Influence of biotic and abiotic factors on adult Odonata (Insecta) in Amazon streams

Abstract Abiotic and biotic factors play an essential role in the structuring of natural communities. Aquatic ecosystems have complex interaction networks, encompassing predator/prey relationships and structural support. Among aquatic organisms, the order Odonata is a model group for understanding those relationships since they can be both predators and prey. Our hypotheses were that Zygoptera are (i) influenced positively by Ephemeroptera, Plecoptera and Trichoptera (EPT) and the Habitat Integrity Index (HII), and negatively by fish and macrophytes; and (ii) Anisoptera are affected positively by EPT and macrophytes, and negatively by fish and HII. We found that Zygoptera were affected by the fish functional trophic groups, while Anisoptera were affected by macrophytes, EPT, fish and HII. Macrophytes affected anisopterans positively because they provide perching sites for adults. The results for EPT and HII may be related since these organisms are also sensitive to environmental changes. More open areas have lower HII values and the negative relationship with Anisoptera may be explained by physiological constraints. The negative relationship between EPT and Anisoptera could be explained by the low occurrence of EPT in open sites, which are the sites that were highly rich in Anisoptera. Finally, the dominance of specific functional trophic groups of fish influences Odonata suborders in different ways. In conclusion, the results show the importance of ecological interactions for Odonata in Amazonian streams in both direct and indirect ways.

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Mycobacterium ulcerans dynamics in aquatic ecosystems are driven by a complex interplay of abiotic and biotic factors

eLife ◽

10.7554/elife.07616 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 19

Author(s):

Andrés Garchitorena ◽

Jean-François Guégan ◽

Lucas Léger ◽

Sara Eyangoh ◽

Laurent Marsollier ◽

...

Keyword(s):

Climatic Factors ◽

Abiotic Factors ◽

Aquatic Organisms ◽

Freshwater Ecosystems ◽

Mycobacterium Ulcerans ◽

Environmental Data ◽

Limiting Factor ◽

Biotic Factors ◽

Abiotic And Biotic Factors ◽

Chemical Conditions

Host–parasite interactions are often embedded within complex host communities and can be influenced by a variety of environmental factors, such as seasonal variations in climate or abiotic conditions in water and soil, which confounds our understanding of the main drivers of many multi-host pathogens. Here, we take advantage of a combination of large environmental data sets on Mycobacterium ulcerans (MU), an environmentally persistent microorganism associated to freshwater ecosystems and present in a large variety of aquatic hosts, to characterize abiotic and biotic factors driving the dynamics of this pathogen in two regions of Cameroon. We find that MU dynamics are largely driven by seasonal climatic factors and certain physico-chemical conditions in stagnant and slow-flowing ecosystems, with an important role of pH as limiting factor. Furthermore, water conditions can modify the effect of abundance and diversity of aquatic organisms on MU dynamics, which suggests a different contribution of two MU transmission routes for aquatic hosts (trophic vs environmental transmission) depending on local abiotic factors.

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The species evenness of “prey” bacteria correlated with Bdellovibrio-and-like-organisms (BALOs) in the microbial network supports the biomass of BALOs in a paddy soil

FEMS Microbiology Ecology ◽

10.1093/femsec/fiaa195 ◽

2020 ◽

Vol 96 (12) ◽

Author(s):

Hang Qian ◽

Chunli Hou ◽

Hao Liao ◽

Li Wang ◽

Shun Han ◽

...

Keyword(s):

Soil Properties ◽

Paddy Soil ◽

High Throughput Sequencing ◽

Abiotic Factors ◽

Negative Relationship ◽

Sequencing Analysis ◽

Nitrogen Use ◽

Microbial Network ◽

Α Diversity ◽

Positive Effect

ABSTRACT To seek how soil biotic and abiotic factors which might shape the Bdellovibrio-and-like-organisms community, we sampled paddy soils under different fertilization treatments including fertilization without nitrogen (Control), the nitrogen use treatment (N) and the nitrogen overuse one (HNK) at three rice growing stages. The abundances of BALOs were impacted by the rice-growing stages but not the fertilization treatments. The abundances of Bdellovibrionaceae-like were positively associated with soil moisture, which showed a negative relationship with Bacteriovoracaceae-like bacteria. High-throughput sequencing analysis of the whole bacterial community revealed that the α-diversity of BALOs was not correlated with any soil properties data. Network analysis detected eight families directly linked to BALOs, namely, Pseudomonadaceae, Peptostreptococcaceae, Flavobacteriaceae, Sediment-4, Verrucomicrobiaceae, OM27, Solirubrobacteraceae and Roseiflexaceae. The richness and composition of OTUs in the eight families were correlated with different soil properties, while the evenness of them had a positive effect on the predicted BALO biomass. These results highlighted that the bottom-up control of BALOs in paddy soil at least partially relied on the changes of soil water content and the diversity of bacteria directly linked to BALOs in the microbial network.

