I am glad you mentioned pleistocene rewilding projects. I don't remember the name of the one in the Arctic, but the one in The Netherlands, north of Amsterdam, is called Oostvaardersplassen
In such instances, my reading of the material suggests that horses are valuable as one of a number of herding species on open plains or grassland, as they graze differently
than, say, bison. By including a diversity of herbivores, we get virtually everything grazed, and we draw more types and numbers of predators, and the resultant scavenger and detrivore species. There is more overlap, and a higher population overall of living organisms, which translates to more soil generation, if it's being done right.
Otherwise, as in, on a homestead level, horses are difficult for me, conceptually, unless they're literally the engines of my tractors. Even as such, they're really expensive tractor
On other levels, it may be another story. I know there was a member on at one point, Travis by name, if I recall correctly, operating an equine rehabilitation and therapy centre somewhere between Oshawa and the Lindsay/Peterborough area here in Ontario, and they were trying to do it according to the principles of permaculture. If the focus of the operation was directed to emphasize the intangible benefits, and their psychological and physiological knock-on effects, of interacting with these animals, in the context of an eco-tourism and educational entertainment attraction, I could see it working much better than trying to justify the expense of a hay-fuelled hairy-fetlocked giant underpowered tractor over the cost of an ever cheaper and ever improving solar
Mind you, I knew a guy who did horse skidding of timber out of his family's managed tree farm in the winters, when the ground was frozen, to harvest selectively whilst not buggering up the soil structure. If they were to operate in such a specialised fashion year-round, that would be another matter altogether.
I would still have to say that they are highly specialised, skilled workers, and cost as much to feed
. If one lacks the need for their speciality, or can't afford them and their maintenance over a mechanical alternative, it becomes more difficult to justify their expense.
that you'd essentially need a horse-centric system, one planned around them, and it might be necessary to add in elements of the rewilding systems, such as other ruminants, or herding dogs in place of predators, to replicate the herding patterns seen in nature.
Though I would be hard-pressed to find traction-oriented tasks more suited to horses than to oxen, which are arguably easier, on the pocketbook and the ecology alike.
Still, I love the look and attitude of those giant beer-wagon-pullers. Makes me think of the determined horse from Orwell's Animal Farm.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein