202
E. IMRE FRIEDMANN AND MARGALITH GALUN
Went and Stark (1968) studied the microfungi of sandy soils in the
Southwestern United States in situ. They found that there is no bonding
whatsoever between soil particles in active sand dunes. But in other desert
soils, where mycorrhizae associated with higher plants or other fungal
hyphae are present: "It is possible to dig the sand away from underneath
the surface without its caving in. This is what many burrowing animals,
from ants to rats to foxes, do especially in dry sandy areas, and their burrows do not collapse." In an experiment in the Nevada Desert, 2-mm-thick
wooden pegs were inserted in the soil during late fall or winter. Provided
that there were one or two rains while the pegs were in place, it took 3-4
months for a mycelium layer 1 mm thick to form that would hold sand
particles to the peg. After 1 year, the pegs were so strongly anchored in
the soil that often a 1 cm
3
mass of soil was removed with the peg. After
2-3 years, the peg was usually sufficiently decomposed so that it could
not be pulled out, but broke off near the soil surface.
D. MACROMYCETES IN DESERTS
Long and Miller (1945) describe a "desert Coprinus" from the Southwestern United States. Davidson and Mielke (1947) report from the same
area a heart-rot fungus, Fomes robustus, which is parasitic on cacti
(saguaro and several chollas) and on other desert plants.
An interesting ecological adaptation is the presence of hypogaeic fungi
in desert soils, e.g., truffles (Tuber sp.) in Iraq (Khudairi, 1954) and
Terfezia leonis Tul. and Tirmania africana Chat, in the Negev Desert
(Rayss, 1959).
IV. Addendum
A. PROBLEMS OF ALGAL TAXONOMY
In the controversy on blue-green algal taxonomy, the recent work of
Stanier, Kunisawa, Mandel, and Cohen-Bazire (1971) presents a novel
approach. The taxonomic status of Palmogloea protuberans is discussed
by Fott and Novâkovâ (1971 ).
Ocampo (1973) studied unicellular blue-green algae which constitute
the flora of chasmolithic and endolithic rocks in North American and Middle Eastern deserts. Among 110 strains isolated in culture, 2 were identified as Chloroococcus turgidus (Kütz.)Näg. while 108 strains, showing
close affinities to the genus Gloeocapsa, were found to form a cluster of
morphological types connected by gradients of intermediary types. There
E. IMRE FRIEDMANN AND MARGALITH GALUN
Went and Stark (1968) studied the microfungi of sandy soils in the
Southwestern United States in situ. They found that there is no bonding
whatsoever between soil particles in active sand dunes. But in other desert
soils, where mycorrhizae associated with higher plants or other fungal
hyphae are present: "It is possible to dig the sand away from underneath
the surface without its caving in. This is what many burrowing animals,
from ants to rats to foxes, do especially in dry sandy areas, and their burrows do not collapse." In an experiment in the Nevada Desert, 2-mm-thick
wooden pegs were inserted in the soil during late fall or winter. Provided
that there were one or two rains while the pegs were in place, it took 3-4
months for a mycelium layer 1 mm thick to form that would hold sand
particles to the peg. After 1 year, the pegs were so strongly anchored in
the soil that often a 1 cm
3
mass of soil was removed with the peg. After
2-3 years, the peg was usually sufficiently decomposed so that it could
not be pulled out, but broke off near the soil surface.
D. MACROMYCETES IN DESERTS
Long and Miller (1945) describe a "desert Coprinus" from the Southwestern United States. Davidson and Mielke (1947) report from the same
area a heart-rot fungus, Fomes robustus, which is parasitic on cacti
(saguaro and several chollas) and on other desert plants.
An interesting ecological adaptation is the presence of hypogaeic fungi
in desert soils, e.g., truffles (Tuber sp.) in Iraq (Khudairi, 1954) and
Terfezia leonis Tul. and Tirmania africana Chat, in the Negev Desert
(Rayss, 1959).
IV. Addendum
A. PROBLEMS OF ALGAL TAXONOMY
In the controversy on blue-green algal taxonomy, the recent work of
Stanier, Kunisawa, Mandel, and Cohen-Bazire (1971) presents a novel
approach. The taxonomic status of Palmogloea protuberans is discussed
by Fott and Novâkovâ (1971 ).
Ocampo (1973) studied unicellular blue-green algae which constitute
the flora of chasmolithic and endolithic rocks in North American and Middle Eastern deserts. Among 110 strains isolated in culture, 2 were identified as Chloroococcus turgidus (Kütz.)Näg. while 108 strains, showing
close affinities to the genus Gloeocapsa, were found to form a cluster of
morphological types connected by gradients of intermediary types. There