Invasion history ofOenotheracongeners in Europe: a comparative study of spreading rates in the last 200 years

Abstract

Aim The dynamics of spread of some representatives of Oenothera, a genus of New World origin and alien to Europe, was analysed. Location Distribution data from six European countries., i.e. Austria, Czech Republic, Hungary, Portugal, Serbia and UK were used. Methods Floristic records covering the last 200 years were collated and the cumulative number of localities was plotted against time. A correction of the number of localities, taking into account the intensity of floristic research in particular countries, was applied based on the total number of available herbarium specimens to make comparisons of the rate of spread in particular countries possible. Results In total, 35 alien taxa of the genus have been reported from the countries considered, the majority of which has only a limited distribution. So far 1800 records of Oenothera species have been reported from the six countries analysed since 1780, with O. biennis, O. erythrosepala, O. salicifolia, O. stricta, O. cambrica, O. rubricaulis, and O. chicaginensis having more than 50 localities. There is a highly significant negative correlation between the total number of localities in Europe and the year of the first introduction. Marked differences were found in the taxonomical pattern of invasion in particular countries. Main conclusions Multivariate analyses have shown that in Europe, there are two distinct groups of species of North and South American origin, respectively, whose invasion is determined by climatic conditions, namely temperature and precipitation. The South American group is represented by perennial and annual species preferring oceanic climate (e.g. O. rosea, O. stricta), while the North American group consists of biennial representatives (O. biennis and others) better adapted to inland conditions with lower mean temperature and more balanced monthly precipitations. In addition, there is a transitional group of species, including namely O. erythrosepala and O. fallax, preferring regions with sufficient rainfall and higher temperatures. The relatively hot climate of Balkan Peninsula seems to prevent invasion by Oenothera representatives. Pattern of invasion of particular taxa corresponds well to the climatic conditions in the regions of their natural distribution.

Strong human association with plant invasion success for Trifolium introductions to New Zealand

“…Species with larger native ranges may have achieved greater intentional and unintentional propagule pressure (43), facilitating rapid spread. Alternatively or additionally, such species may have spread quickly because of ecological versatility (41,42) or preadaptation to the New Zealand climate (15,48). Finally, species with longer flowering periods, particularly in New Zealand, tended to spread more rapidly (Table S10); this attribute is often associated with invasion success (49), via mechanisms such as associated longer fruiting period and increased seed transport probability.…”

“…From 10,000 iterations, we took the mean of these counts for each speciesinterval combination and assigned each species a zero for the time interval before its first database record. To calculate spread rate from such data, previous studies have used a variety of models (48,(61)(62)(63). Simple linear models provided the best fit to our relative data, and we therefore used linear slopes as our measure of relative spread rate.…”

The response of plant community diversity to alien invasion: evidence from a sand dune time series

“…On continental or regional scales, invasion processes have been reconstructed by use of herbarium records (Comin et al 2011;Fuentes et al 2008;Mihulka and Pyšek 2001), but few studies of long-term patterns of local spread (Damgaard et al 2011) are available. To analyse vegetation changes through time on a local scale, several direct, though very demanding, methods are usually adopted, for example repeated surveys, permanent plots, and field experiments.…”

The effects of temporally variable dispersal and landscape structure on invasive species spread

“…Quantifying this spread, however, is nontrivial. Researchers generally recreate invasive species spread from floristic records (e.g., Pysˇek and Prach 1995, Weber 1998, Mihulka and Pysˇek 2001, Lelong et al 2007, Shih and Finkelstein 2008 or county-to national-level inventories (e.g., Forcella 1985, Perrins et al 1993, Smith et al 2002, Evans and Gregoire 2007, Pysˇek et al 2008. These data suffer from collection biases, however, and cannot recreate all spread dynamics adequately as they are effectively aspatial (due to coarse resolutions).…”