Seasonal Variation in Populations of Eurasian Coot Fulica atra: Relationships with Environmental Variables in Mediterranean Wetlands

2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Putri Ayu ◽  
Fernando Ortega ◽  
Francisco J. Márquez ◽  
Juan Diego Gilbert ◽  
Manuel Rendón-Martos ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Environmental Variables ◽  
Mediterranean Wetlands ◽  
Fulica Atra

scholarly journals Space Is More Important than Season when Shaping Soil Microbial Communities at a Large Spatial Scale

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Kaoping Zhang ◽  
Manuel Delgado-Baquerizo ◽  
Yong-Guan Zhu ◽  
Haiyan Chu
Keyword(s):  
Seasonal Variation ◽  
Microbial Community ◽  
Spatial Scale ◽  
Environmental Variables ◽  
Soil Microbial Communities ◽  
Spatiotemporal Variation ◽  
Relative Importance ◽  
Large Spatial Scale ◽  
Environmental Covariates ◽  
Soil Microbial

ABSTRACT The relative importance of spatial and temporal variability in shaping the distribution of soil microbial communities at a large spatial scale remains poorly understood. Here, we explored the relative importance of space versus time when predicting the distribution of soil bacterial and fungal communities across North China Plain in two contrasting seasons (summer versus winter). Although we found that microbial alpha (number of phylotypes) and beta (changes in community composition) diversities differed significantly between summer and winter, space rather than season explained more of the spatiotemporal variation of soil microbial alpha and beta diversities. Environmental covariates explained some of microbial spatiotemporal variation observed, with fast-changing environmental covariates—climate variables, soil moisture, and available nutrient—likely being the main factors that drove the seasonal variation found in bacterial and fungal beta diversities. Using random forest modeling, we further identified a group of microbial exact sequence variants (ESVs) as indicators of summer and winter seasons and for which relative abundance was associated with fast-changing environmental variables (e.g., soil moisture and dissolved organic nitrogen). Together, our empirical field study’s results suggest soil microbial seasonal variation could arise from the changes of fast-changing environmental variables, thus providing integral support to the large emerging body of snapshot studies related to microbial biogeography. IMPORTANCE Both space and time are key factors that regulate microbial community, but microbial temporal variation is often ignored at a large spatial scale. In this study, we compared spatial and seasonal effects on bacterial and fungal diversity variation across an 878-km transect and found direct evidence that space is far more important than season in regulating the soil microbial community. Partitioning the effect of season, space and environmental variables on microbial community, we further found that fast-changing environmental factors contributed to microbial temporal variation.

scholarly journals Fish assemblage in a temperate estuary on the uruguayan coast: seasonal variation and environmental influence

2010 ◽  
Vol 58 (4) ◽  
pp. 299-314 ◽  
Author(s):  
Alicia Acuña Plavan ◽  
Cecilia Passadore ◽  
Luis Gimenez
Keyword(s):  
Seasonal Variation ◽  
Environmental Variables ◽  
Fish Community ◽  
Community Dynamics ◽  
Environmental Influence ◽  
Abundant Species ◽  
Multivariate Techniques ◽  
Micropogonias Furnieri ◽  
Definition Of ◽  
Paralichthys Orbignyanus

The seasonal dynamics of the fish community in the Pando estuary on the Uruguayan coast were studied in relation to environmental sampled monthly between May 2002 and June 2003. Individuals collected were identified, and classified into stages (juveniles, adults) and functional groups. Relationships between community dynamics and environmental variables were evaluated using uni- and multivariate techniques. Twenty-one species, mostly freshwater stragglers, estuarine and marine migrants were collected. The most abundant species were Micropogonias furnieri, Mugil platanus, Paralichthys orbignyanus and Brevoortia aurea and were represented by juveniles. The community varied seasonally with rapid shifts in spring and autumn associated with changes in temperature and salinity. Significant correlations between abundance and temperature may be related to the timing of life cycle events. In this estuary, the salinity appears to play a key role in the functional structure and in the use of the habitat by juveniles. This is relevant for the definition of estuaries as nursery areas: this definition is context-dependent and is determined by the salinity conditions.

