The most prosaic explanations are often the best – possibly it was planted to give cover for breeding pheasants?
or a farmer applies for a grant for tree planting.
It might seem odd that its so geometric but if you’re planting for the purpose of habitat management you’re trying to get particular ratios between species or thresholds between cover and open space (which you might need to promise on the the grant application) then that sort of pushes you towards an easily audit-able design.
You wouldn’t notice its so regimented from the ground as the photo above shows – it just looks unusual from the air. And their are all sorts of unusual land forms that pop up in aerial photos that are just attempts to achieves those measurable / auditable methods of land management
A friend gets a grant for cutting rushes on his land for wildlife management / encouragement. The grant requires a certain percentage is cut and certain percentage is left undisturbed so that theres a mix of cover for nesting and open space for foraging. Given the rushes grow in any distribution they like its up to him to come up for a strategy and pattern of cutting that yields those percentages. It would be interesting to see what his land looks like from the air.