The Wetland

The wetland is situated 7 km NW of the city of Edessa and covers an area of 600 ha. It extends at the former floodplain of of Edessaios river, at the area historically known as the marshes of i Tiavou. The wetland, became a water reservoir during the 50s, after the construction of a dam and dikes by the Public Electricity Corporation, to covering the needs of the Agras hydropower plant.

The pre-existing wetland retained most of its functions, resulting in the development of a valuable ecosystem, of great importance for the biodiversity, especially water birds . Up to now, more than 140 bird species have been recorded, among which the swans, coots, little grebes and little bitterns are the most characteristic, while, among ducks, the ferruginus duck is the most important one.

The presence of human settlements at the area has been related, from ancient time, not only to traditional wetland associated activities, like fishing and stock-raising, but also, to the sustainable use of the waterfalls as a renewable energy resource and for the irrigation of agricultural land, activities that are practised at a wider area, including the city of Edessa.

The wetland is a characteristic case of a long termco-existence of man and nature, the harmony of which has been disturbed over the past few years, due to several problems that the ecosystem is facing. Their impacts provoked the awareness of local community, resulting in the implementation of the LIFE-Nature project entitled “Implementation of management measures at the wetland of Agras”, aiming in the application of multiple purpose wetland management and the conservation of wetland functions and values in a socio-economically compatible way.

The man

The wetland is surrounded by three communities: Agras, Vrytta and Nisi, forming part of the Edessa Municipality. The discovery of ancient pile dwellings at the area of Edessaios springs, as well as other archaeological findings, at the hill of Filokastro, dated back to the classical age, indicate that the co-existence of man and the wetland ecosystem has a history of many thousand years.

Since the ancient times, the area was associated with the city of Edessa, acting both as external border and as a passage to the upper Macedonia. The ancient Egnatia road, crossed the area. The same passage is presently used by the national driveway from Thessaloniki to Florina and the railway line which also crosses the wetland area.

Since the middle of the previous century, the water of Edessaios river provided the waterpower for the operation of the local watermills and of the very important textile-mill factories of Edessa.

Today, the cherry tree cultivation and stock-raising are important activities for the local economy, while the operation of Agras hydropower plant, that employs many inhabitants, has played a significant role for the socio-economic life of the area.

The nature

The wetland of Agras is one of the few remaining active peatlands in Greece. The peat layer exceeds 20 m in certain locations and taking into consideration that peat formation is a very slow natural process, the development of such a thick layer must have occurred through many thousand years.

The local wealth of animal and plant species is directly connected to the abundance and distribution of wetland habitats, but also, to those of the surrounding uplands.

Reedbeds form the predominant wetland habitat type. They are characterised by the presence of reeds, rushes and sedges, and provide valuable habitat for invertebrates, reptiles and amphibians as well as water birds. Wet meadows occur at the west part of the wetland, consituting an important habitat for herons and passing wading birds. Patches of calcareous fens with Cladium mariscus, a priority habitat for E.U., are formed on permanently waterlogged places of the wet meadow area. They are unstable and sensitive ecosystems that depend on the maintenance of a specific water level and are threatened either from hydrological changes, or from the expansion of reedbeds and agricultural fields .

The aquatic vegetation is abundant at the open water habitats especially at the waterways that cross the wetland. It mainly consists of pondweeds, musk grasses and water lilies, creating valuable fish spawning habitats.

Clumps of riparian trees, poplars, willows and alders, remnants of the pre-existing wetland, occur in several spots and along the canal banks, constituting important refuge habitats for water birds.

Cherry trees predominate at the surrounding agricultural land, while, forests, pastureland and meadows cover the hillsides, providing appropriate nesting or foraging habitats for raptors and passerines.

The co – existence

Water is the driving force supporting the precious wetland biodiversity, as well as several activities of vital importance for the local community. After giving life to the wetland ecosystem (1), water reaches the hydropower plant of Agras (2), where it is used for energy production. From there, it flows to Edessa town to feed the urban waterways and the waterfalls (3), the main local tourist attraction. Then it flows through a second hydropower plant (4), and after that it is collected into a reservoir (5) that regulates the irrigation of 5000 ha of agricultural land. What remains unused, continues its route to the sea (6). In this way, a valuable cycle of multiple and beneficial for both man and nature water uses is being completed.

The Natura 2000 network

Due to its ornithological importance the wetland and its surrounding area have been designated as a Special Protection Area under the Birds Directive. It has also been included in the list of proposed Special Areas of Conservation to form part of the Natura 2000 network. Natura is an EU – wide network of nature protection areas established under the Habitats Directive. It comprises the most significant natural sites of Europe and aims at the long term survival of Europe’s most valuable and threatened species and habitats, through the implementation of measures and policies that promote ecologically, economically and socially sustainable management practices such as rural – tourism, ecotourism, biological farming and stock-raising.

