Season 5, episode 13.
From the Northern reaches of the Llano Estacado in Eastern New Mexico to the Big Bend Borderlands of Texas, this is Nature Notes.
Salt Cedar is hated in West Texas. Tamarix, as it’s known botanically, is a native of dry areas of Eurasia and Africa How did it get to the Americas and why is it so despised?
From Marfa Public Radio, in cooperation with the Sibley Nature Center in Midland, Texas, this is Nature Notes. Hello, I’m Dallas Baxter.
Salt cedar is not a “cedar” – that is, it’s not a juniper, often called “cedar” in Texas. Its tiny scale-like leaves cling to twigs similarly to the needles of conifers, but the plant is deciduous, not evergreen. It was first brought to America in the 1800’s as an ornamental, and the Department of Agriculture used it from 1890 to 1915 in erosion control along rivers and as windbreaks. The feathery foliage and pale pink blossoms are, indeed, pretty. But beware!
Salt Cedars begin producing seeds in their first year, and plants only a few years old may produce 600,000 seeds a year. Growing along waterways, the seeds fall into the water and may travel many miles until they are stranded where the water has evaporated. Then they sprout. After one lake in Midland County was flooded one winter and after the water had dried, a walk along the bank found the seedlings so thick that it looked like a newly planted lawn.
Invasive? Yes! But worse - glands excreting salt are located on the leaves. The leaves fall to the ground causing an accumulation of salt on the soil surface, which inhibits the germination and growth of native plants. As the seedlings grow, they thin themselves somewhat, but Salt Cedar creates nearly impenetrable stands in a few decades.
The enemy, thought so useful in stabilizing the river banks, began, once established on southwestern rivers, to spread at the rate of 15 miles a year, traveling up the Pecos, the Rio Grande and other area rivers. Records were kept at Lake Macmillan on the Pecos River near Carlsbad. In 1912, there were a few seedlings. In 1915 the plants covered 600 acres, and in 1925, 12,300 acres. By 1965, the largest area of Salt Cedar in the United States was growing in the Pecos River basin: 57,000 acres in New Mexico and 218,000 acres in Texas. By 1990 more than 500,000 acres of salt cedar existed.
Having made a river bank inhospitable to most every other plant, the tamarisk tries to redeem itself somewhat by providing shade and cover in areas where little else will survive, thanks to its introduction of salt into the soil. While no bird eats any part of the plant, Mourning Doves find Salt Cedar groves a great place to nest, and by 1961, Salt Cedar had become so widespread in the Pecos Basin that the area was the most heavily utilized Mourning Dove nesting area in the State.
White-winged Doves originally lived in the chaparral along the lower Rio Grande Valley. When the chaparral was cleared, they moved into the citrus groves, but then several hard winters killed the citrus. The White-wings began nesting in the Salt Cedar and eventually moved up the Rio Grande to Albuquerque and beyond, and up the Pecos as far as Roswell.
Hordes of butterflies nectar on Salt Cedar blossoms, but no butterfly uses it as a larval food plant.
The inability of native plant species to coexist with Salt Cedar had led to, nearly always, fruitless attempts to eradicate it. Millions have been spent to kill salt cedar -- by herbicide spraying, controlled fires, bulldozing and flooding, all to no avail.
In recent years the attention of botanists has been captured by the northern tamarisk beetle Diorhabda carinulata. This beetle eats nothing but Tamarisk, and it has been released by the National Park Service along the Rio Grande and in the Llano Estacado in Midland County and in Big Spring. The beetles seem to be working - they continue to spread along Beal's Creek in Big Spring, and through Salt Cedar thickets along the Rio Grande.
So far, so good. Let’s keep our fingers crossed.
Nature Notes is sponsored by the Dixon Water Foundation and is produced by KRTS Marfa Public Radio in cooperation with the Sibley Nature Center in Midland, Texas. This episode was written by Burr Williams. Visit sibleynaturecenter.org and join Williams' Facebook page where photos are posted daily. I’m Dallas Baxter. Thanks for listening.