Suitable habitat modelling using GIS for orchids in the Black Sea Region (North of Turkey)

Abstract

Orchids are under continuous threat from many factors, especially human-sourced. Estimating the emerging threat factors linked to habitat losses is very important to understand the effects on biodiversity and to design protection strategies and protected areas. Field assessments and modelling were performed with the aim of determining areas where orchids may spread and to reveal priority areas to create a protection plan. Additionally, the aim was to contribute to development of protection strategies for taxa under threat. This study was performed in the Black Sea region located in the north of Turkey. A total of 40 taxa belonging to 15 Orchidaceae genera were collected. The field assessment process used topographic parameters and threat factors. Habitats where orchids are most commonly distributed comprise open areas, meadows, pastures, and forests. Additionally, the density of orchids was determined to be highest at altitudes from 400 to 1600 m. The highest risk factors for taxa in the region include grazing and trampling. Based on these results, suitable habitats were modelled and mapped according to the observed habitat requirements. The determined suitable habitats will represent the preliminary targets for ex situ protection programs where required. The maps revealed here are important for labeling areas with an estimated orchid density and for protection of these areas if necessary. Our field observations were compatible with the obtained maps. Additionally, we consider these maps to be very important in terms of determining areas where taxa will be spread in preliminary field studies.