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Wildlife, Animals, and Plants
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VALUE AND USE
SPECIES: Carnegiea gigantea | Saguaro
WOOD PRODUCTS VALUE :
NO-ENTRY
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
The flowers, fruits, and seeds of the saguaro are important food sources
for wildlife, such as collared peccary, long-nosed bats, heteromyid
rodents, western white-winged doves, woodpeckers, and insects
[2,19,39,50,56].
Saguaro fruits comprised a small amount (e.g., 1 to 5 percent of
collected rumen contents) of mule deer summer diets [38,60,63,79,80].
The fruits were also utilized by desert bighorn sheep; they were present
in 10 percent of bighorn fecal pellets analyzed [44,83].
Saguaro provides nesting habitat for birds and small mammals [49].
Saguaro mortality can have a high negative impact on bird species that
use it for cover and nesting [9].
PALATABILITY :
Saguaro is highly palatable to rodents and jackrabbits; however, saguaro
tissue contains oxalates that deter some herbivory [47,68].
NUTRITIONAL VALUE :
The nutritional value of saguaro fruits is variable throughout the
season and among studies. Saguaro fruits are moderately digestible
[80]. The amount of protein reported varied from 10 to 26 percent
[33,80]. Acid detergent fiber amounts in the fruits varied from 26 to
62 percent, and dry matter was 11 to 35 percent [33,80].
COVER VALUE :
Saguaro is considered a softwood snag [12]. Cavity-nesting birds,
especially woodpeckers, and sometimes woodrats nest in saguaro
[12,31,43,49,50].
VALUE FOR REHABILITATION OF DISTURBED SITES :
NO-ENTRY
OTHER USES AND VALUES :
Saguaro fruits were a major food staple of the Papago and Pima Indians;
the fruits were processed (i.e., dried, fermented, canned) and stored
for year-round use [18,21,32]. Seeds, rich in fat, were ground for use
as flour and in porridges [55]. Fruits were used for trade and in
religious practices by the Papago Indians [21,57].
The internal heavy, woody ribs were used for firewood and building
houses and fences [1,6,10].
Saguaro is grown in desert gardens as an ornamental [89]. It is the
state flower of Arizona and is used in commercial advertisements of
Southwestern living [40].
MANAGEMENT CONSIDERATIONS :
Intensive grazing can prevent recruitment of saguaro seedlings [47].
Various areas in the Sonoran Desert have been protected from domestic
livestock grazing for 50 years or more. One early study showed that
there was no significant (p>0.05) difference between saguaro abundance
on protected and unprotected plots [8]. More recent studies, however,
have shown that saguaro increased by 33 to 200 percent in protected
areas [27,77]. Saguaro seedlings may be impacted negatively when nurse
plants are browsed [47].
Models to predict saguaro age from growth parameters (for example,
height-age equivalents) have been developed [28,69].
In transplant experiments, mortality was 100 percent for unshaded
saguaro seedlings compared to 65 percent for shaded seedlings [22].
Saguaro are susceptible to few diseases [10]. Healthy saguaro often
wall off larvae tunnels, woodpecker holes, or other wounds [47]. Some
necroses may occur, however, after mechanical damage to saguaro from
breakage, frost, or lightning [71]. Insects, saprophytic yeasts, molds,
and bacteria readily inhabit and breed in saguaro necroses [24,66,72].
Temperatures below 23 degrees Fahrenheit (-5 deg C) will damage saguaro.
Death will occur after exposure to below freezing temperatures for 29 or
more consecutive hours [85]. Fluctuations in saguaro numbers often are
due to recurring catastrophic freezes [37,46,69].
Saguaro is protected under the Arizona Native Plant Law. Cactus
poaching is of concern around Saguaro National Monument and urban
centers [90]. Natural environmental extremes in temperature and
drought, however, are more of a threat to the survival of this species
[37].
Related categories for Species: Carnegiea gigantea
| Saguaro
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