Effects of macroinfauna sediment disturbance on nematode vertical distribution

2006 ◽  
Vol 86 (2) ◽  
pp. 227-233 ◽  
Author(s):  
T.K. Pinto ◽  
M.C. Austen ◽  
C.E. Bemvenuti
Keyword(s):  
Community Structure ◽  
Vertical Distribution ◽  
Distribution Patterns ◽  
Trophic Groups ◽  
Southern Brazil ◽  
Sediment Disturbance ◽  
Subtropical Estuary ◽  
Sediment Layers ◽  
Deposit Feeding ◽  
The Vertical Distribution

Within a subtropical estuary in southern Brazil, an experiment was carried out to test the hypotheses that the deposit feeding macrofaunal polychaete Laeonereis acuta affects nematode community structure and the vertical distribution patterns of nematodes in sediments. Inclusion cages were deployed with two different densities of the polychaete and meiofaunal nematodes were sampled from six different vertical sediment layers: 0–1, 1–2, 2–4, 4–6, 6–8 and 8–10 cm depth. Although L. acuta did change the vertical distribution of both nematode and trophic groups in the sediment, allowing nematodes to inhabit deeper sediment layers, there were no apparent effects of different polychaete densities.

scholarly journals Community structure and vertical distribution of oncaeid copepods in Tosa Bay, southern Japan

2009 ◽  
Vol 89 (3) ◽  
pp. 491-498 ◽  
Author(s):  
Yuichiro Nishibe ◽  
Yuuichi Hirota ◽  
Hiroshi Ueda
Keyword(s):  
Community Structure ◽  
Vertical Distribution ◽  
Water Column ◽  
Distribution Patterns ◽  
Depth Range ◽  
Tosa Bay ◽  
Southern Japan ◽  
Hydrographic Conditions ◽  
Epipelagic Zone ◽  
The Vertical Distribution

Community structure and vertical distribution of oncaeid copepods were investigated at an offshore site in Tosa Bay, southern Japan. Samples were collected with a 0.063 mm closing type net from eight discrete layers between the surface and 500 m depth in August and November 2005. A total of 45 species and three form variants belonging to the genera Triconia, Oncaea, Spinoncaea, Conaea and Epicalymma were identified. The greatest number of species was consistently found in the lower epipelagic zone, at 50–100 m. The vertical distribution patterns of oncaeid copepods were similar between August and November, with the highest abundances in the upper epipelagic zone above the thermocline. The oncaeid maxima corresponded with the depth where appendicularians occurred in high numbers. Dominant species in the water column (0–500 m) were O. venusta small form, O. media, O. scottodicarloi, O. waldemari, O. zernovi, O. tregoubovi, S. ivlevi, S. tenuis and T. conifera. The vertical succession of species composition was almost the same between August and November, although several species showed a downward shift of their depth-range to some extent in November. The oncaeid copepod community could be differentiated into three distinct groups according to the depth layers, each corresponding to different hydrographic conditions in the water column.

Vertical distribution pattern of naidids in granular activated carbon filters and potential technology to control their penetration risk

2018 ◽  
Vol 18 (6) ◽  
pp. 1976-1983
Author(s):  
Xiao-Bao Nie ◽  
Yun-Zi Tang ◽  
Chang-bo Jiang ◽  
Yuan-Nan Long ◽  
Pan-Pan He ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Vertical Distribution ◽  
Distribution Pattern ◽  
Granular Activated Carbon ◽  
Distribution Patterns ◽  
Distribution Data ◽  
Vertical Distribution Pattern ◽  
Filter Bed ◽  
The Vertical Distribution

Abstract Aquatic worms propagated in granular activated carbon (GAC) filter has become a troublesome problem for drinking water supply. This study investigated the vertical distribution patterns of naidids in GAC filter beds and assessed the effect of an additional sand bed, located below the GAC bed, in preventing naidids from being present in effluent. The results indicated that the vertical distribution data of naidids in the GAC filter bed were well fitted by a Gaussian distribution, and the location of peak population density was mainly affected by downward flow. Backwashing experiments revealed that additional pressure air scouring shifted the distribution pattern of naidids in the GAC filter bed, resulting in a significant enhancement in naidid removal efficiency. Additionally, the addition of a sand bed exhibited pronounced interception and inactivation effects on naidids, suggesting that it may be a very promising technology for preventing naidids propagated in GAC filters from being present in the effluent.

