True food forests?

I understand the technique of creating a food forest from scratch, but is anyone just planting things straight into a forest instead of creating every aspect of it?  Obviously I could take a few raspberry or blueberry plants and plant them and they'd do just fine and need nothing from me.  Does anyone do this with fruit or nut trees?  Just plant them somewhere they can get enough water and light?  I am just wondering if this is something I could start one at a time instead of trying to develop a totally man made food forest.

I have planted about 400 fruit and nut trees and another 200 n-fixing or pollinator enticing trees around my native forest. Basically on the south side of the native forest I plant tall canopy trees like oaks, chestnuts and standard fruit trees, with successively smaller trees and shrubs going southward to allow them each to get light. The main challenge is that the open areas I am planting into are on slopes and ridglines with poor, rocky clay soil, but so far over 80% have survived their first year+.

A "food forest" and  "Mother Nature's forest" have significantly different characteristics.

A mature Mother Nature Forest in my area has many very tall overstory trees, and minimal sun on the forest floor, so not a lot of understory plants, although with weather weirding, the overstory trees are in decline and thinning and letting much more light through. Some Indigenous managed forests were like this to facilitate human movement and hunting prior to European diseases arriving.

Most of the human food trees are edge plants, pioneer plants, and shrubby plants with the exception of nut trees like Oak, Walnut, Chestnut etc. So a human food forest is shorter and most of the trees aren't designed to compete and produce in the shade of tall overstory trees.

So step one would be to identify what trees are already growing in the forest you plan to convert. If you can do what Ben suggested and simply thin the south edge and grow south from there, that would work, but I'm not sure that's what you're asking.

What size is the existing forest? How old are its trees (approximately)? Are you prepared to remove some of them to create small open spaces for berry bushes and shorter trees?

Granted, I'm in the Pacific North Coastal area and our "native" trees - Cedar, fir, big leaf maple etc are 75 ft or higher. The huge trees near the coast further south - Giant Sequoia - are so tall that they have trees growing in their canopy and are an entire ecosystem in themselves! Planting an apple tree in the middle of a forest like mine would likely have minimal success. However, a former owner cleared a bunch of trees up a south facing slope in an effort to get a well drilling truck in. I'm now replanting the edges of that swath with apple, currents, seaberry, strawberries etc. I'll watch for and remove any baby Doug Fir that try to establish themselves. There are a few large trees that may also have to come down before I expand to the west.

Yeah, it's doable with seed. You can't really control where stuff ends up or if it will grow at all, but I've managed to stock up a pre-existing patch of woods in Ohio with solomon's seal, ramps & elderberries. I plan to get some other stuff in too & may try to thin out some of the invasive underbrush at some point.

I buy cheap native seed & scatter it around the area around late November- early January. It doesn't seem like its worked for every plant, though & I'm currently trying to figure out why & work out some alternate strategies for encouraging certain plants.

I have a section of "forest" that I am very slowly trying to alter to be a "food forest" of sorts.  Wet soil, not waterlogged all season, but floods in the spring frequently.

Trees present include:
Poplar/cottonwood - I try to remove these when they are like six inches in diameter or smaller, while they are manageable.  Old ones I have to just wait out, let die, and hope they don't make a mess when they fall.
Ash - Dying.  Used the be the dominant tree.  Good firewood, as they will stand dead for awhile.
Soft maple - similar to the poplar, I want to cut them when small, the big ones are too much to do anything with.
Alder - let them grow until I need the space, then cut them.  Easy to manage due to small size
Some sort of crab-apple with thorny growth - Encouraging their growth.  Clearing around them.  
Prickly ash - HATE THIS STUFF.  hard to deal with.  Cut them when I see them and am ambitious.
A few feral apples - clearing around them
Black cherry: only a few, I don't worry about them
Service berries (I think, not positive of ID)
Trout lily (not a tree) - I eat a few leaves in the spring, lots of these growing in this area.  I've heard mixed reviews about eating larger quantities of these.

Plants I have added:
American Plum - transplanted 6 suckers from the tree in the yard, plans to experiment with grafting other stone fruits onto them.
Redbud - transplanted one seedling from the flower bed into the forest, 1 more seedling that I plant to transplant next year (and am watching for more)
Hawthorn - transplanted 2 suckers from a tree by the cow pasture.  Not sure I I can/want to eat the fruit.  Still need to look into it.
Apple: Playing with "air layering" and regular layering (one of the trees has a branch that nearly touches the ground, so I scored the branches, put on some rooting hormones', and stuck them in a bucket of dirt while still attached to "mom" tree) my feral trees, hoping to get more apple trees adapted to this soil and climate, maybe graft onto them (I failed at grafting this year... first try.  I'll try again next year)
Garlic - had some that needed to go somewhere or would be wasted, planted some whole cloves in a sunny opening.  nothing to lose
Hopniss/ground nut - Ordered some from a guy here on permies.  Planted in a few spots.

Thomas, do you ever girdle the undesirable trees to speed their demise?
I realize that girdling can create a hazard but I think that's true of trees that die naturally as well.

I think temperate food forests might work best when they include livestock or wildlife.
The pig seems ideal in this role, from a homestead POV.

I've got about 2 acres of natural forest and  I'm slowly learning how to encourage it to make more food.

I've been planting things like gooseberry and elderberry along the edge and they quite like it there. I have native hazelnuts and want to plant some named cultivars to up the output. We've cleared out invasive blackberries and that's allowing the native blackberries and other native berries to produce more fruit.

Also I've been working on identifying all the plants that grow in there so I know what are edible and how to use them. Plus as I identify things, I can learn about similar cultivated plants that I could possibly grow in the same space that produce more food or more palatable food.

Mushrooms are also on my to-do list and medical forest plants. I'd really like to get some ramps and try to grow those some day as well.

The hardest thing about introducing new plants into the forest is keeping them watered. 2nd hardest is protecting them from the deer.

I have spent a lifetime guerilla gardening food forests. My general strategy is to spew millions of propagules into the forest, without a care about whether they live or die. And then watch the forests in coming decades to see what took.

One strategy is to sit in the forest, and eat my lunch, then bury the seeds of any apricots, plums, or apples that were included in my lunch. I gather seeds from edible trees, nuts,  shrubs, grasses, and forbs, and toss them randomly into the forest. I plant cuttings of berries, asparagus, Egyptian walking onions, mushrooms, and many other species. From time to time, some of them become established. I love the patch of parsnips that naturalized.

I transplant from one part of the forest to another, to spread desired species more widely.

Another strategy is to forage my lunch from the ecosystem. That helps me to become aware of what species already exist in the forests that I visit. I can then focus on adding more of the edible species, and weeding out the less edible species. Dandelions grown in sunny lawns around here are inedible, but those grown in deep shade are delightful.

I plant edible varieties of domesticated species to compete with less-tasty varieties of the same wild species that is already growing in the forest.

Right now, I am foraging rocket (brassica flowers), oyster mushrooms, and lambsquarters from the local forests.

This is all great info!  Thank you so much for all of your replies.  I think I will end up doing both, more conventional food forests polyculture and some attempts to get completely stable and reproducing plants in the woods that needs no care to thrive.

William Bronson wrote: Thomas, do you ever girdle the undesirable trees to speed their demise?
I realize that girdling can create a hazard but I think that's true of trees that die naturally as well.

I have started girdling some of the poplar trees, ones that I just don't have time to cut yet.

Joseph Lofthouse wrote:My general strategy is to spew millions of propagules into the forest, without a care about whether they live or die. And then watch the forests in coming decades to see what took.

I love this approach! Easy and effective.