Darwin’s preadaptation hypothesis and the phylogenetic structure of native and alien regional plant assemblages across North America

Abstract

Aim Studies focusing on relatively small spatial scales have shown that alien plants are more likely to invade phylogenetically clustered communities, and that the introduction of alien plants further increases phylogenetic clustering in the recipient communities. However, whether these patterns hold at a continental scale remains untested. Here, we investigate the phylogenetic structure of native and alien regional assemblages of angiosperms across North America. Location North America north of Mexico. Time period Current. Major taxon studied Angiosperms (flowering plants). Methods We divided North America into 65 regions across two longitudinal zones, and collated native and naturalized alien species lists of angiosperms for each region. Two phylogenetic metrics, which represent different evolutionary depths, were used to quantify phylogenetic structure of angiosperms as a whole and each major clade in each region, and were related to temperature and precipitation using correlation analyses. Results We found that alien angiosperm richness is highest in regions with diverse and phylogenetically dispersed native floras. The introduction of alien species nearly uniformly increases phylogenetic clustering. Main conclusions Alien species are generally from the same major clades as native species, consistent with Darwin’s preadaptation hypothesis. The results of this study are consistent across a wide range of phylogenetic extents, but not always with analyses conducted at smaller spatial extents.

Phylogenetic structure of alien and native species in regional plant assemblages across China: Testing niche conservatism hypothesis versus niche convergence hypothesis

“…Mean values that significantly (p < .05) or marginally significantly (p < .09) differ from zero are indicated with two asterisks or one asterisk, respectively. This stands in some contrast to related results for angiosperms from North America (Qian & Sandel, 2022) and grasses of California . Both studies found consistent support for an increase in phylogenetic clustering with alien species at deep phylogenetic levels and large phylogenetic extents.…”

“…Further, the directions of the relationships between phylogenetic dispersion and climate are consistent between native and alien species of all angiosperms in China (Table 1). The positive associations of phylogenetic dispersion with temperature and precipitation for aliens and natives in China are consistent with those for aliens and natives in eastern North America (Qian & Sandel, 2022). These positive associations of phylogenetic dispersion with temperature and precipitation for aliens and natives are consistent with the tropical niche conservatism hypothesis, which predicts phylogenetic relatedness increases and phylogenetic diversity decreases with increasing environmental stress (Wiens & Donoghue, 2004).…”

“…For each of the 16 taxonomic groups, MPD ses and MNND ses for native species were calculated based on the phylogenetic tree including only native species of the group, and those for alien species were based on the phylogenetic tree including only alien species of the group. Sandel (2022) for angiosperms in North America, both studies having used species assemblages at large spatial grains. However, these findings are contrary to those of two studies on European plant assemblages (Gerhold et al, 2011;Lososová et al, 2015).…”

“…Invasive naturalized species have caused serious ecological, social and economic problems worldwide (Carboni et al, 2013; Pimentel et al, 2005; Vilà et al, 2011). Understanding how alien and native species are phylogenetically related is crucial to predicting potential invaders (Lososová et al, 2015; Qian & Sandel, 2022) and understanding the impacts of introduced species (Lessard et al, 2009).…”

Interacting abiotic and biotic drivers shape woody invasions across Hawaiian forests

“…Particularly on oceanic islands, island age (or soil age) - which typically has been used to address the macroevolutionary processes underlying native biodiversity patterns (Emerson, 2002; Gillespie, 2016; Whittaker et al ., 2017) - may further strengthen the context dependency of biological invasions by differentially shaping the biodiversity patterns for native (Whittaker et al ., 2008; Craven et al ., 2019) and alien species (Leihy et al ., 2018). Older islands with high native biodiversity may be more resistant to invasion (“Eltonian biotic resistance”; Fridley et al ., 2007), yet there is growing evidence that more diverse native plant communities can also be more vulnerable to invasion (Stohlgren et al ., 2003; Qian & Sandel, 2022), possibly due to empty niche space, high habitat heterogeneity or greater resource availability. Absent disturbances, alien species are more apt to establish on older soils that usually have greater resource availability than on younger soils, which tend to be more nutrient poor (Aplet et al ., 1998; Hughes & Denslow, 2005; Zimmerman et al ., 2008).…”