Costas A. Thanos

• Doctor of Philosophy
• Professor Emeritus at National and Kapodistrian University of Athens

Background and AimsThe Campanulaceae is a large cosmopolitan family, but is understudied in terms of germination, and seed biology in general. Small seed mass (usually in the range 10-200 µg) is a noteworthy trait of the family, and having small seeds is commonly associated with a light requirement. Thus, the purpose of this study was to investigat...

Light conditions provide important information about the best time and place for seedling establishment. Photoinhibition of seed germination (PISG), defined as the partial or complete suppression of germination under white light, has been interpreted as a physiological adaptation to avoid germination at or near the soil surface. This review is the...

Translation of the textbook EVOLUTION, Futuyma & Kirkpatrick, 4th ed. into Greek

Masting and regeneration dynamics were investigated in a long-term perspective using Abies cephalonica as a study tree species. Extensive fieldwork was implemented in Parnitha National Park, Greece, following a large-scale wildfire. Annual cone production was monitored for a 5-year period in 130 tagged trees, in 13 plots with 10 individuals each, e...

Climatic data from the region suggest that prolonged dry conditions may adversely impact the limited reproductive capacity of Abies cephalonica, further complicating its ability to regenerate in Parnitha NP, in the face of climate oscillations. A relative decline in cone production during masting years was noted, which can be attributed to the incr...

Riparian ecosystems are essential for ensuring linear habitat connectivity and providing thermal refugia for wildlife. However, they are increasingly vulnerable to global change, resulting in widespread degradation. Four riparian trees, specifically Alnus glutinosa, Alnus incana, Platanus orientalis, and Liquidambar orientalis, have been designated...

Although the seeds of various Orchidaceae members can be readily germinated on sterile nutrient media, numerous species exhibit complete asymbiotic germination failure. Also, while seed morphology in orchids has been previously linked to dispersal, associations with germinability have not been widely explored. We compiled seed morphometric and germ...

The pollination biology of the genus Ophrys has been extensively explored, primarily due to their utilisation of sexual deception to attract pollinators. Typically, members of this genus produce a low number of fruits per individual and are considered obligate crossers. However, instances of self-pollination in Ophrys are not uncommon, although the...

Data on cone/seed morphometric traits and seed viability/germination are analysed with a focus on the implications of climate change and conservation efforts.

Background The evolutionary success of flowering plants is associated with the vast diversity of their reproductive structures. Despite recent progress in understanding angiosperm-wide trends of floral structure and evolution, a synthetic view of the diversity in seed form and function across angiosperms is lacking. Scope Here we present a roadmap...

Complex nutrient media are used for the germination of orchids in the laboratory. These substrates are also suitable for the growth of microbes and thus the sterilization of both the medium and the seeds prior to sowing is mandatory. The surface disinfection of orchid seeds with chemical substances eliminates possible infections and enhances germin...

Juniperus drupacea Labill. is a relict, dioecious tree/shrub found in Turkey, Syria, Lebanon and Israel, while in Europe it is native only in Greece (on Mt. Parnon and in a restricted area of Mt. Taygetos). According to the IUCN Red List criteria, J. drupacea has been assessed as endangered (EN) for Europe, with major threats being grazing of sapli...

Samara 32, 12, 2022

Odissea Seminum 7, 4-7, 2022

Juniperus drupacea Labill. is a relict, dioecious tree/shrub found in Turkey, Syria, Lebanon and Israel, while in Europe it is native only in Greece (in Mt. Parnon and in a small part of Mt. Taygetos). In Europe, according to the IUCN Red List criteria, J. drupacea has been characterized as endangered (EN), the most serious threats being grazing of...

Although several members of Orchidaceae can be germinated easily on sterile nutrient media, there are numerous species where propagation has been completely unsuccessful. On the other hand, seed morphology of orchids has been previously associated with their dispersal ability but relations to germinability have not been generally addressed. We have...

Seed germination traits were assessed on Pinus heldreichii H. Christ, a Tertiary relict, high-elevation Mediterranean pine, endemic in the western Balkan Peninsula and southern Italy; it is naturally grown at the northern Greece mountains, but also found in shrubby form above the timberline. Closed and mature cones were collected (October) for thre...