An Analysis of Factors Determining Seasonal Variation in the Byssal Attachment Strength of Mytilus Edulis

1982 ◽  
Vol 62 (1) ◽  
pp. 147-155 ◽  
Author(s):  
H. A. Price
Keyword(s):  
Seasonal Variation ◽  
Mytilus Edulis ◽  
Northern Hemisphere ◽  
Environmental Variables ◽  
Seasonal Fluctuations ◽  
Sea Temperature ◽  
Scope For Growth ◽  
South Wales ◽  
Attachment Strength ◽  
The Common

INTRODUCTIONThe common mussel Mytilus edulis L. is one of the most successful shore molluscs. It is widely distributed in the northern hemisphere and is abundant not only in the most sheltered bays and loughs but also in conditions of extreme exposure (Lewis, 1964; Seed, 1976). Attachment to the substratum is by means of the proteinaceous byssus complex, the strength of which has been shown to vary seasonally (Price, 1980b). This variation could be a response to seasonal fluctuations in wave action, as suggested by Pieters et al. (1978), or may result from the seasonality of other environmental variables. Some of these, e.g. salinity and sea temperature, have been shown to influence byssus production (Glaus, 1968; Van Winkle, 1970; Allen et al. 1976), Phytoplankton density, spawning and the reduced ‘scope for growth’ during winter months (Bayne & Widdows, 1978) may also play a role in determining byssus strength.In the present study, the relationships between byssal attachment strength and environmental and other variables are examined in a population of mussels on the South Wales coast.

Biomasss and microzooplankton seasonal assemblages in the Bahía Blanca Estuary, Argentinean Coast

2011 ◽  
Vol 91 (5) ◽  
pp. 953-959 ◽  
Author(s):  
M.S. Barría de Cao ◽  
M.C. Piccolo ◽  
G.M. Perillo
Keyword(s):  
Seasonal Variation ◽  
Solar Radiation ◽  
Annual Cycle ◽  
Environmental Variables ◽  
Secchi Depth ◽  
Heterotrophic Dinoflagellate ◽  
Bahía Blanca Estuary ◽  
Point Biserial Correlation ◽  
Physico Chemical ◽  
Blanca Estuary

We investigated the occurrence and seasonal variation of the biomass of rotifers, tintinnids, the heterotrophic dinoflagellate Gyrodinium fusus and copepod nauplii in the Bahía Blanca Estuary (38°42′S61°50 ′W), Argentina, during an annual cycle. The rotifers fauna comprised three species, while the tintinnids were represented by sixteen species. The biomass of the rotifers fluctuated between 0.62 and 8.90 µgC l−1. The biomass of the tintinnids fluctuated between 0.13 and 9.37 µgC l−1, the biomass of the nauplii stages between 1.78 and 7.65 µgC l−1; while the biomass of G. fusus varied from 0.26 and 7.94 µgC l−1, these results are compared to estimates of microzooplankton in other regions. We analysed the presence of the different groups in relation to the environmental variables, based on point-biserial correlation. Salinity fluctuated between 25.14 and 36.64; temperature between 7.5 and 23.2°C, solar radiation between 0.9 and 30.8 MJ m−2d−1 and Secchi distance between 0.25 and 1.43 m. Rotifers were correlated positively with temperature, chlorophyll-a and Secchi depth and negatively with salinity. The tintinnids were positively correlated with salinity. Gyrodinium fusus was positively correlated with Secchi depth, and chlorophyll-a, and negatively with temperature and solar radiation. Nauplii stages were negatively correlated with chlorophyll-a. Based on the occurrence of the microzooplankters in relation to the physico-chemical variables, it was possible to establish two seasonal assemblages: (a) the co-occurrence of the rotifers and the heterotrophic dinoflagellate G. fusus during the winter–spring; and (b) the tintinnids and nauplii larvae during the summer. We conclude that, in this estuary, physico-chemical variables are the forcing factors that directly, or indirectly, influence the seasonal assemblages of the microzooplankton.

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