A Case Study on Pine Forest Management Aimed at Habitat Conservation for the Northern Goshawk (<i>Accipiter gentilis</i>)

Abstract

The Northern Goshawk (Accipiter gentilis Linnaeus 1758), a rare raptor, is listed as an near threatened (NT) species on the red lists by the Ministry of Environment of Japan. Many guidelines about how to manage the forest have been suggested for habitat conservation of the Northern Goshawk, and suggested that active forest management is required to maintain appropriate habitat conditions for extended periods. However, there are few cases of actual active management in Japan. The aim of this study is to evaluate the effectiveness of the active forest management implemented in "The Forest of Accipiter gentilis, Daisen, Tottori Prefecture" by comparing the forest structure and avifauna before and after forest management and to suggest an appropriate management plan. A management plan (Management of pine tree density, improvement by cutting of broad-leaved trees that reached the sub-tall tree layer) was suggested based on the first survey by the Tottori Chapter of the Wild Bird Society of Japan and Tottori University in 2003, and this suggestion was implemented by Tottori Prefecture for the five ensuing years. A second survey, conducted after the management, revealed that pine trees with a large diameter at breast height (DBH) and open spaces between the canopy and understory foliage for flying were preferred as nest areas by the Northern Goshawk. In addition, there was a good foraging range around the case study area. The mosaic of farmland and forest of the Satoyama range was utilized by the Northern Goshawk for foraging. Forest management that includes (1) promoting growth of large diameter trees for nesting and (2) securing flight space in the forest was made clear appropriate for both the conservation of Northern Goshawk habitat and timber cultivation.