Greek Islands: A Wealth of Biodiversity
«… And turning around him with open palms he sowed mulleins crocuses bellflowers…»
Axion Esti, Genesis, 92-93
The Nobel laureate Odysseus Elytis, the poet of the Aegean Sea, in the above verses, alludes to an important feature of our islands beyond the superb sea, sun and picturesque landscape: their extremely rich biodiversity.
Greece's location at the crossroads of three continents has provided a rich and diverse environmental mix. The geological history of the region has played an important role in the variety of fauna and flora.
All Aegean and Ionian islands—with the exception of a few volcanic ones—are continental in origin, constituting the remnants of a former broad land bridge (which we now name Aegeis) connecting the South Balkans and Asia Minor. The arc of the South Aegean islands (Kythera-Crete-Karpathos-Rodos) is a partly submerged mountain range linking Peloponnese with the Cilician Taurus in Southwest Anatolia. In the Central Aegean area (Cyclades), the islands were iso-lated —by underwater land masses that look like ‘sea arms’ and act as barriers— from the south and southeast; thus the southern islands are generally older than the northern ones. The East Aegean islands are separated from the mainland only by relatively shallow waters, and were joined during the ice ages. Their flora is Anatolian in character rather than European; this is particularly evident in the mountains and hills of Samos, Chios and Lesvos. Similarly, the flora of islands in the Saronic Gulf are closely linked to the adjacent mainland. The North Aegean islands —particularly Thasos and Samothrace— have a significant number of continental European species and the habitat does not continue further south. The Cyclades –relatively low islands with a more or less uniform, typically Mediterranean climate– are slightly barren compared to the more lush surrounding regions.
The islands of the Aegean are the peaks of Aegeis. It is on these peaks that plant and animal species —that formerly lived on the continent— were then isolated. In many cases they evolved in different ways because isolation leads to speciation, and the longer the isolation the more opportunities for speciation.
The islands themselves are isolated. Isolated biotopes such as ravines, high mountain peaks, secluded beaches contribute to the increase in the number of species. Often endemic to the area—meaning they can only be found there—they often grow in the wild.
In Greece we have many isolated islets, but also islands with hills, mountains, plains, valleys, rivers, torrents, sandy beaches, pebbles, rocks and many other geomorphological formations. This contributes to the existence of a variety different biotopes and therefore species.
Another factor contributing to great biodiversity is the variance in climate. Even on the same island —as is the case with Crete—we see a wide range of climate differences.
The variety of geological subsoil also plays an important role. The earth where plants grow consists of disintegrated parent rock and ancient organic matter. Differences in the subsoil leads to varying terrains and subsequently to the diversification of plants.
Last but not least, there is a long-standing habitation in our islands. The ancient Greeks were anxious spirits, they traveled, and inadvertently or deliberately transferred new species to their homeland.
It is no surprise, therefore, that various herbs and plants grow wild on our islands. For instance, we have 11 species of sage, 14 species of thyme, 5 different mountain teas (one endemic to Evia, one to Crete), 4 species of mint (including spearmint), 10 species of the genus Oreganum (including Greek Oregano and Dittany of Crete - endemic to Crete), 26 species of St. John's wort, 11 species of tulip (3 endemic to Crete), 4 species of peony.
The Mediterranean climate is such that plants undergo great stress during the winter and even more during the summer. If the temperature is too high and the humidity is too low, the plants cannot complete photosynthesis and they, instead, resort to the process of secondary metabolism. The resulting products (secondary metabolites) are natural substances that may serve as aromatic essences, insect repellents, medicines, food preservatives, etc. The variety of plant products is multiplied if we consider the diverse environments, soils and different microclimates found throughout the islands.
All the above leads us to conclude that all our islands are valuable and unique. Both the fruits of the natural terrain and the cultivated plants, provide biodiversity and quality products. For example, who can deny the amazing aroma, taste and the high nutritional value of the Greek island honey?
It is no coincidence that from the Minoan era, the Greeks understood the use of herbs and actually cultivated plants such as dittany and crocus. During the Roman era, Crete was the official herbal supplier to Rome.
Thus, we can see how biodiversity manifests on our islands: a variety of biotopes, organisms and valuable ingredients of high nutritional and biodiverse value. It is these very products derived from herbs and plants of the Greek is-lands that can be commercially traded with great success.
by Dr. Irini Vallianatou