Common foliage, why is it often dead?
Tamarisk, or tamarix (salt-cedar) was introduced into Utah to slow down erosion of waterways. It has green, skinny stems and pink, fragile-looking flowers. In the winter, the branches are bright red and contrast the other inactive plants. Now it is believed to consume too much water. A beetle was found which would eat (only) the desired tamarisk. This year's spring runoff had rivers flowing over their banks and saturating the surrounding areas. All but the most hardy cottonwood trees simply die with too much standing water. The combination of beetles and too much water has caused tamarisk to die and turn black. The hikers have never appreciated stands of tamarisk because they are dense, abrasive, and difficult to cross through.
Weeding the forest:
You have surely seen plants being cut down in far outlying areas. Two candidates for attention are tamarisk and Russian olive trees. Non-native plants gain attention of volunteers to return the foliage to a natural state. Another invasive plant is a tall, common reed with a pretty looking grassy top called phragmites. (frag-MY-tees) It may also be on someone's list.