ARCUS | Arctic Research Consortium of the United States

6th Annual ARCUS Award for Arctic Research Excellence


Submitted by   Daniel Liptzin
Authors   Daniel Liptzin
Category   Life Science
Title   A Banded Vegetation Pattern in a High Arctic Community on Axel Heiberg Island, Nunavut, Canada
Affiliation   Environmental Population and Organismic Biology, University of Colorado, Boulder, CO, USA

Abstract

Although the plant diversity in the High Arctic is low, little is known about the distribution and ecological characteristics of these species or the factors that determine the structure and function of plant communities. Although banded vegetation patterns have been described in many places before, none have been in the High Arctic. In general the banding has developed in response to a unidirectional abiotic factor: either downslope flow of water or wind from a constant direction. On Axel Heiberg Island, Nunavut, Canada, a banded vegetation pattern occurred on a hillside where neither mechanism was present. However, the soil at the site has developed from five distinct types of flat-lying alluvial deposits that occur multiple times along the hillslope. The plants were counted and identified and soil variables (moisture, carbon, nitrogen, aggregates, and base cations) were measured along three transects. Twelve vascular species of plants, but no non-vascular species, were present at the site. The sand and clay soil had the highest density of plants and the blocky clay soil had the lowest density. However, the sand soil never had higher quantities of any of the measured resources than blocky clay. Neither water, which is thought to limit plant distribution in the High Arctic, nor any of the other soil variables, were correlated with plant abundance. It was not clear why the blocky clay soil could not support high plant densities. The seedling density was higher outside of the vegetation bands, so the pattern was not due to better germination conditions within the bands. Although the bands of vegetation at this site were obvious, and were likely due to some soil factor or combination of factors, the mechanism causing the pattern is still not understood.