Complex sentence: Towards the north there is a community dominated by False oat-grass ("Arrhenatherum elatius"), a constant species in the MG1 and MG2 communities of the British NVC and therefore not typical of an MG5 community.
Split into simpler sentences: Towards the north there is a community dominated by False oat-grass ("Arrhenatherum elatius"). The False Oat-grass is a constant species in the MG1 and MG2 communities of the British NVC and is therefore not typical of an MG5 community.