 have evolved over the millennia with native species flora and fauna including wild horses, and have done so in the face of millennia of normal wildfire cycles. The catastrophic wildfires that have evolved in recent years are not part of any normal fire-cycle. They are in fact man-caused disasters stemming from the mismanagement of wildlife, especially the mismanagement of apex predators. These fires are deforesting America at an alarming rate and are so hot they kill genetic lines of fire-resistant conifers that have survived millennia of wildfires, and which require normal fire-cycles for their seed dispersal. Instead, these conifers that were considered by experts to be fire-resistant are being incinerated by abnormally hot wildfires.
For the past 50 years, some factions in the livestock industry have tried to paint wild horses as a problem on public lands by popularizing a host of myths. One such myth is that wild horses damage range and riparian lands. However, it is well-known scientific fact that cattle and sheep operations have wreaked more havoc on US range-lands than all other species combined over the past 5000 years, as cited by Professor Thomas L. Fleischner, Ph.D: “The most severe vegetation changes of the last 5400 years occurred during the past 200 years. The nature and timing of these changes suggest that they were primarily caused by 19th-century open-land sheep and cattle ranching.”
Yet another invasive species that enters into the discussion on western range-lands and the wildfire regime is the yellow star-thistle, which is prized by bee-keepers for the honey it renders, but as with all invasive species presents its own particular problems on our western lands and in the fire regime: According to the USFS: “Infestations west of the Rocky Mountains are most severe in California, Washington, Oregon, and Idaho [20,38]. Infestations in California cover more area than those in all other states combined .”
In fact, the same citation states that as of 18 years ago, the infestation of yellow star-thistle was endemic to 17 million acres in California alone. I can only imagine how much greater that area might be today, and it presents as an invasive infestation in and around forested areas.
Now, with this basis, if we analyze the earlier question “do wild horses change the fire regime of the area by consuming the natural grasses and allowing the invasive species to become dominate and increase fire spread rates?” using our understanding of animal/plant physiology, we can arrive at a simple conclusion:
Imagine for the moment a native pasture full of ripe yellow star-thistle (Centaurea solstitialisL.) nearing seed stage /w-spikes and native grasses/plants beginning to seed. And then cattle come through and graze this area of mixed yellow star-thistle and other native plants. The cows of course avoid the yellow star-thistle (due to spikes) and instead consume the other fruited grasses and plants. This leaves all of the yellow star-thistle seed in-place and unaffected by the grazing.
As a result of the cow’s complex (complete) digestive system, few grass and plant seeds are redeposited back onto the pasture in their manure. This results in a severe limitation of reseeding by the native grasses and plants of that area, and presents as a huge advantage to the yellow star-thistle as it can then reseed the area with a huge numeric advantage since the seeds from native grasses and plants have been largely digested by the cattle.
However, on the other hand, when wild horses graze that same area, they are incomplete in their digestion and thus they pass most seeds they consume back onto the pasture intact in their droppings, which can then germinate in soil conditions enhanced by the horse droppings which become a seed bed of sorts.
Basically, wild horses reseed the areas where they graze with the seeds from the local native plants.
This allows the grasses and plants to remain established in enhanced conditions and compete more effectively with the likes of the yellow star-thistle.
This naturally evolved mutualism between