Effects of altered temperature and precipitation on desert protozoa associated with biological soil crusts

TitleEffects of altered temperature and precipitation on desert protozoa associated with biological soil crusts
Publication TypeJournal Article
Year of Publication2006
AuthorsDarby BJ, Housman DC, Zaki AM, Shamout Y, Adl SM, Belnap J, Neher DA
JournalJournal of Eukaryotic Microbiology
Date Published2006
ISBN NumberDOI: 10.1111/j.1550-7408.2006.00134.x
Call Number00892
Keywordsarticle, Chihuahuan Desert, climate change, Colorado Plateau, cryptobiotic crust, environmental stress, journal, soil change, soil function, soil crust, biological, soil fauna, soil food webs, soil protozoa, soil, ecosystem function, soil, food web, soil, methods, thermotolerance
AbstractBiological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when associated with cyanobacteria/lichen crusts than with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert (cool desert, primarily winter precipitation) declined 50-, 10-, and 100-fold, respectively, when moved in field mesocosms to the Chihuahuan Desert (hot desert, primarily summer rain). However, this was not observed in protozoa collected from the Chihuahuan Desert and moved to the Sonoran desert (hot desert, also summer rain, but warmer than Chihuahuan Desert). Protozoa in culture began to encyst at 37 1C. Cysts survived the upper end of daily temperatures (37–55 1C), and could be stimulated to excyst if temperatures were reduced to 15 1C or lower. Results from this study suggest that cool desert protozoa are influenced negatively by increased summer precipitation during excessive summer temperatures, and that desert protozoa may be adapted to a specific desert’s temperature and precipitation regime.
Reprint EditionIn File (11/21/2006)