Biogeography and Alaska Floristics

My research will help other researchers, policy makers, and the public to understand how Alaska's biodiversity has been shaped by historical factors and how our flora will respond to future changes in climate and human expansion. The arctic flora has long been viewed as relatively depauperate, given an observed decrease in diversity at high latitudes when species richness is considered on an hemispheric scale. Locally, however, botanists in Alaska and adjacent Chukotka have long noticed a high degree of morphological variation within well-established taxa. It is quite impossible to understand fully the origin of Alaska's flora without understanding its Asian antecedents. A major component of this flora arrived via the Bering Land Bridge when land connections were available repeatedly with continental glaciation during the Ice Ages. It is now 70 years since Eric Hulten focused our attention on the Bering Land Bridge and the importance of this area as the source for repopulating the Arctic with plants in post-glacial time. Hulten's hypothesis that unglaciated Beringia was a Quaternary refugium for plants has been corroborated by recent molecular studies. Species by species, higher genetic diversity is expected within those areas of a species' current distribution that were refugial. Beringia is therefore key to understanding post-glacial dynamics within and among species.

The legume Oxytropis ("loco weed"; Fabaceae) represents an excellent example of a taxon with a Beringian distribution. My research will use a combination of molecular markers to construct rigorous phylogeneitc hypothesis, and will reassess morphological character variation among lineages to answer evolutionary questions about the mechanism of diversification of the Beringian members of this genus (including past migrations and Pleistocene refugia). In addition we will use age estimation from molecular sequences as a powerful tool for inferring the timing of arrival of a plant lineage in a particular area. Knowing the tenure of lineages within a region is key to understanding the evolution of traits, biotic interactions, and floras, and may be predictive about how biota will respond to future changes in climate and human development.

Presentations

Ickert-Bond, S.M., DeChaine, E. and D. F. Murray. Dispersal of Asian Plants to North America via Beringia: Relict or Recent Mosaic? AK Park Science, NPS. Beringia Days 2008 International Conference. [pdf]

Meyers, Z., Ickert-Bond, S.M. and F. Huettmann. 2007. Predictive Modeling of Vicia cracca in Alaska: A First Model using Bagging and Boosting (TreeNet). Conference for Noxious and Invasive Plant Management, Cooperative of Extension Service, UAF, Fairbanks, Alaska. Nov. 2007

Fackler, K. and S.M. Ickert-Bond. 2007. Understanding the Artemisia globularia complex. Alaska Rare Plant Forum, USFWS Regional Office, Anchorage, AK. April 2007