Neighbouring trees can show widely differing apparent impacts which in part may be due to differences in the genetic potential of individual ash trees to tolerate the fungus.
Gall coed cyfagos ddangos effeithiau amlwg amrywiol iawn a allai fod yn rhannol oherwydd gwahaniaethau ym mhotensial genetig coed ynn unigol i oddef y ffwng.