scholarly journals Deep Soil Layers of Drought-Exposed Forests Harbor Poorly Known Bacterial and Fungal Communities

2021 ◽  
Vol 12 ◽  
Author(s):  
Beat Frey ◽  
Lorenz Walthert ◽  
Carla Perez-Mon ◽  
Beat Stierli ◽  
Roger Köchli ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Vertical Distribution ◽  
Soil Depth ◽  
Shannon Index ◽  
Fungal Communities ◽  
Soil Microbiome ◽  
Deep Soil ◽  
Soil Layers ◽  
The Vertical Distribution

Soil microorganisms such as bacteria and fungi play important roles in the biogeochemical cycling of soil nutrients, because they act as decomposers or are mutualistic or antagonistic symbionts, thereby influencing plant growth and health. In the present study, we investigated the vertical distribution of the soil microbiome to a depth of 2 m in Swiss drought-exposed forests of European beech and oaks on calcareous bedrock. We aimed to disentangle the effects of soil depth, tree (beech, oak), and substrate (soil, roots) on microbial abundance, diversity, and community structure. With increasing soil depth, organic carbon, nitrogen, and clay content decreased significantly. Similarly, fine root biomass, microbial biomass (DNA content, fungal abundance), and microbial alpha-diversity decreased and were consequently significantly related to these physicochemical parameters. In contrast, bacterial abundance tended to increase with soil depth, and the bacteria to fungi ratio increased significantly with greater depth. Tree species was only significantly related to the fungal Shannon index but not to the bacterial Shannon index. Microbial community analyses revealed that bacterial and fungal communities varied significantly across the soil layers, more strongly for bacteria than for fungi. Both communities were also significantly affected by tree species and substrate. In deep soil layers, poorly known bacterial taxa from Nitrospirae, Chloroflexi, Rokubacteria, Gemmatimonadetes, Firmicutes and GAL 15 were overrepresented. Furthermore, archaeal phyla such as Thaumarchaeota and Euryarchaeota were more abundant in subsoils than topsoils. Fungal taxa that were predominantly found in deep soil layers belong to the ectomycorrhizal Boletus luridus and Hydnum vesterholtii. Both taxa are reported for the first time in such deep soil layers. Saprotrophic fungal taxa predominantly recorded in deep soil layers were unknown species of Xylaria. Finally, our results show that the microbial community structure found in fine roots was well represented in the bulk soil. Overall, we recorded poorly known bacterial and archaeal phyla, as well as ectomycorrhizal fungi that were not previously known to colonize deep soil layers. Our study contributes to an integrated perspective on the vertical distribution of the soil microbiome at a fine spatial scale in drought-exposed forests.

scholarly journals Pollen-ovule relation in Adesmia tristis and reflections on the seed–ovule ratio by interaction with pollinators in two vertical strata

2014 ◽  
Vol 86 (3) ◽  
pp. 1327-1336 ◽  
Author(s):  
NADILSON R. FERREIRA ◽  
LUCIA B. FRANKE ◽  
BETINA BLOCHTEIN
Keyword(s):  
Vertical Distribution ◽  
Breeding System ◽  
Vertical Profile ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Catholic University ◽  
Pollination Deficit ◽  
Foraging Pattern ◽  
The Vertical Distribution

The vertical distribution of pollinators is an important component in the foraging pattern of plants strata, and it influences the reproductive system (pollen/ovule ratio) and seed/ovule ratio. Niches in two different strata from Adesmia tristis Vogel were evaluated in these aspects. This plant is an endemic shrub from the Campos de Cima da Serra in Southern Brazil. The studies were carried out from January 2010, to January 2011, at Pró-Mata/PUCRS (Catholic University of Rio Grande do Sul) (29°27′-29°35′S and 50°08′-50°15′W), São Francisco de Paula, sate of Rio Grande do Sul, Brazil. Breeding system of A. tristis is mandatory allogamy. The vertical profile in A. tristis has differentiated foraging niches among the most common pollinators. Bees of Megachile genus forage in the upper stratum, and representative bees of the Andrenidae family explore the lower stratum. The upper stratum of the vertical profile had more contribution to seed production. Adesmia tristis showed evidence of pollination deficit.