The problems

Until two decades ago, the wetland communicated with the large karstic lake Vegoritis through a tunnel, constructed by Public Electricity Corporation. This communication has been broken up because of the severe decline of Vegoritis water level, resulting in the reduction of surface water inflows to the wetland. Furthermore, the water quality deterioted due to the increased use of agrochemicals that followed the intensification of cherry tree cultivation. The excessive development of reedbed vegetation is the most obvious impact of increased nutrient input, resulting in the restriction of water circulation. The quality of habitat for the aquatic organisms, including fish and crayfish, deteriorated and their populations decreased, in such an extend, that they are not form anymore a significant resource either for fishermen or for fish-eating birds. Namely, an important from the ecological and socio-economical point wetland value that existed before the Public Electricity Corporation interventions significantly declined.

The LIFE project

The LIFE project is implemented by the Municipality of Edessa in collaboration with the Prefecture of Pella, the Pella Development Agency, NAGREF and Endiaitima. It includes actions that are expected to improve wetland habitat conditions and result in the recovery of plant and animal populations, especially of priority bird species. Furthermore, traditional wetland associated human activities such as fishing and stock raising will be supported, and the local environmental information and interpretation capabilities will be enhanced in a way compatible to the conservation of wetland functions and values.

These measures are expected to restore the harmony between man and nature. Off course co-operation of the local community and visitors is a pre-requisite of vital importance. Lets all help today, to celebrate tomorrow for the success of the effort.

The EVS project

Since 2008, Hellenic Ornithological Society/ Birdlife Greece has been running a European Volunteer Service in the wetland with the support of the “Youth in Action” project of European Commission. The target of HOS is this very important wetland is to have around it people who care about the environment and they try to do their best.

EXPERIENCING THE BEAUTY OF THE AGRAS-VRYTTA-NISI WETLAND

(AN INTRODUCTION TO THE WETLAND)

Opportunities for information and interpetation

The wetland Information Center (IC) is located at the entrance of the area, close to the intersection of the national driveway from Edessa to Florina with the provincial road to Kerasia. The visitor, after gathering the necessary information and material at the IC, may start from this point and drive around the wetland, following the peripheral road or, hike, following the local road and trail network. On the adjacent map, the peripheral road is plotted in grey colour while, hiking trails that visitors may follow to experience the natural beauty of the wetland, are plotted in orange colour. Interesting view points around the wetland are presented with the symbol……and the distances between several points are shown on the signs….

Habitats

Calcareous fens, mainly consisting of reeds, rushes and sedges are among the most important wetland habitats. Nuphars are among the species that occur at the open water areas.

Several alleys exist in places around the wetland and are composed of broad-leaved trees, characteristic of the vegetation of the wider area, like the macedonian oaks at the peninsula of St George church and limes at the Agras railway station.

The most characteristic mammal present at the wetland, introduced here by man, is the coypu, but the most important one is the otter, a rare fish – eating species. There are also common species, like the weasel. Regarding amphibians and reptiles, the most common are the marsh frog and the grass snake.

Many fish species are present, but in sparse populations (carp, southern barbell, wells, rudd, tench, pike, roatch). Last years crucian carp, goldfish, mosquito fish and grass carp have been introduced by man. It is worth mentioning the presence of two crayfish species, an endemic one and an American species introduced by man.

But, the special conservation value of the wetland is attributed to the presence of rare birds. Threatened species, such as the ferruginus duck and little bittern, breed at the area together with common birds like the swans, coots, little grebes and moorhens. Migratory birds, like the dalmatian and white pelicans, many herons but also, rare raptors, such as osprey, pass during spring and autumn migration, while, during winter, the visitor may observe several duck species (mallard, ferruginus duck, wigeon, pochards and red –crested pochard), pygmy cormorants, raptors, such as the marsh harrier, the hen harrier and, occasionally the golden eagle.

The man

Fishing, especially of crayfish, used to be one of the main income resources for the local inhabitants. Today, the excessive growth of reedbeds and the water eutrophication have resulted in the significant decline of fisheries.

One of the traditional activities is stock – raising. Cows, horses and sheep graze at the wet meadows and at the surrounding grasslands .

In recent years, cherry tree cultivation is the predominant agricultural activity. But, the accompanying excessive use of pesticides and fertilisers provokes the eutrophication of the wetland.

The operation of the Agras hydropower plant has a decisive effect in the local landscape, as it controls the water level of the wetland. Its personnel periodically removes the aquatic vegetation from the wetland canals.

The churches of St George at Vrytta and Panagia Mesonisiotissa are important local monuments and are both surrounded by beautiful alleys, where traditional celebrations are taking place.

The railway line, passing through the wetland, constitutes a unique element of the local landscape.

Ecotourism and environmental education are rather new, but rising activities at the area, that create an opportunity for the revitalisation of the coexistence of man and nature.

Comments