sidd
I think we have a conceptual problem here. You have a patch of ailanthus altissima and you want to use that land for something and then ailanthus can really be a pain in the ass. However, when we try to grow a food forest, we try to use every plant according to its place in succession.
And what is the role of these fast growing pioneer species (ailanthus altissima, paulownia spp, robinia pseudoacacia) in nature? They are Sun-loving, fast growing trees, that create the environment for secondary and climax species by improving the soil, helping biodiversity. They grow quickly and in their semishade long-lliving species (eg. oaks) will grow up slowly. Once the oaks shade them out, they slowly die. This process can take centuries in nature, but we can speed it up. How?
Let's say I want to plant a tree-row in a food-forest. What do I do?
I plant an apple tree (maybe from seed, and I might graft it later on). 1 meter to the North of the apple tree, I plant a shade tolerant elderberry, then 1 meter to the North a blackberry, another meter and an ailanthus altissima (or any other pioneer), another meter and a maple/ash/oak/beech, another meter and raspberries, and then another meter and a pear tree or any other fruit tree. In between the rows I plant grasses, alfalfa, clovers, etc., and I cut them twice a year and use them as mulch around the trees (or in some spots can grow vegetables here as well). Within the row, the pioneer's sidebranches will be cut, and only the top 2 meter will be allowed to grow branches. In 5 years time, the pioneer will likely be 5-7 meter tall, but will have no side branches at the bottom 4-5 meters, so will only slightly shade the now growing apple/pear trees which willl also shade the berries below them to some extent. Anything cut from the pioneers will be used as mulch (in my case after chipping). After 5-6 years I start pollarding the pioneers every year or every second year cutting them completely at 4-5 meters height. This means that my fruit trees will have no shade in April-May, and only some shade during the summer which is just perfect for them, as they are mostly forest edge species. After some years doing this, the oak/maple will have grown and now is obstructed by the pioneer, so I cut the pioneer at ground level. It has no place in the system any longer. I will likely have to cut it a couple more times every month or every other month, but its root reserves will be depleted and it is already shaded out, so it will go. This is how I want to use pioneers and in this context I do not think that ailanthus is more difficult than black locust (which as much as I like it has a big drawback: it is very thorny)