Characteristics that Predict Success for Warmed Tundra Vegetation
Location
Steelcase Lecture Hall
Description
INTRODUCTION: The Arctic is more profoundly affected by climate change than lower latitude regions. Warming has been more pronounced in the Arctic and this trend is expected to continue; vegetation in high latitude regions is also expected to respond to climate change more than vegetation in other parts of the world. In this study we examine the response to experimental warming of plant species at four sites in northern Alaska. METHODS: Sites were established at the coastal city of Barrow, Alaska (71°17′44″N 156°45′59″W) in 1994 and at the inland village of Atqasuk (70°28’40”N 157°25′5″W) in 1996. Plant community data was collected using a point frame method in 2007 and 2008. Species were classified using a variety of grouping methods based on geography, morphology, and phenology of the plants. Groupings were determined using both observations collected in the field, such as the classification of species as those that with leaf bud burst before and those with leaf bud burst after the mean bud burst date, and observations reported in the literature. Groupings from the literature included geographic distribution schemes based on Hultén (1968) and Young (1971), and morphological criteria based on Sørensen (1941) and Raunkiær (1934). RESULTS: Young’s zones divided plants into low and high arctic species and were a good predictor of response to warming. Groups from Hultén’s maps included circumpolar distribution and distribution within Alaska, and were also good predictors of response. Sorensen described Arctic vascular plant species using a variety of morphological criteria, such as wintering state of leaves, a good predictor. Wintering state of buds, thawing types of species, floral wintering stage, and Raunkiær’s life forms were not good predictors of warming response. CONCLUSIONS: Preliminary findings show that the most useful classification schemes are those based on distribution of the species. In general, species classified as low Arctic plants tend to increase in absolute cover under conditions of warming, while species classified as high Arctic plants decrease. However, each of the grouping schemes provided insights into potential drivers of vegetation change.
Characteristics that Predict Success for Warmed Tundra Vegetation
Steelcase Lecture Hall
INTRODUCTION: The Arctic is more profoundly affected by climate change than lower latitude regions. Warming has been more pronounced in the Arctic and this trend is expected to continue; vegetation in high latitude regions is also expected to respond to climate change more than vegetation in other parts of the world. In this study we examine the response to experimental warming of plant species at four sites in northern Alaska. METHODS: Sites were established at the coastal city of Barrow, Alaska (71°17′44″N 156°45′59″W) in 1994 and at the inland village of Atqasuk (70°28’40”N 157°25′5″W) in 1996. Plant community data was collected using a point frame method in 2007 and 2008. Species were classified using a variety of grouping methods based on geography, morphology, and phenology of the plants. Groupings were determined using both observations collected in the field, such as the classification of species as those that with leaf bud burst before and those with leaf bud burst after the mean bud burst date, and observations reported in the literature. Groupings from the literature included geographic distribution schemes based on Hultén (1968) and Young (1971), and morphological criteria based on Sørensen (1941) and Raunkiær (1934). RESULTS: Young’s zones divided plants into low and high arctic species and were a good predictor of response to warming. Groups from Hultén’s maps included circumpolar distribution and distribution within Alaska, and were also good predictors of response. Sorensen described Arctic vascular plant species using a variety of morphological criteria, such as wintering state of leaves, a good predictor. Wintering state of buds, thawing types of species, floral wintering stage, and Raunkiær’s life forms were not good predictors of warming response. CONCLUSIONS: Preliminary findings show that the most useful classification schemes are those based on distribution of the species. In general, species classified as low Arctic plants tend to increase in absolute cover under conditions of warming, while species classified as high Arctic plants decrease. However, each of the grouping schemes provided insights into potential drivers of vegetation change.