A new distribution area of the Ophrys isaura Renz & Taubenheim in Türkiye and some ecologic characteristics

Ophrys isaura Renz & Taubenheim., is one of the rarest endemic species in Türkiye and belongs to the Orchidaceae family. According to a literature survey, the species at risk of extinction in nature is distributed in the C3 and C4 squares of the Turkish flora. In this study, it was observed that the plant has also distribution within a narrow range of between 1100 and 1200 meters in the Pinus nigra subsp. pallasiana forest clearing near Akdoğan village in the Eğirdir district in Isparta from southern Türkiye. O. isaura was identified for the first time at this locality and represents the southwestern most record of this species in Türkiye. Some morphological, phenological and ecological characteristics of the species were revealed by examinations of the newly detected population. The morphological characteristics of the new population were compared with the descriptions of O. isaura in Flora of Türkiye and Illustrated Flora of Türkiye. Some morphological characteristics exhibit minor differences compared to the information available in the early studies. In the study, some ecological characteristics of the new distribution area of the species were identified. The dominant rock formation in the area is fractured and cracked limestone. The radiation index was calculated to be 0.46, while the temperature index was determined to be 0.89. These measurements indicate that the area generally receives sunlight in the early morning and has moderate illumination throughout the day. Soils up to 10 cm depth layer within areas characterized by humid and wet soil conditions are of clay type and exhibit very low skeletal content. The high levels of lime (30.65%), organic matter (6.12%), and weakly alkaline conditions (pH: 7.11) in the habitat of the species provide a favorable environment for water, air, and nutrient economy within this soil depth layer. Overall, the plant species diversity in the open forest area where O. isaura was sampled was found to be higher compared to that in the understorey of the surrounding black pine forest areas.