31st Bn was part of the 2nd Cdn Division which, in mid - late September 1916, was tasked to capture the ground around Courcellette, a village to to the north of Pozieres, during the later stages of the Battle of the Somme.
31st Bn was part of the Bde that was tasked to capture the sugar factory, supported by the tanks of C Company Heavy Section of the Machine Gun Corps (later to become the Tank Regiment) on 15th September 1916. They captured the village itself quite quickly bu then there was a slogging battle, from 26th September, to take the ground aound the Regina Trench to the north east of the village.
I have done a quick scan on the key candian sites with no joy. I also cannot find no mention of William March on the Alberta Battalion site but this may be because he was not a native of Alberta.
I would guess that he was killed in the Courcellete area, perhaps by artillery fire, during the build up to the second attack
. However, knowing the Pals, some-one will quickly let me know whtehr i have got it right.
If you wish to know more about the CEF, the Candian Veterans Affairs runs a good web site.