OK, So I did some digging and found a bit more on the Canadian Foresty Corps ... Based on what I found, for Worthy Down we're talking District 54 and the 2 Companies who were involved with Aerodrome construction in Britain: 123 & 124.
So with some more digging I found the War diaries for District 54 and a brief skim through found the following ...
25th September commencing operations at Worthy Down
Jan. 1st,1918: STRENGTH At DIFFERENT LOCATIONS:-
Worthy Down, near Winchester, Hants;
Lieut. F.D.I. Honeyman, 38 Other Ranks and 5 R.F.C.Other
Ranks attached. Completing work as shown in Historical Record on 1st December,1917
Jan. 21st,1918 Pte. Bigelow, shoeing smith, proceeded to Worth Down,
Winchester, to shoe horses there
Feb 1st, 1918 STRENGTH AT DIFFERENT OPERATIONS
Worthy Down, Winchester, Hants;
Lieut, F.D.I. Honeyman, 39 Other Ranks and 2 R.F.[C].
Other Ranks. Preparing aerodrome
Feb. 14th,1918 Sgt. Duncan, 17 Other Ranks and 1 R.F.C. Other Ranks,
proceeded from Worthy Down to Handley Page, to join
Feb 14th 1918 (Cont'd) detachment.
Ptr Bigelow, shoeing smith, proceeded from Lopcombe
Corner, to Handley Page, to shoe horses
Which is pretty conclusive that it should have been Forestry rather than Pioneer in the Worthy Down booklet.