FIGURE 2 - uploaded by James I. Watling
Content may be subject to copyright.
A map of 10 Florida regions (left) as defined by the Florida Fish and Wildlife Conservation Committee Upland Invasive Plant Working Group, and box plots (right) of MaxEnt-predicted median probability and number of species above minimum training thresholds in each region. For the box plot, the thick horizontal lines are the medians, the boxes encompass the 1 st to 3 rd quartiles, and the open circles are outliers.
Source publication
Invasive species are among the primary threats to biodiversity and risk assessment is one problem-solving approach that can prioritize and guide efforts to reduce the negative consequences of invasion. We used a nich-emodeling framework to conduct a geographic risk assessment of exotic reptiles in the state of Florida, USA, a region with the highes...
Context in source publication
Context 1
... predicted index of suitable conditions and number of species above the threshold probability were highly variable across the state (Fig. 1, Appendix 1). The predicted number of species increased in the lower latitude, and the regional summary showed distinct differences between northern and southern regions (Fig. 2); for example, 11 species were above the threshold index in the southern part of the state (Fig. 1). However, this trend was not necessarily consistent for all species. This inverse trend held for most of the species (11 species; Spearman's ρ: ˗0.94 to ˗0.74, P < 0.001 for all); but for three species (Hemidactylus turicus, Stellagama ...
Similar publications
Genetic diversity provides insight into heterogeneous demographic and adaptive history across organisms’ distribution ranges. For this reason, decomposing single species into genetic units may represent a powerful tool to better understand biogeographical patterns as well as improve predictions of the effects of GCC (global climate change) on biodi...
Citations
... Within the past century, the introduction of tropical non-native reptiles to Florida has had a tremendous impact on native ecosystems. Florida has had more non-native herpetofaunal species introductions than anywhere in the world (Engeman et al., 2011;Fujisaki et al., 2015;Krysko et al., 2011). Of the estimated 180 reptile and amphibian taxa that have been introduced to Florida, 63 species have become established, including 54 reptiles (48 lizards, 5 snakes, and 1 crocodile; Krysko et al., 2016). ...
Tropicalization is a term used to describe the transformation of temperate ecosystems by poleward‐moving tropical organisms in response to warming temperatures. In North America, decreases in the frequency and intensity of extreme winter cold events are expected to allow the poleward range expansion of many cold‐sensitive tropical organisms, sometimes at the expense of temperate organisms. Although ecologists have long noted the critical ecological role of winter cold temperature extremes in tropical‐temperate transition zones, the ecological effects of extreme cold events have been understudied, and the influence of warming winter temperatures has too often been left out of climate change vulnerability assessments. Here, we examine the influence of extreme cold events on the northward range limits of a diverse group of tropical organisms, including terrestrial plants, coastal wetland plants, coastal fishes, sea turtles, terrestrial reptiles, amphibians, manatees, and insects. For these organisms, extreme cold events can lead to major physiological damage or landscape‐scale mass mortality. Conversely, the absence of extreme cold events can foster population growth, range expansion, and ecological regime shifts. We discuss the effects of warming winters on species and ecosystems in tropical‐temperate transition zones. In the twenty‐first century, climate change‐induced decreases in the frequency and intensity of extreme cold events are expected to facilitate the poleward range expansion of many tropical species. Our review highlights critical knowledge gaps for advancing understanding of the ecological implications of the tropicalization of temperate ecosystems in North America.
... Within the past century, the introduction of tropical non-native reptiles to Florida has had a tremendous impact on native ecosystems. Florida has had more non-native herpetofaunal species introductions than anywhere in the world (Engeman et al., 2011;Fujisaki et al., 2015;Krysko et al., 2011). Of the estimated 180 reptile and amphibian taxa that have been introduced to Florida, 63 species have become established, including 54 reptiles (48 lizards, 5 snakes, and 1 crocodile; Krysko et al., 2016). ...
... In recent years, determining the explicit distribution range of a species and predicting future changes has become more important because of rapid population declines due to habitat destruction and alteration, climate change, and introduced species (Gibbons et al. 2000;Thomas et al. 2004;Todd et al. 2010;Urban 2015). In particular, accurate species distribution is a key for predicting dispersal possibilities and assessing the potential ecological impacts in the face of changing ecosystems (Fujisaki et al. 2014;Kraus 2015). Studies determining current and predicting potential future distributions, based on changing environmental conditions, are increasingly important for reptiles (Sinervo et al. 2010;Acheson and Kerr 2018;Sancholi 2018). ...
