In my masters thesis, I will examine the recovery of previously grazed tundra in ambient-temperature plots and in plots that have undergone long-term summer warming as part of the International Tundra Experiment (ITEX). Because a suite of biotic and abiot ic factors determine how plant communities respond to grazing (Speed et al., 2010), I will compare the response to herbivore exclusion in both a high-arctic site on Svalbard and a low-arctic site in Kilpisjarvi, Finland, to see whether one ecosystem is mo re vulnerable than the other.