Photo: Kochia, southwest Montana. © 2020 Delena Norris-Tull
Do invasive species perform better in the new environment than in their native environment?
Summaries of the research and commentary by Dr. Delena Norris-Tull, Professor Emerita of Science Education, University of Montana Western, July 2020.
Parker, et al., 2013, challenged the assumption that invasive species perform better in their non-native ranges than in their native ranges. They conducted a meta-analysis on the performance data for non-native species (plants and animals), compared between their native and non-native ranges. Studies on invasive success tend to focus on comparative sizes, fecundity, or abundance, when invasive species are compared between their home and new ranges. Some studies do show that certain invasive species are indeed larger, or have higher reproductive rates, or are more abundant, in their non-native range. But a number of studies also demonstrate no performance differences, between the native and non-native ranges. Parker, et al., 2013, concluded that success in the non-native range is related more to traits of species, as they interact with the environmental context, than to novel ecological or environmental contexts they encounter in the new setting.
Parker, et al., 2013, extracted population data from studies of 53 introduced species, including 37 from the list of the “100 of the World’s Worst Invasive Alien Species.” For many of the species on this list, comparative performance data was not available, so they expanded their choices by including 16 additional invasive species (which included 15 plant species). In total, they were able to get useful performance data on 26 plants and 27 animals.
Unfortunately, they found that there is little research on the extent to which some species may be as ecologically dominant in their native range as in their non-native range, as most studies only examined performance in the non-native range, making comparisons challenging. And most studies examined only one of the three factors (comparative sizes, fecundity, or abundance).
Parker, et al., 2013, found that these 53 invasive species were “strongly likely… to be larger and more fecund in their introduced ranges, but less likely… to be more abundant.”
However, of the 35 species for which there were size data, only the species (both plant and animal) on the “World’s Worst” list “were strongly likely… to show larger sizes.” Species not on that list did not demonstrate larger sizes in their introduced ranges.
Of the 21 species for which they found reproductive data, “there was a high probability… of increased reproductive performance in the introduced range.” But only the plant species showed increased reproductive performance.
Parker, et al., 2013, found data on abundance for 33 of the species. “On average, there was a lower probability… that introduced species were more abundant in their new ranges, as all three groups (plants and animals on the WW list, and plants not on the list) were only moderately likely to be more abundant in their introduced range.” The abundance patterns were weaker for animals than for plants. Only eight species (seven plant species) were “strongly likely to be more abundant in their new ranges…, and 13 (plants and animals) showed no tendency to be more or less abundant across geographic ranges.”
When Parker, et al., 2013, pooled “data from all three separate matrics, there was a high probability… of increased performance in the new range across all 53 species.” Plants from both lists were “likely to perform better in the introduced range.” Animals on the WW list showed a weaker trend.
They found that, “15 of 53 invasive species were strongly likely to perform better in their new ranges…, but 27 showed no tendency to perform better or worse.” “WW plants were likely to perform better than” plants not on the WW list. “And WW plants were likely to perform better than WW animals.”
Parker, et al., 2013, found no performance differences between species that were accidentally versus intentionally introduced. Time since introduction also “did not appear to be a strong factor in performance.”
Across all 53 species, Parker, et al., 2013, found overall “a 96% likelihood of enhanced performance in their introduced ranges, including strong increases in organism size,… and reproductive performance,… along with a more modest increase in abundance… Increases in overall performance were stronger for plants vs. animals,… and roughly half the species (27/53)… showed little evidence of increased performance.” They found considerable variation in performance across species. They found it notable that they were “not able to find comparative data for 60% (53/89) of species labeled as the world’s worst invaders. In particular, there was a general lack of data from the native ranges of the invasive species.”
Reference:
Next Sections on research on the success of invasive species:
Do invasive species perform better in the new environment than in their native environment?
Summaries of the research and commentary by Dr. Delena Norris-Tull, Professor Emerita of Science Education, University of Montana Western, July 2020.
