A touch of orchids from Samos (Greece)

Abstract

The International Conference about Temperate Orchids Research and Conservation (TORC’15) was held on the island of Samos, Greece, from 14 to 18 April 2015. It was organized by the Sails-For-Science Foundation (a non-profit organization based in Germany, promoting a sustainable balance between nature and society for small island communities worldwide) under a sponsorship by the Société Botanique de France and several other societies. In this issue, we publish three papers spanning from this international meeting. The plant family Orchidaceae emerged on our planet 112 million years ago branching out to over 25,000 species with compatible populations of dazzling diversity comprising almost 8% of all vascular plants, unlike any other plant family (Pridgeon et al. 2001–2014). Their resilience to extremes reaches from tropical abundance to remote places in high latitudes and from sea level to high altitudes into the upper limit of continuous vegetation, with colonization of outstanding niches such as epiphytic habitats or heterotrophic nutrition in forests (Givnish et al. 2015). Moreover, they display tight interactions, sometimes mutualistic, sometimes parasitic, with their associated pollinators and mycorrhizal fungi (Selosse 2014). Why did this angiosperm family become so dominant during the race for the tree of life? What innovative mechanisms, behaviours and physiological processes have made its conquest so successful? Although a number of intriguing phenomena of the orchid life cycle, relating to mycorrhiza, pollination, epiphytism, crassulacean acid metabolism (CAM), among others, has been unveiled, vast gaps in understanding of this success story of ecology and evolution remain. (A) On the molecular level, what are the physiological modes of action of the orchid plant itself and its choices for a thriving environment in respect to the geochemical, microbiota, embryophyta, insect and herbivore cross-signalling? (B) On the ecological level, what networks of co-evolutionary processes and which implications from abiotic change alter the homeostasis of orchid populations? Land abandonment for economic reasons and global climate change are the assumed main factors for the change or even the irretrievable decline of orchid biodiversity (e.g. Robbirt et al. 2014). The greatest challenge facing anybody interested in these charismatic plants is the vanishing of valuable orchid species in human-sculpted landscapes (Swarts, and Dixon 2009). Europe has now less than 1% land remaining in intact wilderness vegetation (Gillespie 2013). In Australia alone, 25% of the global orchid biodiversity has disappeared. Valuable secondary metabolites of orchids providing original potentials as therapeutics may be lost forever. (C) Therefore, the application of orchid research for their conservation needs to become mainstream. Only concerted interdisciplinary research and the involvement of the general public, starting with the orchid enthusiasts, all united by the passion for this family of flowers, may deepen our understanding. The aim of this conference was to provide a stimulating forum to this diverse group of people and to address the above-mentioned cornerstones (A), (B) and (C). Botanists, biologists, conservationists, chemists, ecologists, pharmacists, geneticists, orchidologists and others from more than 30 countries and five continents gathered on Samos contributing cutting edge science in seven sessions: (i) updates on the Greek and world orchid flora, (ii) systematics and population genetics, (iii) mycorrhizal studies, (iv) pollination, floral deception and reproductive success, (v) ethnobotany and propagation, (vi) population dynamics and determinants, and (vii) conservation. The island of Samos is embedded in an archipelago in close proximity to Minor Asia. These biogeographic conditions of the island sustain a high number of orchid taxa, especially in the genus Ophrys (see list below). The conference included extensive field trips to the charismatic flora during the blooming season on the island. Successful conferences are judged by their outcomes. The stimulating and convivial surroundings strengthened existing collaborations, and started a number of new research and conservation initiatives around the globe. To name a few examples, the establishment of an urgently needed European orchid conservation centre is being pursued, building on the experiences and in coordination with other continental conservation centres such as the North American Orchid Conservation Center. The closely interrelated orchid populations of the Aegean and Minor Asia are subject to immense habitat destruction, particularly through the unsustainable production of the traditional salep. In consequence of this conference, several research and conservation organizations from Greece, Germany and Turkey formed a consortium and formulated an international orchid conservation programme with the