Date of Award

Spring 2010

Document Type

Restricted Thesis

Terms of Use

© 2010 Bethanne Albert-Bruninga. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Biology Department


The current literature on the effect of warming on the timing of plant senescence is inconclusive, with some studies suggesting advanced senescence and other suggesting delayed senescence. This study investigates the possible effect of elevated soil temperature over two field seasons on the timing of senescence in goldenrod (genus Solidago) and consequences of this effect on other plant processes such as nutrient resorption. The timing of leaf senescence was determined by measuring leaf color throughout the season. Percent nitrogen was measured per leaf (2008) and per plot (2009) to determine whether there was an effect of warming on plant nitrogen cycling. Leaf color data from both 2008 and 2009 showed no significant difference between warmed and control plots. Percent nitrogen was significantly higher in warmed plots in 2008 but not significant by treatment in 2009. The inconclusive percent nitrogen results suggest that further research should investigate this question and include an analysis of the soil nitrogen pool.