Is there a core set of organisms that structure macroinvertebrate assemblages in freshwater wetlands?

Abstract

Summary We analysed taxa lists from 447 individual wetlands from several ecoregions across the world using nestedness and similarity‐based multivariate analyses. We examined how similar wetland assemblages are across regions, whether variation in assemblages is ordered (nested) or unpredictable (idiosyncratic), whether individual taxa occur predictably or unpredictably across wetland habitats, and if any of these patterns differed between temporary‐ and permanent water habitats. We found that macroinvertebrate assemblages were highly nested (N = 0.947), but unexpectedly 37 of the 40 most widespread taxa (>10% occurrence) were idiosyncratic. Of the 447 wetlands, we identified 277 that shared more than 40% similarities in assemblages, were mostly nested, and clustered together in ordination space, and thus could be considered a core set of wetlands in terms of assemblage structure. Assemblages in the 170 wetlands outside this core (mostly idiosyncratic) tended to be depauperate sites in arid or high elevation areas, or alternatively taxonomically rich sites supporting numerous lotic or lacustrine organisms. The ‘Core’ itself split into two main parts, one comprised of wetlands from semi‐arid or mild climate areas dominated by strong flying insects, and the second comprised of wetlands from wetter, more northerly areas where non‐insects with passive dispersal were very prevalent. Climate and geology appear to be major controls on macroinvertebrate distributions across the set of 447 wetlands. Hydrology (temporary versus permanent) of wetlands was a lesser control on assemblage structure over the set of 447 wetlands. That wetlands are dominated by about 40 widely‐occurring macroinvertebrate taxa, and those taxa tend to occur idiosyncratically, suggests that overall assemblages across wetlands may share many similarities, but some of widespread taxa may still be missing from many individual wetlands. Why these otherwise fairly ubiquitous taxa do not occur in specific wetlands may shed important light on how those wetlands are controlled ecologically; in other words, do sites lack specific factors required by these taxa?

Drought effects on the colonization of benthic macroinvertebrate communities in the early successional phases in experimental mesocosm wetlands

“…This also supports previous findings of a rapid colonization of benthic macroinvertebrates in small wetlands in temperate regions (Szalay & Resh 2000;Ruh ı et al 2009;Kim et al 2014). Batzer and Ruh ı (2013) analyzed macroinvertebrate taxa from 447 individual natural wetlands over the world and classified them into a set of core taxa belonging to the group inhabiting either permanent habitats with nested (ordered) assemblages or temporary habitats with idiosyncratic (unpredictable) assemblages. Our mesocosm data also showed similar colonization patterns between the pre-drought colonizers and the post-drought recolonizers represented in the permanent and temporary core sets, respectively, in the natural wetlands.…”

“…Vanschoenwinkel et al (2010) classified benthic macroinvertebrates into two groups, the passive dispersal and active dispersal groups, and explained the spatiotemporal fluctuations of the community using colonization and extinction dynamics. Recently, comprehensive studies were conducted to investigate successional patterns and trajectories of freshwater wetland macroinvertebrates and to discriminate a core set of organisms that comprise nested and idiosyncratic communities (Ruh ı et al 2012Batzer & Ruh ı 2013).…”

Bioaccumulation and trophic magnification of pharmaceuticals and endocrine disruptors in a Mediterranean river food web

“…However, sedentary lives may make biofilm and many aquatic macroinvertebrate taxa (including aquatic life stages of insects) particularly realistic indicators of local exposure. In particular, some invertebrate groups have long been known to denote anthropogenic disturbance (Goodnight, 1973;Cairns and Pratt, 1993) and hydroclimatic conditions (Barbour et al, 1992;Batzer and Ruhí, 2013), hence their ability to reflect emerging pollution could even increase their indicator use. Despite the number and variety of emerging pollutants detected in this study (and the presence of compounds like diclofenac, recently included in the watch list of substances for EUwide monitoring), observed concentrations did not represent a clear risk to exposed organisms.…”

Evaluating macroinvertebrate community shifts in the confluence of freestone and limestone streams

“…These physical and chemical changes due to geology have been shown to have corresponding effects on the biological community of the aquatic system (Glazier and Gooch, 1987;Dow et al, 2006;Kratzer et al, 2006;Neff and Jackson, 2011;Batzer and Ruhí, 2013). Streams of different geological origin have innately different levels of macroinvertebrate diversity.…”