SCI207: Dependence of Man on the Environment (ADN1245B)
17 Nov 2012
The Russian Thistle
The “Russian Thistle” or tumbleweed has been an icon for the west for many, many years. Just think about those old western movies we see with the wind blowin the lone tumbleweed across a deserted street. I have always wondered what they were and how they came to be. According to ehow.com, A tumbleweed or salsola tragus, was introduced to the western United States in the late 1800’s. Russian thistle is bushy, and as it grows it becomes spiny and obtains an oval to round shape that can reach several feet in diameter. The stem becomes brittle and breaks off at soil level, making the thistle able to travel for miles in the wind. This invasive can have several negative effects on environments where it has been introduced.
The tumbleweed is used by many insects as a home, and gives them a safe place to stay during the times herbicides and chemicals were being used to kill the pests. It also acts as a food source for these insects and helps them grow. The weeds also get in the way of the farm tillers and interrupt the process and deplete soil moisture. It also causes problems with grazing animals. Although they can be eaten easily when plants are young, as they get older the produce sharp nasty thimbles that can deter animals from grazing. The tumbleweed also has really deep and strong roots that can outgrow and push out other plants in the area. A single large plant can produce more than 200,000 seeds and can capably outcompete native plants and crops in loosened soils and desert environments.
A safety issue is also a problem with this plant. I remember driving home from Albuquerque New Mexico to Clovis New Mexico, and a tumbleweed that was at least four and a half feet was coming directly at me. I wanted to swerve but didn’t, because I was in a rental, and it scraped and churned its way under my vehicle and out the...