scholarly journals Effects of a natural precipitation gradient on fish and macroinvertebrate assemblages in coastal streams

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12137
Author(s):  
Sean Kinard ◽  
Christopher J. Patrick ◽  
Fernando Carvallo
Keyword(s):  
Water Cycle ◽  
Habitat Characteristics ◽  
Predatory Fish ◽  
Fish Diversity ◽  
Precipitation Gradient ◽  
Rainfall Gradient ◽  
Coastal Prairie ◽  
Environmentally Sensitive ◽  
Water Ecosystems ◽  
Semi Arid

Anthropogenic climate change is expected to increase the aridity of many regions of the world. Surface water ecosystems are particularly vulnerable to changes in the water-cycle and may suffer adverse impacts in affected regions. To enhance our understanding of how freshwater communities will respond to predicted shifts in water-cycle dynamics, we employed a space for time approach along a natural precipitation gradient on the Texas Coastal Prairie. In the spring of 2017, we conducted surveys of 10 USGS-gauged, wadeable streams spanning a semi-arid to sub-humid rainfall gradient; we measured nutrients, water chemistry, habitat characteristics, benthic macroinvertebrates, and fish communities. Fish diversity correlated positively with precipitation and was negatively correlated with conductivity. Macroinvertebrate diversity peaked within the middle of the gradient. Semi-arid fish and invertebrate communities were dominated by euryhaline and live-bearing taxa. Sub-humid communities contained environmentally sensitive trichopterans and ephemeropterans as well as a variety of predatory fish which may impose top-down controls on primary consumers. These results warn that aridification coincides with the loss of competitive and environmentally sensitive taxa which could yield less desirable community states.

Soil erosion controlled by biota along a climate gradient in Chile

2020 ◽  
Author(s):  
Nicolás Riveras ◽  
Kristina Witzgall ◽  
Victoria Rodríguez ◽  
Peter Kühn ◽  
Carsten W. Mueller ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Biological Soil Crust ◽  
Environmental Filtering ◽  
Soil Surface ◽  
Climatic Conditions ◽  
Rainfall Simulation ◽  
Soil Erodibility ◽  
Rainfall Gradient ◽  
The Impact ◽  
Semi Arid

<p>Soil erosion is one of the main problems in soil degradation nowadays and is widely distributed in many landscapes worldwide. Particularly water erosion is widespread and determined by rain erosivity, soil erodibility, topographic factors and the management carried out to mitigate this phenomenon. Although this process is mostly known as a consequence of human management such as agriculture or forestry, it is a process that also occurs naturally, being one of the factors that regulate the shape of the landscape.</p><p>One of the main agents that stabilize the soil surface is biota and its activity, either in the form of plants, microorganisms or as an assemblage in the form of a biological soil crust (biocrusts). However, there are limited studies about how and what extent biota drives soil-stabilizing processes. With particular view on the impact of biocrusts on soil erosion, most studies have been carried out in arid and semi-arid regions, so its influence under other climates is largely unknown.</p><p>This study focuses on the influence of biota on soil erosion in a temperature and rainfall gradient, covering four climate zones (arid, semi-arid, mediterranean and humid) with very limited human intervention. Other variables such as the origin of the geological formation, geographical longitude and glacial influence were kept constant for all study sites. The effect of vegetation (biocrusts) and its abundance, microbiology and terrain parameters are investigated using rainfall simulation experiments under controlled conditions and by a physico-chemical evaluation of the soil, surface runoff, percolation and sediment discharge, in order to determine the different environmental filtering effects that the soil develops under different climatic conditions.</p><p>It is expected that as vegetation vigor and cover increase, soil erodibility will decrease. The biocrust is the protagonist of this stabilization in conditions of low pedological development and will become secondary as edaphoclimatic conditions favor the colonization of plants.</p><p>The results of this study will help to achieve a better understanding of the role of biota in soil erosion control and will clarify its influence on soil losses under different climate and slope conditions. Analyses are currently ongoing and first results of our work will be presented at the EGU 2020.</p>

Does habitat complexity influence the ability of fathead minnows to learn heterospecific chemical alarm cues?

2003 ◽  
Vol 81 (5) ◽  
pp. 923-927 ◽  
Author(s):  
M S Pollock ◽  
D P Chivers
Keyword(s):  
Habitat Complexity ◽  
Complex Structure ◽  
Pimephales Promelas ◽  
Ecological Factors ◽  
Habitat Characteristics ◽  
Predatory Fish ◽  
Skin Extract ◽  
Alarm Cues ◽  
Fathead Minnows ◽  
Chemical Alarm Cues

Numerous aquatic animals release chemical cues when attacked by a predator. These cues "warn" other individuals of danger and have been termed alarm cues. Cross-species responses to alarm cues are common and in some cases result from learned recognition. However, little is known about the ecological factors that could influence this learned recognition. The current study focuses on the role of habitat complexity in the learning of heterospecific alarm cues. We introduced brook stickleback (Culaea inconstans) into outdoor pools containing fathead minnows (Pimephales promelas) naïve to stickleback. The pools all contained a predatory fish (northern pike, Esox lucius) but varied in habitat characteristics. Pools representing high-complexity habitats had a large amount of structure to obscure the visual environment, while pools representing low-complexity habitats had minimal structure. After 8 days, fish were removed from the pools and behavioural assays were conducted in the laboratory. We tested the minnows for a response to either stickleback skin extract (experimental) or swordtail (Xiphophorus helleri) skin extract (control) and found that minnows conditioned in pools with little structure had learned to recognize stickleback alarm cues, while those from pools with complex structure did not recognize stickleback alarm cues.

