RESEARCH ARTICLE Ice-cover is the principal driver of ecological change in High Arctic lakes and ponds Katherine Griffiths¤*, Neal Michelutti, Madeline Sugar, Marianne S. V. Douglas, John P. Smol Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, Ontario, Canada ¤ Current address: Department of Biology, McGill University, MontreÂal, QueÂbec, Canada *
[email protected] a1111111111 a1111111111 a1111111111 a1111111111 Abstract a1111111111 Recent climate change has been especially pronounced in the High Arctic, however, the responses of aquatic biota, such as diatoms, can be modified by site-specific environmental characteristics. To assess if climate-mediated ice cover changes affect the diatom response to climate, we used paleolimnological techniques to examine shifts in diatom assemblages OPEN ACCESS from ten High Arctic lakes and ponds from Ellesmere Island and nearby Pim Island (Nuna- Citation: Griffiths K, Michelutti N, Sugar M, vut, Canada). The sites were divided a priori into four groups (ªwarmº, ªcoolº, ªcoldº, and Douglas MSV, Smol JP (2017) Ice-cover is the ªoasisº) based on local elevation and microclimatic differences that result in differing lengths principal driver of ecological change in High Arctic lakes and ponds. PLoS ONE 12(3): e0172989. of the ice-free season, as well as about three decades of personal observations. We charac- doi:10.1371/journal.pone.0172989 terized the species changes as a shift from Condition 1 (i.e. a generally low diversity, pre- Editor: Liping Zhu, Institute of Tibetan Plateau dominantly epipelic and epilithic diatom assemblage) to Condition 2 (i.e. a typically more Research Chinese Academy of Sciences, CHINA diverse and ecologically complex assemblage with an increasing proportion of epiphytic Received: September 30, 2016 species).