The invention concerns a mobile load compartment (3) for logs from young forest during thinning and intended to be coupled in a jointed manner behind a harvester of the type that demonstrates a front assembly (1A) and a rear assembly (1 B) that are united through a joint (8) in a manner that allows pivoting and where the rear assembly is equipped with a driver's cabin (2) and the front assembly with a crane (10) that can be rotated around a vertical axis (Z1 ) and, supporting a harvester unit (20), can be used for the gripping and handling of logs, a loading arrangement arranged at the said mobile compartment and including a timber receiver (26) in order to receive the said logs and support them in a retaining manner. In order to obtain a higher degree of exploitation, a loading arrangement is arranged to receive a log directly from the harvester unit (20) and to retain it, and - independently of the motion of the harvester unit - to carry out displacement using the crane (10) of a delivered log to a position in and above the said mobile load compartment (3), whereby the loading arrangement is arranged to receive a log from a position within the working area (25) of the harvester unit in front of or at the side of the front assembly (1 A) of the harvester.