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Two Species with an Unusual Combination of Traits Dominate Responses of British Grasshoppers and Crickets to Environmental Change.

Beckmann BC, Purse BV, Roy DB, Roy HE, Sutton PG, Thomas CD - PLoS ONE (2015)

Bottom Line: Once they were omitted from the analysis, trait effects were no longer statistically significant.The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks.We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but results need to be interpreted with caution and may have limited predictive power.

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom; Department of Biology, University of York, York, United Kingdom; Orthoptera and Allied Insects Recording Scheme of Britain and Ireland, c/o Biological Records Centre, Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom.

ABSTRACT
There are large variations in the responses of species to the environmental changes of recent decades, heightening interest in whether their traits may explain inter-specific differences in range expansions and contractions. Using a long-term distributional dataset, we calculated range changes of grasshoppers and crickets in Britain between the 1980s and the 2000s and assessed whether their traits (resource use, life history, dispersal ability, geographic location) explain relative performance of different species. Our analysis showed large changes in the distributions of some species, and we found a positive relationship between three traits and range change: ranges tended to increase for habitat generalists, species that oviposit in the vegetation above ground, and for those with a southerly distribution. These findings accord well with the nature of environmental changes over this period (climatic warming; reductions in the diversity and increases in the height of vegetation). However, the trait effects applied mainly to just two species, Conocephalus discolor and Metrioptera roeselii, which had shown the greatest range increases. Once they were omitted from the analysis, trait effects were no longer statistically significant. Previous studies on these two species emphasised wing-length dimorphism as the key to their success, resulting in a high phenotypic plasticity of dispersal and evolutionary-ecological feedback at their expanding range margins. This, combined with our results, suggests that an unusual combination of traits have enabled these two species to undertake extremely rapid responses to recent environmental changes. The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks. We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but results need to be interpreted with caution and may have limited predictive power.

No MeSH data available.


Related in: MedlinePlus

Range changes of grasshoppers and related species in Britain between 1980–9 and 2000–9.The figure shows “uncorrected” and “corrected range change” values for four levels of recording effort—i.e. based on four sets of “surveyed squares” with a minimum of 1 to 4 grasshopper or related species recorded in both time periods. Species are arranged in order of average uncorrected change. Note different y-axis scales.
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pone.0130488.g002: Range changes of grasshoppers and related species in Britain between 1980–9 and 2000–9.The figure shows “uncorrected” and “corrected range change” values for four levels of recording effort—i.e. based on four sets of “surveyed squares” with a minimum of 1 to 4 grasshopper or related species recorded in both time periods. Species are arranged in order of average uncorrected change. Note different y-axis scales.

Mentions: Our analysis of grasshopper and related insect range changes in Britain between the 1980s and 2000s showed moderate or large range size increases for a few species, with range size decreases for a smaller number, and less or no consistent change for the remaining majority of species. The species with the largest positive range changes were Conocephalus discolor, Metrioptera roeselii, Chorthippus albomarginatus and Tetrix subulata; those with the largest range size decreases were Stethophyma grossum and Myrmeleotettix maculatus (Fig 2).


Two Species with an Unusual Combination of Traits Dominate Responses of British Grasshoppers and Crickets to Environmental Change.

Beckmann BC, Purse BV, Roy DB, Roy HE, Sutton PG, Thomas CD - PLoS ONE (2015)

Range changes of grasshoppers and related species in Britain between 1980–9 and 2000–9.The figure shows “uncorrected” and “corrected range change” values for four levels of recording effort—i.e. based on four sets of “surveyed squares” with a minimum of 1 to 4 grasshopper or related species recorded in both time periods. Species are arranged in order of average uncorrected change. Note different y-axis scales.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482502&req=5

pone.0130488.g002: Range changes of grasshoppers and related species in Britain between 1980–9 and 2000–9.The figure shows “uncorrected” and “corrected range change” values for four levels of recording effort—i.e. based on four sets of “surveyed squares” with a minimum of 1 to 4 grasshopper or related species recorded in both time periods. Species are arranged in order of average uncorrected change. Note different y-axis scales.
Mentions: Our analysis of grasshopper and related insect range changes in Britain between the 1980s and 2000s showed moderate or large range size increases for a few species, with range size decreases for a smaller number, and less or no consistent change for the remaining majority of species. The species with the largest positive range changes were Conocephalus discolor, Metrioptera roeselii, Chorthippus albomarginatus and Tetrix subulata; those with the largest range size decreases were Stethophyma grossum and Myrmeleotettix maculatus (Fig 2).

Bottom Line: Once they were omitted from the analysis, trait effects were no longer statistically significant.The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks.We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but results need to be interpreted with caution and may have limited predictive power.

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom; Department of Biology, University of York, York, United Kingdom; Orthoptera and Allied Insects Recording Scheme of Britain and Ireland, c/o Biological Records Centre, Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom.

ABSTRACT
There are large variations in the responses of species to the environmental changes of recent decades, heightening interest in whether their traits may explain inter-specific differences in range expansions and contractions. Using a long-term distributional dataset, we calculated range changes of grasshoppers and crickets in Britain between the 1980s and the 2000s and assessed whether their traits (resource use, life history, dispersal ability, geographic location) explain relative performance of different species. Our analysis showed large changes in the distributions of some species, and we found a positive relationship between three traits and range change: ranges tended to increase for habitat generalists, species that oviposit in the vegetation above ground, and for those with a southerly distribution. These findings accord well with the nature of environmental changes over this period (climatic warming; reductions in the diversity and increases in the height of vegetation). However, the trait effects applied mainly to just two species, Conocephalus discolor and Metrioptera roeselii, which had shown the greatest range increases. Once they were omitted from the analysis, trait effects were no longer statistically significant. Previous studies on these two species emphasised wing-length dimorphism as the key to their success, resulting in a high phenotypic plasticity of dispersal and evolutionary-ecological feedback at their expanding range margins. This, combined with our results, suggests that an unusual combination of traits have enabled these two species to undertake extremely rapid responses to recent environmental changes. The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks. We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but results need to be interpreted with caution and may have limited predictive power.

No MeSH data available.


Related in: MedlinePlus