scholarly journals A place in space - the horizontal vs vertical factors that influence zooplankton (Rotifera, Crustacea) communities in a mesotrophic lake

2019 ◽  
Vol 78 (2) ◽  
Author(s):  
Maciej Karpowicz ◽  
Jolanta Ejsmont-Karabin ◽  
Adam Więcko ◽  
Andrzej Górniak ◽  
Adam Cudowski

The factors that influence plankton distribution in lakes are currently widely debated. The primary objective of this study was to determine a combination of factors that influence the three-dimensional distribution patterns of both rotifer and crustacean communities in a pelagic ecosystem. We compared the abiotic (temperature, oxygen and nutrients) and biotic (phytoplankton) factors that affect the horizontal and vertical distribution of zooplankton in different habitat conditions in Lake Wigry. The results of our study indicate that the vertical gradient in a water profile is much more important for microcrustaceans than horizontal changes in environmental conditions, whereas Rotifera showed a strong spatial autocorrelation when connected with differences in trophic status. Generally, large zooplankton prefer cold, darker waters of the metalimnion-hypolimnion, while smaller zooplankton prefer the warm epilimnion. This niche segregation in water profiles promotes a large diversity of pelagic zooplankton. The vertical distribution of dominant Daphnia cucullata was strongly related to the phytoplankton distribution. Moreover, we found that the large-bodied Daphnia cucullata prefers the lower water layers, despite the presence of less optimal food resources, while smaller individuals clearly prefer the warm surface water with high quality resources.

1986 ◽  
Vol 43 (9) ◽  
pp. 1812-1817 ◽  
Author(s):  
C W. Pugsley ◽  
H. B. N. Hynes

Changes in the three-dimensional distribution patterns of stonefly nymphs, Allocapnia pygmaea, beneath the streambed in the Speed River, southern Ontario, were monitored throughout their 1-yr life cycle using 270 colonization chambers. These were filled with organism-free, sieved stream gravel and buried in vertical groups of three, at three depth intervals, in three trenches positioned across a riffle. Nymphs were present throughout the year. Seasonal changes in the distribution pattern of nymphs indicated that they were able to move beneath the streambed in both the horizontal and vertical planes. Nymphs were most abundant at depth during the summer diapause, but moved up to the surface once diapause had been broken in the autumn. There was no evidence of any bankwards migration of nymphs prior to emergence. We have therefore confirmed in detail previous suggestions that stream insects move freely into and out of the hyporheic, using it as a refuge from adverse conditions on the streambed. Stream ecologists should therefore be aware of the possibilities of movement to and from the hyporheic when working with benthic invertebrates.


2002 ◽  
Vol 205 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Tomoko Ishikawa ◽  
Yasuaki Ichikawa ◽  
Yoshiko Abe ◽  
Junzoh Kitoh ◽  
Kazuo Yamashita

2022 ◽  
Vol 22 (1) ◽  
pp. 139-153
Author(s):  
Xinqi Xu ◽  
Jielan Xie ◽  
Yuman Li ◽  
Shengjie Miao ◽  
Shaojia Fan

Abstract. The distribution of meteorological elements has always been an important factor in determining the horizontal and vertical distribution of particles in the atmosphere. To study the effect of meteorological elements on the three-dimensional distribution structure of particles, mobile vehicle lidar and fixed-location observations were collected in the western Guangdong–Hong Kong–Macao Greater Bay Area of China during September and October in 2019 and 2020. Vertical aerosol extinction coefficient, depolarization ratio, and wind and temperature profiles were measured using a micro pulse lidar, a Raman scattering lidar, and a Doppler wind profile lidar installed on a mobile monitoring vehicle. The mechanism of how wind and temperature in the boundary layer affects the horizontal and vertical distribution of particles was analysed. The results show that particles were mostly distributed in downstream areas on days with moderate wind speed in the boundary layer, whereas they were distributed homogeneously on days with weaker wind. There are three typical types of vertical distribution of particles in the western Guangdong–Hong Kong–Macao Greater Bay Area (GBA): surface single layer, elevated single layer, and double layer. Analysis of wind profiles and Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) backward trajectory reveals different sources of particles for the three types. Particles concentrating near the temperature inversion and multiple inversions could cause more than one peak in the extinction coefficient profile. There were two mechanisms affecting the distribution of particulate matter in the upper and lower boundary layers. Based on this observational study, a general model of meteorological elements affecting the vertical distribution of urban particulate matter is proposed.


