The contrast in colours between the arid lands surrounding the confluence and the water from the two rivers make this place unique. In addition, it is often exposed to changes deriving from river regulation and hydraulic work that affect the fauna which inhabit it.
The area preserves and effectively represents riparian vegetation from the Ponent region, such as Eurosiberian plants which permeate the plain of Lleida. The riparian forests encompass a number of interesting species of fauna, including both invertebrates and vertebrates, especially birds, which seek refuge or breeding grounds within it.
FLORA AND VEGETATION
One of the most abundant elements in this area are the riparian forests located on the banks of the Noguera Ribagorçana, which include very good examples of the riverside vegetation of western Catalonia.
The river network also provides the necessary conditions for typically Eurosiberian species (Equisetum arvense, Ranunculus repens), which are surprising to find within this markedly Mediterranean context. The most frequent riparian forests include willow and poplar groves (Populetalia albae), as well as alder (Alnus glutinosa) formations, the latter of Eurosiberian influence. Other remarkable environments include the basophilic peaty reed beds dominated by swamp sawgrass (Cladium mariscus), classified as habitats of priority community interest, and Mediterranean rushes (Molinio-Holoschoenion).
The aquatic environments of this area contain species such as Scirpus lacustris, Zanichellia palustris, Potamogeton densus, or Potamogeton crispus.
Aquatic ecosystems serve a rich invertebrate fauna typical of the middle courses of rivers.
The area is very interesting in terms of the diversity of its mammals: here we can find the common genet (Genetta genetta), the beech marten (Martes foina), the common weasel (Mustela nivalis), the badger (Meles meles) and the wild boar, which has found an effective breeding ground and refuge in this area of the Lleida plain. The otter (Lutra lutra) and the southern water vole (Arvicola sapidus) also inhabit the area.
The area is also important for migratory birds that use river banks as a shelter and a resting point. Moreover, it is a favourable feeding area for the white stork (Ciconia ciconia).
Some species of birds find excellent breeding grounds in the riverside and marsh vegetation. As a result, species such as the purple heron (Ardea purpurea), the black-crowned night heron (Nycticorax nycticorax), the common kingfisher (Alcedo atthis) and the Eurasian penduline tit (Remiz pendulinus) can be found here.
During the winter period, the great cormorant (Phalacrocorax carbo) enjoys the refuge that the area provides.
The fish populations are a good sample of lower reach Iberian Mediterranean fauna with species of European origin. The area includes some interesting elements, such as the South-west European nase (Chondrostoma toxostoma).