Ground depression around a beech tree ?

[phill]

Just wondering if anyone can help with this

Just been out to price up a site and one of the trees was this beech at first I thought the soil level had been changed but there's no other signs of this ?

 

Hope the pictures do it justice,it's about 3 inches higher around the stem

 

Thanks in advance

Phill

[Stubby]

Is it the root flair were its been origionally planted just a little shallow ?

[Will Heal]

Looks like someone has dig the soil away in the past

[phill]

Looks like someone has dig the soil away in the past

 

i thought that at first but there doesn't seem to be any other signs of someone lowering the soil level?