In the rolling agricultural landscapes of Spain and France, a quiet ecological experiment is reshaping how scientists think about tree farms. A new study published in Landscape Ecology reveals that fast-growing poplar plantations, long seen as production machines for wood and biomass, can also serve as vital stepping stones helping forest birds navigate across fragmented countryside — provided they're planted in the right places.
Sara Pineda-Zapata, a doctoral researcher at the University of Eastern Finland, led the investigation across two European river sub-catchments. Using spatial connectivity models, her team tracked how existing forest patches — including those within protected Natura 2000 areas — and poplar plantations interacted to support movement for three forest bird species with contrasting dispersal abilities.
The results were striking. In Spain, poplar plantations generated connectivity gains that exceeded what their mere area would suggest. Certain plantation patches played an outsized role in maintaining ecological corridors for forest bird networks, including connections to protected Natura 2000 areas. In France, the picture was different: plantation patches tended to be more isolated, contributing less effectively to bird movement. The difference came down to landscape configuration and where the plantations sat within it.
"Plantations can act as stepping stones between forest patches, although their effectiveness depended strongly on their location within the landscape," Pineda-Zapata explained. "We wanted to understand whether plantations, often viewed only through the lens of wood and biomass production, could also support ecological processes in fragmented landscapes."
The benefits were most pronounced for species capable of traveling longer distances. For short-distance dispersers like the common chaffinch, plantations had a more limited effect unless positioned very close to existing forest habitat — a reminder that even narrow gaps can form major barriers for less mobile species.
Professor Blas Mola, also at the University of Eastern Finland, emphasized the practical implications: "Plantations are often assessed only in terms of production, but when strategically located, they can provide much more than wood. They can contribute to landscape structure, help maintain ecological flows and complement conservation efforts in intensively used agricultural regions. The key message is that location matters, and that planning matters."
Rémi Duflot from the University of Jyväskylä offered a note of caution alongside the optimism: plantations cannot replace natural forests in ecological quality, and increasing tree cover may reduce habitat for open-habitat species that need open fields to survive.
Still, the findings open a door. "What our results show is that in fragmented landscapes, well-placed plantations can become part of the solution," Pineda-Zapata concluded, "opening up interesting possibilities for designing productive landscapes that are also more supportive of biodiversity."