Predators mitigate the destabilising effects of heatwaves on multitrophic stream communities

2021 ◽  
Author(s):  
Samuel R. P‐J. Ross ◽  
Jorge García Molinos ◽  
Atsushi Okuda ◽  
Jackson Johnstone ◽  
Keisuke Atsumi ◽  
...  
Keyword(s):  
Stream Communities

scholarly journals Landscape heterogeneity and the biodiversity of Arctic stream communities: a habitat template analysis

2005 ◽  
Vol 62 (8) ◽  
pp. 1905-1919 ◽  
Author(s):  
Alexander D Huryn ◽  
Karie A Slavik ◽  
Rex L Lowe ◽  
Stephanie M Parker ◽  
Dennis S Anderson ◽  
...  
Keyword(s):  
Landscape Heterogeneity ◽  
Detrended Correspondence Analysis ◽  
Functional Feeding Groups ◽  
Mountain Glacier ◽  
Stream Communities ◽  
Stream Community ◽  
Arctic Alaska ◽  
Template Analysis ◽  
Habitat Template ◽  
And Function

We predicted that substratum freezing and instability are major determinants of the variability of stream community structure in Arctic Alaska. Their effects were conceptualized as a two-dimensional habitat template that was assessed using a natural experiment based on five stream types (mountain-spring, tundra-spring, tundra, mountain, glacier). Detrended correspondence analysis (DCA) indicated distinct macroinvertebrate assemblages for each stream type. The contribution of functional feeding groups to assemblage biomass varied systematically among stream types, indicating that structure and function are linked. Assemblage position within a DCA biplot was used to assess factors controlling its structure. Springs separated from other stream types along a gradient of nutrient concentration and freezing probability. Glacier and mountain streams separated from springs and tundra streams along a gradient of substratum instability and freezing probability. Owing to differences in sources of discharge to streams, the effects of nutrients and substratum stability could not be separated from freezing. Although many factors likely contribute to the variability of Arctic stream communities, the major determinants may be conceptualized as a template structured by gradients in (i) nutrient supply and substratum freezing and (ii) substratum instability and substratum freezing. This template provides a basis for predicting the response of Arctic stream communities to climate change.

Patch history, invertebrate patch dynamics and heterogeneous community composition: perspectives from a manipulative stream experiment

2007 ◽  
Vol 58 (4) ◽  
pp. 307 ◽  
Author(s):  
D. A. Olsen ◽  
C. D. Matthaei ◽  
C. R. Townsend
Keyword(s):  
Community Composition ◽  
Patch Dynamics ◽  
Invertebrate Drift ◽  
Macroinvertebrate Communities ◽  
Disturbance History ◽  
Patch Type ◽  
Entire Study ◽  
Stream Communities ◽  
Different Types ◽  
Stable Control

Recent research after bed-moving flow events has shown that local disturbance history can contribute to patchiness in stream communities. Patterns of recolonisation were studied following experimental disturbances in which patches of sediment were manipulated by removing 10 cm of surface sediment (scour) or by depositing 10 cm of clean sediment (fill) on top of existing sediments. Six invertebrate samples were collected from each patch type (including stable control patches) on five occasions up to six weeks after the manipulation. Immediately after the disturbance, distinctive macroinvertebrate communities occurred in scour, fill and stable patches. Community composition in scour patches remained distinct from fill and stable patches for the entire study period. Immediately after the manipulation, scour patches contained higher densities of hypogean taxa than did fill patches, but this difference did not persist for long, indicating that the relict community had little influence on the subsequent pattern of recovery. In contrast, fill patch communities were indistinguishable from stable patches by Day 14, most likely owing to recolonisation by buried invertebrates and invertebrate drift. Differences in patterns of recolonisation following different types of disturbance can result in patchy invertebrate communities that persist for several weeks after the disturbance.

scholarly journals Regional hydrology controls stream microbial biofilms: evidence from a glacial catchment

2004 ◽  
Vol 1 (1) ◽  
pp. 497-531 ◽  
Author(s):  
T. J. Battin ◽  
A. Wille ◽  
R. Psenner ◽  
A. Richter
Keyword(s):  
Landscape Heterogeneity ◽  
Low Flow ◽  
Detection Rates ◽  
Stream Communities ◽  
Stream Discharge ◽  
Carbon Production ◽  
Microbial Biofilms ◽  
Short Period ◽  
Alpine Stream

