Drop times! Ok so that answers the first part of how to choose what is planted together.
So the next question is how many are truly needed for a medium to high population?
I don't think there is a direct answer to this. I'd say there are two somewhat different objectives. One is to attract game to a specific location for hunting, and another is to feed game. For the first, you don't really need a lot of trees. Consider things like how the pollinate as well as drop times.
For feeding deer, I'd look at planted trees kind of like food plots. My objective is to provide food sources that supplement the native foods. So, I look for mast trees (like food plots) that will provide food when my native foods are scarce. In my case summer is a greater stress period than winter. At the same time I'm looking for attraction.
I have many native American persimmons growing on my land, but many trees are male and don't produce fruit. The best bang for the buck in my area was to cut down native persimmons and bark graft female scions to them. I've traded scions of native trees with folks to cover the late period, Nov, Dec, and Jan. My native trees can drop anywhere from Sep through Nov depending on the year. Many commercially named varieties were selected for early ripening so I used those to cover the early period. Scions are free if traded or inexpensive. If the rootstock is in the 1" - 5" diameter class, trees can produce their first persimmons in the third leaf after grafting.
For feeding purposes, my primary consideration is volume. A few trees are not going to produce enough for feeding purposes. So, for me, the primary criteria in choosing kinds of mast trees is low long-term maintenance. One reason I'm going to permaculture is that sustaining the current scale of my food plot program is difficult both in finance and time. In order to achieve both volume and low cost, I decided to make an up-front investment in an indoor setup and a root pruning container system. There was some significant setup cost, but starting trees from seeds and nuts reduces my cost per tree significantly. I don't count my labor cost. I'm enjoying learning about and growing trees. It is a cabin fever project and most of the labor occurs during the winter when I have time available. This method is not for everyone, but it works well for me.
One tree that I have been experimenting with because of the low maintenance is Jujube. One issue with these is that most are sold grafted to wild or sour jujube root stock which tends to thicket and produce a cluster of low quality thorny trees. I'm working with some Tigertooth I found sold on their own roots. It is less prone to thicketing and the suckering trees produce the same quality fruit as the parent. Unfortunately, I can't recommend Jujube in my area. I think we my be too wet and humid to encourage fruiting. Folks with hot, dry summers seem to get good fruiting. The upside (if I can get it to fruit here) is that it has few pests and is not susceptible to much disease. You may want to look at these depending where you are in Tx.
I'm generally working with trees that are well adapted to my area. I'm in the original zone of the American chestnut. While blight is of course an issue with American chestnuts, I know hybrids with Chinese will do well in my area so Dunstan chestnut is one I'm using. We have Allegheny Chinquapins growing natively on our farm, so I'm propagating these. They are susceptible to the blight, but unlike American chestnuts, they bounce back from the root system and still produce nuts. I'm hoping to get a more blight resistant Chinese Chinquapin (Sequin) chestnut variety that produces at a young age going as well.
Apples were low on my list because of the maintenance required. However, after learning more, I think there may be a low maintenance approach that may work with apples. I'm starting to experiment with them now.
As for how many trees, I've probably either grafted or planted around 500 trees so far and I'll probably continue for a few more years.
This is all in the context of a larger management plan that includes timber management , controlled burns, and other large scale habitat projects.
Thanks,
Jack
