I would like to do some landscaping to raise (and level) the ground in my front yard. One concern I have is the fact that I have a mature birch tree in the yard in the area I would like to raise. I seem to recall that there may be a problem with raising the ground around the trunk of a tree. What precautions should I take (if any) and are there any tips I could have. Thanks.

Generally, the problems associated with adding soil above existing grade within the rooting area of a tree includes:
1. tendency for collar rot (root crown pathogenic diseases)
2. suffocation of small roots and root hairs
3. possible compaction or changes in: water percolation, soil nutrient status, and balance of soil microbial community
4. possible introduction of diseases from unknown & contaminated soils

Some trees may be able to adjust to small additions of soil, as long as it is kept away from the trunk. Attention should be paid not to create a drainage problem where water stands around the trunk.
Sometimes elaborate drainage and aeration systems are installed to offset some of the effects of root burying. Lowering grade, of course will damage roots close to the surface.

It might help to create a reasonably thick layer of mulch above a modest addition of mineral soil, to encourage soil fauna to turn and aerate the soil. Perhaps soil test to be sure nutrients and pH are within recommended range.