Population and habitat characteristics of caracal in semi-arid landscape, western India

2014 ◽  
Vol 103 ◽  
pp. 92-95 ◽  
Author(s):  
Randeep Singh ◽  
Qamar Qureshi ◽  
Kalyanasundaram Sankar ◽  
Paul R. Krausman ◽  
Surendra Prakash Goyal
Keyword(s):  
Habitat Characteristics ◽  
Western India ◽  
Semi Arid

scholarly journals Preliminary results of the Analysis of Precipitation Processes in the Eastern Ebro Subbasin (WISE-PreP) Field Campaign within HILIAISE

2021 ◽  
Author(s):  
Joan Bech ◽  
Mireia Udina ◽  
Bernat Codina ◽  
Sergi Gonzalez ◽  
Albert Garcia ◽  
...  
Keyword(s):  
Land Surface ◽  
Water Cycle ◽  
Weather Prediction ◽  
Surface Characteristics ◽  
Ensemble Prediction ◽  
Field Campaign ◽  
Preliminary Results ◽  
The World ◽  
Precipitation Processes ◽  
Semi Arid

<p>Understanding future changes of the terrestrial water cycle and their interaction with human activity, with emphasis on agricultural areas, was selected as one of the World Climate Research Programme (WCRP) Grand Challenges, entitled “Water for the Food Baskets of the World”. Within this framework, the scientific objectives of the “Human Imprint on Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment” (HILIAISE) are the characterization of evapotranspiration and other key processes of water cycle in semi-arid environments. For this purpose, an international field campaign, scheduled for 2021, has been planned focused on a region with highly contrast surface characteristics (irrigated vs non-irrigated areas), particularly during summer.</p><p>An overview and preliminary results of a specific project (WISE-PreP) within HILIAISE is given here. WISE-PreP was designed to study precipitation processes aiming to characterize possible differences in precipitation induced by surface characteristics. For this purpose, planned instrumentation for the campaign includes the deployment of three sites equipped each with a vertical radar Doppler Micro Rain Radar (MRR) and a laser disdrometer (PARSIVEL), covering both irrigated and non-irrigated sites, with three disdrometers (model PARSIVEL-2) and three MRRs (one model MRR-2 and two MRR-PROs). Time series of vertical precipitation profiles will be recorded to study microphysical processes trough the evolution of raindrop size distributions and related variables including precipitation intensity or convective vs stratiform rainfall regimes. Additional observations include raingauge data, C-band Doppler weather radar observations, and satellite products, as well as high resolution deterministic numerical weather prediction model data plus Ensemble Prediction Systems (EPS) model output. Funding for this research was provided by “Analysis of Precipitation Processes in the Eastern Ebro Subbasin” (WISE-PreP, RTI2018-098693-B-C32) and the Water Research Institute (IdRA) of the University of Barcelona.</p>

scholarly journals Mineralogia de luvissolos formados sob gradiente pluviométrico no semiárido Paraibano / Mineralogy of luvisols formed under rainfall gradient in the semi-arid region of Paraíba

2020 ◽  
Vol 3 (4) ◽  
pp. 4416-4433
Author(s):  
Sebastiana Maely Saraiva ◽  
Vânia da Silva Fraga ◽  
José Coelho de Araújo Filho ◽  
Roseilton Fernandes dos Santos ◽  
Evaldo dos Santos Felix ◽  
...  
Keyword(s):  
Arid Region ◽  
Rainfall Gradient ◽  
Semi Arid Region ◽  
Semi Arid

scholarly journals Pulse Effect of Precipitation: Spatial Patterns and Mechanisms of Soil Carbon Emissions

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhaoxia Jiang ◽  
Hongfeng Bian ◽  
Li Xu ◽  
Mingxu Li ◽  
Nianpeng He
Keyword(s):  
Arid Regions ◽  
Scientific Basis ◽  
Climate Change Scenarios ◽  
Precipitation Gradient ◽  
Desert Grassland ◽  
Pulse Effect ◽  
Simulated Precipitation ◽  
Precipitation Pulses ◽  
Semi Arid ◽  
Grassland Types