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Macroecological analyses support an overkill scenario for late Pleistocene extinctions

Brazilian Journal of Biology ◽

10.1590/s1519-69842004000300005 ◽

2004 ◽

Vol 64 (3a) ◽

pp. 407-414 ◽

Cited By ~ 6

Author(s):

J. A. F. Diniz-Filho

Keyword(s):

Body Mass ◽

Population Dynamic ◽

High Selectivity ◽

Environmental Changes ◽

Dynamic Parameters ◽

Allometric Relationships ◽

Ecological Data ◽

Predator Prey ◽

A Value ◽

Complex Models

The extinction of megafauna at the end of Pleistocene has been traditionally explained by environmental changes or overexploitation by human hunting (overkill). Despite difficulties in choosing between these alternative (and not mutually exclusive) scenarios, the plausibility of the overkill hypothesis can be established by ecological models of predator-prey interactions. In this paper, I have developed a macroecological model for the overkill hypothesis, in which prey population dynamic parameters, including abundance, geographic extent, and food supply for hunters, were derived from empirical allometric relationships with body mass. The last output correctly predicts the final destiny (survival or extinction) for 73% of the species considered, a value only slightly smaller than those obtained by more complex models based on detailed archaeological and ecological data for each species. This illustrates the high selectivity of Pleistocene extinction in relation to body mass and confers more plausibility on the overkill scenario.

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Biogeomorphic feedbacks and the ecosystem engineering of recently deglaciated terrain

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133318816536 ◽

2018 ◽

Vol 43 (1) ◽

pp. 24-45 ◽

Cited By ~ 7

Author(s):

Hannah R Miller ◽

Stuart N Lane

Keyword(s):

Environmental Stress ◽

Ecosystem Engineer ◽

Abiotic Factors ◽

Ecosystem Engineering ◽

Soil Development ◽

Water Dynamics ◽

Biotic Factors ◽

Successional Stage ◽

Abiotic And Biotic Factors

Matthews’ 1992 geoecological model of vegetation succession within glacial forefields describes how following deglaciation the landscape evolves over time as the result of both biotic and abiotic factors, with the importance of each depending on the level of environmental stress within the system. We focus in this paper on how new understandings of abiotic factors and the potential for biogeomorphic feedbacks between abiotic and biotic factors makes further development of this model important. Disturbance and water dynamics are two abiotic factors that have been shown to create stress gradients that can drive early ecosystem succession. The subsequent establishment of microbial communities and vegetation can then result in biogeomorphic feedbacks via ecosystem engineering that influence the role of disturbance and water dynamics within the system. Microbes can act as ecosystem engineers by supplying nutrients (via remineralization of organic matter and nitrogen fixation), enhancing soil development, either decreasing (encouraging weathering) or increasing (binding sediment grains) geomorphic stability, and helping retain soil moisture. Vegetation can act as an ecosystem engineer by fixing nitrogen, enhancing soil development, modifying microbial community structure, creating seed banks, and increasing geomorphic stability. The feedbacks between vegetation and water dynamics in glacial forefields are still poorly studied. We propose a synthesized model of ecosystem succession within glacial forefields that combines Matthews’ initial geoecological model and Corenblit's model to illustrate how gradients in environmental stress combined with successional time drive the balance between abiotic and biotic factors and ultimately determine the successional stage and potential for biogeomorphic feedbacks.

