Intensive Forestry and Biodiversity: Use of Poplar Plantations by Woodpeckers in a Lowland Area of Northern Italy

A growing portion of woodlands worldwide is allocated to tree plantations. These are intensively managed and support significantly lower biodiversity than natural forests. However, given their rising extension and importance, understanding how to enhance the role of plantations in aiding biodiversity is crucial. In the present study, we assessed the suitability of traditional poplar plantations for two woodpecker species (Great Spotted Woodpecker Dendrocopos major and Lesser Spotted Woodpecker Dryobates minor), in the western Po Plain (Northern Italy). During Spring 2019, we counted woodpeckers in 29 plots located in plantations. As a comparison, 30 plots placed in semi-natural woodlands nearby were also surveyed. Moreover, within plantations, we monitored the breeding activity of woodpeckers by camera inspection, and we recorded micro-habitat, stand, and landscape variables for every plot. Densities of both species were significantly lower in plantations than in woodlands. In plantations, the occurrence of Lesser Spotted Woodpecker and abundances of Great Spotted Woodpecker were positively related to the amount and size of standing dead trees, respectively. No relationship with the landscape composition were detected. Only 11 woodpecker nests were found in a surveyed area of 274 ha, indicating scarce breeding activity. In stands with breeding woodpeckers, the loss of revenue due to the presence of dead trees ranged from 0.15% to 1.81%. We conclude that poplar plantations are marginal habitats for woodpeckers. To improve the suitability of plantations for these species, a management strategy should pursue the retention of standing dead wood, the increment of natural elements within and close by the plantation and the establishment of multi-age stands. Simultaneous implementation of these measures would buffer the detrimental effects of intensive management, thus acting as a step forward towards the achievement of a multipurpose forest.