Choi K.H., Kim, Y.M., and Jung, P.M., 2013. Adverse effect of planting pine on coastal dunes, Korea.

Forestation on the coastal dunes has been regarded as one of the best programs that help to stabilize the dune landscapes and protect the residential area from strong winds, blown sands, and salt spray. Introducing exotic species for dune stabilization was very common in the past. However, it could deprive coastal land of its ability to naturally recover, causing a retreat of coastline as well. As a typhoon passed through the Korean Peninsula early September in 2010, coastal dunes along the west coast of the peninsula were severely damaged during the storm. Some dunes retreated landward more after erosion, while others recovered their original profile through aeolian transport processes mainly in winter season. Vegetated dunes with pine trees recovered relatively less after the erosion than grass-covered dunes. Planting pine trees may interfere in these interactions, weakening natural recuperative power. We compared the characteristics of wind environment, morphology, and vegetation between the grass-covered dunes and the dunes covered with pine trees, for the purpose of the effectiveness of planting trees on dunes. The pine forest decreases the wind velocity on the front side of the dune to less than 50% of the grass-covered dune. Especially, the velocity of the strong winds faster than 4.5 m/s diminished to 25% of the control sites, resulting in decreased blown sand supply. Flora is also changed in the forested area. Terrestrial plants have invaded after pines were planted. In contrast, natural flora gets disappeared after the introduction of alien and exotic species. This study suggests that planting tree is likely to lead negative impact on coastal dunes. It may result in a retreat of coastline, loss of land, and devastation of dune ecosystems.