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Lake water dissolved inorganic carbon dynamics revealed from monthly measurements of radiocarbon in the Fuji Five Lakes, Japan

Elem Sci Anth ◽

10.1525/elementa.2020.00149 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Kosuke Ota ◽

Yusuke Yokoyama ◽

Yosuke Miyairi ◽

Shinya Yamamoto ◽

Toshihiro Miyajima

Keyword(s):

Lake Water ◽

Inorganic Carbon ◽

Environmental Changes ◽

Dissolved Inorganic Carbon ◽

Anthropogenic Activities ◽

Aquatic Organisms ◽

Human Society ◽

History Of ◽

Lake Waters ◽

Reservoir Age

Lakes are sensitive recorders of anthropogenic activities, as human society often develops in their vicinity. Lake sediments thus have been widely used to reconstruct the history of environmental changes in the past, anthropogenic, or otherwise, and radiocarbon dating provides chronological control of the samples. However, specific values of radiocarbon in different carbon reservoirs due to the different pathways of radiocarbon from the upper atmosphere to the lake, called the radiocarbon reservoir age, is always difficult to evaluate because of dynamic processes in and around lakes. There are few systematic studies on radiocarbon reservoir ages for lakes owing to the complex radiocarbon transfer processes for lakes. Here, we investigate lake waters of the Fuji Five Lakes with monthly monitoring of the radiocarbon reservoir effects. Radiocarbon from dissolved inorganic carbon (DIC) for groundwater and river water is also measured, with resulting concentrations (Δ14C) at their lowest at Lake Kawaguchi in August 2018 (–122.4 ± 3.2‰), and at their highest at Lake Motosu in January 2019 (–22.4 ± 2.5‰), despite a distance of 25 km. However, winter values in both lakes show similar trends of rising Δ14C (about 20‰). Our lake water DIC Δ14C results are compared to previously published records obtained from sediments in Lake Motosu and Lake Kawaguchi. These suggest that total organic carbon and compound-specific radiocarbon found in sediments are heavily influenced by summer blooms of aquatic organisms that fix DIC in water. Thus, future studies to conduct similar analyses at the various lakes would be able to provide further insights into the carbon cycle around inland water, namely understanding the nature of radiocarbon reservoir ages.

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Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands – responses to climatic and environmental changes

Biogeosciences Discussions ◽

10.5194/bgd-9-3693-2012 ◽

2012 ◽

Vol 9 (3) ◽

pp. 3693-3738 ◽

Cited By ~ 1

Author(s):

M. S. Carter ◽

K. S. Larsen ◽

B. Emmett ◽

M. Estiarte ◽

C. Field ◽

...

Keyword(s):

Global Warming ◽

Greenhouse Gas ◽

Air Temperature ◽

Environmental Changes ◽

Negative Relationship ◽

Co2 Efflux ◽

Soil Co2 ◽

Prolonged Drought ◽

Mean Annual Air Temperature

Abstract. In this study, we compare annual fluxes of methane (CH4), nitrous oxide (N2O) and soil respiratory carbon dioxide (CO2) measured at nine European peatlands (n = 4) and shrublands (n = 5). The sites range from northern Sweden to Spain, covering a span in mean annual air temperature from 0 to 16 °C, and in annual precipitation from 300 to 1300 mm yr−1. The effects of climate change, including temperature increase and prolonged drought, were tested at five shrubland sites. At one peatland site, the long-term (>30 yr) effect of drainage was assessed, while increased nitrogen deposition was investigated at three peatland sites. The shrublands were generally sinks for atmospheric CH4 whereas the peatlands were CH4 sources, with fluxes ranging from −519 to +6890 mg CH4-C m−2 yr−1 across the studied ecosystems. At the peatland sites, annual CH4 emission increased with mean annual air temperature, while a negative relationship was found between net CH4 uptake and the soil carbon stock at the shrubland sites. Annual N2O fluxes were generally small ranging from –14 to 42 mg N2O-N m−2 yr−1. Highest N2O emission occurred at the sites that had highest concentration of nitrate (NO3−) in soil water. Furthermore, experimentally increased NO3− deposition led to increased N2O efflux, whereas prolonged drought and long-term drainage reduced the N2O efflux. Soil CO2 emissions in control plots ranged from 310 to 732 g CO2-C m−2 yr−1. Drought and long-term drainage generally reduced the soil CO2 efflux, except at a~hydric shrubland where drought tended to increase soil respiration. When comparing the fractional importance of each greenhouse gas to the total numerical global warming response, the change in CO2 efflux dominated the response in all treatments (ranging 71–96%), except for NO3− addition where 89% was due to change in CH4 emissions. Thus, in European peatlands and shrublands the feedback to global warming induced by the investigated anthropogenic disturbances will be dominated by variations in soil CO2 fluxes.

