All my plants are in areas where 75-80% of the trees are sugar maples, the rest are white ash, poplars and red oaks. The majority of my mulch covering the beds is Sugar Maple leaves. I know maple leaves have some calcium in them, but not enough to increase the calcium level alot.
When I first started planting four years ago I had several soil test done that were taken from different spots over a 15 acre area. All the tests showed low calcium even though I had an abundance of Sugar Maples. Calcium levels showed any where from 900-1100 lbs per acre. So after planting and before raking the leaves back over area I added Gypsum at the rate of 5 lbs per 100 sq ft. Then in the spring before the plants had emerged I added the same amount on top of the leaves.
After a second soil test, the calcium levels where around 2800-3050 lbs per acre. Since then I have added more Gypsum and need to get some more tests done.
You could have low levels of calcium even though you have alot of maples.
When in doubt, there is no substitute for a soil test by a lab. Most Universities have soil testing services. Univerity of maine charges $12.
Also, for planting small 1 yr roots, do not bury the growth bud more than about 3/4\" deep.