Habitat assessment of Green Woodpecker (Picus viridis) in Golestan National Park using classification tree method

The Green Woodpecker (Picus viridis) is one of the most important and an umbrella species in Golestan National Park. In this study, habitat suitability of the Green Woodpecker was studied in reproductive and non-reproductive seasons in Golestan National Park. Habitat characteristics, including forest vegetation type and structural characteristics of vegetation as well as the presence/absence of woodpeckers were recorded within a 25-m radius of each of 112 sampling plots. The Classification tree model was used to identify the relationship between the presence of Green Woodpecker and habitat variables in reproductive and non-reproductive seasons. Results of statistical analysis showed that during the reproductive season, the accessibility to areas with a dense canopy cover and tall snags, determined the reproductive territory. In the non-breeding season, the site selection by the Green Woodpecker was based on the presence of live trees with DBH between 50 -100 cm and tall snags. Totally, areas with dense canopy cover (>62%) supported more density of woodpeckers. In open areas (canopy cover