Estudio de la vegetación y flora vascular de la cuenca del río Asón

摘要: The study zone includes the Ason river basin (Cantabria, N Spain) in an area that extends from Cantabrian coast to headwaters of river. relief this is very abrupt, especially towards innermost part, where there are mountains up 1600 m. predominant geological materials correspond Cretaceous era: urgonian limestone, paraurgonian marls and supraurgonian sandstone Weald facies. catalogue vascular flora gathers a total amount 1088 taxa which 1062 were collected by us. distribution some these plants has been enlarged according new data. Most noteworthy are: Crassula tillaea, Eleusine tristachya, Salicornia dolichostachya, fragilis, obscura, Juncus foliosus, Kickxia commutata, Malva parviflora Verbascum nigrum. vegetation resulted recognition 90 plant communities. 20 syntaxa described: 1 suballiance, 8 associations 11 subassociations. New systematic models have proposed, coastal vegetation. following series recognized area: a)     Climatic series: Basque-Cantabrian Eastern Asturian ash tree mesophytic serie ( Polysticho setiferi-Fraxineto excelsioris S.); oak oligotrophic Hyperico pulchri-Querceto roboris Quercus pyrenaica , montane Melampyro-Querceto pyrenaicae S .); Cantabro-Atlantic Orocantabrian, beech Carici sylvaticae-Fageto Saxifrago hirsutae-Fageto S.) b)     Edaphic holm Lauro nobilis-Querceto ilicis Basque-Cantabrian, Orocantabrian hygrophilic alder androsaemi-Alneto S. ) A map at 1:50.000 scale current shown. In map, most significant units represented.