Differences in vegetative growth of two invasive hawkweeds at temperatures simulating invaded habitats at two altitudes

Data was from laboratory trials using seeds collected from a range of sites and plants from pots grown in glasshouse conditions. Two species were investigated: Hieracium aurantiacum (orange hawkweed, OHW) and Hieracium pilosella (mouse ear hawkweed, MEHW) Three kinds of data are presented: 1. Germination data based on 25 seeds placed into petridishes and followed through time. Petri dishes were either placed in cabinets at ambient temperature, temperatures simulating 1000m or 1700m asl. Germination was followed through time. Old seeds collected from sites in previous years are contrasted with new seeds collected in the season prior to experimentation. 2. We followed growth through time for 20 germinants grown at either 1000m or 1700m. Dry biomass of above ground and below ground parts are presented. 3. Using ramets from plants grown in pots and kept in the glasshouse for some years, growth rates (no. leaves through time) are measured at temperatures representative of the altitude where populations have invaded in the field (wither 1700m or 1000m). Only a subset of plants were grown through the latter part of the experiment after repotting.