... Among them, the MaxEnt model reliably predicts suitable habitat using presence records and pseudo-absence points (Phillips et al. , 2009Elith et al. 2006). Reptile studies have used MaxEnt to estimate potential distributions (Rödder et al. 2008;Huang et al. 2011;Solhjouy-Fard et al. 2012), predict distribution changes due to climate change (Srinivasulu and Srinivasulu 2016;Ofori et al. 2017;Berriozabal-Islas et al. 2018), and evaluate range expansions of introduced species (Buckland et al. 2014;Fujisaki et al. 2014;Weterings and Vetter 2018). ...
Background
Understanding the geographical distribution of a species is a key component of studying its ecology, evolution, and conservation. Although Schlegel’s Japanese gecko ( Gekko japonicus ) is widely distributed in Northeast Asia, its distribution has not been studied in detail. We predicted the present and future distribution of G. japonicus across China, Japan, and Korea based on 19 climatic and 5 environmental variables using the maximum entropy (MaxEnt) species distribution model.
Results
Present time major suitable habitats for G. japonicus , having greater than 0.55 probability of presence (threshold based on the average predicted probability of the presence records), are located at coastal and inland cities of China; western, southern, and northern coasts of Kyushu and Honshu in Japan; and southern coastal cities of Korea. Japan contained 69.3% of the suitable habitats, followed by China (27.1%) and Korea (4.2%). Temperature seasonality (66.5% of permutation importance) was the most important predictor of the distribution. Future distributions according to two climate change scenarios predicted that by 2070, and overall suitable habitats would decrease compared to the present habitats by 18.4% (scenario RCP 4.5) and 10.4% (scenario RCP 8.5). In contrast to these overall trends, range expansions are expected in inland areas of China and southern parts of Korea.
Conclusions
Suitable habitats predicted for G. japonicus are currently located in coastal cities of Japan, China, and Korea, as well as in isolated patches of inland China. Due to climate change, suitable habitats are expected to shrink along coastlines, particularly at the coastal-edge of climate change zones. Overall, our results provide essential distribution range information for future ecological studies of G. japonicus across its distribution range.
... Among animal species, the Great Lakes region represents a center for invertebrate introductions in particular, harboring 55% of invertebrate NAS recorded in the US ( Figure 5). More recently, NAS introductions to the Southeast have been driven largely by importation of aquarium, pet, and ornamental species, trades that are dominated by taxa derived from tropical sources in Central and South America and Asia (Fukisaki et al. 2015;Krysko et al. 2011). Fish and amphibians exhibit unusually high levels of animal species introduction to the region (Figure 5), very likely reflecting prevailing trade patterns. ...
Understanding the spatial and temporal dynamics underlying the introduction and spread of nonindigenous aquatic species (NAS) can provide important insights into the historical drivers of biological invasions and aid in forecasting future patterns of nonindigenous species arrival and spread. Increasingly, public databases of species observation records are being used to quantify changes in NAS distributions across space and time, and are becoming an important resource for researchers, managers, and policy-makers. Here we use publicly available data to describe trends in NAS introduction and spread across the conterminous United States over more than two centuries of observation records. Available data on first records of NAS reveal significant shifts in dominance of particular introduction patterns over time, both in terms of recipient regions and likely sources. These spatiotemporal trends at the continental scale may be subject to biases associated with regional variation in sampling effort, reporting, and data curation. We therefore also examined two additional metrics, the number of individual records and the spatial coverage of those records, which are likely to be more closely associated with sampling effort. Our results suggest that broad-scale patterns may mask considerable variation across regions, time periods, and even entities contributing to NAS sampling. In some cases, observed temporal shifts in species discovery may be influenced by dramatic fluctuations in the number and spatial extent of individual observations, reflecting the possibility that shifts in sampling effort may obscure underlying rates of NAS introduction.
... Also worth noting in the current study is the degree of NAS richness observed in Florida, which for animals in particular was far higher than any other region. This finding is unsurprising, given that Florida represents the largest centre of exotic pet trade in the United States (Krysko et al., 2011;Fukisaki, Mazzotti, Watling, Krysko, & Escribano, 2015). These observations draw attention to the potential importance of vectors other than recreational activities driving NAS distributions, and especially to the possibility that vectors associated with initial introduction may be distinct from those driving secondary spread. ...
Aim
Mapping the geographic distribution of non-native aquatic species is a critically important precursor to understanding the anthropogenic and environmental factors that drive freshwater biological invasions. Such efforts are often limited to local scales and/or to single species, due to the challenges of data acquisition at larger scales. Here, we map the distribution of non-native freshwater species richness across the continental United States and investigate the role of human activity in driving macro-scale patterns of aquatic invasion.
Location
The continental United States.
Methods
We assembled maps of non-native aquatic species richness by compiling occurrence data on exotic animal and plant species from publicly accessible databases. Using a dasymetric model of human population density and a spatially explicit model of recreational freshwater fishing demand, we analysed the effect of these metrics of human influence on the degree of invasion at the watershed scale, while controlling for spatial and sampling bias. We also assessed the effects that a temporal mismatch between occurrence data (collected since 1815) and cross-sectional predictors (developed using 2010 data) may have on model fit.
Results
Non-native aquatic species richness exhibits a highly patchy distribution, with hotspots in the Northeast, Great Lakes, Florida, and human population centres on the Pacific coast. These richness patterns are correlated with population density, but are much more strongly predicted by patterns of recreational fishing demand. These relationships are strengthened by temporal matching of datasets and are robust to corrections for sampling effort.
Main conclusions
Distributions of aquatic non-native species across the continental US are better predicted by freshwater recreational fishing than by human population density. This suggests that observed patterns are driven by a mechanistic link between recreational activity and aquatic non-native species richness and are not merely the outcome of sampling bias associated with human population density.
... Front Cover. Shannon Plummer. in the world (Krysko et al. 2011a Fujisaki et al. 2015). In this paper, we update our previous lists of nonindigenous herpetofaunal species (Krysko et al. 2011a ) by adding newly confirmed introductions and interceptions , and by providing taxonomic corrections, updated invasion stages, introduction pathways, and earliest introduction dates to previously documented species. ...
More nonindigenous species occur in Florida, USA, than any other region worldwide and may threaten many of Florida's natural resources. The frequency of new reports mandates the need for regular updates. Herein, we use photographic and specimen vouchers in addition to literature records to provide updated information on verified nonindigenous amphibians and reptiles in Florida. Between our most recent summary in 2012 and the end of 2015, 38 additional species are known to have been intercepted (n=2) or introduced (n=36). We also update the invasion stage of seven species previously reported from Florida and report that five additional taxa are now established. In total 191 independent known introductions of 180 herpetofaunal taxa led to the establishment of 63 taxa. This suggests that one in three introduced herpetofaunal species becomes established in Florida. The pet trade represents the most common introduction pathway among these species and a single animal importer in Hollywood, Broward County, is the probable source for introduction of a quarter of all herpetofauna introduced to Florida.
Invasive species are one among many threats to biodiversity. Brazil has been spared, generically, of several destructive invasive species. Reports of invasive snakes’ populations are nonexistent, but the illegal pet trade might change this scenario. Despite the Brazilian laws forbid to import most animals, illegal trade is frequently observed and propagules are found in the wild. The high species richness within Brazilian biomes and accelerated fragmentation of natural reserves are a critical factors facilitating successful invasion. An efficient way to ease damages caused by invasive species is identifying potential invaders and consequent prevention of introductions. For the identification of potential invaders many factors need to be considered, including estimates of climate matching between areas (native vs. invaded). Ecological niche modelling has been widely used to predict potential areas for invasion and is an important tool for conservation biology. This study evaluates the potential geographical distribution and establishment risk of Lampropeltis getula (Linnaeus, 1766), Lampropeltis triangulum (Lacépède, 1789), Pantherophis guttatus (Linnaeus, 1766), Python bivittatus Kuhl, 1820 and Python regius (Shaw, 1802) through the Maximum Entropy modelling approach to estimate the potential distribution of the species within Brazil and qualitative evaluation of specific biological attributes. Our results suggest that the North and Midwest regions harbor major suitable areas. Furthermore, P. bivittatus and P. guttatus were suggested to have the highest invasive potential among the analyzed species. Potentially suitable areas for these species were predicted within areas which are highly relevant for Brazilian biodiversity, including several conservation units. Therefore, these areas require special attention and preventive measures should be adopted.