Diel vertical distribution of fish larvae during the winter-mixing period in the Northwestern Mediterranean

2004 ◽  
Vol 61 (8) ◽  
pp. 1243-1252 ◽  
Author(s):  
A. Sabatés
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Fish Species ◽  
Fish Larvae ◽  
Distribution Patterns ◽  
Diel Variation ◽  
Surface Layers ◽  
Light Levels ◽  
Vertical Distributions ◽  
The Vertical Distribution

Abstract The vertical distributions of the larvae of shelf and oceanic fish species that spawn during the winter-mixing period in the Mediterranean are described from 22 vertically stratified plankton tows. Diel differences in the vertical distribution patterns in relation to physical data and potential prey abundance throughout the water column were examined. Even in absence of stratification, the larvae of the various fish species showed different patterns of vertical distribution and diel changes. The larvae of shelf-dwelling species were found in the surface layers, mainly above 50-m depth, and with some exceptions, with very little diel variation in depth distribution. Therefore, the vertical distribution of the larvae of these species coincided with the maximum concentrations of their potential food, nauplii and copepodite stages of copepods. The larvae of mesopelagic fishes showed deeper distributions in the water column and most of these species were located closer to the surface during the day than at night. Given the homogeneity of the physical characteristics throughout the water column, except for light, this behaviour may be determined not only by the higher concentration of prey in the surface layers but also by adequate light levels for feeding.

scholarly journals Community structure and tree diversity in a subtropical forest in southern Brazil

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Kauane Maiara Bordin ◽  
Letícia Daiana Ferreira ◽  
Adriano Rosina ◽  
Marciana Malacarne ◽  
Patricia Zanotelli ◽  
...  
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Distribution Patterns ◽  
Taxonomic Diversity ◽  
Abundant Species ◽  
Subtropical Forest ◽  
Southern Brazil ◽  
Floristic Similarity ◽  
Thermal Amplitude ◽  
Linkage Method

Abstract: Local and regional environmental variations lead to different species composition, creating transitional areas. An example is the Araucaria and Seasonal forest in southern Brazil. Our objectives were (1) to describe the tree community structure and composition of a subtropical forest in southern Brazil and (2) to compare the floristic relationships between two forest typologies (Araucaria and Seasonal forest) in order to characterize the study area and the distribution patterns of tree species. We conducted a survey at Chapecó National Forest (in southern Brazil) in an area of 1.2 ha, where all individuals ≥ 30 cm of circumference at breast height were sampled. Community structure was described using the traditional phytosociological parameters. The floristic relationships were obtained by comparing our results with compiled data from other scientific papers through cluster analyses using an unweighted average linkage method, based on Jaccard similarity coefficient. We sampled 809 individuals belonging to 61 species and 28 families. The richest family was Fabaceae and Coussarea contracta (Walp.) Müll.Arg. was the most abundant species. Taxonomic diversity was 3.06 and the evenness was 0.74. The floristic similarity revealed that species composition of our study area is more similar to Seasonal forest. Species composition is related to environmental factors such as great thermal amplitude and seasonality. This subtropical forest is well structured, highly diverse and extremely important for the local and regional biodiversity conservation.

scholarly journals Ichthyofaunal diversity and vertical distribution patterns in the rockpools of the southwestern coast of Yaku-shima Island, southern Japan

Check List ◽  
2015 ◽  
Vol 11 (4) ◽  
pp. 1682 ◽  
Author(s):  
Atsunobu Murase
Keyword(s):  
Species Richness ◽  
Vertical Distribution ◽  
Distribution Patterns ◽  
Habitat Partitioning ◽  
Northwest Pacific ◽  
Transient Species ◽  
Southern Japan ◽  
Voucher Specimens ◽  
The Vertical Distribution ◽  
The Western Pacific

