Circles in the Forest #1 Mystery Cache

This is a very easy one-step on-site mystery cache just to make it a bit more interesting than just searching for a container in the woods ;-)
The coordinate you are looking for is single-digit, so you may chose to solve this mystery at home by trial and error and arrive with the final coordinates solved 😉😉.

Note: The cache is not at the posted coordinates - but very close!

Welcome to the Knysna Forest!
After parking at the Daleen Matthee memorial and Big Tree and picnic parking (see parking waypoint), walk through the boom ahead. After about 150m the "Circles in the Forest" hiking trail, which offers an option of 3km or 9km hiking trail, turns off to the right at the signpost.
Note there is no cellphone reception on the hiking trail, but still at the parking lot. To find this cache you will need a proper GPS device or to download the caches for offline use - see here how to do it. 

The hiking trail leads into the densely vegetated forest with fantastic Yellowwoods, Ironwoods, Cherrywoods, Tree Ferns and many other remarkable trees indigenous to our unique coastal forests. In areas there are wooden walkways where the path otherwise would get too wet. Be careful as these can be very slippery, as can be the path especially when a bit moist in areas where roots are exposed! Take your time and soak in the sounds and smells of the forest, see the diversity of mushrooms growing here (a little taste here: INaturalist Garden Route mushrooms) and hear and see some of our birds, like the Knysna Lourie or, more rarely, the Narina Trogon.

This first of the Circles in the Forest cache series is placed at around 1 km into the trail before it splits up into the shorter and longer loops.

Note that there are signboards explaining what trees are prevalent in the forest. These might help you finding this cache if you read this text carefully.
 

Question at the posted coordinates: What diameter of the trunk of the tree described here is not uncommon?
Your answer will be the added value of the digits  = A

You will find your cache further along the path at these coordinates:

S 33 54.A8A E22 57.388

The cache, by the way, is NOT in a Forest Tree-Fern ;-)

Please hide again unobtrusively and cover with some bark.