Habitat type 92A0 Salix alba and Populus alba galleries Factsheet
Habitat type 92A0 – Salix alba and Populus alba galleries is one of the six habitat types on which the project LIFE ForestLife focuses. This factsheet presents basic information on the physiognomy, ecology, geographical distribution, current management, conservation status, as well as pressures and threats.
Description
The habitat type includes riverine gallery forests dominated by species of poplar and willow. It does not include other riverine forest types such as alluvial forests with Alnus glutinosa, riparian forests with hardwood species of the genera Quercus, Ulmus and Fraxinus, forests of Platanus orientalis, thermophilous scrub with Tamarix spp. or non-riparian forests with Populus tremula [2,5].
Figure 1. Riparian gallery forests of the habitat type 92A0 at Nestos river (NE Greece). ΕΚΒΥ Photoarchive/L. Logothetis
Other classifications
EUNIS G1.31 Mediterranean riparian Populus forests
European forest types < 6.12.3 Mediterranean and Macaronesian riparian forest
Palearctic Habitat Classification 44.141 Mediterranean white willow galleries, 44.162 Pontic willow galleries και 44.6 Mediterraneo-Turanian riverine forests
Copernicus Riparian Zones 3.1.1.1 Riparian and fluvial broadleaved forest
Ramsar Xf — Freshwater, tree-dominated wetland
Distribution
The forests of the habitat type 92A0 are distributed in the Mediterranean, the Black Sea and Central Eurasia. In Greece, they occur along rivers and in their estuaries in Northern, Central and Western Greece, with a few isolated occurrences in Western Peloponnese and the Aegean islands. The habitat type is present in 40 Natura 2000 sites, with a total surface area of 4,000 hectares [1,2,3,8].
Distribution and range map of the habitat type 92A0 in Greece [12].
Physiognomy
These forests show a multilevel structure, which, in concert with the presence of climbing vines, gives a characteristic form of a gallery or tunnel. Species of poplar or willow, that usually dominate, reach a height of 6-8 m and more rarely 20 m. The tree layer is usually stratified in two heights. The overstorey is dominated by poplar species and the understorey by species of willow. The surface area of shrub and herbaceous layers varies, depending on the light conditions inside the forests [2].
Floristic composition
Salix alba, S. fragilis, Populus alba, S. eleagnos, S. purpurea, Ulmus spp., Fraxinus spp., Alnus glutinosa, Clematis vitalba, Vitis vinifera, Cynanchum acutum, Periploca graeca, Hedera helix, Smilax aspera, Humulus lupulus, Solanum dulcamara, Urtica dioica, Agrostis stolonifera [2,11].
Ecology
It is a riparian habitat type usually distributed along rivers and in their floodplains. Its presence depends on the underground water level, while occasional inundations are vital for its conservation. The soils are usually sandy clay formed from alluvial deposits, enriching them in nutrients. The inclination is very small to zero and the elevation can vary from 0 to 1200 m, but rarely exceeds 600 m. The characteristic presence of many climbing plant species forms a complex ecological environment [2,3,8,9].
Figure 2. Multilayered structure of the habitat type 92A0. ΕΚΒΥ Photoarchive/L. Logothetis.
Economic value
The high protective value of these forests in concert with the sensitivity of the riparian ecosystems in which they occur, have led to the abandonment of logging. These forests offer a variety of ecosystem services, such as the stabilization of river banks, the filtering of pollutants before the water enters water bodies and the creation of suitable microhabitats for the river and stream fauna through shading, provision of dead organic material etc. Also, they form “ecological corridors” for wildlife, interconnecting natural areas in the often fragmented landscape of the plains. They also offer a high aesthetic value, attracting many visitors [3,8].
Management
The management of riparian forests is focused on protection, restoration and promotion of its values. Often, a multidisciplinary approach and synergies with competent authorities are vital, such as in the case of the determination of environmental flow of the rivers, regulating and providing the water flow needed in order to ensure the necessary influx of water and nutrients for the conservation of these forests [3,13].
