Date Approved

12-2020

Graduate Degree Type

Thesis

Degree Name

Biology (M.S.)

Degree Program

Biology

First Advisor

Dr. Robert Hollister

Second Advisor

Dr. Priscilla Nyamai

Third Advisor

Dr. James Dunn

Academic Year

2020/2021

Abstract

The Arctic is experiencing rapid climate change. This research documents vegetation change near Atqasuk and Utqiaġvik, Alaska. At each location, 30 plots distributed in a matrix across the landscape, were sampled annually from 2010 to 2019 using a point frame. For every encounter we recorded the height and classified it into eight broad functional groups (deciduous shrubs, evergreen shrubs, forbs, graminoids, bryophytes, lichens, litter and standing dead vegetation); for vascular plants we also identified the species. We found a consistent increase in plant stature and cover over time which was dramatic at Atqasuk. Graminoid cover and height increased at both sites. At Atqasuk shrub and forb cover and height increased. Species diversity decreased at both sites. Year was generally the strongest predictor of vegetation change suggesting a cumulative change over time; however, soil moisture and soil temperature were also predictors of vegetation change in many cases. We anticipate plants in the region will continue to grow taller as the region warms resulting in further increases in plant cover, especially graminoids. The accumulation of litter will likely result in a decline of bryophytes and lichens. These changes in community structure will impact energy balance and carbon cycling and habitat quality for wildlife and therefore have regional and global consequences.

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