| temporal variation in community composition, pigmentation, and f(v)/f(m) of desert cyanobacterial soil crusts. | summers on the colorado plateau (usa) are typified by harsh conditions such as high temperatures, brief soil hydration periods, and high uv and visible radiation. we investigated whether community composition, physiological status, and pigmentation might vary in biological soil crusts as a result of such conditions. representative surface cores were sampled at the ene, wsw, and top microaspects of 20 individual soil crust pedicels at a single site in canyonlands national park, utah, in spring an ... | 2002 | 11984625 |
| response of desert biological soil crusts to alterations in precipitation frequency. | biological soil crusts, a community of cyanobacteria, lichens, and mosses that live on the soil surface, occur in deserts throughout the world. they are a critical component of desert ecosystems, as they are important contributors to soil fertility and stability. future climate scenarios predict alteration of the timing and amount of precipitation in desert environments. because biological soil crust organisms are only metabolically active when wet, and as soil surfaces dry quickly in deserts du ... | 2004 | 14689292 |
| diazotrophic community structure and function in two successional stages of biological soil crusts from the colorado plateau and chihuahuan desert. | the objective of this study was to characterize the community structure and activity of n2-fixing microorganisms in mature and poorly developed biological soil crusts from both the colorado plateau and chihuahuan desert. nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the colorado plateau site and chihuahuan desert site, respectively. analysis of nifh sequences by clone sequencing and the terminal restriction fragment length poly ... | 2004 | 14766579 |