NaTurE at Symi Plateau, Crete

The Plateau of Kato Symi the dry wetland of September

A report on the field trip to the plateau during the COMENIUS NaTurE meeting in Ierapetra (25th – 29th September 2012) Written by Maria Sourgiadaki and Thomas Gerl

Photos by Thomas Gerl Peter de Deyn Jan Leybaert Darja Silan Despina Papadopoulou

On Thursday the 26th of September 2012, the Center of Environmental Education of Lasithi offered us a day devoted to the biodiversity in Crete.

A trip up the mountains was organized, with the participation of experts from WWF Hellas and the Museum of Natural History of Crete, too. We headed to the west of Ierapetra.

The Omalos Viannou Plateau, or Plateau of Kato Symi is located in the south of Dikty mountain, close to the village of Kato Symi, at an altitude of 1350m. It’s about 4,5 km long and 600 meters wide.

Before arriving at the plateau, on the southern slopes of the mountain we drove through a pine forest.

There are lots of bee-houses, brought in the area even from far away, because of the high quality of honey that the local flora offers.

At the plateau there is no infrastructure except a little chapel in the Name of the Holy Spirit. The plateau is used only by the shepherds of the area during the summer months and is visited by a few tourists that discover it.

During the winter the plateau is covered with snow. When the snow starts melting, a little lake, a wetland, is created in the center of the plateau. The solid underground rocky layer preserves the water till the end of summer and the wetland offers shelter to migrating birds then.

The landscape changes a lot throughout the seasons. The time we visited the area, it looked like a savanna, with no water at all, due to a long dry period of 5 months.

As in most parts of Crete even in this wetland area, aridity is one of the most important abiotic factors that influences the fauna and flora of the area. The plants show xerophytic adaptations, like reduction of leaf size and thick cuticles to avoid evaporation.

The arched up fold between the two mountain ridges at the west side of the plateau and the falling ridge at the east end, channels the wind in this direction. A lot of trees indicate this main wind direction by being bent in a west-east direction or by showing dismantled branches due to the influence of storms.

The combination of a lack of precipitation and a strong wind increases the transpiration rates of the plants and therefore leads to an extreme aridity on

the slopes, while the plateau basin benefits from the snow cover in winter and the melting water that is dammed until the late spring season.

Especially the northern slopes of the area are almost free of vegetation due to these extreme abiotic conditions.

Phrygana and maquis formations are found on the lower levels of the hills, near the wetter parts.

But it is not only the extreme abiotic situation on the plateau that complicates the life of plants. The vegetation is also characterized by a long period of overgrazing by goats and sheep, so a lot of plants show characteristic adaptations to prevent herbivores from consuming them. On the plateau we could observe several different strategies to cope with grazing, like e. g. the dominance of plants with spiny leaves or branches:

These special structures prevent herbivores from eating the plant, because each bite will hurt them.

A second strategy we could observe is the miniaturization of all plant organs.

The smaller the leaves and branches are, the more difficult it is for herbivores to pick them with their tongues and lips.

Due to this fact all around the overgrazed area of the plateau there are very tiny shrubs with miniaturized leaves covering the ground and the rocks.

Over a long period of time, that can last for decades or even centuries, these trees are not able to grow higher until one day a single branch gets out of reach for the herbivores. This branch can grow really fast after that and a normal tree appears with a shrubby layer at the ground.

As we visited the plateau at the end of the dry season not many flowering plants could be discovered. In the wetter part of the year a lot of poisonous or bad tasting plants are expected to be found, because this is a third strategy to avoid damages by grazing.

Looking up in the sky we saw birds of prey flying.

The vultures Gypaetus barbatus, Gyps fulvus, the eagles Aquilla chrysaetos, Hieraaetus fasciatus and the hawk Falco peregrinus have their nests up in the mountain.

The area of the plateau is a Natura 2000 protected area. There are endemic species of fauna and flora, some of them rare. It’s not easy to find them and that’s exactly the reason why they still exist. One way or another, nature finds the way to balance wildlife no matter what natural conditions exist. When careless man appears the balance is threatened.

The more we know the better we can protect nature. That’s why NaTurE is wandering around Europe! What will our next stop be?