Eradicating the Tamarisk Tree

Nature is composed of a delicate balance between plants and animals, so when something happens to disturb that balance, the ecosystem will suffer. Invasive or exotic species such as the tamarisk tree, or salt cedar, can completely change an area for the worse. The tamarisk, Tamarix ramosissima, is a small tree or shrub that inhabits riparian or river, stream or creek habitat. It can dominate an area with very densely packed vegetation. Unfortunately, since it is not native, it is extremely detrimental to the environment.

It is a native of the Mediterranean area, China, Mongolia and Europe, and was brought in as an ornamental tree, landscaping or erosion control. Because it is a water loving plant with long tap roots, it can inhabit a wide variety of areas, preferring those areas around creeks, lakes and desert washes. It's a hardy plant that can withstand alkaline or saline soil, which allows it to take over entire areas. Because of its ability to extend its root systems deep into the water table, it tends to cause a lowering of that water table, leaving no water for the other, native plants.

As an invasive species, it does not provide the necessary food that local insects require. That means that the insects that birds need for survival aren't available, so the bird species have to seek other areas. With the birds gone, animals that rely on the birds for food must also move away or die. The lack of insects also affects fish and amphibians. The tamarisk also changes the shape and flow characteristics of creeks and streams, which also affect fish and other species.

Once a wetland or riparian area is infested with tamarisk, it's very hard to get rid of it. Tamarisk grows very well from cuttings, so simply cutting back the plant is not effective. The cut branches on the ground can take root very effectively. Tamarisk prefers to move into an area that has been graded or cleared, as in development or over grazing, where it has no competition from native species. There is also a fire hazard created from the dropped leaves of tamarisk. But, even if there is a fire, the plants will still come back later on.

There are several somewhat effective methods for eradicating tamarisk, such as pulling small saplings by hand. Of course, if any of the roots are left behind, they will likely sprout again. Then there are chemical methods. Spraying herbicides is generally quite effective, but only certain herbicides approved for use around water can be used. There can be a combination of methods used, which tends to be more effective. Burning an area infested with tamarisk and then spraying chemical when small sprouts emerge is a good method to try. Since it might take several years for tamarisk to resprout, monitoring is necessary, but with lots of care and diligence, the eradication can be permanent. Revegetating with native plants is essential to prevent reinfestation.