Friday, February 19, 2010

Liptzin 2006

Liptzin D. 2006. A banded vegetation pattern in a High Arctic community on Axel Heiberg Island, Nunavut, Canada. Arctic, Antarctic, and Alpine Research 38: 216-223.

This author attempted to explain the observation of banded vegetation on a slope that lacked the usual factors that generate such patterns. In temperate and tropical locations, banded vegetation, also known as “tiger stripes”, forms on shallow slopes in dry areas with a consistent direction of water flow. Plants at a position on the slope increase water retention and facilitate further colonization by plants. Similarly, some locations experience consistent wind direction carrying sea spray that kills trees at some positions. In cold environments, patterned ground from cryoturbation on shallow slopes can also lead to banded vegetation. However, the study site in this paper lacks all of these features, including cryoturbation despite the presence of permafrost within 50cm at most locations.

Some aspect of soil properties is the obvious explanatory hypothesis, which this author explores after describing the transects measuring plant diversity and the soil pits used to examine soil properties. In general, features that would normally be expected to influence plant diversity and abundance such as soil moisture or exchangeable cation levels, had no significant impact in the various statistical tests employed in this study. However, soil type did have some effect, as a few species of plants were found only on sandy soil, and nitrogen levels were negatively correlated with species richness.

The discussion section of this paper is an excellent example of a chain of logical reasoning working through a series of potential explanations. While this paper is interesting, it’s only relevant to my own studies in a narrow area around potential starting points in looking for explanations for whatever patterns I may find in my biogeography studies in 2010. However, this paper seems remarkably suitable as an introduction to the basics of modern soil science research, and may be relevant to my not-quite-mothballed interest in an undergraduate course about the current state of the scientific literature.

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