I was assuming Ferne was talking about so-called Eastern Red Cedar (Juniperus virginiana).
I have a lot of the stuff here. Lots of people talk about it sucking
water and creating a dead zone beneath itself, but I don't really see that happening. It's a bushy plant much beloved of birds and wildlife because it's good cover even in winter when other trees (mostly deciduous) are bare. But the bare ground underneath most of these trees on my property is just the result (IMO) of how heavily these trees shade the ground beneath themselves. I have plenty of vegetation around and under most for these trees except where they are very large or densely packed. I've seen no evidence of a true allelopathic effect, though some people argue these trees have one. They are just robust competitors for water and light.
As for clearing them? The word I would suggest is "thin" -- and don't be hasty. As I try to make my cross-timbers woods more food forest-y, my observation has been that all trees are valuable. Establishing new trees is hard, and they support each other in many ways, serving as wind protection, reflecting light and heat, and (some say) exchanging water and nutrients with each other and with other plants via the mycelium network in the forest floor. So I don't take down a tree until I've discovered a particular reason that a particular tree is offending me. Often this is just because an area needs thinning (I am going for an open savanna type landscape) so that light and water resources can be focused on other trees I want to preference, like wild fruit and nut trees or valuable hardwoods. Sometimes I just need the physical space for another tree or plant, or so that I can move through the forest. And when I have too many trees in an area, I rank them by what I want from them. Existing fruit and nut trees get priority, but I also think about wind protection, nitrogen fixing ability of some trees, and wildlife values. My Eastern Red Cedars are among my least valuable trees and are usually a priority target when I need to thin an area, but I am careful to maintain large healthy specimens where I want a windbreak to protect another valuable tree or where there's not another excellent winter habitat tree nearby.
If I cut a substantial tree in error, I've lost between five and thirty years of time before its functions can be replaced with another tree. And because I'm new at this, my track record of getting new trees established (I don't have much budget for large nursery trees) is still pretty poor. So I'm really careful about what I cut. If I'm in doubt, I don't cut it. I leave it. Maybe a week or a month or a year later, if the tree's still bothering me, I cut it then. There are a bunch of trees I considered cutting when I didn't know so much about pemaculture and food forests, that I am now really glad I didn't cut. And since I'm working with hand tools, the list of trees I need to get rid of is essentially endless; I'll never get to them all. So I can afford to focus my efforts on trees that absolutely need to go today.
My advice is not to clear the cedar. You'll have a lot of thinning to do in general as you establish your food tree crops, and you'll probably find that your cedars (actually junipers) are frequently your preferential cut. But in your shoes I wouldn't cut them until -- individually -- you find them in your way.