An Investigation of the Cryptobiotic Community from Sandstone Cliffs in Southeast Ohio
Because of harsh environmental conditions, cliff walls tend to have depauparate vascular plant floras. However, the resistance to desiccation and low light requirements of algae and cyanobacteria make them integral components of cliff walls. In addition, protozoa may be present within moist microhab...
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Veröffentlicht in: | International journal of plant sciences 2002-09, Vol.163 (5), p.837-845 |
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Zusammenfassung: | Because of harsh environmental conditions, cliff walls tend to have depauparate vascular plant floras. However, the resistance to desiccation and low light requirements of algae and cyanobacteria make them integral components of cliff walls. In addition, protozoa may be present within moist microhabitats. To document part of the cryptobiotic flora of these habitats, nine cliffs were sampled in the Hocking Hills, Ohio, vicinity over a 3‐mo period in the spring of 1999. A total of 140 infrageneric algal and 25 nonphotosynthetic protozoan taxa were recorded. The algal flora was dominated by bacillariophytes (80 taxa), with cyanobacteria (43), chlorophytes (12), euglenophytes (4), and xanthophytes (1) comprising the remainder of observed taxa. The majority of cyanobacterial taxa were chroococcalian forms that were collected at all nine sites. In addition, 15 nonnitrogen‐fixing filamentous forms were observed but tended to be less abundant. Protozoan taxa were comprised of ciliates (18 taxa), heliozoans (4), and rhizopods (3). All major groups of taxa exhibited the greatest abundance and diversity during March and decreased throughout April and May. Environmental parameters (light, temperature, humidity, moisture, and aspect) were measured and combined with species data for cluster (unweighted pair group mean average clustering) and canonical correspondence analysis (CCA). Cluster analysis showed little geographical grouping of sites, but the sites appeared to be clustered based on moisture level. The CCA showed four significant (
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) axes, primarily related to aspect, which accounted for 22.47% of the total variance. This axis was negatively correlated with light and moisture. Mesic cliffs tended to have a greater diversity of taxa than xeric ones, and open sites more than shaded sites. |
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ISSN: | 1058-5893 1537-5315 |
DOI: | 10.1086/341514 |