The health of a certain type of birch, called Malbrethil by the Elves, seems to strongly affect the overall health of the forest. Mallendathor is worried about their declining numbers and health and wants you to investigate.
'Mae govannen, ${CLASS}. I am Mallendathor, one of the wardens of the revered woodlands of Cerin Amroth. I and my fellows have accepted the solemn charge of custodianship; we ensure that the forests are not thrown out of balance.
'A problem has come to my attention within the last few decades: a particular birch, the Malbrethil, has not been seen as often as in days past, and when it is sighted, the saplings seem spindly and overly delicate. I want you to find and examine some of these saplings, if you would, that we might determine the cause of their malady.
'I would suggest heading east, then north-east once you are past the low white cliff.'
Malbrethil-saplings can be found in Taur Hith, north-east of Cerin Amroth.
Mallendathor would like you to find and examine some Malbrethil-saplings.
Mallendathor is near Cerin Amroth, south-west of Taur Hith.
You should tell Mallendathor about the Malbrethil-saplings you found.