Conservation status
The conservation status of the habitat type has been evaluated as inadequate (U1), according to the 3rd national report on the implementation of Article 17 of Directive 92/43/EEC (reporting period 2007-2012), and its trend has been estimated as stable (=) [11].
Pressures and threats
Among the main pressures identified for the habitat type are cultivation, mowing of grassland, grazing, forest planting on open ground, forest exploitation, mining and quarrying, the presence of roads, structures and urbanised areas, soil pollution and solid waste and discharges, outdoor sports and leisure activities, human induced changes in hydraulic conditions, storms and cyclones and forest and plantation management. Potential threats for the future, except the above-mentioned pressures, include the construction of sports and leisure structures, as well as human intrusion with its associated impacts [2,11].
General literature
1.Arvela, M., J. Bailly Maitre, D. Evans, Mac Sharry & M. Aronsson. 2013. Pre-scoping Document for the Natura 2000 Seminar at the Mediterranean Region.http://ec.europa.eu/environment/nature/natura2000/platform/knowledge_base/135_mediterranean_region_en.htm#NBP.
2. Ntafis, S., Eva Papastergiadou, Efthalia Lazaridou & Maria Tsiafouli (). 2001. Technical manual for identification, description and mapping of habitat types of Greece Greek Biotope/Wetland Centre (ΕΚΒΥ). Thermi. 393 p. [in Greek]
3. Ntafis, S. 2010. The forests of Greece. The Goulandris Museum of Natural History. Thermi. 192 [in Greek]
4. Devillers, Pierre & Jean Devillers-Terschuren. A classification of Palearctic habitats. Council of Europe, Strasbourg: Nature and environment, No 78.
5. European Commission. 2013. Interpretation Manual of European Union Habitats -EUR28.
6. EEA. 2006. European forest types – Categories and types for sustainable forest management reporting and policy. EEA Technical report No 9/2006. European Environment Agency, Copenhagen, Denmark.
7. European Environmental Agency. Habitat types search. http://eunis.eea.europa.eu/habitats.jsp.
8. San-Miguel-Ayanz, J., de Rigo, Daniele, Caudullo, Giovanni, Houston Durant, Tracy, Mauri, Achille. Eds. 2016. European Atlas of Forest Tree Species. (Eds.) Publication Office of the European Union, Luxembourg. ISBN: 978-92-79-36740-3. DOI: 10.2788/038466.
Specific literature
9. Zogaris, S., V. Chatzivarsanis, A.N. Ikonomou, G. Chatzinikolaou, Sofia Giakoumi & P. Dimopoulos. Riparian zones in Greece. Protecting riparian oases of life. Special publication HCMR. Interreg IIIC Sud. 95 p. [in Greek].
10. GAF 2013. CS-3/17 Nomenclature Guideline, Issue 3.0 Copernicus Riparian Zones.
11. Report on the main results of the surveillance under article 17 for annex I habitat types (Annex D). Code 92A0. Name Salix alba and Populus alba http://biodiversity-info.gr/images/DOCUM/3rd_Art17_Report/Habitat_types/terrestrial/92A0.pdf.
12. Distribution and range map of the habitat type http://www.biodiversity-info.gr/images/DOCUM/3rd_Art17_Report/Habitat_types/terrestrial/maps/92A0_map.pdf.Chatzicharalambous Elena, Maria Dimaki, D. Zervas, E. Koutrakis, G. Poulis, A. Sapounidis & E. Chatziiordanou. 2015. Detailed identification of the ecological requirements in water of the habitat types and the target-species that depend on water in the areas of Axios Delta, Aliakmon Delta and Kitros Lagoon. Greek Biotope/Wetland Centre (EKBY) Thermi. 71 p. + 7 maps + geospatial files. [in Greek]
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