The climate and soil of an area will determine the range of potential plant species that can grow in a particular area. However, it is management alone that will determine the actual plants growing in any one area.
For example, apple trees do really well in my area because they are well adapted to the climate and soil on my property. However, if I simply planted 100 apple trees on a nearby piece of land in full sun conditions such as an open field environment and did no further management then most likely none of them would survive.
Why is this you might ask? Well it is because of the management of our area. Apple tree buds are highly sought after by deer and elk. These game species, especially the deer, have relatively high populations, and especially in winter as these game migrate from higher elevations to the lower elevation areas. So in this scenario the deer and elk would likely over-browse the apple trees until the point they would die out. So in order to get apples to grow in our area we would need to manage these high game populations. This could be done several different ways.
One way would be simply through hunting to lower game numbers. However because game populations are managed through the state and only a limited number of tags are allowed per individual hunter it would be nearly impossible to control the deer and elk populations in my area to the point where the apple trees in this scenario could grow.
Another, much more viable option would be through exclusion. By constructing a barrier, generally a tree cage or fence, one could prevent access to the apple trees from the game and thus allow them to grow without getting browsed into oblivion. Besides fencing, other barriers one could use would be piles of thorny brush around a tree or even planting the tree within a thick patch of roses or briars.
In my area there are actually wild apples that have been naturally planted from wildlife eating and spreading the seed and because of the abundant roses some were lucky enough to have the natural barrier of a rose bush grow around them and thus allow them to escape the browse pressure from the deer and elk. I have used all 3 methods to plant trees on my property, that being tree cages, brush piles and rose bushes, in order to prevent overbrowsing and they all have been successful.
Another example of management determining vegetation type is the large amount of invasive weeds, like yellow star thistle and medusahead grass, on south facing slopes in our area. These plants are growing in areas that used to be vibrant native prairies with native perennial grasses and wildflowers, but because of poor management annual weeds have been allowed to take over.
These weeds dominate these areas mainly because of 2 management actions. These are overgrazing and rest. Because of the high wild game populations in the area the more palatable plants are overgrazed while the least palatable plants are avoided and left to mature and reproduce. This over time favors the unpalatable weeds such as starthistle and medusahead and the more palatable natives die out.
The second management action leading to these weeds is rest. Surprisingly it's the fact that there are not enough large animals on these landscapes that are allowing the weeds to dominate. This is because the weeds shade out any new perennial native seedlings before they can establish because the weeds are not being trampled to the ground, which is what the native perennial plants are adapted to. In the past larger herds of elk, bighorn sheep and even bison herds would have moved through the area periodically grazing and trampling everything to the ground allowing the native perennial grasses and forbs to thrive. And if you go back far enough there were even larger animals such as mammoths, mastodons, etc that would have definitely contributed to the periodic trampling of native plants.
So if one were wanting to get rid of weeds in our area and return their property to a more natural prairie state then the best option would be to periodically allow livestock to graze and trample down the weeds and allow the perennials to come back.
As you can see in these examples it's management alone that will determine what kind of vegetation is growing in any one area. This is an empowering realization that you have complete control over what types of plants could grow on your property (assuming they are adapted to the climate and soils), but it also means you have complete responsibility for managing it and any negligence would lead to undesirable outcomes including a lack of habitat for the wildlife you are trying to manage for. Therefore it is of the utmost importance to practice responsible management of the ecosystems in our control in order to create ecological paradises for wildlife and ourselves.