Horizontal distribution of moisture and Tardigrada in a single moss cushion
| Authors | |
|---|---|
| Year of publication | 2011 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Zoological Systematics and Evolutionary Research |
| MU Faculty or unit | |
| Citation | |
| Web | http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0469.2010.00602.x/abstract |
| Doi | http://dx.doi.org/10.1111/j.1439-0469.2010.00602.x |
| Field | Applied statistics, operation research |
| Keywords | Horizontal distribution; moisture; Tardigrada; moss cushion; ecology |
| Description | We carried out a study of the moisture distribution and the horizontal distribution of Tardigrada in a single moss cushion. During one field trip, we collected 25 equal samples from a growth of the moss Hypnum cupressiforme Hedwig. Using two-way anovas without replications and linear regression analyses, we determined that there was no significant gradient of absolute or relative moisture along the moss slope. We isolated 224 specimens of seven Tardigrada species from the 25 samples. Using both chi-square tests of independence and chi-square goodness-of-fit tests as well as by calculations of the coefficients of dispersion, we found that the horizontal distribution of tardigrade specimens in general, as well as the distribution of each species, was aggregated. By contrast, species number was random in the observed moss samples. Based on the comparison of all polynomial regression models with the null model and between each other, the distribution of Tardigrada specimens as a whole as well as the distribution of M. hufelandi was related neither to absolute nor relative amount of water in the moss cushion. Based on these results, we formulated a hypothesis explaining tardigrade heterogeneity in randomly sampled mosses, which stayed unexplained up to now. We hypothesize that aggregated Tardigrada distribution in each moss cushion is the most likely reason for the large variability in tardigrade abundance in random samples taken from different moss cushions. Hence, we believe that introduced hypothesis and the resulting consequences have a considerable significance in the ecological studies based on random sampling. |
| Related projects: |