Protecting the forest habitats of Golestan province by determining the high suitability of the green woodpecker (Picus viridis) habitat

Abstract

Introduction: Hyrcanian forests are known for their rich biological diversity and valuable fauna
and flora, are among threatened ecosystems due to the wide level of human activities. Woodpeckers
are also considered as the indicator of the biodiversity of forest birds and they need a large home
range and thick trees and snags or nesting and feeding. Changes in forest structure and canopy will
reduce woodpeckers in all forest habitats. Therefore, aim of this study is modeling the habitat
suitability of the indicator species of Green Woodpecker to determine the valuable forest
conservation patches in the forests of Golestan province.
Materials & Methods: For this, the green woodpecker presence points extracted from the Global
Biodiversity Information Facility (GBIF) database were combined with the data obtained from field
observations throughout the study area, and then the environmental variables affecting the
distribution of the species based on published sources for the construction of its habitat suitability
model including climatic variables, topography (slope and altitude) and Normalized Difference
Vegetation Index (NDVI) were determined as predictive variables in the modeling. In order to
model habitat suitability, the Maximum Entropy model was used in MaxEnt software, and the data
analysis of MaxEnt software was done in ArcGIS. The Jackknife index was used to evaluate the
importance of variables in the preparation of the model and to determine the most important
variables affecting species distribution, and the efficiency of the model was evaluated by calculating
the Area Under Curve (AUC).
Results: The Area Under Curve for the training data (AUC= 0.948) showed that the efficiency and
predictive power of the Maximum Entropy model for determining the optimal habitat areas of the
Green Woodpecker species is at very excellent level. The model, finally obtained, also showed that
the majority of forest habitats suitable for protection are located in the central and eastern parts of
the forests of Golestan province. Based on the Jackknife index, NDVI, Slope, Isothermality and
Seasonal Changes of Precipitation were identified as the most influential variables for building the
final habitat suitability model.
Conclusion: Referring to the results, flat to moderate slope areas of Hyrcanian forests and oak tree
communities along with areas with dense canopy were recognized as priority for conservation. It is,
therefore, necessary and inevitable to ecologically enrich the forests through forest proper
management and make them more sustainable ecologically.