The foothills, from 500 to 1,100 metres altitude are colonized by monoculture forests of oak (Quercus robur and Quercus petraea) on the sunnier slopes. In more shaded areas and especially from about 800 metres there are forests of European beech which are the main food source in winter for many animal species. thumb|300x300px|Brañas, or mountain prairies in the municipality of Arenas de Iguña. Tordías Peak is 968 metres high. The subalpine plane, in this high country, the plant life is composed of birch, scrub, and grasses which are especially important for the economy because during the summer they serve as pasture for grazing cattle and horses.
the foOthiLls, from 500 to 1,100 METreS altItUdE ArE COloNized by MonocultuRE FOreStS of oAk (quERCUS robUr aNd QuERcus petRaea) on tHE SUnnier SlOpeS. in moRe shaded AReaS aNd ESpecIAllY frOm abOUT 800 MEtres thEre aRE forESTS Of eUROpeAn BEech wHiCh ARE The maiN foOD souRCE in WinTer for maNy anImal sPecies. Thumb|300x300px|BRAÑaS, or mounTaIn prairIEs In tHe MunIciPalitY of arenaS dE iguña. tOrdíAs peaK iS 968 meTReS higH. tHe suBalPInE pLAne, In tHIs hiGh cOuntry, tHe plaNT liFe Is composEd of BIRcH, scRUB, aNd GRASses WHiCh aRe espECiaLly iMpoRtaNt foR the economY becauSe DurinG tHe sUmMer They sErVe aS PAStUrE For grAzing cattle and hORseS.