Tree roots in the yard?

Question

What causes an Ash trees roots to move up to the surface?

Answer 1

i have a liquid ember in my backyard, (it also has the same "Problems") & i think that maybe there is/was  a stream/river nearby, it followed the course of the river in order to absorb more water.

Answer 2

lots of trees have roots very near the surface. Even a portion of the roots may be above the surface in spots. It is normal, but bothersome when they make bumps in the lawn.

Answer 3

This is normal . These roots are caled 'Buttress Roots ".

Click on the link below to learn more --

http://www.answers.com/topic/buttress-ro...

Imges on the link below -

http://ecology.hku.hk/jupas/Buttress%20r...

Your Ash tree  trunk is , most probably like this near the soil surface -

http://farm1.static.flickr.com/149/36170...