Chemical quality of the burnt and non-burnt grass layer in the Nylsvlei Nature Reserve, South Africa

afrique du sud aliment pour animaux burning chemical composition composition chimique comunidades vegetales conservation de la nature contenido mineral eragrostis feeds flood plains forage fosforo gramineae grasslands herbage llanura aluvial mineral content minerales minerals nature conservation nature reserves nutritive value organic matter phosphore phosphorus piensos plaine d'inondation plant communities poaceae potasio potassium praderas quema reservas naturales sabanas savane south africa sporobolus valeur nutritive valor nutritivo vegetation