Gray rangeland is the sign of old moribund plants that are dying of old age and neglect. Grass plants need to have their old growth removed so that growth nodes can be stimulated to promote new growth. In dryer climates those old nongrowing leaves must oxidate over long periods of time to reach the point that they fall away from the grass structure so that new growth can occur. Thus, without some sort of disturbance -in a low humidity environment- the plant slowly dies, producing little new growth even during wet rainfall periods. Yes, some green up with limited growth will occur during those periods, but over time it begins to die from the center of the plant that slowly spreads to the outside of the plant. Thus, producing the gray color of the grass, many times having an open center with no life at all. Producing an excellent place for woody plants like mesquite to germinate and flourish. Some grasses develop this gray look faster than others and it seems that the white grasses are more prone to it than the reds, possibly because the reds are more likely to be grazed before becoming moribund.
These grasses need some ‘event’ to breakoff or remove this old dead structure.
It can come in the form of fire, hailstorm, high wind event (tornado), human intervention -mechanical (dozer-tractor-chain-rake-grubber, vehicle tires-etc.), or the impact of a grazing animal stepping on-laying on-trampling-pooping on-peeing on etc. The grazing animal, most likely, will not graze the gray plant as there is very little-if any- nutritive value of that gray grass and if it were to be grazed from lack of anything else to eat animal performance would be sadly reduced.
The large gray areas that seem to dominate many rangeland areas is the result of over rest of the range. Managers that remove all livestock from the rangeland see dramatic increase in grass growth for a few years then those happy grasses that have no impact start get old and die, turning the range to that regrettable gray color. Even rangeland with light continuous grazing can do the same thing. As the old grasses die, few new plants or seedlings are established -a process that is the result of lack of that same necessary disturbance to the unhealthy rangeland- the range becomes bare soil resulting in erosion issues from water and wind and-or covered in brush that establishes itself within those old dying plants. Either way the ecosystem suffers, and much rangeland diversity is lost because of the influence of the land manager that does not understand these processes. (We will discuss bare soil and rocks next time.)
First photo is of an old moribund plant circled in blue. Note the ‘very’ few young seedlings that are of the ‘white’ variety and are most likely annuals. These young plants will probably not survive on this poor ecological site. With proper grazing management and patience this site can be changed to a productive one.
The second photo shows the same plant circled in red that has been raked by fingers. (No pulling just raked with open fingers.) The blue circle is dead plant material piled next to the ‘now much happier’ formerly dying plant. If one were to return to this spot this spring -with adequate rainfall- this plant would show active new growth, which would still be limited at best as it is a three-awn. (Could be wrong with ID.)