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What drives interaction strengths in complex food webs? A test with feeding rates of a generalist stream predator

10.1101/259697 ◽

2018 ◽

Author(s):

Daniel L. Preston ◽

Jeremy S. Henderson ◽

Landon P. Falke ◽

Leah M. Segui ◽

Tamara J. Layden ◽

...

Keyword(s):

Food Webs ◽

Body Mass ◽

Prey Density ◽

Scaling Laws ◽

Community Dynamics ◽

Abiotic Factors ◽

Interaction Strength ◽

Feeding Rates ◽

Predator Prey ◽

Mass Ratios

AbstractDescribing the mechanisms that drive variation in species interaction strengths is central to understanding, predicting, and managing community dynamics. Multiple factors have been linked to trophic interaction strength variation, including species densities, species traits, and abiotic factors. Yet most empirical tests of the relative roles of multiple mechanisms that drive variation have been limited to simplified experiments that may diverge from the dynamics of natural food webs. Here, we used a field-based observational approach to quantify the roles of prey density, predator density, predator-prey body-mass ratios, prey identity, and abiotic factors in driving variation in feeding rates of reticulate sculpin (Cottus perplexus). We combined data on over 6,000 predator-prey observations with prey identification time functions to estimate 289 prey-specific feeding rates at nine stream sites in Oregon. Feeding rates on 57 prey types showed an approximately log-normal distribution, with few strong and many weak interactions. Model selection indicated that prey density, followed by prey identity, were the two most important predictors of prey-specific sculpin feeding rates. Feeding rates showed a positive, accelerating relationship with prey density that was inconsistent with predator saturation predicted by current functional response models. Feeding rates also exhibited four orders-of-magnitude in variation across prey taxonomic orders, with the lowest feeding rates observed on prey with significant anti-predator defenses. Body-mass ratios were the third most important predictor variable, showing a hump-shaped relationship with the highest feeding rates at intermediate ratios. Sculpin density was negatively correlated with feeding rates, consistent with the presence of intraspecific predator interference. Our results highlight how multiple co-occurring drivers shape trophic interactions in nature and underscore ways in which simplified experiments or reliance on scaling laws alone may lead to biased inferences about the structure and dynamics of species-rich food webs.

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Temperature alters the physiological response of spiny lobsters under predation risk

Conservation Physiology ◽

10.1093/conphys/coaa065 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Felipe A Briceño ◽

Quinn P Fitzgibbon ◽

Elias T Polymeropoulos ◽

Iván A Hinojosa ◽

Gretta T Pecl

Keyword(s):

Climate Change ◽

Predation Risk ◽

Environmental Changes ◽

Environmental Drivers ◽

Climate Change Scenarios ◽

Metabolic Rates ◽

Energetic Costs ◽

Predator Prey ◽

Predator Prey Model ◽

Spiny Lobsters

Abstract Predation risk can strongly shape prey ecological traits, with specific anti-predator responses displayed to reduce encounters with predators. Key environmental drivers, such as temperature, can profoundly modulate prey energetic costs in ectotherms, although we currently lack knowledge of how both temperature and predation risk can challenge prey physiology and ecology. Such uncertainties in predator–prey interactions are particularly relevant for marine regions experiencing rapid environmental changes due to climate change. Using the octopus (Octopus maorum)–spiny lobster (Jasus edwardsii) interaction as a predator–prey model, we examined different metabolic traits of sub adult spiny lobsters under predation risk in combination with two thermal scenarios: ‘current’ (20°C) and ‘warming’ (23°C), based on projections of sea-surface temperature under climate change. We examined lobster standard metabolic rates to define the energetic requirements at specific temperatures. Routine metabolic rates (RMRs) within a respirometer were used as a proxy of lobster activity during night and day time, and active metabolic rates, aerobic scope and excess post-exercise oxygen consumption were used to assess the energetic costs associated with escape responses (i.e. tail-flipping) in both thermal scenarios. Lobster standard metabolic rate increased at 23°C, suggesting an elevated energetic requirement (39%) compared to 20°C. Unthreatened lobsters displayed a strong circadian pattern in RMR with higher rates during the night compared with the day, which were strongly magnified at 23°C. Once exposed to predation risk, lobsters at 20°C quickly reduced their RMR by ~29%, suggesting an immobility or ‘freezing’ response to avoid predators. Conversely, lobsters acclimated to 23°C did not display such an anti-predator response. These findings suggest that warmer temperatures may induce a change to the typical immobility predation risk response of lobsters. It is hypothesized that heightened energetic maintenance requirements at higher temperatures may act to override the normal predator-risk responses under climate-change scenarios.