The use of unmanned aerial vehicles (UAVs) as an application on forestry applications has been limitedly investigated in Greece compared to other productive sectors (e.g. agriculture, energy, etc.). The aim of the research project "Innovative use of Unmanned Aerial Vehicle Systems in Forest Ecosystem Management-Pilot implementation on the endangere...

Mt. Oeta, the Hercules Mountain, with a highest summit of 2152 m, is located in Central Greece about 200 km to the north of Athens and has been designated a National Park and a SAC (GR2440004) of the European Natura 2000 Network. Four ‘small alpine lakes’ are found in the high-altitude alpine meadows; three out of these mountain Mediterranean tempo...

The asymbiotic seed germination of orchids is a complex process with considerable technical difficulties, due to the natural requirement of a plant-fungus symbiotic relationship under field conditions. Only on rare occasions, orchid seeds are known to germinate readily in water. Anacamptis sancta is a relatively common orchid species with its main...

Samara 37, 8 (2021)

Greece, one of the richest countries in orchid taxa in the Mediterranean, hosts c. 135 orchid taxa (100 species, 35 subspecies, 18% endemics), according to a rather conservative approach (Vascular Plants of Greece 2020, Kuhn et al. 2019, Tsiftsis & Antonopoulos 2017). Data on storage behaviour and longevity of orchid seeds are generally scarce. For...

Σκοπός του έργου είναι η προστασία και η αειφορική διαχείριση των αυτοφυών πληθυσμών δρυπώδους αρκεύθου (Juniperus drupacea Labill., κοινή ονομασία: δενδρόκεδρο) που σε εθνικό και ευρωπαϊκό επίπεδο απαντώνται αποκλειστικά στη ΝΑ Πελοπόννησο. Tο είδος προστατεύεται από το ΠΔ 67/1981, ανήκει στον οικότοπο προτεραιότητας «9560* - Μεσογειακά δάση με εν...

Cephalanthera cucullata Boiss. & Heldr. is an endemic orchid of Crete, growing in wooded, shaded locations on most mountain massifs of the Island. It is a species of European priority (Annex II, 92/43/EEC Directive) and is characterized as endangered (EN) by both the Red Data Book of Rare and Threatened Plants of Greece (2009) and the latest evalua...

Juniperus drupacea Labill. is a relict, dioecious tree/shrub found in Turkey, Syria, Lebanon and Israel, while in Europe it is native only in Greece (on Mt. Parnon and in a small part of Mt. Taygetos). Its height may reach 20 m and it is usually multi-trunked, with a DBH up to 105 cm. In Europe, according to the IUCN Red List criteria, J. drupacea...

Intraspecific and interspecific diversity between Phoenix theophrasti individuals (92 from Turkey and 70 from Crete, Greece) and P. dactylifera specimens (28 from Turkey) were investigated by inter-simple sequence repeat (ISSR) analysis. A total of 45 polymorphic fragments, 360–3454 bps long, were produced. Intraspecific diversity for P. dactylifer...

The genus Ophrys L. is the most widespread orchid genus in Greece, with about 20 distinct species. Ophrys species produce pheromone-like substances, leading to a species-specific pattern of pollination. Besides the recorded pollinators, there are many arthropods, that are attracted to orchid flowers, but still, for most of the cases the reason of t...

Caprine overbrowsing is a main threat to trees of pastoral mountain woodlands in the Mediterranean region of Europe. In this study, we assess the impact of browsing exclusion on the growth and regeneration of the endangered Zelkova abelicea, a Paleogene relict tree endemic to Crete (Greece). Shoot elongation, height growth and natural regeneration...

2004-2009 στον Κίσσαβο και μελετήθηκε σε νεαρά αρτίβλαστα της Ιπποκαστανιάς η επιβίωση και η φαινολογική πορεία ανάπτυξής τους κατά τον πρώτο χρόνο αύξησης, δηλαδή από τη φύτρωσή τους έως και την πτώση των φύλλων (Μάρτιος-Οκτώβριος). Συγκεκριμένα, μελετήθηκε η πορεία ανάπτυξης και επιβίωσης 534 αρτιβλάστων του είδους σε 14 θέσεις: 43 αρτιβλάστων σε...

The asymbiotic seed germination of orchids is a complex process with considerable technical difficulties, due to the natural requirement of a plant-fungus symbiotic relationship under field conditions. Only on rare occasions, orchid seeds are known to readily germinate in water. Neotinea maculata is a relatively common orchid species with its main...

