The influence of environmental and spatial factors on benthic invertebrate metacommunities differing in size and dispersal mode

Abstract

Understanding the drivers of species distribution is an important topic in conservation biology and ecology, pertaining to species traits like dispersal strategies and species-environment interactions. Here we examined the drivers of benthic species distribution at 20 sections of a second-order stream network. Environmental and spatial factors and the dispersal modes of the organisms were considered. We expected that species with aerial dispersal capabilities like insects would be less restrained by distance between sites and thus mostly affected by environmental factors. In contrast, we hypothesized that completely benthic species would mainly be affected by spatial factors due to limited dispersal. However, microscopic species like nematodes characterized by a high passive dispersal potential may be less limited by spatial factors. When using redundancy analyses and subsequent variance partitioning, the included variables explained 24% (insects), 24% (non-flying macrobenthos), and 32% (nematodes) of the variance in the respective community composition. Spatial factors mainly explained the species composition of all tested groups. In contrast with other larger species, nematodes were characterized by fine-scale patterns that might have been induced by random processes (e.g., random distribution and priority effects). Our study showed that dispersal processes are crucial in shaping benthic communities along streams albeit the relatively small sampling area (max. distance between sampling sites: 2 km). The demonstration of spatial factors as important drivers of the species distribution of passively dispersing benthic organismal groups highlights the role played by connectivity in determining species distribution patterns in river systems.

Colonization of novel algal habitats by juveniles of a marine tube-dwelling amphipod

“…This process has been related to ultimate and proximate causes (Bowler & Benton, 2005;Burgess et al, 2016), and also depends on organismal traits that often vary among individuals within a population, such as body size, sex, and developmental stage (Lawrence, 1987;Munguia, Mackie & Levitan, 2007;Munguia, 2015). A variety of strategies related to dispersal are found among aquatic invertebrates, involving passive and/or active components and allowing the movement of these organisms across short and long distances (Martel & Chia, 1991;Palmer, Allan & Butman, 1996;Kinlan & Gaines, 2003;Ptatscheck et al, 2020).…”

The river health of Alista River based on macroinvertebrates communities at Selorejo Village Dau Subdistrict Malang Regency

“…Macroinvertebrates are invertebrates that are confined to mesh sizes >200 to 500 µm [7], [8]. Abundant invertebrates in upstream river ecosystems are dominated by 95 percent insect larvae and nymphs [9], [10].…”

Role of the Hyporheic Zone in Increasing the Resilience of Mountain Streams Facing Intermittency

“…Stygobitic taxa typically dominate upwelling groundwater zones, whereas downwelling surface water facilitates stygoxenes and occasional hyporheos (see review in [30]). Body size is another factor which affects the movement and colonization mechanism: meiobenthic invertebrates (organisms passing through a sieve of 500-µm mesh size but retained on a 44-µm mesh [46]) can actively move through the streambed and some taxa are able to swim; however, their dispersal along the surface of the riverbed is mainly passively due to drift ( [47], and references therein). Ref.…”