Unicellular organisms in benthic habitats on different substrates in a first-order stream and their contribution to secondary production

Meiofauna in stream habitats: temporal dynamics of abundance, biomass and secondary production in different substrate microhabitats in a first-order stream

“…Within the course of a year, the contribution of microhabitats to secondary production in one stream might change. Nevertheless, similarly to Benke et al (1985) and Brüchner-Hüttemann et al (2019), our results show that next to the sediment, dead wood is a highly productive microhabitat not only in terms of macrofaunal and microfaunal communities but also for meiofaunal organisms. Our findings are especially relevant for low-order streams surrounded by forested areas.…”

“…No effect of season on the meiofaunal community at all was found on the surface of dead wood. Brüchner-Hüttemann et al (2019) showed that the biofilm on dead wood is highly colonized by protozoans and bacteria, organisms determined in the present study to strongly influence the meiofaunal density distribution in that microhabitat. Nevertheless, there was no seasonal pattern obvious for the unicellular community (Brüchner-Hüttemann et al 2019) which is in line with the results in the present study for the meiofaunal community.…”

“…However, in the annual mean dead wood covered only 9% of the investigated stream area in the Furlbach and with respect to the stream area covered by the microhabitat the percentages of secondary production decreased. Nonetheless, dead wood still accounted for 14% of the total meiofaunal secondary production (this study) and for one-third of total unicellular secondary production (Brüchner-Hüttemann et al 2019).…”

“…For example, the high production rates of the periphyton (i.e., attached micro-communities) on stony hard substrates demonstrate the importance of this meiofaunal microhabitat, as determined in a study of three Swedish lakes (Schroeder et al 2012). Moreover, studies of dead wood in flowing waters prove that macrofaunal invertebrates and unicellular organisms colonizing this habitat have a considerable amount on secondary production of the system (Benke et al 1985;Brüchner-Hüttemann et al 2019).…”

“…This procedure was chosen to guarantee an appropriate amount of material for the different analyses, and as meiofauna distribution may be affected by small-scale variability (Silver et al 2002), pooling randomly chosen samples minimize the effect of small-scale heterogeneity. In the laboratory, subsamples for the analysis of the accompanying parameters (abundances of protozoans and bacteria, AFDM, Chl-a) were prepared (see Brüchner-Hüttemann et al 2019). Meiofaunal organisms were then extracted from the rest of each sediment sample (45.3 mL) by density centrifugation with LudoxTM50 (Sigma-Aldrich, Munich, Germany; 1.14 g mL -1 , mesh size 10 lm) according to Pfannkuche and Thiel (1988).…”