Developing a monitoring system and a conservation strategy against the negative impact of global change on threatened plant species, is nowadays the challenge for conservation experts. The Plant Micro-Reserve (PMR) approach became a highly effective approach in protecting plant species, since mild active management of vegetation plots and protectio...

Germination in the family Orchidaceae, under laboratory conditions, is a complex process due to the extraordinary requirements of orchid seeds, most important of which is the necessity of a seed/seedling/plant – fungus symbiosis in the field. Thus, orchids are generally hard to germinate, in asymbiotic culture; however, several species can germinat...

In Greece, based on the VPG Checklist, Orchidaceae comprises 141 taxa, belonging to 101 species and 19 genera; 26 of them are endemic to Greece and 34 (24% of the total number of taxa, 54% of the endemics) are included in one of the IUCN threat categories (Tsiftsis S. & Tsiripidis I., 2016). Asymbiotic seed germination has been studied in about 80%...

Masting and regeneration dynamics were investigated in a long-term perspective using Abies cephalonica as a study tree species. Extensive fieldwork was implemented in Parnitha National Park, Greece, following a large-scale wildfire. Annual cone production was monitored for a 5-year period in 130 tagged trees, in 13 plots with 10 individuals each, e...

During the IDS Crete tour in early May 2018 members heard a lecture on the conservation of this rare Cretan endemic and visited plantation sites where trees are grown, protected from grazing goats. LAURENCE FAZAN and colleagues in Greece, Switzerland and Italy (see end of article) write about the conservation project.

Keywords: Orchidaceae, Germination, Distribution, Hymettus, Urban area. Introduction: In Greece, 140 taxa of οrchids are growing native (according to the List of the Vascular Plants of Greece). This study presents the distribution of orchids in the Campus of N.K.U.A. and an overview of the efforts in understanding the physiology of seed germinatio...

Asymbiotic seed germination of orchids is a complex process and most of the technical difficulties are due to the requirement for a plant-fungus symbiotic relationship under field conditions. More than 100 Orchidaceae species grow natively in Greece; mature seeds of 11 orchid species (belonging in 7 genera) were collected in 3 localities (Mt. Hymet...

Abies cephalonica cone and seed morphometric characteristics as well as seed germination behaviour were investigated during an 8-year-long diachronic study (2007–2015). The research was carried out in Parnitha National Park, in the part of this Greek endemic, silver fir population that was spared from an unprecedented wildfire (2007). A statistical...

The family Orchidaceae uses a broad spectrum of strategies to attract different pollinators. The genus Ophrys is well known for sexual deception; however, a different strategy has been observed in Ophrys helenae - shelter mimicry. Yet the identities of the pollinators have remained poorly understood. In the recent flowering season, we recorded cons...

Light conditions provide important information about the optimal time and place for seedling establishment. In this context, photoinhibition of seed germination, defined as the partial or complete suppression (or retardation) of germination under white light (daylight) conditions, has been interpreted as a physiological adaptation to avoid germinat...

In this study we have examined the comparative ecophysiology of seed germination in two pairs of related pines of Mediterranean and Himalayan origins. One pair comprises Pinus canariensis and Pinus roxburghii, and the second Pinus peuce and Pinus wallichiana. Each pair has close taxonomic and morphological affinities. We have observed considerable...

Cone and seed morphometric characteristics, seed germination behaviour and seed viability during storage were studied in Cedrus brevifolia, a threatened endemic forest tree of Cyprus. The number of seeds per cone, seed mass and number of cotyledons per seed followed normal distributions. Seeds germinated promptly in darkness at 20°C after eight wee...

Contribution to the postfire management of the endemic Grecian fir (Abies cephalonica) forest in Parnitha National Park, Attica, Greece.

Mediterranean characteristics are attributed to the genus Crocus , which is inadequately studied in terms of seed germination. An afterripening requirement is very common in environments with warm and dry periods, and photoinhibition has been detected in many angiosperms inhabiting dry and open areas. The effects of afterripening and light on seed...

Cone and seed morphometric characteristics, seed germination behaviour and seed viability during storage were studied in Cedrus brevifolia, a threatened endemic forest tree of Cyprus. The number of seeds per cone, seed mass and number of cotyledons per seed followed normal distributions. Seeds germinated promptly in darkness at 20°C after eight wee...