The community composition of rockpool fish on the southwestern coast of Yaku-shima Island, southern Japan, in the northwest Pacific was investigated by sampling of 22 rockpools and recording the range of vertical heights (a total of 76 sampling events from May 2009 to February 2010). A total of 72 species belonging to 19 families were collected from the study site. This species richness is the highest recorded of similar studies undertaken worldwide, reflecting the highest diversity of coastal fishes in the western Pacific. Increases in species richness due to transient and accidental visitors increased the total number of species in the lower vertical zones. Variations in the vertical distribution pattern of the resident and transient species suggests habitat partitioning and/or physical preferences for a particular habitat of each species. Color images of rockpool fish recorded at the site and a list of all the voucher specimens are provided.

scholarly journals Diversity and distribution of the millipedes (Diplopoda) of Georgia, Caucasus

ZooKeys ◽  
2020 ◽  
Vol 930 ◽  
pp. 199-219
Author(s):  
Mzia S. Kokhia ◽  
Sergei I. Golovatch
Keyword(s):  
Vertical Distribution ◽  
Distribution Patterns ◽  
Future Research ◽  
The Caucasus ◽  
Karst Caves ◽  
Black Sea Coast ◽  
West Black Sea ◽  
Alpine Environments ◽  
The Vertical Distribution ◽  
Sea Coast

The diplopod fauna of Georgia, Transcaucasia, is very rich given the country’s relatively small territory; it presently comprises 103 species from 44 genera, 12 families, and 7 orders. Most of the Diplopoda known from Georgia (86 species, or 83%) demonstrate Caucasian distribution patterns, 36 and 46 species, as well as 8 and 9 genera being endemic or subendemic to the country, respectively. A single Holarctic family, Anthroleucosomatidae (order Chordeumatida), contains 44 Caucasian species and 20 genera, of which 27 species and 14 genera are endemic or subendemic to Georgia. Likewise, all species from the orders Polyzoniida, Siphonocryptida, Glomerida and Chordeumatida, as well as most species of Julida and Polydesmida are native, also endemic or subendemic to the Caucasus, but the genera and families they represent are widely distributed at least across the Euro-Mediterranean Realm. Most of the presumed troglobionts in the Caucasus appear to be confined to western Georgia’s karst caves (14 species, 5 genera). Within Georgia, the fauna of the western part (= Colchis) is particularly rich and diverse, while that of the central and eastern parts of the country grows increasingly depauperate inland following the gradual climatic aridisation from west (Black Sea coast) to east (Armenia and Azerbaijan). The vertical distribution of the Diplopoda in Georgia, as well as the Caucasus generally, shows the bulk of the fauna restricted to forested lowland to mountain biomes or their remnants. Only very few Chordeumatida and Julus species seem to occur solely in the subalpine to alpine environments and thus may provisionally be considered as high-montane elements. Ongoing and future research on the millipedes of the Caucasus, especially in cave and montane environments, will undoubtedly allow for many more novelties and details of the diversity and distribution of Georgia’s Diplopoda to be revealed or refined.

scholarly journals Reverse engineering field-derived vertical distribution profiles to infer larval swimming behaviors

2019 ◽  
pp. 201900238 ◽  
Author(s):  
M. K. James ◽  
J. A. Polton ◽  
A. R. Brereton ◽  
K. L. Howell ◽  
W. A. M. Nimmo-Smith ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
State Of The Art ◽  
Distribution Patterns ◽  
Environmental Cues ◽  
Biophysical Models ◽  
Marine Larvae ◽  
In Situ Observations ◽  
The Vertical Distribution ◽  
Larval Swimming

Biophysical models are well-used tools for predicting the dispersal of marine larvae. Larval behavior has been shown to influence dispersal, but how to incorporate behavior effectively within dispersal models remains a challenge. Mechanisms of behavior are often derived from laboratory-based studies and therefore, may not reflect behavior in situ. Here, using state-of-the-art models, we explore the movements that larvae must undertake to achieve the vertical distribution patterns observed in nature. Results suggest that behaviors are not consistent with those described under the tidally synchronized vertical migration (TVM) hypothesis. Instead, we show (i) a need for swimming speed and direction to vary over the tidal cycle and (ii) that, in some instances, larval swimming cannot explain observed vertical patterns. We argue that current methods of behavioral parameterization are limited in their capacity to replicate in situ observations of vertical distribution, which may cause dispersal error to propagate over time, due to advective differences over depth and demonstrate an alternative to laboratory-based behavioral parameterization that encompasses the range of environmental cues that may be acting on planktic organisms.

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