Onshore Wind Energy Development Causes Localized but Lasting Shifts in Plant Community Composition and Function.

Wind power plants are frequently placed in natural ecosystems, but their impacts on plant communities are rarely considered. Therefore, it is unknown how far potential impacts extend into adjacent vegetation and how long they persist. To address this, we surveyed vegetation at different distances to roads at three wind power plants in Norway that were commissioned 4, 12, and 19 years ago. We then used Grime's CSR strategies to document functional shifts in plant community composition and Ellenberg Indicator Values (EIVs) to identify the abiotic gradients driving these shifts. We found that shifts in plant community composition were related to road distance and time since disturbance. At the youngest site, the proportion of plants with ruderal strategies was significantly increased within 10.4 m of roads, effectively expanding the footprint of roads by more than two-fold. At the oldest site, this impact was reduced to 2.8 m, suggesting that the original stress-tolerant communities recovered at a rate of 0.5 m per year. Increased ruderality near roads was associated with plant communities indicating higher nutrient availability and more reactive soils. This study provides novel knowledge regarding the spatial and temporal impact of wind energy development on plant communities. As road construction appears to shift community composition toward ruderal dominance by increasing nutrient availability, we recommend keeping road- and construction areas to a minimum. Overall, this can reduce the footprint of wind power plants and ensure that the transition to renewable energy does not come at the expense of ecosystems.