Salix Caprea
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Salix caprea Salix caprea in Europe: distribution, habitat, usage and threats C. M. Enescu, T. Houston Durrant, D. de Rigo, G. Caudullo sylvatica) and Norway spruce, it is present with other understorey species such as hazel (Corylus avellana), elder (Sambucus nigra) Salix caprea L., commonly known as goat willow, is a pioneer and a fast-growing plant, which has a wide distributional and bramble shrubs of the genus Rubus, occurring principally in area across Europe and Asia in the boreal and temperate zones. The scientific name caprea means goat, which probably forest clearings and open areas24-26. derives from the fact that its leaves were used as goat fodder. Due to its wide distribution range and its high ecological amplitude, goat willow represents a very valuable multi-purpose species, used principally for biomass plantation and for gardening and hedges. The goat willow (Salix caprea L.) is a deciduous small to medium-size tree or shrub with heights up to 10 m1, 2, reaching Frequency 3 only exceptionally 15 m . It has a far-reaching and especially < 25% well-developed fibrous root system1. The trunks are small, 25% - 50% 50% - 75% occasionally reaching a diameter of 40 cm4. The bark is smooth > 75% 2 Chorology at the beginning, forming a thin rhytidome, irregularly cracked . Native The twigs are greenish, thick and with grey hairs. The leaves are alternate, broadly elliptic and up to 5-12 cm long. The upper side of the leaf is green and glossy, while the underside is covered by densely and softy white-downy hairs1, 5. The goat willow is a dioecious species and catkins appear in early spring (usually in March or April, depending on the site conditions). Male catkins have spreading yellow stamens, while female catkins are greenish and insect-pollinated. The catkins are erect, with approximately 100- 200 flowers in each female catkin and 200-300 flowers in each male catkin, respectively. Catkins are produced abundantly and they appear before the leaves3. This willow naturally hybridises with a number of other Salix species, producing fertile descendants with intermediate characteristics. Hence, this makes it difficult to determinate taxonomical limits and to assign individuals to a Map 1: Plot distribution and simplified chorology map for Salix caprea. Frequency of Salix caprea occurrences within the field observations as 6, 7 particular species within the Salix genus . reported by the National Forest Inventories. The chorology of the native spatial range for S. caprea is derived after several sources9, 52-56. Distribution This species is native to cool temperate and boreal regions types17. Compared with other willow species, the goat willow is Goat Willow in Hesse, Germany. of Europe and Asia, occurring in a large range of habitats across more sensitive to continuous flooding18, avoiding the saturated (Copyright Willow, commons.wikimedia.org: CC-BY) Europe and Asia8. Its wide distribution spreads from Spain to soils of wetlands19. Regarding its demand for light, it is a very China, from Turkey and northern Iran to Fennoscandia and shade intolerant species, occurring in open areas with full sun1, Importance and Usage Siberia reaching up to 70° north latitude1, 9-11. It has been also but it is one of the few willow species able to grow in forest This species has a wide variety of uses. The scientific name introduced in eastern North America and is now naturalised12. 8 understories . Unlike almost all other willows, the goat willow can caprea actually means goat, which probably derives from the only occasionally be propagated vegetatively by cuttings8, 20. Habitat and Ecology fact that its leaves are used as fodder27. In northern Europe, it In boreal forests, it is found in the dominant Norway spruce is a common species in the agricultural landscape, used as a The goat willow is a pioneer13 and a fast-growing plant14, (Picea abies), Scots pine (Pinus sylvestris) and birch (Betula spp.) windbreak and hedge28, and its foliage is used as fodder for cattle tolerating a wide variety of edaphic and climatic conditions1. It forests, in admixture with other deciduous species such as aspen and goats29, 30. In traditional medicine, goat willow extracts are shows a high adaptability to different habitat conditions15, such 21, 22 (Populus tremula) and rowan (Sorbus aucuparia) , favoured used as a painkiller, astringent, antiseptic, eye tonic28, or even to as dry or wet sites16, usually growing in mesic to moist stands4. 23 by disturbances which create open areas . In temperate forests 31 It prefers the calcareous sites, but it grows on almost all soil treat malaria, gout, neuralgia and intestinal diseases . As is also dominated by oaks (Quercus spp.), European beech (Fagus the case with other willows, a good charcoal can be obtained from its burnt wood, which in the past was used for gunpowder and for drawing pencils32, 33. The goat willow is particularly valuable for its high biomass production in short rotation plantations and its role in landscape restoration34, as it is able to tolerate even Uncertain, no-data polluted land35. Worldwide, this willow is also used for its ability Marginal/no presence < 5% to extract heavy metals, such as Cd and Zn, (i.e. phyto-extraction Low presence 5% - 10% strategy) from polluted sites34-36. During spring holidays, in several places across Europe, its flowering branches are in high Mid-low presence 10% - 30% demand37. It is also appreciated as a melliferous plant species38, Medium presence 30% - 50% 39, supplying a honey production of 150-200 kg/ha40. The goat Mid-high presence 50% - 70% willow distribution range overlaps with many areas in Europe with high erosion rates, including European boreal areas and moist High presence 70% - 90% slopes with high drainage-area within the European mountain Very-high presence > 90% systems41. In these critically erosion-prone areas, it contributes to key ecosystem services such as watershed protection and soil stabilisation42. As for other willows and poplars, it is also useful for ecosystem restoration and phytoremediation43,44. Finally, the goat willow plays an important role in maintaining species diversity, by being the host of several lichen species4, 37. Map 2: High resolution distribution map estimating the relative probability of presence. Male catkins turn yellow when the pollen is ready for release. (Copyright AnRo0002, commons.wikimedia.org: CC0) 170 European Atlas of Forest Tree Species | Tree species Salix caprea This willow is among the first flowering plants in the spring, the catkins providing a high quantity of pollen and nectar as a food source, to bees, insects or birds, such as Eurasian blue tits (Cyanistes caeruleus)3. Uncertain, no-data Tundra, cold desert Negligible survivability Low survivability Mid-low survivability Medium survivability Mid-high survivability High survivability Female catkins are insect pollinated. (Copyright AnRo0002, commons.wikimedia.org: CC0) Threats and Diseases The goat willow is a short-living plant and has no severe threatening diseases in its natural habitats. Pests are reported to result in economic loss only in biomass coppice plantations. The fungus Rhytisma salicinum, the leaf-galler sawfly Pontania pedunculi and the leaf-folder sawfly of genus Phyllocolpa may Map 3: High resolution map estimating the maximum habitat suitability. cause damage to individuals, by affecting the leaves45. The rust gardening plants46, 47. The goat willow is susceptible to attacks fungus Melampsora capaearum may infect the goat willow and [20] M. Liesebach, G. Naujoks, Plant Cell, Tissue [39] A. C. Băloi, I. Csosz, S. C. Martin, A. Bogluţ, from the Asian longhorned beetle (Anoplophora glabripennis), and Organ Culture 79, 239 (2004). Lucrări Ştiinţifice. Management Agricol 15, its hybrids, raising dusty orange spots or pustules on the leaves, [21] E. Lähde, T. Eskelinen, A. Väänänen, 241 (2013). despite showing noticeable resistance and thus potentially acting Forestry 75, 395 (2002). [40] D. C. Popovici, E. Crăiniceanu, D. S. resulting in lower photosynthetic performance and eventually 48, 49 as overwintering reservoir of the beetle . It is also vulnerable [22] T. Kuuluvainen, Silva Fennica 36 (2002). Bistrean, O. Colibar, Lucrări Ştiinţifice defoliating the trees. Breeding programmes have been promoted Medicină Veterinară 40, 46 (2007). to the gypsy moth (Lymantria dispar)48, 50, 51. Nematus miliaris [23] O. Engelmark, Boreal forest disturbances for selecting rust resistant willows in biomass plantations and (Elsevir, 1999), chap. 6, pp. 161–186. [41] C. Bosco, D. de Rigo, O. Dewitte, J. Poesen, can completely defoliate the goat willow, which in Poland has P. Panagos, Natural Hazards and Earth [24] M. Budzáková, D. Galvánek, P. Littera, System Science 15, 225 (2015). been reported to be preferentially attacked (along with Salix J. Šibìk, Acta Societatis Botanicorum Poloniae 82, 13 (2013). [42] J. E. Norris, A. Di Iorio, A. Stokes, B. C. Nicoll, A. Achim, Slope Stability and [25] R. Van Couwenberghe, C. Collet, Erosion Control: Ecotechnological References E. Lacombe, J.-C. Pierrat, J.-C. Gégout, Solutions, J. E. Norris, et al., eds. (Springer [1] F. Clinovschi, Dendrologie (Editura [11] J. Jalas, J. Suominen, Atlas Florae Forest Ecology and Management 260, Netherlands, 2008), pp. 167–210. 146 (2010). Universitatii Suceava, 2005). Europaeae: distribution of vascular [43] Y. Kuzovkina, M. Quigley, Water, Air, and [2] I. D. Trava, G. F. Borlea, W. Hollerbach, plants in Europe Vol. 3 Salicaceae to [26] T. Degen, F. Devillez, A.-L. Jacquemart, Soil Pollution 162, 183 (2005). Balanophoraceae (Committee for Mapping Annals of Forest Science 62, 429 (2005). Journal of Horticulture, Forestry and [44] J. Ball, J. Carle, A. Del Lungo, Unasylva 56, Biotechnology 18, 209 (2014). the Flora of Europe and Societas Biologica Fennica Vanario, Helsinki, 1976). [27] J. E. Smith, The English Flora Vol. 4 3 (2005). [3] Q. O. N. Kay, Bird Study 32, 40 (1985). (Longman, Rees, Orme, Brown and Green, [12] G. W. Argus, Flora of North America North London, 1830), second edn.