Cryptogamic soil or cryptobiotic crust is very fragile and is vital to some prairie plants and soil biota. Cryptogams form a spongy layer that helps protect soil from erosion, absorbs moisture, and provides nitrogen and other nutrients for plant growth. During drought and frost, the cryptogamic crust uplifts and cracks. Cracks in the layer can provide germination sites for seeds from grasses and forbs. Reference: Fact sheet developed and funded by an Eisenhower Grant to the Partnership for Arid Lands Stewardship. Written by: Christine Sandahl.
Below are photos of cryptogamic soil at Spring Creek on exposed caliche or limestone.. This cryptogamic crust is the dark bumpy soil prevalent in drier areas of Spring Creek outside the forest and covers the surface of soil between grasses, shrubs, and flowering plants. This fragile crust is made up of mosses, lichens, algae, and bacteria and a microcosm of other inhabitants such as mites, springtails, nematodes, and other biota.
Jelly Fungus Moss with sporophytes Collema sp.? cryptogam
Also present are
jelly fungi (ear fungus) including
Auricularia species - Ear Fungus which has
gelatinous fruitbodies contorted into strange shapes
like ears or raisins. In dry periods, it is a crusty blackish growth on
exposed caliche soils and is easily missed by the casual observer. During rains,
however, Tree-Ear absorbs water, and expands to look like a human ear.
Above right: Cryptogams after a rain (click on to enlarge)
Above : Cryptogams during dry weather.
Succession on shallow soils and exposed rocks:
These soils were most likely maintained by periodic wildfires. The shallow soil depth limits growth to cryptogams and a few species of forbs and grasses. Once organic matter is built up, the cryptogamic stage typically succeeds to moss-covered soil with Woolly Ironweed, Barbara's Buttons, Queen's Delight, Thelesperma, Yucca, Ratany, Winecup, Redroot or New Jersey Tea, Whitlow-Wort, Missouri Primrose, and other prairie species(see lower right photo). According to Shinners & Mahler's, "species seen in this type of setting in the northern Blackland Prairie (Grayson County) include Baptisia australis (wild blue-indigo), Callirhoe pedata (finger poppy-mallow), Eriogonum longifolium (long-leaf wild buckwheat), Grindelia lanceolata (gulf gumweed), Ipomopsis rubra (standing-cypress), Linum pratense (meadow flax), Marshallia caespitosa (Barbara's-buttons), Oenothera macrocarpa (Missouri primrose), Paronychia jamesii (James' nailwort), and Thelesperma filifolium (greenthread). At some seasons, these outcrops have the aspect of barren eroded rock; in the spring, however, they are covered with spectacular displays of color."
Shinners & Mahler's Illustrated Flora of North Central Texas, 1999, George Diggs, Jr., Barney L. Lipscomb, and Robert J. O'Kennon, Austin College & Botanical Research Institute of Texas (BRIT).
Effects of fire on lichens as well as other community species is described in the Forest Service Fire Effects Information database. The FEIS database contains synoptic descriptions, taken from current English-language literature of almost 900 plant species, about 100 animal species, and 16 Kuchler plant communities found on the North American continent. The emphasis of each synopsis is fire and how it affects each species
More infomation on soil crusts can be found at the Biological Soil Crust page by the Bureau of Land Managment, U.S. Geological Survey, and National Park Service.
Effects of cattle grazing on cryptogamic soils can be found at: http://www.rangenet.org/directory/hudakm/overview.html
National Soil Survey Center - Soils & Science Web Sites
Tardigrades or "Water Bears"
False Earth Star
Although not cryptogams, false earth stars are sometimes found in nearby areas of shallow soil during fall. Other interesting inhabitants include a camouflaged grasshopper which blends in with the Austin chalk...it is probably the Three Banded Grasshopper, Hadrotettix trifasciatus.
Special thanks to Barbara Keeler, US Environmental Protection Agency, for her discovery of cryptogamic soils at Spring Creek.
This web site was created by Derek Hill