Data from: Germination performance of native and non-native Ulmus pumila populations

Germination is a crucial step for invasive plants to extend their
distribution under different environmental conditions in a new range.
Therefore, information on germination characteristics of invasive plant
species provides invaluable knowledge about the factors which might
contribute to the invasion success. Moreover, intra-specific comparisons
under controlled conditions will show if different responses between
non-native and native populations are caused by evolutionary changes or by
phenotypic plasticity towards different environmental influences. This
paper focuses on the germination of native and non-native Ulmus pumila
populations. We expected that non-native populations would be
characterized by their higher final germination percentage and enhanced
germination rate, which might indicate an influence due to corresponding
climatic conditions. Germination experiments with a moderate and a warm
temperature treatment did not reveal significant differences in final
germination percentage. However, seeds from the North American non-native
range germinated significantly faster than native seeds (p <
0.001). Additionally, mean time to germination in both ranges was
significantly negatively correlated with annual precipitation (p = 0.022).
At the same time, this relationship is stronger in the native range
whereas mean time to germination in non-native populations seems to be
less influenced by climatic conditions. Different germination responses of
the North American populations could be caused by a fast evolutionary
change mediating a higher tolerance to current climatic conditions in the
non-native range. However, our findings could also be caused by artificial
selection during the introduction process and extensive planting of Ulmus
pumila in its non-native range. Nevertheless, we assume that the faster
germination rate of non-native populations is one potential explanation
for the invasion success of Ulmus pumila in its new range since it might
provide a competitive advantage during colonization of new sites.

Hirsch et al. -
germination dataGermination records used
for the survival analysis. For each seed the corresponding origin
(population and range), the day of germination (germination_day), the
status in regards to the right censoring (1 = germinated; 0 =
non-germinated but viable at the end of the experiment) and the
corresponding temperature condition during the experiment
(temperature_treatment) are provided.germination paper
data2.xlsx