%, subsequently Norway Spruce 28.9%, and Silver Birch 18.4%. Inclined root plate and root plate of large surface were often chosen by Wrens for building a nest. A week positive correlation was found between the height at which the nest was built and the height of the root plate.