Parker, et al., 2013, challenged the assumption that invasive species perform better in their non-native ranges than in their native ranges. They conducted a meta-analysis on the performance data for non-native species (plants and animals), compared between their native and non-native ranges. Studies on invasive success tend to focus on comparative sizes, fecundity, or abundance, when invasive species are compared between their home and new ranges. Some studies do show that certain invasive species are indeed larger, or have higher reproductive rates, or are more abundant, in their non-native range. But a number of studies also demonstrate no performance differences, between the native and non-native ranges. Parker, et al., 2013, concluded that success in the non-native range is related more to traits of species, as they interact with the environmental context, than to novel ecological or environmental contexts they encounter in the new setting.
Parker, et al., 2013, extracted population data from studies of 53 introduced species, including 37 from the list of the “100 of the World’s Worst Invasive Alien Species.” For many of the species on this list, comparative performance data was not available, so they expanded their choices by including 16 additional invasive species (which included 15 plant species). In total, they were able to get useful performance data on 26 plants and 27 animals.
Unfortunately, they found that there is little research on the extent to which some species may be as ecologically dominant in their native range as in their non-native range, as most studies only examined performance in the non-native range, making comparisons challenging. And most studies examined only one of the three factors (comparative sizes, fecundity, or abundance).
Parker, et al., 2013, found that these 53 invasive species were “strongly likely… to be larger and more fecund in their introduced ranges, but less likely… to be more abundant.”
However, of the 35 species for which there were size data, only the species (both plant and animal) on the “World’s Worst” list “were strongly likely… to show larger sizes.” Species not on that list did not demonstrate larger sizes in their introduced ranges.
Of the 21 species for which they found reproductive data, “there was a high probability… of increased reproductive performance in the introduced range.” But only the plant species showed increased reproductive performance.
Parker, et al., 2013, found data on abundance for 33 of the species. “On average, there was a lower probability… that introduced species were more abundant in their new ranges, as all three groups (plants and animals on the WW list, and plants not on the list) were only moderately likely to be more abundant in their introduced range.” The abundance patterns were weaker for animals than for plants. Only eight species (seven plant species) were “strongly likely to be more abundant in their new ranges…, and 13 (plants and animals) showed no tendency to be more or less abundant across geographic ranges.”
When Parker, et al., 2013, pooled “data from all three separate matrics, there was a high probability… of increased performance in the new range across all 53 species.” Plants from both lists were “likely to perform better in the introduced range.” Animals on the WW list showed a weaker trend.
They found that, “15 of 53 invasive species were strongly likely to perform better in their new ranges…, but 27 showed no tendency to perform better or worse.” “WW plants were likely to perform better than” plants not on the WW list. “And WW plants were likely to perform better than WW animals.”
Parker, et al., 2013, found no performance differences between species that were accidentally versus intentionally introduced. Time since introduction also “did not appear to be a strong factor in performance.”
Across all 53 species, Parker, et al., 2013, found overall “a 96% likelihood of enhanced performance in their introduced ranges, including strong increases in organism size,… and reproductive performance,… along with a more modest increase in abundance… Increases in overall performance were stronger for plants vs. animals,… and roughly half the species (27/53)… showed little evidence of increased performance.” They found considerable variation in performance across species. They found it notable that they were “not able to find comparative data for 60% (53/89) of species labeled as the world’s worst invaders. In particular, there was a general lack of data from the native ranges of the invasive species.”
Reference:
- Parker, J.D., Torchin, M.E., Hufbauer, R. A., Lemoine, N. P., Alba, C., Blumenthal, D.M., Bossdorf, O., Byers, J.E., Dunn, A.M., Heckman, R. W., Hejda, M., et al. (May, 2013). Do invasive species perform better in their new ranges? Ecology, 94 (5), 984-994.
Next Sections on research on the success of invasive species: