Riparian forests, gallery forests or copses, are forests of deciduous trees that grow on both sides of the rivers. This vegetation, known as riparian vegetation, does not depend so much on the climate (precipitation and temperature) as on soil humidity, given that the river provides it with its own water reserves.
The plant formations that grow along the rivers are not evenly distributed along their banks, rather their distribution is determined by the water requirements of each species, their mechanical resistance to floods and their ability to withstand occasional total or partial flooding. More water is available for vegetation closer to the river, while the amount lessens the further away the plants are. This is why the vegetation along the river appears in different 'bands' that more or less run parallel to the river itself.
SOURCE: Riverbank restoration manual for the Segura Basin. Department of the Environment, Rural and Marine Environment – Confederación Hidrográfica del Segura. 2008
One of the most beautiful and unique water-related landscapes in the Segura River basin is the last remaining gallery forest in the Region of Murcia: the “Reserva Natural de Sotos y Bosques de Ribera de Cañaverosa” (The Cañaverosa River Groves and Forest Nature Reserve), found in the mid section of the river. Covering an area of approximately 200 ha, it runs for 20 km over the boroughs of Moratalla, Calasparra and Cieza.
In this section there a two distinct bands of vegetation:
In the first band, which is in direct contact with the watercourse, the conditions are less favourable for tree growth as it is directly affected by natural increases in water levels. The vegetation is, therefore, predominantly shrubs that are around 5-10 m high, flexible and with a great capacity for regeneration, which means that are able to withstand the effects of the floods. In this band of vegetation we mainly find willow (Salix purpurea) and oleander (Nerium oleander). The herbaceous layer is mainly composed of nitrophilous plants that are carried there by the river itself. The most striking of these is the yellow iris (Iris pseudacorus).
Baladre (Nerium oleander)
The second band, where the water table is higher and water levels rise more frequently, is dominated by large trees that are between 15m and 25 m high when fully grown. However, in exceptional cases these trees may reach over 30 m. Here we principally find the white poplar (Populus alba), black poplar (Populus nigra) and the field elm (Ulmus minor). Other species that form part of this layer, although at a lesser height of 10-15 m, are the narrow-leafed ash (Fraxinus angustifolia), different species of willow (Salix alba, S. fragilis, S. atrocinerea and S. neotricha) and species of tamarisk (Tamarixafricana, T. canariensis and T. gallica).
Álamo blanco (Populus alba) y Olmo (Ulmus minor)
The shrub layer contains species such as white honeysuckle (Lonicera biflora), oleander (Nerium oleander), elderberry (Sambucus nigra) and redoul (Coriaria myrtifolia). There are also a large number of thorn bushes such as Elmleaf blackberry (Rubus ulmifolius) and the dog rose (Rosa canina), as well as creepers such as bindweed (Smilax aspera).
Rosa silvestre (Rosa canina)
Riverbanks have a wide range of ecological functions. They are the habitat for species of flora and fauna, and act as river corridors that allow different species to move and disperse, making them fundamental for maintaining biological diversity in aquatic and terrestrial ecosystems. In addition, they filter pollution from agriculture and are responsible for maintaining the stability and structure of riverbanks.
The human settlements on the banks of our rivers, the hydraulic works for controlling and regulating flow, the channels, the breaks in fertile soils on the banks of the rivers and their colonisation by exotic and invasive species, among other things, have all led the riparian vegetation to be considered that most intensely transformed by human activity.
One of the main problems associated with riparian vegetation in the Segura River basin its replacement with crops and reed beds. The giant cane (Arundo donax) is an invasive exotic species (originating from Asia), which presents an extremely serious ecological problem and makes the management of water resources highly difficult. Much effort is currently being made to develop and test different techniques for eradicating these canes, as they must disappear from our rivers if we want to restore the native riparian forests and recover a good ecological status of our watercourses.
