| Generally, you remove anything that competes with the roots, water supply, & canopy shape of your "estate trees" (the big ones). So I'd remove the smaller ones, *one by one*. Remove the spindliest, step back & observe, maybe wait a day or a week to see how the view pleases you over time. Pecan trees need a lot of canopy space & a lot of root zone & a lot of water: Since you have an acre, put the flowering trees well away from the pecans somewhere where they won't interfere with your pecans' shape, root zone, or water supply-closer to the house where they can be seen from inside if possible. Don't allow anyone to "limb up" the pecan trees. So-called arborists often want to cut off lower limbs, & we're so accustomed to seeing trees pruned into the shape of broccoli that we don't think about the alternative. Ancient pecan trees with enormous limbs sweeping close to the ground are graceful & impressive. (& magnolias whose lower limbs haven't been hacked off are gorgeous & stately; they're the Southern version of a Christmas tree!) These are just some minor "rules of thumb", but the main thing is to practice caution when cutting trees. Once you remove a tree, you can't put it back, & your estate-sized pecan trees are treasures. | 
