Kt. Harper et Rl. Pendleton, CYANOBACTERIA AND CYANOLICHENS - CAN THEY ENHANCE AVAILABILITY OF ESSENTIAL MINERALS FOR HIGHER-PLANTS, The Great Basin naturalist, 53(1), 1993, pp. 59-72
In both field and greenhouse studies, cyanobacteria and cyanolichens o
f cold-temperate deserts often enhance growth and essential element up
take by associated herbs. That effect is associated with better seedli
ng establishment and larger seedlings. The following are possible mech
anisms for these effects: (1) the microbiota concentrate essential ele
ments in available forms in soil surface layers, (2) the microbial sur
face covers are usually darker colored than the soil itself and produc
e warmer soils during cool seasons when soil water is most available,
(3) the gelatinous sheaths of several cyanobacterial genera common on
alkaline deserts contain chelating compounds, and (4) conditions that
favor persistent microbial growths on soil surfaces also favor mainten
ance of larger populations of microorganisms that form mycorrhizal and
/or rhizosheath associations with seed plants. There is evidence that
associated animals may be nutritionally benefited by the enhanced mine
ral content of forage plants growing in well-developed cyanobacterial
crusts.