Systematic conservation planning has become a standard approach globally, but prioritization of conservation efforts hardly considers species traits in decision-making. This can be important for species persistence and thus adequacy of the conservation plan. Here, we developed and validated a novel approach of incorporating trophic information into a systematic conservation planning framework. We demonstrate the benefits of this approach by using fish data from Europe´s second largest river, the Danube. Our results show that adding trophic information leads to a different spatial configuration of priority areas at no additional cost. This can enhance identification of priority refugia for species in the lower position of the trophic web while simultaneously identifying areas that represent a more diverse species pool. Our methodological approach to incorporating species traits into systematic conservation planning is generally applicable, irrespective of realm, geographical area and species composition and can potentially lead to more adequate conservation plans.
figure1
Best solution of planning units with a target of 10 without and with trophic weighting (= scaling 0.01-1). (a) red coloured areas show planning units (pu) selected in scenarios without trophic weighting (b) green coloured areas show planning units selected in scenarios with trophic weighting (c) difference in selected planning units with (green area) and without (red area) trophic weighting, grey coloured areas show planning units selected in both scenarios. Broad blue line indicates main stem; thin blue lines indicate tributaries of the Danube River.
Figure2
Effect of incorporating trophic level information and different weightings on average proportion of predator species per planning unit in chosen area. Average proportion of predator species for all planning units is indicated by orange line; Average proportion of predator species in chosen areas is shown for each target in runs without trophic information and for each target and weighting in runs with trophic information. Proportion of predator species for each target of runs without trophic information are drawn with thicker, solid lines and over all weightings, although no weighting was performed, to illustrate the difference between runs with trophic information, which are drawn with thinner, dashed lines. Trophic weighting is ratio highest to lowest with 3 being a weighting of 0.3-1, 4 being 0.25-1, 5 being 0.2-1, 6 being 0.15-1, 10 being 0.1-1, 20 being 0.05-1 and 100 being 0.01-1. a indicates significant difference (p <0.001) between scenarios with the same target.
figure3
Effect of incorporating trophic level information and different weightings on average proportion of predator species per planning unit in unique chosen area. Average proportion of predator species for all planning units is indicated by orange line; Average proportion of predator species in chosen area unique to either runs without or with trophic information is shown for each target and each weighting. Proportion of predator species for runs without trophic information are drawn with thicker solid lines. Proportion of predator species for runs with trophic information are drawn with thinner dashed lines. Trophic weighting is ratio highest to lowest with 3 being a scaling of 0.3-1, 4 being 0.25-1, 5 being 0.2-1, 6 being 0.15-1, 10 being 0.1-1, 20 being 0.05-1 and 100 being 0.01-1. a and b indicate significant difference (p < 0.001 and p < 0.05 respectively) between scenarios with the same target.
Appendix S1_ Species trophic level according to FishBase and assigned group
Species trophic level according to FishBase and assigned group
Appendix S2_ Number of species and their occurrence rate in planning units that could not achieve the target
Number of species and their occurrence rate in planning units that could not achieve the target
Appendix S3_ Cohen's kappa value for all targets and weightings
Cohen's kappa value for all targets and weightings
Appendix S4_ Average predator proportion of randomized batches of 1000 samples
Average predator proportion of randomized batches of 1000 samples