Abstract. Glaciers are highly responsive to global warming and important agents of landscape heterogeneity. While it is well established that glacial ablation and snowmelt regulate stream discharge, linkage among streams and streamwater hydrogeochemistry, the controls of these factors on stream microbial biofilms remain insufficiently understood. We investigated glacial (metakryal, hypokryal), groundwater-fed (krenal) and snow-fed (rhithral) streams – all of them representative for alpine stream networks – and present evidence that these hydrologic and hydrogeochemical factors differentially affect sediment microbial biofilms. Average microbial biomass and bacterial carbon production were low in the glacial streams, whereas bacterial cell size, biomass, and carbon production were higher in the tributaries, most notably in the krenal stream. Whole-cell in situ fluorescence hybridization revealed reduced detection rates of the Eubacteria and higher abundance of α-Proteobacteria in the glacial stream, a pattern that most probably reflects the trophic status of this ecosystem. Our data suggest low flow during the onset of snowmelt and autumn as a short period (hot moment) of favorable environmental conditions with pulsed inputs of allochthonous nitrate and dissolved organic carbon, and with disproportional high microbial growth. Krenal and rhithral streams with more constant and favorable environments serve as possible sources of microbes and organic matter to the main glacial channel during periods (e.g. snowmelt) of elevated hydrologic linkage among streams. Ice and snow dynamics have a crucial impact on microbial biofilms, and we thus need better understanding of the microbial ecology and enhanced consideration of critical hydrological episodes in future models predicting alpine stream communities.

Triazine herbicide contamination of Tasmanian streams: Sources, concentrations and effects on biota

1994 ◽  
Vol 45 (2) ◽  
pp. 209 ◽  
Author(s):  
PE Davies ◽  
LSJ Cook ◽  
JL Barton
Keyword(s):  
Surface Waters ◽  
Biological Effects ◽  
Invertebrate Drift ◽  
Triazine Herbicide ◽  
Short Term ◽  
Rainfall Events ◽  
Agricultural Catchments ◽  
Stream Communities ◽  
Forestry Industry ◽  
Forestry Plantations

Concentrations of the triazine herbicides atrazine, simazine, cyanazine, metribuzin and propazine were determined in streams draining forestry and agricultural catchments in Tasmania, Australia, between 1989 and 1992. Atrazine and simazine were used extensively by the forestry industry in a winter spraying programme, and applications of the other herbicides occurred in cropped agricultural catchments during spring and summer. Of 29 streams sampled intensively for triazines, 20 contained detectable residues. Median contaminations over all samples were 2.85, 1.05, <0.05, <0.05 and <0.05 �g L-1 for atrazine, simazine, cyanazine, metribuzin and propazine, respectively. All herbicide concentrations ranged over several orders of magnitude up to 53 mg L-1, with atrazine and simazine having significantly higher concentrations than the others. Atrazine concentrations were examined in streams draining forestry plantations for periods of up to two years. A decline in concentration was observed with time, but this was strongly influenced by rainfall events. Atrazine contamination from single spraying events persisted at a low level for up to 16 months. Contamination of Big Creek with atrazine to 22�g L-1 after aerial spraying led to an increase in stream invertebrate drift only on the day of spraying and to a short-term increase in movement of brown trout. On examination of biological effects of triazines in surface waters reported in the literature, it was concluded that the observed frequent contamination of Tasmanian streams with triazines may cause occasional minor short-term disturbance to stream communities.

Functional and trophic diversity of tropical headwater stream communities inferred from carbon, nitrogen and hydrogen stable isotope ratios

Food Webs ◽  
2021 ◽  
Vol 26 ◽  
pp. e00181
Author(s):  
B. Hayden ◽  
S. Tongnunui ◽  
F.W.H. Beamish ◽  
P. Nithirojpakdee ◽  
D.X. Soto ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Ratios ◽  
Headwater Stream ◽  
Stable Isotope Ratios ◽  
Trophic Diversity ◽  
Stream Communities

scholarly journals Do alpine macroinvertebrates recover differently in lakes and rivers after alien fish eradication?

2019 ◽  
pp. 37
Author(s):  
Rocco Tiberti ◽  
Stefano Brighenti
Keyword(s):  
Fish Populations ◽  
Mountain Lake ◽  
Macroinvertebrate Communities ◽  
Italian Alps ◽  
Introduced Fish ◽  
Habitat Features ◽  
Stream Communities ◽  
Mechanical Methods ◽  
Eradication Campaign ◽  
Alien Fish

Introduced fish can have detrimental effects on native biota inhabiting alpine freshwaters with the extent of their impact depending on variables such as habitat features. The present study aims to compare the recovery of macroinvertebrate communities following a fish eradication campaign in a mountain lake (Lake Dres, 2087 m a.s.l., Western Italian Alps) and its inflowing and outflowing streams. All fish were removed using mechanical methods, not producing side-effects for macroinvertebrates. During eradication, the lake community, which had previously been greatly affected, rapidly recovered to levels typical of never-stocked lakes. Stream communities, however, were apparently not impacted by fish populations and remained relatively stable, proving their greater capacity to withstand fish presence. The abundance of spatial refugia and invertebrate recruitment (via birth or immigration) can explain the observed stability in stream communities. Drifting macroinvertebrates are often called into question to explain the resistance of stream communities as they can partially offset predation via benthic recruitment, but our results show that stream resistance can be high even where drift is low, i.e., in the outflowing stream.

Stream communities across a rural-urban landscape gradient

2006 ◽  
Vol 12 (4) ◽  
pp. 337-350 ◽  
Author(s):  
Mark C. Urban ◽  
David K. Skelly ◽  
Denise Burchsted ◽  
William Price ◽  
Sarah Lowry
Keyword(s):  
Urban Landscape ◽  
Stream Communities ◽  
Landscape Gradient
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