Assessment of the data on distribution, habitats and population size of Liparis loeselii (Orchidaceae) in Lithuania

Abstract Liparis loeselii is a declining orchid species in almost all European countries, mostly because of habitat loss. Therefore, good knowledge about the species ecology, distribution and populations is required in order to substantiate measures for its conservation. The aim of this research was to evaluate all available information about distribution, habitat types and population sizes of L. loeselii in Lithuania, in order to reveal the current state of our knowledge and identify information gaps. The study was based on the analysis of herbarium specimens and information in publications and various databases (a total of 481 unique records were used: 118 from herbaria, 121 from literature and 242 from databases). Intensive accumulation of information about L. loeselii started in the second half of the 20th century and a particularly large number of records were made in the period from 2010 to 2015 during the implementation of inventory and mapping of EU Habitats all over Lithuania. A summary of all information about L. loeselii revealed that it was registered in a total of 93 grid squares, and is mainly confined to uplands. The available information is quite sufficient for the evaluation of the species distribution and prevailing habitats, but is incomplete for the evaluation of population sizes, demographic structures and population trends under changing habitat conditions. Additional investigations are, therefore, required to enable a more accurate assessment of the size and viability of the L. loeselii metapopulation in Lithuania.