Taxonomic and biological trait differences of stream macroinvertebrate communities between mediterranean and temperate regions: implications for future climatic scenarios

Abstract

Streams in mediterranean regions have highly seasonal discharge patterns, with predictable torrential floods and severe droughts. In contrast, discharge is less variable in temperate regions and intermittent flow conditions are uncommon. Hydroclimatic models predict that climate change would increase frequency and severity of floods and droughts across Europe, thus increasing the proportion of streams with mediterranean characteristics in actually temperate areas. Correspondingly, understanding actual ecological differences between mediterranean and temperate streams may help to anticipate large‐scale ecological impacts of climate change. Given that large‐scale factors determine local community composition, we hypothesized that climatic differences between mediterranean and temperate regions should affect the taxonomic and biological trait composition in streams. We assembled the abundance of stream macroinvertebrate genera of 265 sites each from the Mediterranean Basin and from temperate Europe and linked these abundances to published information on 61 categories of 11 biological traits reflecting the potential of resilience from and resistance to disturbances. Although regional taxonomic richness was higher in the mediterranean than in the temperate region, local taxonomic richness and diversity did not significantly differ between regions. Local trait richness and diversity were significantly higher in the mediterranean region. Both local taxonomic and trait‐community composition differed between regions, but the former varied much more than the latter, highlighting that climate change could produce large changes in the taxonomic but rather weak changes in the trait composition. The mediterranean region was characterized by macroinvertebrates with higher dispersion and colonization capabilities, suggesting that species loss in the temperate region, by extinction or northward emigration of taxa, would be compensated for by immigration of southern mediterranean taxa. Thus, climate change would likely have stronger implications for the local conservation of taxa than for the trait composition of stream macroinvertebrate communities.

Impacts of climate change and land-use scenarios on Margaritifera margaritifera, an environmental indicator and endangered species

“…The effects of the ongoing global warming can be observed in many terrestrial, freshwater and marine species that have shifted their geographic ranges, seasonal activities, migration patterns, abundances, and species interactions, namely: freshwater fishes (Regier and Meisner, 1990), plants (Araujo et al, 2004;Lemieux and Scott, 2005), mammals (Burns et al, 2003), small birds (Wilby and Perry, 2006), and macroinvertebrates (Bonada et al, 2007). According to McLaughlin et al (2002) as well as to Pounds et al (2006), these changes in climate may have already caused several species extinctions.…”

Severity Multipliers as a Methodology to Explore Potential Effects of Climate Change on Stream Bioassessment Programs

“…The modification of temperature and precipitation regimes have the potential to have detrimental (or beneficial) effects and cause synergistic or antagonistic effects on species and communities [1]. Expected changes vary between cold, temperate and warm ecoregions, and could affect species due to changes in, among others, temperature, flow patterns, and nutrient concentrations [2][3][4][5]. However, estimates of effects from such changes on stream bioassessment results are rare.…”

“…For fish, the Fish Region Index (FRI, or Fish Zone Index) describes each fish species' preferred niche along the longitudinal upstream-downstream gradient [17] (Table 1). These ecological traits have been shown to mirror changes in fish communities due to climate change through a change in fish regions [17][18][19] and are also suggested in invertebrate communities [4,5,20]. Pletterbauer et al [17] showed mean increases of the Fish Zone Index between 0.25 and 0.41 up to the 2080s and maximum values of 0.92 and 1.18 under three climate change scenarios as developed by the Intergovernmental Panel on Climate Change (IPCC).…”

Effects of vineyard coverage and extent on benthic macroinvertebrates in streams of Northern California

“…However, many studies have shown a strong relationship between streamflow reductions and benthic response in Mediterranean-climate streams (Bonada et al, 2006(Bonada et al, , 2007aTorne´s et al, 2007;Morais, 2008). Furthermore, prolonged drought in Mediterranean-climate regions has particularly strong effects on the abundance and composition of benthic-macroinvertebrate communities in small streams (Beˆche et al, 2006;Beˆche and Resh, 2007a, b).…”

“…The biological traits for a given taxon may include, for example, the number of generations per year, the ability to enter a state of diapause, and the ability to burrow into the streambed to obtain food, seek refuge from predators, or escape low-flow conditions (Beˆche and Resh, 2007a, b). Biological traits of benthic-macroinvertebrate communities in Mediterranean-climate regions have been shown to be affected by long-term climate variability (Beˆche et al, 2006;Beˆche and Resh, 2007a, b;Bonada et al, 2007a, b;Lawrence et al, 2010) and seasonal differences (Mouthon and Daufresne, 2006;Cordellier and Pfenninger, 2008;Spooner and Vaughn, 2008;Clausnitzer et al, 2009;Hering et al, 2009).…”