Prioritizing areas for biodiversity conservation at fine scale: Beyond the number of species

Background/Question/Methods

Representation of biodiversity plays a central role in conservation planning. Given that resources for conservation are limited, geographical areas need to be ranked according to their biological diversity. Priority areas have traditionally been delineated on the basis of species and endemism distribution, ignoring other components such as the phylogenetic and functional diversity, which inform about historical and potential evolution of species, and the processes that maintain ecosystem functions. Recent studies have demonstrated spatial non-congruences among these diversity components at global and continental scale. However, this relationship among components remains little explored at finer scales. In this study we analyzed how the spatial distribution of species, endemism and phylogenetic and functional diversity affects the selection of priority areas in the Ordesa-Monte Perdido National Park (Spanish Pyrenees). To do so, we identified hotspots and complementary sites of multiple facets of vascular plant diversity, and assessed their degree of overlap across hierarchical spatial scales.

Results/Conclusions

We found that priority areas (i.e. hotspots and complementary sites) of different diversity component were spatially segregated regardless of the scale. A low congruence was detected between species and endemism richness hotspots, whereas the overlap among other types of hotspots was minor. The congruence between priority areas based on complementarity was lower (less than 10% of the area was common to any pair of diversity components) than that of hotspots regardless of the scale. Species richness hotspots sheltered a great proportion of other diversity components at Park scale, but the proportion diminished when downscaling. These results evidence limitations of traditional conservation planning to protect multiple facets of diversity at fine scale. However, when phylogenetic and functional information is lacking, fine scale priority areas should be defined according to species richness hotspots rather than complementary sites in order to encompass as much as diversity of any component as possible.