Global diversity patterns and cross‐taxa convergence in freshwater systems

Abstract

Summary 1.Whereas global patterns and predictors of species diversity are well known for numerous terrestrial taxa, our understanding of freshwater diversity patterns and their predictors is much more limited. 2. Here, we examine spatial concordance in global diversity patterns for five freshwater taxa (i.e. aquatic mammals, aquatic birds, fishes, crayfish and aquatic amphibians) and investigate the environmental factors driving these patterns at the river drainage basin grain. 3. We find that species richness and endemism patterns are significantly correlated among taxa. We also show that cross-taxon congruence patterns are often induced by common responses of taxa to their contemporary and historical environments (i.e. convergent patterns). Apart from some taxa distinctiveness (i.e. fishes), the 'climate/productivity' hypothesis is found to explain the greatest variance in species richness and endemism patterns, followed by factors related to the 'history/dispersion' and 'area/environmental heterogeneity' hypotheses. 4. As aquatic amphibians display the highest levels of congruency with other taxa, this taxon appears to be a good 'surrogate' candidate for developing global freshwater conservation planning at the river drainage basin grain.

Global meta-analysis reveals low consistency of biodiversity congruence relationships

“…Further, considerations of study location and design-such as spatial scale (defined here as the areal extent of the study region), grain size (the size of each sampling unit) or sample size (the number of sampling units in the study)-can strongly influence observed congruence relationships [12][13][14]24 . Finally, different pairs of taxa vary in their degree of congruence 24,43,44 , but identifying taxon-specific attributes that influence congruence is difficult. One simple approach is to use phylogenetic relatedness as a proxy for ecological traits (such as body size 28 ) that influence congruence patterns.…”

Cross‐Shelf Habitat Occupancy Probabilities for Juvenile Groupers in the Florida Keys Coral Reef Ecosystem

“…Our first objective was to determine whether grouper distribution patterns varied in relation to cross-shelf habitat characteristics at two spatial scales. In riverine ecosystems, nested spatial hierarchies can be used to describe fish distributions in relation to watershed-scale climate patterns, catchment-scale surface runoff and stream flow, and stream-scale substrate characteristics (Harig and Fausch 2002;Harford and McLaughlin 2007;Tisseuil et al 2013). In coral reef ecosystems, fish distributions can be described in relation to cross-shelf categorization of reef structures and local habitat characteristics within reef strata (Done 1983;Sluka et al 1994;Connell and Kingsford 1998;GroberDunsmore et al 2008;Kendall et al 2011;Pittman and Brown 2011;Yeager et al 2011).…”

Environmental Impacts—Lake Ecosystems

“…Climate conditions are as important for freshwater biodiversity as for terrestrial and marine biodiversity, and consistently explain a major proportion of the geographic variation in species richness of different freshwater taxa such as amphibians, fish, mammals, crayfish and waterbirds (Tisseuil et al 2013). Even so, other geographic patterns such as the latitudinal gradient in biodiversity is not as strong in freshwater as it is in the marine or terrestrial realms (Hillebrand 2004).…”