Range expansion or contraction? A bibliometric and systematic review of biological invasions of animals in the context of climate change

Climate change may affect the invasiveness of invasive alien species (IAS) by altering habitats and the distribution of hosts, altering the frequency and intensity of extreme climatic events, and by prompting changes to land use patterns, which collectively may facilitate species movement, and increase opportunities for IAS to cross historical geographic barriers. The impact of climate change on range contraction/expansion of IAS is complex and remains controversial. To elucidate this important issue, we conducted a review to examine numerical and thematic trends in research related to climate change and IAS. We also conducted a systematic review of the predicted effects of climate change on range contraction/expansion of animal IAS reported in the literature. This comprehensive analysis aimed to identify the most probable outcomes of climate change on the spatial distribution of IAS. American, Australian, and British researchers have published the largest number of papers on the subject and have had the greatest influence on the research topics investigated. In terms of productivity (number of documents), Plos One (n=101) published the most papers; however, in terms of network influence (total link strength), Biological Invasions (TLS=13,289) ranked highest. "Climate change", "invasive species", "global warming", "biodiversity" and "biological invasion" are the most common informative words in the word clouds. Additionally, "invasive alien species", "fire" and "risk assessment" were identified as the emerging areas of research in the climate and IAS field. Insecta (41.58%), Actinopterygii (12.87%), and Amphibia (7.93%) were among the most studied animal taxa in research focused on climatic effects on animal IAS. The geographic range of most invasive species (71.28%) is expected to expand under projected climate change. However, the range of some species is predicted to both contract and expand, depending on the scenario and context (20.8%). Notably, our review found that few invasive species are expected to contract their range under climate change (7.2%). Our results show that most IAS will expand their range and occupy more new habitats in the future due to climate change.