Pond Boss Forums AQUATIC VEGETATION Balance of plants in the environment shade trees for a lined pond

I've got a lined pond. Liner is buried under 2 ft of soil and at about 2 feet past the water line, then dives down into a trench a couple feet deep (all this is buried). I've been told not to let trees near the liner or dam as it will cause leaks. But there is absolutely shade surrounding this pond. Anyone have any recommendations for shade trees with shallow roots? distance to plant trees safely from the liner? Creative shade ideas that don't involve building a structure?