Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E84

Plant populations in a warmer world: a natural experiment

Bryndís Marteinsdóttir (1), Johan Ehrlén (2)

1. Háskóli Íslands, 2. Stokkhólmsháskóli

Kynnir / Presenter: Bryndís Marteinsdóttir

Tengiliður / Corresponding author: Bryndís Marteinsdóttir (bryndism@hi.is)

With global warming the growing conditions for plants in arctic and alpine ecosystems are going to change. While phenotypic responses of plant populations to warming have been well documented little is known about the potential of plants to adapt to changing environments (evolutionary responses). In this study we use the geothermal system in Hengill, SE-Iceland to access the effect of warming on plant populations. The soil in this system is heated by the steam of deep geothermal water reservoirs, spanning a temperature gradient of more than 25 °C, while being less than 2 km apart. This system therefore offers a unique natural experiment to study the effect of long time warming on plant phenology and evolution. In 2015, 100 individuals of Cardamine pratensis, Cerastium fontanum and Pinguicula vulgaris growing at soil temperatures from 7-34 °C were marked. Plant size and reproductive phenology was estimated for each plant in the end of June and seeds (or leaflets) collected in September. First results indicate that plant phenology depends on soil temperature, with plants developing earlier at warmer sites. Common garden experiment have been initiated to assess if this difference is caused by genetic or plastic responses. The result from this and further studies planned in Hengill should allow us to answer questions on how arctic plant species will respond to global warming.