A regeneration predictor (RP) has been elaborated to forecast the minimal inter-fire period, required for full recovery (assumed at 1,000 mature stems ha-1, a typical value for a dense pine forest) of an even-aged, postfire regenerating Pinus halepensis population after a subsequent wildfire, in the future. The study has been conducted in three Ale...

Acorn morphometric characteristics from Quercus aucheri Jaub. & Spach were measured in four different collections (Samos Island provenance). Seed germination was tested under three experimental conditions: a) “Entire” acorns were put for germination in alternating temperature and light conditions (20/10 °C, 12:12 h L/D) b) “Pre-treated” acorns unde...

The chapters of this book illustrate efficiently and support competently the declaration that the Plant Micro-Reserve (PMR) approach has been proven, over the last 20 years, a successful method for the conservation of endemic, rare and threatened plants, in several European countries. The European Commission has acknowledged and in fact promoted th...

In: Coll L, Climent J, Ximenis L, Bravo-Oviedo A & Mutke S (eds.) 2014. 5th International Conference on Mediterranean Pines (medPINE5), Solsona 2014. Book of Abstracts. INIA, 104 p.

Evaluation of the climate change impacts on the germination of seeds and the survival of seedlings of the narrow-endemic species Alyssum troodi of Cyprus

Abstract Post fire, field measurements of sapling growth and reproductive dynamics were carried out in three, even -aged, Aleppo pine populations of northern Euboea Island, Greece(Gouves, Rovies, and Pili, burned in 1994, 1996, and 1997, respectively) for three, successive growing seasons(2004-2006). Four permanent experimental plots were establis...

Η Οικοφυσιολογία Φυτών ασχολείται -όπως υποδηλώνει το όνομά της (από τις λέξεις οίκος και φυσιολογία)- με την αλληλεπίδραση των φυτικών λειτουργιών με το περιβάλλον και την απόκρισή τους στην περιβαλλοντική καταπόνηση (stress), με προσαρμοστικούς μηχανισμούς. Στο βιβλίο δίνεται έμφαση: 1) στο φυσικό περιβάλλον των φυτών, 2) στην οικοφυσιολογία των...

We investigated the potential contribution of the persistent soil seed bank in post-disturbance restoration of the herb layer in a long-term overgrazed, mixed oak forest (NW Greece). We examined the impacts of grazing on plant richness and density in the soil seed bank in regard to the different dispersal and life strategy types of the herb layer t...

Aesculus hippocastanum L.)-Κπξηόηεξνη πεξηνξηζηηθνί παξάγνληεο. Πεξίιεςε ΢ηελ παξνύζα εξγαζία δηεξεπλώληαη νη πεξηνξηζηηθνί παξάγνληεο πνπ ζπληεινύλ ζηελ πεξηνξηζκέλε θαη θαηαθεξκαηηζκέλε γεσγξαθηθή εμάπισζε ηεο Ιππνθαζηαληάο (Aesculus hippocastanum L.) ζηελ Διιάδα. Πξόθεηηαη γηα κηα έξεπλα, ε νπνία δηεμήρζε θαηά ηελ ρξνληθή πεξίνδν 2003-2008, ζε η...

The two typical Mediterranean pines of Greece (Pinus halepensis Mill. and P. brutia Ten.) show a distinct, natural geographical distribution. However, in sites where they grow in sympatry (mainly due to extended reforestations), their morphological discrimination is not always easy. In the present study, three new morphometric indicators are introd...

Postfire dynamics of Aleppo pine seedling density, survival and growth were assessed in five burned forests of Attica, Greece (Stamata, Villia, Avlona, Kapandriti and Agios Stefanos) through the establishment of permanent experimental plots. All emerging seedlings were tagged and their survival and growth monitored at regular intervals. Seedling de...

This paper presents the details of a LIFE+ project titled " Establishment of a Plant Micro-reserve Network in Cyprus for the Conservation of Priority Species and Habitats " (Life+08 NAT/CY/000453). The main objective of this project is to improve the conservation status of four priority plant species (*Arabis kennedyae, *Astragalus macrocarpus ssp....

We investigate the persistent soil seed bank composition and its relation to the above-ground flora of grazed and non-grazed sub-Mediterranean deciduous oak forests of NW Greece. Twenty-eight taxa were recorded in the soil seed bank and 83 taxa (70 taxa in plots of seed bank sampling) in the above-ground vegetation. The dominant tree species and ma...