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.

Decreasing Richness And Biomass During A Flood Pulse Observed In A Southeastern US Coastal Floodplain Following A Multi-Year, Supra-Seasonal Drought

2021 ◽  
Author(s):  
Erica L. Johnson ◽  
Erin F. Abernethy ◽  
J. Checo Colón-Gaud
Keyword(s):  
Community Composition ◽  
Climate Change Impacts ◽  
Flood Pulse ◽  
Macroinvertebrate Communities ◽  
Biological Productivity ◽  
Aquatic Communities ◽  
Functional Feeding Group ◽  
Seasonal Flooding ◽  
Southeastern Us ◽  
Feeding Group

Abstract Floodplains of the southeastern United States exhibit high biological productivity, maintained by periodic floodplain inundation as a result of seasonal flooding. To examine the relationship between biological productivity and seasonal flooding following periods of drought, we quantified aquatic macroinvertebrate communities monthly in an inundated floodplain during the annual flood pulse (December-April) in two years, one following a multi-year drought and one following a larger than average flooding event. We predicted that floodplain communities would differ in richness, biomass, and community composition between years and that differences would be driven by discharge at the main stem and organic matter availability. We collected macroinvertebrates from the floodplain of the Altamaha River, an unimpounded 6th order river in the Coastal Plain region of the southeastern US that experiences floodplain connectivity. With invertebrates identified to genus, we elucidated richness, abundance, biomass, community composition, and functional feeding group. Richness was generally higher in the drought year but decreased throughout the flood pulse, while during the flood year richness was lower and increased. Biomass decreased throughout the flood pulse following the drought year and increased during the flood year. There was a high degree of overlap in invertebrate community composition based on abundance data during both years of the study with collector gatherers being the most highly abundant functional feeding group. As climate change impacts (i.e., severe droughts) become more common, it is critical to investigate how aquatic communities are responding to increasingly unpredictable flow conditions in unimpounded and seemingly unaltered rivers.

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.

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.

scholarly journals Coral Reef Community Composition in the Context of Disturbance History on the Great Barrier Reef, Australia

PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e101204 ◽  
Author(s):  
Nicholas A. J. Graham ◽  
Karen M. Chong-Seng ◽  
Cindy Huchery ◽  
Fraser A. Januchowski-Hartley ◽  
Kirsty L. Nash
Keyword(s):  
Coral Reef ◽  
Great Barrier Reef ◽  
Community Composition ◽  
Barrier Reef ◽  
Disturbance History ◽  
Coral Reef Community ◽  
Reef Community

scholarly journals Pattern and process of vegetation change (succession) on two northern New Zealand island volcanoes

2015 ◽  
Vol 13 ◽  
pp. 45-48
Author(s):  
Bruce D. Clarkson ◽  
Beverley R. Clarkson ◽  
James O. Juvik
Keyword(s):  
Vegetation Change ◽  
Light Availability ◽  
Patch Dynamics ◽  
Volcanic Eruptions ◽  
Vegetation Succession ◽  
Disturbance History ◽  
Pattern And Process ◽  
Island Species ◽  
New Information ◽  
Volcanic Islands

Pattern and process of vegetation change (succession) were compared on two northern North Island volcanoes: Whakaari (White Island) and Rangitoto Island where the endemic woody tree Metrosideros excelsa is the primary colonizer of raw volcanic substrates. Quantitative data from our previous publications (see References) and the references therein illustrate sequences of vegetation succession following significant volcanic eruptions. New information on Rangitoto Island M. excelsa patch dynamics and updated vascular species statistics for Whakaari have also been included. We also draw on supporting data from M. excelsa forest on the mainland and long-inactive volcanic islands in the Bay of Plenty, to provide a context for understanding the vegetation dynamics on Whakaari and Rangitoto Island. Species facilitation, light availability, humidity, substrate and disturbance history are all key determinants of vegetation succession across these volcanic landscapes.

scholarly journals Recovery of Subtidal Benthic Macroinvertebrate Communities Following Natural and Experimental Disturbances

2021 ◽  
Author(s):  
◽  
Kerstin Kroger
Keyword(s):  
Community Composition ◽  
Complete Recovery ◽  
Hydrodynamic Regime ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Community Recovery ◽  
Recovery Processes ◽  
Plankton Bloom ◽  
And Control ◽  
First Time

