Plant communities accompanying plantations of Salix cordata Americana Hort. and Salix viminalis L. in the Podkarpackie voivodeship [Poland]

arable land campo champ comunidades vegetales especies fields malezas mauvaise herbe meadows plant communities poland pologne polonia prados de siega prairie de fauche salix viminalis site factors soil texture soil types species terre arable textura del suelo texture du sol tierras arables tipos de suelos type de sol weeds