The rapid and strong release of CO2 caused by precipitation (known as the pulse effect) is a common phenomenon that significantly affects ecosystem C cycling. However, the degree to which the pulse effect occurs overlarge regional scales remains unclear. In this study, we conducted continuous and high-frequency measurements of soil CO2 release rates (Rs) for 48 h after simulated precipitation, along a precipitation gradient of different grassland types (i.e., meadow, typical, and desert) in Inner Mongolia, China. Pulse effects were assessed using the maximum Rs (Rsoil–max) and accumulated CO2 emissions (ARs–soil). Strong precipitation pulse effects were found in all sites; however, the effects differed among grassland types. In addition, an apparent decrease in both Rsoil–max and ARs–soil was observed from the east to west, i.e., along the decreasing precipitation gradient. ARs–soil values followed the order: temperate meadow grassland (0.097 mg C g–1 soil) > typical temperate grassland (0.081 mg C g–1 soil) > temperate desert grassland (0.040 mg C g–1 soil). Furthermore, Rsoil–max and ARs–soil were significantly positively correlated with soil quality (SOC, POC, and N, etc.; P < 0.01). ARs–soil (P < 0.05) and ARs–SOC (P < 0.01) were significantly affected. ARs–soil and ARs–SOC were also positively correlated with soil microbial biomass significantly (P < 0.05). Rsoil–max and ARs–soil had similar spatial variations and controlling mechanisms. These results greatly support the substrate supply hypothesis for the effects of precipitation pulses, and provide valuable information for predicting CO2 emissions. Our findings also verified the significant effect of soil CO2 release from precipitation pulses on the grasslands of arid and semi-arid regions. Our data provide a scientific basis for model simulations to better predict the responses of ecosystem carbon cycles in arid and semi-arid regions under predicted climate change scenarios.

scholarly journals First record of exotic alligator gar, Atractosteus spatula (Actinopterygii: Lepisosteiformes: Lepisosteidae), from Ganga River system, India: A possible threat to indigenous riverine fish diversity

2021 ◽  
Vol 51 (4) ◽  
pp. 385-391
Author(s):  
Ranjan Kumar Manna ◽  
Archisman Ray ◽  
Supriti Bayen ◽  
Tanushree Bera ◽  
Debashis Palui ◽  
...  
Keyword(s):  
Environmental Parameters ◽  
River System ◽  
First Record ◽  
Ganga River ◽  
Predatory Fish ◽  
Fish Diversity ◽  
Exotic Fish ◽  
Alligator Gar ◽  
Riverine Fish ◽  
Atractosteus Spatula

A new record of an exotic alligator gar, Atractosteus spatula (Lacepède, 1803), from an open wetland of the Ganga River was presented in this paper and discussed along with the environmental parameters. Entry of the exotic fish into the natural system was probably a result of uncontrolled ornamental fish trading. Considering threats of this predatory fish to become invasive and disturb riverine fish diversity, possible ways to avoid such risk have been discussed.

scholarly journals Fish diversity in freshwater and brackish water ecosystems of Russia and adjacent waters

2020 ◽  
Vol 45 ◽  
pp. 47-116
Author(s):  
YURY V. DYLDIN ◽  
LUBOMIR HANEL ◽  
RONALD FRICKE ◽  
ALEXEI M. ORLOV ◽  
VLADIMIR I. ROMANOV ◽  
...  
Keyword(s):  
Brackish Water ◽  
Fish Diversity ◽  
Water Ecosystems

scholarly journals Ichthyofaunal Diversity and Physico-Chemical Factors of Melamchi River, Sindhupalchok, Nepal

2016 ◽  
Vol 21 (1) ◽  
pp. 10-18
Author(s):  
Abha R. Mishra ◽  
Chitra Bahadur Baniya
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Diversity Index ◽  
Chemical Properties ◽  
Habitat Characteristics ◽  
Fish Diversity ◽  
Physico Chemical ◽  
Chemical Factors ◽  
High Level

The fish community and physico-chemical properties at five sites of Melamchi River were studied monthly from January 2011 to December 2013.    Melamchi River is one of tributaries larger Indrawati River basin, originates from the high snowy Jugal Mountain (5,875 m asl). Eleven fish species within two orders and five families were recorded.   Cypriniformes  was  found  to  be  the  most  dominant  order  with  ten  fish  species. Schizothorax plagiostomus  was the most common fish species followed by  Neolissochilus hexagonolepis, and  Psilorhynchus pseudecheneis.  Shannon Wiener fish diversity index and species richness recorded were highest at site 2 and lowest at site 5, whereas, evenness index was highest at site 3. The cluster analysis revealed  that  similarity  between  fish  species  decreased  as  the  distance  between  the  sites  increased.  Fish species were found distributed among four groups with respect to the significant habitat characteristics in the redundancy analysis (RDA). River water was found well-oxygenated and alkaline at all sites. However, high level for turbidity (43.25/ NTU) was observed at site 5, which exceeded compliance levels of WHO indicating the influence of intensive agriculture and deforestation along river area. To improve fish diversity and water quality of this river proper monitoring and management are an urgent need.Journal of Institute of Science and TechnologyVolume 21, Issue 1, August 2016, Page: 10-18

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