Population status and ecology of Platanthera chlorantha (Orchidaceae) in the Greater Caucasus (Azerbaijan)

Abstract

Long-term conservation schemes usually concern the rarest species, extremely threatened. Investigating Red Data Book species is inescapable for determining their threatened category and optimal measures for the protection. Orchidaceae is the most attractive plant family among all plant families of the world. Due to decorative, medicinal, food features of orchid species, their populations are declining. Seventeen threatened orchid species are included in the Red Data Book of the Republic of Azerbaijan. One of them is Platanthera chlorantha. The ontogenetic and morphometric structure of P. chlorantha populations was previously studied fragmentarily. However, the vitality structure, and the environment influence on its populations have not been studied in Azerbaijan yet. The aim of the present paper was to study its ontogenetic, demographic and vitality structure in order to elucidate the influence of climatic and edaphic factors on morphometric variability. The field investigations were carried out in 2016–2019 in Khizi, Siyazan, Guba, Gusar, Shamakhi, Ismayilli and Gakh districts of the Greater Caucasus using both population-based and geobotanical methods. A morphometric analysis was performed on 30 randomly selected generative individuals in the nine studied populations. Relationships between distribution of some orchid species, their environmental preferences and environmental variables were analysed using canonical correspondence analysis (CCA). The phenology of P. chlorantha has been studied. We revealed that a temperate, warm, humid climate and mountain-brownish soil type are most favourable for P. chlorantha.

Keywords

• endangered species
• morphological variability
• ontogenetic structure
• orchid
• ordination
• phenology
• species abundance
• vitality structure