Exotic taxa less related to native species are more invasive

Abstract

Some species introduced into new geographical areas from their native ranges wreak ecological and economic havoc in their new environment. Although many studies have searched for either species or habitat characteristics that predict invasiveness of exotic species, the match between characteristics of the invader and those of members of the existing native community may be essential to understanding invasiveness. Here, we find that one metric, the phylogenetic relatedness of an invader to the native community, provides a predictive tool for invasiveness. Using a phylogenetic supertree of all grass species in California, we show that highly invasive grass species are, on average, significantly less related to native grasses than are introduced but noninvasive grasses. The match between the invader and the existing native community may explain why exotic pest species are not uniformly noxious in all novel habitats. Relatedness of invaders to the native biota may be one useful criterion for prioritizing management efforts of exotic species.biological invasions ͉ community phylogenetics ͉ grass ͉ novel weapons ͉ supertree

Species coexistence: macroevolutionary relationships and the contingency of historical interactions

“…In our study, distant relatives from Spain had much lower or much higher mean fitness than competitors from California, a result that reconciles previous work [40,41]. Specifically, our results suggest that at the earliest stage of invasion, divergence in fitness may generally predict why some species fail to establish (distant relatives of lower fitness [40]) while others have spectacularly negative impacts on native diversity (distant relatives of higher fitness [41]). Although this result does not establish plant characteristics that make some species noxious invaders [42], it supports the general finding that species have a greater potential to become noxious invaders when they are naive to a region [43].…”

Phylogenetic structure and host abundance drive disease pressure in communities

“…In our grassland, the total amount of disease was most accurately explained not by the abundance of the focal host alone, but by the abundance of all species in the community weighted by their phylogenetic distance to the host. Furthermore, the model strongly predicted observed disease pressure for 44 novel host species we introduced experimentally to our study site, providing evidence for a mechanism to explain why phylogenetically rare species are more likely to become invasive when introduced 8,9 . Our results demonstrate how the phylogenetic and ecological structure of communities can have a key role in disease dynamics, with implications for the maintenance of biodiversity, biotic resistance against introduced weeds, and the success of managed plants in agriculture and forestry.…”

“…At the same time, the great majority of introduced species do not become invasive, and disease pressure from resident species may contribute 'biotic resistance' 22,27 . Darwin's naturalization hypothesis suggests that those introduced species that are most successful are less closely related to residents 8 , a pattern observed in California grasslands 9 although not universally supported 28 . One possible mechanism for this phenomenon is disease pressure originating from closely related resident species.…”

The importance of phylogeny to the study of phenological response to global climate change

“…However, the extent to which the phylogenetic distribution of non-native species success can be explained by climate change response has not been tested. This is relevant because a better understanding of such patterns can shed light on the utility of phylogeny as a tool for assessing the likelihood of future naturalizations and invasions (Fisher & Owens 2004;Strauss et al 2006;Proches et al 2008). For example, if non-native species status and favourable phenological response to climate change exhibit phylogenetic signal and are correlated, then the phylogenetic placement of newly introduced species can inform their likely phenological response, and thus their potential of future success in light of continued climate change.…”