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Evaluating the metapopulation consequences of ecological traps.

Hale R, Treml EA, Swearer SE - Proc. Biol. Sci. (2015)

Bottom Line: How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored.We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context.Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible.

View Article: PubMed Central - PubMed

Affiliation: School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia robin.hale@unimelb.edu.au.

ABSTRACT
Ecological traps occur when environmental changes cause maladaptive habitat selection. Despite their relevance to metapopulations, ecological traps have been studied predominantly at local scales. How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored. We propose that assessing the metapopulation consequences of traps depends on a variety of factors that can be grouped into four categories: the probability of encounter, the likelihood of selection, the fitness costs of selection and species-specific vulnerability to these costs. We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context. Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible. We provide the first evidence that (iii) traps may be beneficial for metapopulations in rare instances, and (iv) preferences for natal-like habitats can magnify the effects of traps. Our study provides important insight into the effects of traps at landscape scales, and highlights the need to explicitly consider spatial context to better understand and manage traps within metapopulations.

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Related in: MedlinePlus

Results of generalized linear model (GLM) describing the relative influence of variables on differences in metapopulation (a) growth rate (λM IMPACT) and (b) mean lifetime (MMLTIMPACT) between metapopulations with and without ecological traps. Bars show 95% CIs associated with slopes and interactions between slopes. The x-axis describes the effect of a one standard deviation change in each model parameter on the response. Parameters (statistically significant at p < 0.05) are organized according to the direction and strength of their influence on the response. Overall fits (R2) of GLM: (a) 0.91 and (b) 0.77. Model parameters are defined in table 1.
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RSPB20142930F3: Results of generalized linear model (GLM) describing the relative influence of variables on differences in metapopulation (a) growth rate (λM IMPACT) and (b) mean lifetime (MMLTIMPACT) between metapopulations with and without ecological traps. Bars show 95% CIs associated with slopes and interactions between slopes. The x-axis describes the effect of a one standard deviation change in each model parameter on the response. Parameters (statistically significant at p < 0.05) are organized according to the direction and strength of their influence on the response. Overall fits (R2) of GLM: (a) 0.91 and (b) 0.77. Model parameters are defined in table 1.

Mentions: All criteria in our framework influenced the negative consequences of traps. The proportion of traps (T.pro) in the landscape was a strong influence on both λM IMPACT and MMLTIMPACT (figures 2 and 3), and is likely to be the most important determinant of whether animals encounter traps. We found some evidence to suggest that highly vagile species (i.e. higher Disp) may also be more susceptible to the effects of traps, but perceptual range was less important.Figure 2.


Evaluating the metapopulation consequences of ecological traps.

Hale R, Treml EA, Swearer SE - Proc. Biol. Sci. (2015)

Results of generalized linear model (GLM) describing the relative influence of variables on differences in metapopulation (a) growth rate (λM IMPACT) and (b) mean lifetime (MMLTIMPACT) between metapopulations with and without ecological traps. Bars show 95% CIs associated with slopes and interactions between slopes. The x-axis describes the effect of a one standard deviation change in each model parameter on the response. Parameters (statistically significant at p < 0.05) are organized according to the direction and strength of their influence on the response. Overall fits (R2) of GLM: (a) 0.91 and (b) 0.77. Model parameters are defined in table 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4375870&req=5

RSPB20142930F3: Results of generalized linear model (GLM) describing the relative influence of variables on differences in metapopulation (a) growth rate (λM IMPACT) and (b) mean lifetime (MMLTIMPACT) between metapopulations with and without ecological traps. Bars show 95% CIs associated with slopes and interactions between slopes. The x-axis describes the effect of a one standard deviation change in each model parameter on the response. Parameters (statistically significant at p < 0.05) are organized according to the direction and strength of their influence on the response. Overall fits (R2) of GLM: (a) 0.91 and (b) 0.77. Model parameters are defined in table 1.
Mentions: All criteria in our framework influenced the negative consequences of traps. The proportion of traps (T.pro) in the landscape was a strong influence on both λM IMPACT and MMLTIMPACT (figures 2 and 3), and is likely to be the most important determinant of whether animals encounter traps. We found some evidence to suggest that highly vagile species (i.e. higher Disp) may also be more susceptible to the effects of traps, but perceptual range was less important.Figure 2.

Bottom Line: How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored.We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context.Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible.

View Article: PubMed Central - PubMed

Affiliation: School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia robin.hale@unimelb.edu.au.

ABSTRACT
Ecological traps occur when environmental changes cause maladaptive habitat selection. Despite their relevance to metapopulations, ecological traps have been studied predominantly at local scales. How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored. We propose that assessing the metapopulation consequences of traps depends on a variety of factors that can be grouped into four categories: the probability of encounter, the likelihood of selection, the fitness costs of selection and species-specific vulnerability to these costs. We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context. Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible. We provide the first evidence that (iii) traps may be beneficial for metapopulations in rare instances, and (iv) preferences for natal-like habitats can magnify the effects of traps. Our study provides important insight into the effects of traps at landscape scales, and highlights the need to explicitly consider spatial context to better understand and manage traps within metapopulations.

Show MeSH
Related in: MedlinePlus