Yes! this happens sometime becuase

1. of adoption of inadequate technology and involvement of inefficient labours.

2. It also depends on methods of sawing adopted in the felling operation.

3. Its usually found in trees which lack clear bole heights and unsymmetric growth of the plant.

Thanks Abdul

I can agree with the technology and sawing method, although we've kept this relatively constant and the plantations are pretty well maintained - but there are always some bad ones, I haven't tracked which compartments these logs come from to be able to say.

Any explanation for the older (dryer) logs breaking more than the fresher logs?

YES.

THIS IS A PROBLEM FACED DURING HARVESTING AND STORAGE OF LOGS SPECIFICALLY FOR THE PINE SPECIES OR OTHER SOFT WOOD SPECIES.

IT MAY HAPPEN BECAUSE OF EXCESSIVE LOSS OF MOISTURE FROM THE CROSS SECTIONAL AREA AND THUS DEVELOPMENT OF INTERNAL STRESSES.

ONE SOLUTION IS APPLICATION OF BITUMINOUS PAINT IMMEDIATELY AFTER HARVESTING ON THE CUT SURFACES.  

Thanks Amey.

Have you done, or do you know of research in this regard? I'd like to prove if its the loss of moisture, harvesting practices, or just week timber causing these breaks.