Graminoids Benefit from Decreased Competition in a Tundra Plant Environment

Abstract

Global warming is currently changing both the diversity and structure of the Arctic vegetation. Warmer air temperatures are thawing permafrost making more nutrients available for plant uptake, while at the same time climate conditions become too challenging for some species. Shifts in dominating species on both local and regional scales have been observed, which is believed to change the climate further. More specifically an expansion of shrubs has been observed at several locations in the Arctic. Still, little is known about how these changes in both biotic and abiotic factors affect Species-species interaction. To investigate possible outcomes, plant species were removed from designated areas in an Arctic tundra landscape in northern Sweden. Plants were removed based on their mycorrhizal associations, either arbuscular, ericoid, ecto, or non-mycorrhizal, or depending on their dominance, for four consecutive years. Changes in plant abundance in all treatment areas were reported both prior to and post the experiment to see what plants seem to have made use of the opened niches. Based on their plant functional types, graminoids increased from the treatment whilst there was a decrease in both shrubs and forbs. Generally, species that benefitted the most from the treatment were those with either arbuscular or no mycorrhizal associations. The changes are found to be due to the characters of the plant functional type rather than their mycorrhizal associations.