Does anyone know why so many of my trees roots grow above ground?

Its mostly the shade trees, (teen phet, pradu, etc.). Its not much of a problem except around the house where I have a lawn and its unsightly and difficult to mow the grass. Some of the roots are up 3-4 inches, and extend out as much as 20 feet.

Could it be that you have a slow but persistent erosion problem? My mother in laws house used to have bare dirt everywhere. She kept chickens and let them run everywhere so the ground was pretty much bare everywere. Gradually over time the level of the ground was lowered by erosion from rainwater and the scratching of chickens I guess. They have put concrete almost everywhere now so that has solved the problem....not my preferred solution but it seems to have made them happy.

Chownah

As well as erosion mentioned by chownah there are suggestions this could be caused by soil with high clay content. Roots tend to take the easiest route away from the hard clay.

The guides on Oz rainforest eco tours also mention these above ground roots provide stability for the trees, help the trees to exchange air in waterlogged soils plus trap nutrients from fallen leaves and animal waste.

I'd cover them with dirt. Trying to mow around those trees would be a nightmare.

Got a similar problem . That one big tree growing under the cement , slowly breaking it .

Considering to cut it all out , but it is a pretty tree

I think no, to the erosion or clay. Also, I would think the trees would be more stable, if the roots were underground.

Ive been covering them with soil. That works, but I can only go so high.

Well, if thats the worst of my problems, Im not complaining!