Common and rare species respond to similar niche processes in macroinvertebrate metacommunities

Abstract

Ecologists have long investigated why communities are composed of a few common species and many rare species. Most studies relate rarity to either niche differentiation among species or spatial processes. There is a parallel between these processes and the processes proposed to explain the structure of metacommunities. Based on a metacommunity perspective and on data on stream macroinvertebrates from different regions of Brazil, we answer two questions. 1) Are sets of common and rare species affected by similar niche and spatial processes? 2) How does the community composition of common and of rare species differ? The main hypothesis we test is that common species are mainly affected by environmental factors, whereas rare species are mostly influenced by dispersal limitation. We used variation partitioning to determine the proportion of variation explained by the environment and space in common and rare species matrices. Contrary to our expectations, evidence supported the idea that both common and rare species are affected mainly by environmental factors, even after controlling for the differing information content between common and rare species matrices. Moreover, the abundance of some common species is also a good predictor of variation in rare species matrices. Niche differences are unlikely to be the sole cause of patterns of rarity in these metacommunities. We suggest that sets of common and rare species react to similar major environmental gradients and that rare species also respond to processes that operate at a more fine‐grained spatial scale, particularly biotic interactions. We extend the view that species sorting is the dominant process structuring metacommunities and argue that future studies focusing on rarity would benefit from a metacommunity perspective.

The taxonomic distinctness of macroinvertebrate communities of Atlantic Forest streams cannot be predicted by landscape and climate variables, but traditional biodiversity indices can

“…Thus, although we estimated both pure environmental and spatial components in variation partitioning, our main intention was to use spatial variables as a way to control for inflated Type I error in assessing the environmental component. Together with previous studies about Atlantic Forest streams, these results indicate that by using local, landscape and spatial predictors (or a combination of them), we are usually able to explain around 40% or less of the of variation in macroinvertebrate abundance and distribution (Siqueira et al, 2009), taxa associations (Roque et al, 2010), diversity metrics ), common and rare taxa (Siqueira et al, 2012b) and functional diversity metrics (Colzani et al, 2013). Recent studies have tested the performance of taxonomic diversity and taxonomic distinctness in several systems and taxonomic groups.…”

“…Moreover, studies that have examined patterns of macroinvertebrates under a variety of measures of stream conditions in relation to land use at multiple scales report mixed influences (Allan, 2004). Thus, given the absence of specific information, we consider our exploratory approach an appropriate option for our purpose of estimating the effect of landscape processes on the structure of the macroinvertebrate community (see Roque et al, 2010;Siqueira et al, 2009Siqueira et al, , 2012b for a similar approach).…”

“…Macroinvertebrate community data were collected by the research group from the Laboratory of Aquatic Entomology at the Universidade Federal de São Carlos Siqueira et al, 2012b). We standardized the sampling procedure according the following criteria: i) samples were taken during the lowest rainfall period (May, June, September, and October); ii) all sampled streams were low order (first or second order) and their springs were located within the area of dominant land use (vegetation, sugarcane, pasture or Eucalyptus).…”

Disentangling the influences of habitat structure and limnological predictors on stream fish communities of a coastal basin, southeastern Brazil

“…In community ecology, variance partitioning was popularized by Borcard et al (1992) as a method to extract the spatial and environmental components of community variation. In this context, most applications are motivated to put forward evidences for niche versus neutral theories of metacommunity regulation (Falke & Fauch, 2010;Landeiro et al, 2012;Siqueira et al, 2012;Grönroos et al, 2013). In addition, few studies have also compared the influence of different sets of environmental predictors related for example to aquatic and riparian habitats, while others had included factors related to predation pressure, resource availability or biotic interactions (Peltonen et al, 2007;Holmes et al, 2011;Siqueira et al, 2012).…”

Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

“…These taxa were rare and occurred only in too low abundances (16% and 3% of the total abundance in spring and in autumn, respectively) to be associated with significant spatial patterns, thereby leading to stochastic noise. This is not surprising given that species distributions in streams are generally characterized by having a few dominant species and a relatively long tail of numerically rare species (Resh et al 2005, Arscott et al 2006, Siqueira et al 2012). Focusing our evaluation on significant patterns only may therefore have resulted in a conservative estimate of resilience.…”