Kimmerer R W and T F H Allen 1982 The role of disturbance in

Kimmerer, R. W. and T. F. H. Allen. 1982. The role of disturbance in the pattern of a riparian bryophyte community. American Midland Naturalist 107:370-383.

https://www.jstor.org/stable/2425387?seq=1#page_scan_tab_contents

Questions

1. What hypothesis are the authors testing in this paper?

2. Describe the sampling design. What was the sample unit and what was its size. How were samples chosen and how many replicates were there?

3. Describe the spatial patterns that the authors observed in terms of elevation and patchiness.

4. The authors use graphical representations of their field data to assert that the distributions of Conocephalum and Fissidens are controlled by flood frequency. Explain the relationships between flood frequency, elevation, and species distributions as shown in Figures 1 and 3.

5. The authors contend that the patchiness of bare substrate and bryophyte diversity is related to flood magnitude. Explain the relationships between disturbance magnitude, mean patchiness, and species diversity as shown in Figures 4 and 6.

6. The authors contend that the spatial patterns that they observed are associated with flood disturbance. List two other potential influences on these patterns that the authors evaluated.

Solution

1.The hypothesis the authors are testing here is that whether the disturbance by flooding is the major cause of the spatial patternin the riparian brypophyte community.

2.The sampling design involves the usage of the the additive partitioning procedure in which the total species richness which is also called as the gamma diversity is usually partitioned into the various alpha and beta components which happend according to a spatially nested sampling design .Moreover the diversity components that are present among the various different spatial scales are usually expressed in the same unitsand this allows them to be directly compared.

3.The spatial design involves the large elevation zones on which the patchy distribution of species and opn substrate are superimposed.This resulted in a gradient of species composition to be found corresponding to the coincident gradients of elevation and frequency.Small scale patches are found here.