Potential distributional shifts in North America of allelopathic invasive plant species under climate change models

Predictive studies play a crucial role in the study of biological invasions of terrestrial plants under possible climate change scenarios.Invasive species are recognized for their ability to modify soil microbial communities and influence ecosystem dynamics.Here,we focused on six species of allelopathic flowering plants-Ailanthus altissima,Casuarina equisetifolia,Centaurea stoebe ssp.micranthos,Dioscorea bulbifera,Lantana camara,and Schinus terebinthifolia-Xhat are invasive in North America and examined their potential to spread further during projected climate change.We used Species Distribution Models(SDMs)to predict future suitable areas for these species in North America under several proposed future climate models.ENMEval and Maxent were used to develop SDMs,estimate current distributions,and predict future areas of suitable climate for each species.Areas with the greatest predicted suitable climate in the future include the northeastern and the coastal northwestern regions of North America.Range size estimations demonstrate the possibility of extreme range loss for these invasives in the southeastern United States,while new areas may become suitable in the northeastern United States and southeastern Canada.These findings show an overall northward shift of suitable climate during the next few decades,given projected changes in temperature and precipitation.Our results can be utilized to analyze potential shifts in the distribution of these invasive species and may aid in the development of conservation and management plans to target and control dissemination in areas at higher risk for potential future invasion by these allelopathic species.

Potential effects of climate change on a marine invasion： The importance of current context

Species invasions threaten marine biodiversity globally. There is a concern that climate change is exacerbating this problem. Here, we examined some of the potential effects of warming water temperatures on the invasion of Western Atlantic habitats by a marine predator, the Indo-Pacific lionfish （Pterois volitans and P. miles）. We focussed on two temperature-dependent aspects of lionfish life-history and behaviour： pelagic larval duration, because of its link to dispersal potential, and prey consump- tion rate, because it is an important determinant of the impacts of lionfish on native prey. Using models derived from fundamental metabolic theory, we predict that the length of time spent by lionfish in the plankton in early life should decrease with warming temperatures, with a concomitant reduction in potential dispersal distance. Although the uncertainty around change in dispersal distances is large, predicted reductions are, on average, more than an order of magnitude smaller than the current rate of range expansion of lionfisli in the Caribbean. Nevertheless, because shorter pelagic larval duration has the potential to increase local re- tention of larvae, local lionfish management will become increasingly important under projected climate change. Increasing tem- perature is also expected to worsen the current imbalance between rates of prey consumption by lionfish and biomass production by their prey, leading to a heightened decline in native reef fish biomass. However, the magnitude of climate-induced decline is predicted to be minor compared to the effect of current rates of lionfish population increases （and hence overall prey consumption rates） on invaded reefs. Placing the predicted effects of climate change in the current context thus reveals that, at least for the lionfish invasion, the threat is clear and present, rather than future [Current Zoology 58 （1）： 1-8, 2012].

No consistent legacy effects of invasion by giant goldenrod(Solidago gigantea)via soil biota on native plant growth

Aims Changes in soil microbial communities after occupation by invasive alien plants can represent legacy effects of invasion that may limit recolonization and establishment of native plant species in soils previously occupied by the invader.In this study,for three sites in southern Germany,we investigated whether invasion by giant goldenrod(Solidago gigantea)leads to changes in soil biota that result in reduced growth of native plants compared with neighbouring uninvaded soils.Methods We grew four native plant species as a community and treated those plants with soil solutions from invaded or uninvaded soils that were sterilized,or live,with live solutions containing different fractions of the soil biota using a decreasing sieve mesh-size approach.We measured aboveground biomass of the plants in the communities after a 10-week growth period.Main FindingsAcross all three sites and regardless of invasion,communities treated with<20μm soil biota or sterilized soil solutions had significantly greater biomass than communities treated with the complete soil biota solution.This indicates that soil biota>20μm are more pathogenic to the native plants than smaller organisms in these soils.Across all three sites,there was only a non-significant tendency for the native community biomass to differ among soil solution types,depending on whether or not the soil was invaded.Only one site showed significant differences in community biomass among soil solution types,depending on whether or not the soil was invaded;community biomass was significantly lower when treated with the complete soil biota solution than with soil biota<20μm or sterilized soil solutions,but only for the invaded soil.Our findings suggest that efforts to restore native communities on soils previously invaded by Solidago gigantea are unlikely to be hindered by changes in soil microbial community composition as a result of previous invasion.