<p>The recovery processes of subtidal benthic macroinvertebrate communities following large-scale natural and meso-scale experimental disturbances were studied in Wellington Harbour, New Zealand, a temperate semi-enclosed embayment. This is the first time that long-term effects (>1 year post-disturbance) of a naturally occurring toxic plankton bloom have been investigated in the Southern hemisphere. For 2 years macroinvertebrate communities were studied at three sites of differing hydrodynamic regime. Samples were taken with a Van Veen grab and washed through a 500 [mu]m mesh. Community recovery following the bloom was site-specific. Multivariate analyses revealed that at two sites community recovery was not completed >3 years post-bloom, whereas at the third site the community composition oscillated from year to year, but did not show any signs of a sequential recovery process. The hydrodynamic regime was identified as a major factor influencing the observed recovery processes. Communities exposed to an active hydrodynamic regime were less affected by the bloom and recovered faster, as they were naturally in a perpetual state of recovery as indicated by a dominance of r-selected species. The community at the hydrodynamically less active site was more affected by the bloom. Complete recovery to the pre-disturbance climax community dominated by K-selected species was estimated to take 4-5 years, if not interrupted by other disturbances. For the first time a defaunation experiment was conducted in a hydrodynamically active site to mimic the effects of a plankton bloom on the benthic macroinvertebrate community. Three sediment plots of 25 m2 were covered by plastic tarpaulins, thereby creating a benthic die-off caused by oxygen depletion. This method of defaunation had not been used in the subtidal before. Community recovery was studied for 1 year and compared with community composition in undisturbed control plots. Macroinvertebrate samples were taken by diver-operated cores and washed through a 500 [mu]m mesh. Recovery was slow until after 70 days when abundance and number of species increased synchronously in disturbed and control plots. Multivariate analyses showed that community composition fluctuated strongly in the first 100 days. After 1 year, although disturbed and control communities were converging, differences in community composition were still significant. Time for complete recovery was estimated to be approximately 2 years. Predictions of current succession models were generally fulfilled in both studies. Recovered communities were similar in their composition to either pre-disturbance or surrounding communities. The major deviation from model predictions was that no abundance peak of opportunistic species occurred in either study. Timing of the disturbance, in both studies past the major macroinvertebrate recruitment peak, and the hydrodynamic regime were identified as major factors influencing recovery processes of the communities studied. Such deviation from model predictions indicates that the general models cannot take into account the multiplicity and complexity of factors influencing recovery processes. Thus, their applicability in predicting recovery times and endpoints for specific disturbances at specific locations is limited. Location-specific models might be a useful alternative. Recommendations are made to combine uni- and multivariate techniques to assess recovery processes due to their different sensibilities to changes in community composition.</p>

scholarly journals The role of ecosystem engineers in shaping the diversity and function of arid soil bacterial communities

SOIL ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 611-637
Author(s):  
Capucine Baubin ◽  
Arielle M. Farrell ◽  
Adam Št'ovíček ◽  
Lusine Ghazaryan ◽  
Itamar Giladi ◽  
...  
Keyword(s):  
Community Composition ◽  
Bacterial Communities ◽  
Soil Microbial Communities ◽  
Ecosystem Engineers ◽  
Patch Type ◽  
Arid Soil ◽  
Soil Bacterial Communities ◽  
Ant Nests ◽  
Soil Bacterial ◽  
And Function

Abstract. Ecosystem engineers (EEs) are present in every environment and are known to strongly influence ecological processes and thus shape the distribution of species and resources. In this study, we assessed the direct and indirect effect of two EEs (perennial shrubs and ant nests), individually and combined, on the composition and function of arid soil bacterial communities. To that end, topsoil samples were collected in the Negev desert highlands during the dry season from four patch types: (1) barren soil; (2) under shrubs; (3) near ant nests; or (4) near ant nests situated under shrubs. The bacterial community composition and potential functionality were evaluated in the soil samples (14 replicates per patch type) using 16S rRNA gene amplicon sequencing together with physico-chemical measures of the soil. We have found that the EEs affected the community composition differently. Barren patches supported a soil microbiome, dominated by Rubrobacter and Proteobacteria, while in EE patches Deinococcus-Thermus dominated. The presence of the EEs similarly enhanced the abundance of phototrophic, nitrogen cycle, and stress-related genes. In addition, the soil characteristics were altered only when both EEs were combined. Our results suggest that arid landscapes foster unique communities selected by patches created by each EE(s), solo or in combination. Although the communities' composition differs, they support similar potential functions that may have a role in surviving the harsh arid conditions. The combined effect of the EEs on soil microbial communities is a good example of the hard-to-predict non-additive features of arid ecosystems that merit further research.

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