Spatio-temporal variation in the distribution and abundance of marine cladocerans in relation to environmental factors in a productive lagoon (Güllük Bay, SW Aegean Sea, Turkey)

AbstractIn order to understand the effects of some physical (temperature and salinity) and chemical (dissolved oxygen, nitrate and chlorophyll a) factors on the abundance and distribution of cladoceran species, zooplankton samples were seasonally collected between August 2015 and July 2016 from three stations near the entrance to the Boğaziçi Lagoon in Güllük Bay (Aegean Sea, Turkey) using a WP2 plankton net with a mesh size of 200 μm. Four cladoceran species – Penilia avirostris, Pseudevadne tergestina, Evadne spinifera and Pleopis polyphemoides – were found during all sampling events throughout the study period. They showed high abundance in August (4774 ind. m−3) and October (10 706 ind. m−3) as the dominant zooplankton group. The abundance of Penilia avirostris – the dominant cladoceran at all sampling locations – was estimated up to 10 871 ind. m−3 in October. Pseudevadne tergestina was the second dominant cladoceran. In September, only Pseudevadne tergestina and Pleopis polyphemoides were found in samples in small numbers. The abundance of cladocerans varied significantly throughout the seasons. Two physicochemical factors, temperature and dissolved oxygen, were the main drivers of changes in the cladoceran composition.

Download Full-text

The Abundance and Distribution of the Early Life Stages of Sardine (Sardina pilchardus) in Central of the Aegean Sea (Sığacık Bay) and their Interactions with Certain Environmental Factors

Thalassas An International Journal of Marine Sciences ◽

10.1007/s41208-020-00216-w ◽

2020 ◽

Vol 36 (2) ◽

pp. 507-515

Author(s):

Orçin Uygun ◽

Belgin Hoşsucu

Keyword(s):

Environmental Factors ◽

Early Life ◽

Aegean Sea ◽

Life Stages ◽

Sardina Pilchardus ◽

Early Life Stages ◽

Abundance And Distribution

Download Full-text

Seasonal control of spatial distribution of soil moisture on a steep hillslope

Water Science & Technology ◽

10.2166/wcc.2018.173 ◽

2018 ◽

Vol 79 (3) ◽

pp. 556-565

Author(s):

Xiaoyi Dong ◽

Eunhyung Lee ◽

Yongseok Gwak ◽

Sanghyun Kim

Keyword(s):

Soil Moisture ◽

Environmental Factors ◽

Temporal Variation ◽

Principal Component Regression ◽

Principal Component ◽

Ecological Processes ◽

Moisture Profile ◽

Humid Forest ◽

Control Factors ◽

Spatio Temporal

Abstract Spatio-temporal variation in soil moisture plays an important role in hydrological and ecological processes. In the present study, we investigated the effect of environmental factors on variation in soil moisture at a hillslope scale. The relationships among various environmental factors, including soil properties, topographic indices, and vegetation of a humid forest hillslope, and soil moisture distributions were evaluated based on soil moisture data collected at 18 sampling locations over three seasons (spring, rainy, and autumn) at depths of 10, 30, and 60 cm. In order to evaluate the multi-dimensional data sets without the interaction among factors, the principal component regression (PCR) model was applied to identify the factors controlling the spatio-temporal variation in soil moisture. The effects on soil texture and topography were significant in spring. In addition, clay and sand appeared as critical control factors for the study area in all seasons. The transitional control patterns in the soil moisture profile indicated that the control varied depending on features, such as total amount, intensity, and duration, of rainfall events in spring and during the rainy season. The transitional control pattern for autumn showed that vegetation and local slope controlled transitions in topography.

Download Full-text

Spatio-temporal variation of karst ecosystem service value and its correlation with ambient environmental factors

CHINESE JOURNAL OF ECO-AGRICULTURE ◽

10.3724/sp.j.1011.2010.00189 ◽

2010 ◽

Vol 18 (1) ◽

pp. 189-197

Author(s):

Ming-Yang ZHANG ◽

Ke-Lin WANG ◽

Hui-Yu LIU ◽

Hong-Song CHEN ◽

Chun-Hua ZHANG ◽

...

Keyword(s):

Environmental Factors ◽

Temporal Variation ◽

Ecosystem Service ◽

Ecosystem Service Value ◽

Service Value ◽

Karst Ecosystem ◽

Spatio Temporal

Download Full-text

Spatio-temporal variation of microphytoplankton communities in Obhur Creek, the central Red Sea

Oceanological and Hydrobiological Studies ◽

10.2478/oandhs-2021-0010 ◽

2021 ◽

Vol 50 (1) ◽

pp. 98-114

Author(s):

Mohsen M. El-Sherbiny ◽

Mamdouh A. Al-Harbi ◽

Anand J. Kumar

Keyword(s):

Red Sea ◽

Algal Species ◽

Open Water ◽

Nutrient Concentrations ◽

Phytoplankton Species ◽

Phytoplankton Abundance ◽

Physicochemical Factors ◽

Spatio Temporal ◽

Study Sites ◽

Abundance And Distribution

Abstract The abundance and distribution of microphyto-plankton and related physicochemical factors were assessed monthly in Obhur Creek, the central Red Sea. Sampling was carried out near the entrance, the middle and end parts of the creek. During the course of the present study, the Red Sea was characterized by predominantly oligotrophic conditions. Nutrient concentrations were relatively higher in the end part of the creek compared to the two other study sites. Chlorophyll a was also low throughout the year (average: 0.35 ± 0.32 mg m−3), except in May when it showed clear peaks at open-water and middle sites of the creek (1.85 and 1.04 mg m−3, respectively). Phytoplankton abundance followed a similar pattern to that of chlorophyll a with considerably higher abundance at these sites in May (3063.27 × 103 and 1082.34 × 103 individuals m−3, respectively). This unusually higher abundance was mostly due to the proliferation of the diatom Pseudo-nitzschia cf. delicatissima (Cleve) Heiden. Silicate concentrations were statistically significantly correlated with total phytoplankton. A total of 220 phytoplankton species were recorded during the study period (117 diatoms, 99 dinoflagellates and four cyanophytes). Diatoms dominated in the phytoplankton abundance (75%) and were followed by dinoflagellates (20%), while cyanophytes accounted for a minimal proportion. Of all phytoplankton species observed during the study, 21 diatom and four dinoflagellate species were considered as new records for the Red Sea, and two diatom and 14 dinoflagellate species were listed as harmful algal species worldwide.

Download Full-text