Invasive of the Day: Tamarix ramossisima

Despite its lack of thorns, the Tamarix ramossisima presents some very prickly problems. Also known as the salt cedar, the tamarisk is a woody shrub native to Central Asia and Eastern Europe.

It was imported into America in the mid 18th-Century and has become a poster child as it were for habitat and ecosystem destruction in the southwestern United States. It has cost the government millions of dollars in eradication fees and is further damaging compromised river systems throughout the area. It also, however, supplies habitat to the endangered willow fly-catcher in Utah. The tamarisk creates many problems for ecosystem health as it secretes saline into soils to prevent native plants from growing, and chokes out river channels so that native fish cannot spawn.

The presence of tamarisk in river channels has been brought about because of human activity such as damming, which has compromised flood waters so that tamarisk seeds are not drowned; and increased saline and pollutants to levels which native vegetation cannot withstand, but the tamarisk can.

Eradication of these shrubs has been incredibly costly, and the root causes of its presence have not been addressed. There are both benefits and drawbacks that can be seen under these programs, and thus the question arises should these efforts should continue? How could we better manage trying to eliminate harmful invasive plants?

Most of the eradication efforts have been focused on areas which impact human water supply or developments in flood plains. The tamarisk is also creating new fuel load levels in desert areas within the United States. This means that fires will become more frequent and of longer duration in an area which is not biologically adapted to frequent burns. Because these areas are isolated and far from human settlements, these areas have received little attention. The desert environment is incredibly delicate, and change is difficult to recover from. Restoration efforts in these areas have not previously been attempted and bring up an incredibly difficult question to answer: Would eradication efforts in these areas would be harmful? How can we best deal with this problem?

The tamarisk presents difficulties of both management and ecosystem adaptability. Because of this, its situation is a classic demonstration of the conundrum of ignorance and action in relation to our environment. How can we formulate a resolution to the problem of tamarisk invasion when the biosphere is in constant flux and evolution?
Should we intervene in areas where there is no human development because we are the fundamental cause of changes that have taken place? Or does nature know best?

I for one don't know how to answer all of these questions which the tamarisk presents, but I believe that an important first step is the acknowledgment of our ignorance, and the recognition that we need to offer a systems wide solution with input from a wide range of scientific knowledge. There is currently too little cooperation between disciplines and a variety of piece meal approaches to the problem.

Thanks to the Tamarix ramossisima for appearing in this post...
Tune in next week for a brand new invasive and a whole new slew of issues to work with.