2021 ◽  
Author(s):  
Xinqi Xu ◽  
Jielan Xie ◽  
Yuman Li ◽  
Shengjie Miao ◽  
Shaojia Fan

Abstract. The distribution of meteorological elements has always been an important factor in determining the horizontal and vertical distribution of particles in the atmosphere. To study the effect of meteorological elements on the three-dimensional distribution structure of particles, mobile vehicle lidar observations, and in situ observations were presented in the western Guangdong–Hong Kong–Macao Greater Bay Area of China during September and October of 2019 and 2020. Vertical aerosol extinction coefficient, depolarization ratio, wind and temperature profiles were measured by using a micro pulse lidar, a Raman scattering lidar, and a Doppler wind profile lidar installed on a mobile monitoring vehicle. The mechanism of how wind and temperature in the boundary layer affects the horizontal and vertical distribution of particles was analyzed. The result showed that particles were mostly distributed in downstream areas on days with moderate wind speed in the boundary layer, while they presented homogeneously on days with weaker wind. There are three typical types of vertical distribution of particles in the western Guangdong–Hong Kong–Macao Greater Bay Area (GBA): surface single layer, elevated single layer, and double layer. Analysis of wind profiles and Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) backward trajectory revealed different sources of particles for the three types. Particles concentrated near the temperature inversion and multiple inversions could cause more than one peak in the extinction coefficient profile. There are two mechanisms that affected the distribution of particulate matter in the upper and lower boundary layers. Based on observational study, a general model of meteorological elements affecting the vertical distribution of urban particulate matter was made.


2007 ◽  
Vol 73A (1) ◽  
pp. 16-21 ◽  
Author(s):  
Georges Jung ◽  
Eckart Wunder ◽  
Alain Dieterlen ◽  
Philippe Hénon ◽  
Serge Jacquey

Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.


2015 ◽  
Vol 6 (1) ◽  
pp. 19-29 ◽  
Author(s):  
G. Bitelli ◽  
P. Conte ◽  
T. Csoknyai ◽  
E. Mandanici

The management of an urban context in a Smart City perspective requires the development of innovative projects, with new applications in multidisciplinary research areas. They can be related to many aspects of city life and urban management: fuel consumption monitoring, energy efficiency issues, environment, social organization, traffic, urban transformations, etc. Geomatics, the modern discipline of gathering, storing, processing, and delivering digital spatially referenced information, can play a fundamental role in many of these areas, providing new efficient and productive methods for a precise mapping of different phenomena by traditional cartographic representation or by new methods of data visualization and manipulation (e.g. three-dimensional modelling, data fusion, etc.). The technologies involved are based on airborne or satellite remote sensing (in visible, near infrared, thermal bands), laser scanning, digital photogrammetry, satellite positioning and, first of all, appropriate sensor integration (online or offline). The aim of this work is to present and analyse some new opportunities offered by Geomatics technologies for a Smart City management, with a specific interest towards the energy sector related to buildings. Reducing consumption and CO2 emissions is a primary objective to be pursued for a sustainable development and, in this direction, an accurate knowledge of energy consumptions and waste for heating of single houses, blocks or districts is needed. A synoptic information regarding a city or a portion of a city can be acquired through sensors on board of airplanes or satellite platforms, operating in the thermal band. A problem to be investigated at the scale A problem to be investigated at the scale of the whole urban context is the Urban Heat Island (UHI), a phenomenon known and studied in the last decades. UHI is related not only to sensible heat released by anthropic activities, but also to land use variations and evapotranspiration reduction. The availability of thermal satellite sensors is fundamental to carry out multi-temporal studies in order to evaluate the dynamic behaviour of the UHI for a city. Working with a greater detail, districts or single buildings can be analysed by specifically designed airborne surveys. The activity has been recently carried out in the EnergyCity project, developed in the framework of the Central Europe programme established by UE. As demonstrated by the project, such data can be successfully integrated in a GIS storing all relevant data about buildings and energy supply, in order to create a powerful geospatial database for a Decision Support System assisting to reduce energy losses and CO2 emissions. Today, aerial thermal mapping could be furthermore integrated by terrestrial 3D surveys realized with Mobile Mapping Systems through multisensor platforms comprising thermal camera/s, laser scanning, GPS, inertial systems, etc. In this way the product can be a true 3D thermal model with good geometric properties, enlarging the possibilities in respect to conventional qualitative 2D images with simple colour palettes. Finally, some applications in the energy sector could benefit from the availability of a true 3D City Model, where the buildings are carefully described through three-dimensional elements. The processing of airborne LiDAR datasets for automated and semi-automated extraction of 3D buildings can provide such new generation of 3D city models.


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