How to choose trees to thin out?

I have several areas of real dense brushy woods. Some spots are dense with trees and some spots are dense with multiflora rose and poison ivy... This part of the state is near overrun with black walnut trees. Which make good lumber and I'm hoping to find out about having an amish neighbor mill some boards for me. I know there are other trees, some being nut trees. I'm not too good on tree identifying but I do have a north American tree manual book to take with and make notes.

I'd like to thin out the trees and make this into silvopasture. I have sheep and hoping to add hogs in the spring to help with a lot of this woods work. (And yummy meat!) I've been finding some videos that are kind of common sense helpful (Greg Judy) and some that are more technical (woodland resources webinars, etc). But there is a gap where one assumes you kind of know some stuff about trees and the other is assuming you have a crew to cut and haul trees and that you're going to be making good money logging. Neither is quite what I'm looking for.

I'd love to hear how you all decide on thinning out trees and some links to articles/videos that you've found helpful.

Hey Kadence, best wishes on your efforts. Some techniques from conventional forestry that could be helpful:

- Think in terms of basal area (https://en.wikipedia.org/wiki/Basal_area) in planning and in implementing plans. This makes it easier to see the forest through the trees. I get stuck doing silviculture because I think about every tree, but with a prescription based on species and basal area for a forest stand (area of homogeneous characteristics), it's much easier for me to walk through and apply a prescription: if basal area is 100sqft/ac and I want to bring that down to 60sqft/ac, I can figure out what kind of trees translate into what amount of basal area (using wedge prism as in "variable plot sampling", very quick and requires simple tool), then walk the stand systematically considering clusters of trees and removing X trees to drop basal area as desired, making selections based on the silviculture prescription.

- Plan out a silvicultural prescription and stick to it. Even better if you can mark trees for a prescription in a separate time than cutting, so you can focus on doing each process well, each one deserves careful attention (silviculture for forest health, cutting requires full attention for your own health!)

- As you mark out your plan in the woods: think about access, light and seed bank. Natural regeneration forestry is a lot about using logging to manage light and soil exposure. Think about how cuts will change what plants and soil get light. Also it can be worth marking out your trail in a thoughtful way, as it will do damage skidding logs out of the woods and you want to be strategic about that damage. The way I used to do it with a company was to mark all trees to either cut or not to cut in a stand, then we lay out trails to access all the cut areas, making trails high and dry and strategic about what trees will get banged up when dragging logs out.

I would guess shelterwood cuts (https://en.wikipedia.org/wiki/Shelterwood_cutting) are appropriate for Ohio's mixed hardwoods, but that's a very rough guess lacking lots of important details. Reading up on good conditions for the silvopasture you desire, and appropriate cuts for the forest you're working with, is where I would start. Trying to find where those two converge: what change to the forest (e.g. reduction in basal area, species and age composition) suits the silvopasture, what cuts are appropriate to get the current forest there.

Eventually that all becomes more intuitive. But starting out if you can I think it's wise to be more systematic about it, to minimize long-term mistakes and build that intuition more thoroughly.

So Basal area is kind of like I have X sqft and X sqft of that is tree trunk..?

From the second link, I think what mostly fits my thoughts is the seed tree cutting. I don't want to do this regularly though. More like it's a crazy mess and unutilized other than some deer and wildlife. I want to thin it out so you can actually walk through it. Definitely cutting standing dead and dying trees. In the nicer areas there is going to be far too many young trees coming up really close together, thin those out.
It's thinning the nice healthy trees and deciding which should stay. Other than preferring not-black-walnut because we're about overrun.

Once the areas are worked through I would want to be able to graze/forage the sheep and hogs through it and do fairly minimal upkeep. When all the seed bank trees come up I know I'll have to thin them once they establish to the nicer ones spaced out. To some extent too the animals will cull off a lot of young sprouts.

I'm thinking once the heavy work is done and I'm rotating the animals through I can pick spots to plant trees I want. I have a neighbor with some wild pawpaws and I want to collect some and just lightly bury fruits scattered around. Since apparently they are finicky to deal with seeds and prefer to grow that way anyhow.

There is many very big old trees I will want to leave as much of those as possible as long as they aren't dying or rotten inside.

Thanks! I'll continue to research

You can think of basal area that way. I've usually worked with it as a single number to describe all trees in an entire stand: this area of forest has 80sqft/ac stump surface area if we cut it all at 4.5ft high (standard height, 'breast height', to measure tree diameter). Some foresters use a single number describing only the marketable trees in the stand, merchantable basal area. You could also find that number on a per species basis with forest sampling methods, but you can probably get by without that much detail. It's more to figure out overall density and desired density (e.g. basal area of 70sqft/ac total is generally considered a good density for growing timber, so when density gets up to 100 and higher it's a good time to cut it back to 70). That sets the medium-level goals for silviculture prescriptions.

As for how you change the density, those low-level details are the prescription, and seed tree approach is good for creating a savanna feel. It's less forgiving than shelterwood, but the fact that you're a landowner-operator working on a small-scale makes up for that as I presume you'll take more care in what you cut vs leave.

Sounds like picking the seed trees is what you're most unsure of. Prioritize good genetics and species composition for what you want the future forest to look like. Make an effort to remove the bad genetics. This is the opposite of greedy logging: short-sighted folks will take the good stuff and leave the bad, but the best forestry is taking as much of the bad as you can and just enough of the good to pay for the operation, limiting yourself to ensure enough good genes are around for regeneration. Also think about spacing of those genetics, that's where basal area comes in. The change in basal area you desire can translate to how many trees are kept or removed in a cluster of say 5 or 10. That way you walk around and 10 trees at a time decide which to leave or take, then walk away and decide for the next cluster, do that systematically and eventually you should have an evenly spaced distribution of good selections getting you to the overall desired density.

Those old huge trees are great. Some standing dead wood is good for wildlife too, but that needs to balance with the need to mitigate hazard trees.

Lastly for deciding what to take or leave, consider if you want more even-aged or mixed-age future forest. It will be mixed-age unless you really try to even it out. But in seed tree you could be selecting an ancient tree to keep in one cluster, a middle-aged one in another cluster, a young adult in another etc. so the woods will develop into quite a mix over time until the next major disturbance.

As for regeneration with seed tree, I don't know how silvopasture will affect the regeneration from that cut. I've done seed tree cuts and seen results of past seed tree cuts, it can be really nice. One beautiful tree over here, a small cluster of great genes over there, pouring seed out on top of an existing seed bank now released - like a much sparser 'shelterwood' cut, as shelterwood has strips or larger clusters to reseed rather than seed tree's sparse individuals or small groups. Thing is with silvopasture, livestock might hinder natural regeneration or affect the seed bank somehow. Probably if you're hands on about it, planting trees and protecting them from livestock during establishment, it's a nonissue. Just something that comes to mind. Wildlife have an impact on natural regeneration for sure, but I bet it's a different kind of pressure on the new trees in intensity and timing than silvopasture.