Up here, having a woodlot/forest of trembling aspen is the typical situation. If you have a few hundred feet of dense trembling aspen, they do fine as a windbreak. But when people start to cut down aspen on the upwind side, you eventually reach the point where the remaining aspen are not effective, and they start to get broken and die. There is the odd balsam poplar, willow and spruce in their as well.
I have one "woodlot" on the windward side of the house that is 100-ish feet deep on my side of the property line, where one windward neighbour is cutting down aspen and the other windward neighbour has horses that are slowly taking down aspen as well. That block of aspen is not dense, and is becoming non-viable. We are marginal for
water here, and so there typically isn't
enough moisture in the soil or held in by the weeds, to allow broken
trees and branches to break down at any reasonable speed. I have been thinking about planting clover and/or vetch on the ground, to hold in more moisture, and to also provide nitrogen to the aspen in the hopes of helping them last until I can transition the woodlot.
I have a second woodlot, which has a sewage lagoon in the middle of it. The density of trees here is higher in places, but also contains willow which are not as tall as the aspen and poplar. The upwind trees are all being knocked down by horses in this area. But a significant chunk of the centre of this woodlot is now more littered with dead and failing trees, than trees that are capable of fighting the wind.
Both woodlots have some trees right up to the property line on my side.
Way back when on the Great Plains, people would plant a lot of Osage-orange to define field boundaries (aka hedge). Horse high, bull strong, pig tight. I ran across some mention somewhere, of a mixed Osage-orange and
honey locust hedge, but not enough to plan from. I have a
deer problem (deer being whitetail, mule deer and moose - possibly elk) and I have a wind problem (I am 5 miles downwind of a 130+ MW wind farm.
So, the first row of several different kinds of windbreak will mostly be "hedge". I'm hoping for 20 foot tall, I can live with 15. If I don't do the fancy bending and tying of English hedges, I can get the tops of these trees out of grazing distance in 4 or 5 years. I am planning to space the trees at 2 foot intervals, which is not as dense as some hedge was done.
The plans for the area directly west of the house, was to put a double row of Siberian pine on a 20 foot spacing immediately downwind of the hedge, where the second row is offset and =placed another 13-14 feet downwind. There are some trees where I would want to put hedge, and where I would want to put pine. I am hoping to have a 50-ish horsepower
tractor for next season, at the moment everything is manual. If the hedge gets to 15-20 feet in 4-5 years, it
should start to shoulder some wind burden from the aspen that are closest to the house. I'm thinking that once the pines get over 25 feet, I can start removing all the aspen, poplar and willow in this area.
The pines will shade the hedge in the morning. But, on the summer solstice, we have light for maybe 20 hours of the day? The mountains are to the west, so it does get dark, but not long after midnight you start to see light coming from the NE. Sunrise is still a few hours away at that point. So the hedge would still be getting 10 hours of sunlight in the afternoon (on the solstice).
To plant the Osage-orange or the pines, in places I need to cut aspen down. There is a stump and aspen
roots to deal with (of my 40 acres, I suspect 10 acres have aspen roots through the area). The recommendation with doing any kind of property line change affecting the flow of deer into and out of your property, that you do so slowly. Because the fenceline is so bad here, this is one of the main routes for deer using our
land.
On the north side (downhill) of the barn and west of the sewage lagoon, I would probably look to put pines downwind of the hedge as well. I've got more trees, including more willow close to that section of property line. I will have to use the tractor to help in falling most of the trees in here, because the power line runs about 100 feet east of the property line in much of this area.