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Temperature and Estrogen Alter Predator–Prey Interactions between Fish Species

Integrative Organismal Biology ◽

10.1093/iob/obaa008 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

J L Ward ◽

V Korn ◽

A N Auxier ◽

H L Schoenfuss

Keyword(s):

Prey Capture ◽

Abiotic Factors ◽

Pimephales Promelas ◽

Lepomis Macrochirus ◽

Environmental Estrogens ◽

Fathead Minnows ◽

Predator Prey ◽

Food Web Interactions ◽

Capture Success ◽

High Concentrations

Synopsis A variety of environmental estrogens are commonly detected in human-impacted waterways. Although much is known about the effects of these environmental estrogens on the reproductive physiology and behavior of individuals within species, comparatively less is known about how these compounds alter the outcomes of interactions between species. Furthermore, few studies have considered how the effects of contaminants are modulated by natural variation in abiotic factors, such as temperature. To help fill this knowledge gap, we conducted a factorial experiment to examine the independent and combined effects of estrone (E1) and temperature on the outcome of predator–prey interactions between two common North American freshwater fishes, fathead minnows (Pimephales promelas) and bluegill sunfish (Lepomis macrochirus). Larval fathead minnows and adult sunfish were exposed to either a low (mean±standard deviation, 90.1 ± 18 ng/L; n = 16) or high (414 ± 147 ng/L; n = 15) concentration of E1 or to a solvent control for 30 days at one of four natural seasonal temperatures (15°C, 18°C, 21°C, and 24°C) before predation trials were performed. Exposure to E1 was associated with a significant increase in larval predation mortality that was independent of temperature. Across all temperature treatments, approximately 74% of control minnows survived; this survivorship significantly exceeded that of minnows exposed to either concentration of E1 (49% and 53% for minnows exposed to the low and high concentrations, respectively). However, exposure to E1 also impaired the prey-capture success of sunfish, partially mitigating predation pressure on exposed minnows. Overall prey-capture success by sunfish showed an inverted U-shaped distribution with temperature, with maximal prey consumption occurring at 21°C. This study illustrates the vulnerability of organismal interactions to estrogenic pollutants and highlights the need to include food web interactions in assessments of risk.

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Environmental factors influencing fine-scale distribution of Antarctica’s only endemic insect

Oecologia ◽

10.1007/s00442-020-04714-9 ◽

2020 ◽

Vol 194 (4) ◽

pp. 529-539

Author(s):

Leslie J. Potts ◽

J. D. Gantz ◽

Yuta Kawarasaki ◽

Benjamin N. Philip ◽

David J. Gonthier ◽

...

Keyword(s):

Antarctic Peninsula ◽

Spatial Scales ◽

Abiotic Factors ◽

Ecological Factors ◽

Biotic Interactions ◽

Species Distributions ◽

Biotic Factors ◽

Belgica Antarctica ◽

Abiotic And Biotic Factors ◽

The Antarctic

AbstractSpecies distributions are dependent on interactions with abiotic and biotic factors in the environment. Abiotic factors like temperature, moisture, and soil nutrients, along with biotic interactions within and between species, can all have strong influences on spatial distributions of plants and animals. Terrestrial Antarctic habitats are relatively simple and thus good systems to study ecological factors that drive species distributions and abundance. However, these environments are also sensitive to perturbation, and thus understanding the ecological drivers of species distribution is critical for predicting responses to environmental change. The Antarctic midge, Belgica antarctica, is the only endemic insect on the continent and has a patchy distribution along the Antarctic Peninsula. While its life history and physiology are well studied, factors that underlie variation in population density within its range are unknown. Previous work on Antarctic microfauna indicates that distribution over broad scales is primarily regulated by soil moisture, nitrogen content, and the presence of suitable plant life, but whether these patterns are true over smaller spatial scales has not been investigated. Here we sampled midges across five islands on the Antarctic Peninsula and tested a series of hypotheses to determine the relative influences of abiotic and biotic factors on midge abundance. While historical literature suggests that Antarctic organisms are limited by the abiotic environment, our best-supported hypothesis indicated that abundance is predicted by a combination of abiotic and biotic conditions. Our results are consistent with a growing body of literature that biotic interactions are more important in Antarctic ecosystems than historically appreciated.

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