Instead of food crops, we have genetically modified trees taking up land that make no fruit or nuts and the quality of wood would be questionable since it is fast-growing. What else could go wrong?

If the trees reproduce and their manipulated DNA gets onto a neighbor's land, will the patent holder seek compensation? Monsanto has sued farmers when their GMO seeds were used in a way they did not approve of.

The article posted here admits that these GMO trees could spread onto other land, even if they say it is unlikely:

they could be pollinated by wild trees and produce seeds...