The Alien Saltcedar

• Description: The Alien Saltcedar American Forests January/February 1995
• State: CO
• Date: 1/1/1995
• Author: Friederici, Peter
• Title: The Alien Saltcedar
• Water Supply Pro - Doc Type: Publication

Tough
By PETER FRIED.ERICI
rolific, and exclusionary, the
marisk i's "plants non grata" in the
Southwest, but -it's a a�ently hereto stay.
is probably just as well that the name of the
first person to plant a saltcedar in the
Southwest is lost to history. He, or she, was
no doubt praised some 200 years ago for the
inspiration that brought a source of-shade and
wood to the sun -baked desert. But today's
reaction would be quite-different.
In two centuries the alien saltcedar has established itself along
numerous rivers and reservoirs, where biologists and land managers
regard it as a noxious plant pest. It stands accused of degrading
wildlife habitat, ruining the recreational amenities of riparian areas,
wasting scarce water, and even increasing the severity of floods. Its
impact has been especially great on riparian woodlands, which sup-
port the greatest quantity and diversity of life —both animal and
human —in the desert landscape, and which are among the most
imperiled ecosystems in North America.
Saltcedar's negative effects are a direct reflection of exactly
those qualities early settlers in the Southwest found so positive. Its
roots stabilize streambanks against the flooding typical of desert
washes and rivers. Its foliage provides precious shade for poultry
and; livestock. It can be cut for firewood. Its abundant sprays of
white or pink flowers provide some ornamentation in an area
where the vegetation often seemed alien, if not outright hostile, to
new immigrants.
And it is remarkably hardy. "It'll grow anywhere it can get its
feet in water," says Mary Irish, director of horticulture at the Desert
Botanical Garden in Phoenix. "It's extremely tolerant of any soil,
including salty soil, and it doesn't mind the heat at
all..
The tamarisk family is native to southern
Eurasia, and over time, several species were intro-
duced here. One —the evergreen athel tamarisk or
Tamarix aphylla —grows at least 50 feet high and is
a valued shade tree. Beekeeper say its flowers pro-
duce excellent honey. The other species, which
are deciduous, are referred to as Tamarix chinensis,
T. ramo4onta, and T. pawiflora. Because they appear to hybridize,
and are virtually impossible to tell apart, some botanists consider
them all to be members ofthe same species.
This is the shrub or tree called saltcedar, a name whose latter
half refers to tiny, scaly leaves that resemble cedar scales. And it is
saltcedar because the plant exudes-salt from glands on its leaves.
Grab a branch, and you end up with a residue thick enough to
taste. When the leaves drop in the autumn, they pass that salt to the
soil, which may eventually become too saline to support most
native plant species.
Given ample water and space, a saltcedar can become a nredi-
umeized tree ---the largest known in the U.S. is a 44- footer in New
Mexico. In the wild, though, it more commonly forms dense thick-
ets of many- branched shrubs, all growing to a height of 15 or 20
feet. The foliage is so dense that almost nothing can grow under it.
Saltcedar is not really adapted to aridity. It grows only where
water runs near the surface, and it is spendthrift —a large specimen
uses perhaps 200 gallons a day. It has been estimated that all the
saltcedar in the Southwest uses, per year, twice as much water as all
the cities of southern California.
Dense stands of saltcedar trap sediment during floods, narrow-
ing water channels and perhaps increasing the severity of subse-
quent floods. Along the Colorado River, saltcedar thickets have
overgrown many beaches long favored for camping and recreation.
Wildlife is far less abundant in saltcedar thickets than in sup-
planted native woodlands, largely because native plants act as host to
many more insect species. A study along the lower Colorado River
showed that during the winter an undisturbed native woodland of
cottonwood and willow supported an average of
154 birds per loo acres. Only four birds lived in an
equivalent area of saltcedar. Fear birds nest in
saltcedar, perhaps because the feathery leaves do
not provide the same protection from intense
summer heat as do the broad leaves of cotton-
woods and willows.
It is extremely difficult to destroy an estab-
lished thicket. "After any environmental calamity
PETER FRiEDMCi- - - - - - - -
a freelance writer specializing
in nature and conservation
topics, writes a quarterly
nature - education leaflet for
the Roger Tory Peterson
Institute of Natural History.
AMERICAN FORESTS JANUARY /FEBRUARY 1995 -• - - 45