Combining ecological niche modeling with genetic lineage information to predict potential distribution of Mikania micrantha Kunth in South and Southeast Asia under predicted climate change

摘要

Ecological niche models (ENM), an effective tool to predict the potential distribution of invasive species, are often built on assumptions of niche conservatism between native and invasive ranges and genetic uniformity of the invasive population. In this study, we have incorporated genetic information with ENM to generate projected distribution of the invasive species Mikania micrantha for which two genetic clusters were identified in South and Southeast Asia. Climatic niches were compared between native and invasive ranges, as well as between invasive ranges of two lineages by using multivariate and univariate analyses. Ecological niche models were built with MaxEnt, using occurrence data of two lineages separately, together and also using native range data. Predictive abilities of the models were compared and potential distributions of the two lineages were predicted under present and future climate scenarios. The models were projected on the native range to identify climatically suitable areas for each lineage. Significant differences between climatic niches of the two invasive lineages were found and unique climatically suitable areas for each lineage were identified. A large area of South and Southeast Asia was found to be climatically suitable for both lineages. Under climate change scenarios, pole ward range expansion for one lineage and decrease in range size along marginal areas for another lineage were predicted. However, high amount of niche unfilling for both the lineages indicated that if introduced, the lineages can establish in cold and dry areas of the invasive range. The evidence of niche abandonment between native and invasive ranges indicated presence of other lineages in its native range which are not yet introduced in this region. These findings provided baseline data for implementing management strategies at early stage of invasion and quarantine measures to protect this region from future invasions. Climatically suitable areas in the native range were identified for both lineages which can be prioritized for conducting surveys for identification of source populations and biological control agents. Our study highlights the importance of integrating genetic data in future ENM approaches to have finer scale information of species’ distribution, which can be utilized to develop region-specific and climate change-integrated management strategies for invasive species.