scholarly journals Living in the intertidal: desiccation and shading reduce seagrass growth, but high salinity or population of origin have no additional effect

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5234 ◽  
Author(s):  
Wouter Suykerbuyk ◽  
Laura L. Govers ◽  
W.G. van Oven ◽  
Kris Giesen ◽  
Wim B.J.T. Giesen ◽  
...  
Keyword(s):  
High Salinity ◽  
Antagonistic Effect ◽  
Interactive Effects ◽  
Salinity Range ◽  
Emergence Time ◽  
Local Conditions ◽  
Salinity Regime ◽  
Upper Limit ◽  
Negative Effect ◽  
General Response

The limiting effects of stressors like desiccation, light and salinity on seagrass growth and distribution are well-studied. However, little is known about their interactive effects, and whether such effects might differ among populations that are adapted to different local conditions. In two laboratory experiments we tested (a) if growth and development of intertidal, temperate Zostera noltii is affected by emergence time (experiment 1 and 2), and (b) how this is affected by an additional, second stressor, namely shading (experiment 1) or high salinity (25, 30 and 35, experiment 2). In addition, we tested (c) whether the effects of emergence time and salinity varied between three different European seagrass populations (Saint-Jacut/France, Oosterschelde/The Netherlands, and Sylt/Germany), which are likely adapted to different salinity levels (experiment 2). In both experiments, emergence of 8 h per tidal cycle (of 12 h) had a negative effect on seagrass relative growth rate (RGR), and aboveground biomass. Emergence furthermore reduced either rhizome length (experiment 1) or belowground biomass (experiment 2). Shading (experiment 1) resulted in lower RGR and a two-fold higher aboveground/belowground ratio. We found no interactive effects of emergence and shading stress. Salinity (experiment 2) did not affect seagrass growth or morphology of any of the three populations. The three tested populations differed greatly in morphology but showed no differential response to emergence or salinity level (experiment 2). Our results indicate that emergence time and shading show an additive negative effect (no synergistic or antagonistic effect), making the plants still vulnerable to such combination, a combination that may occur as a consequence of self-shading during emergence or resulting from algal cover. Emergence time likely determines the upper limit of Z. noltii and such shading will likely lower the upper limit. Shading resulted in higher aboveground/belowground ratios as is a general response in seagrass. Z. noltii of different populations originating from salinity 30 and 35 seem tolerant to variations in salinity within the tested range. Our results indicate that the three tested populations show morphotypic rather than ecotypic variation, at least regarding the salinity and emergence, as there were no interactive effects with origin. For restoration, this implies that the salinity regime of the donor and receptor site of Z. noltii is of no concern within the salinity range 25–35.

scholarly journals Living in the intertidal; desiccation and shading reduce seagrass growth, but high salinity or population of origin have no additional effect

2018 ◽  
Author(s):  
Wouter Suykerbuyk ◽  
Laura L. Govers ◽  
W. G. van Oven ◽  
Kris Giesen ◽  
Wim B.J.T. Giesen ◽  
...  
Keyword(s):  
High Salinity ◽  
Belowground Biomass ◽  
Antagonistic Effect ◽  
Interactive Effects ◽  
Emergence Time ◽  
Local Conditions ◽  
Depth Limit ◽  
North West ◽  
Negative Effect ◽  
Lower Depth

The limiting effects of stressors like desiccation, light and salinity on seagrass growth and distribution are well-studied. However, little is known about their interactive effects, and such interactive effects might differ among populations that are adapted to different local conditions. In two laboratory experiments we tested a) if growth and development of intertidal, temperate Zostera noltii is affected by emergence time (experiment 1 and 2), and b) how this is affected by an additional, second stressor, namely shading (experiment 1) or high salinity (25, 30 and 35 PSU, experiment 2). In addition, we tested c) whether the effects of emergence time and salinity varied between three different European seagrass populations (Saint-Jacut / France, Oosterschelde / The Netherlands, and Sylt / Germany), which are likely adapted to different salinity levels (experiment 2). In both experiments, emergence of 8 hours per tidal cycle (of 12 hours) had a negative effect on seagrass relative growth rate (RGR), and aboveground biomass. Emergence furthermore reduced either rhizome length (experiment 1) or belowground biomass (experiment 2). Shading (experiment 1) resulted in lower RGR and a two-fold higher above ground / below ground (AG/BG) ratio. We found no interactive effects of emergence and shading stress. Salinity (experiment 2) did not affect seagrass growth or morphology of any of the three populations. The three tested populations differed greatly in morphology but showed no differential response to emergence or salinity level (experiment 2). Our results indicate that the two applied stressors: emergence time (desiccation stress) and shading, simply add-up (no synergistic or antagonistic effect), making the plants still vulnerable to such combination, whereas Z. noltii of different populations seem tolerant to variations in salinity within the tested range. Secondly, our results indicate that the three tested populations show morphotypic rather then ecotypic variation, at least regarding the salinity and emergence, as there were no interactive effects with origin. Intruigingly, North-west European Z. noltii beds generally do not extend downwards to the subtidal, while our study shows that the shorter emergence periods towards the subtidal are more favourable. In our study areas, where light is ample, the lower depth limit may be determined by increasing sediment dynamics.

scholarly journals Living in the intertidal; desiccation and shading reduce seagrass growth, but high salinity or population of origin have no additional effect

2018 ◽  
Author(s):  
Wouter Suykerbuyk ◽  
Laura L. Govers ◽  
W. G. van Oven ◽  
Kris Giesen ◽  
Wim B.J.T. Giesen ◽  
...  
Keyword(s):  
High Salinity ◽  
Belowground Biomass ◽  
Antagonistic Effect ◽  
Interactive Effects ◽  
Emergence Time ◽  
Local Conditions ◽  
Depth Limit ◽  
North West ◽  
Negative Effect ◽  
Lower Depth

The limiting effects of stressors like desiccation, light and salinity on seagrass growth and distribution are well-studied. However, little is known about their interactive effects, and such interactive effects might differ among populations that are adapted to different local conditions. In two laboratory experiments we tested a) if growth and development of intertidal, temperate Zostera noltii is affected by emergence time (experiment 1 and 2), and b) how this is affected by an additional, second stressor, namely shading (experiment 1) or high salinity (25, 30 and 35 PSU, experiment 2). In addition, we tested c) whether the effects of emergence time and salinity varied between three different European seagrass populations (Saint-Jacut / France, Oosterschelde / The Netherlands, and Sylt / Germany), which are likely adapted to different salinity levels (experiment 2). In both experiments, emergence of 8 hours per tidal cycle (of 12 hours) had a negative effect on seagrass relative growth rate (RGR), and aboveground biomass. Emergence furthermore reduced either rhizome length (experiment 1) or belowground biomass (experiment 2). Shading (experiment 1) resulted in lower RGR and a two-fold higher above ground / below ground (AG/BG) ratio. We found no interactive effects of emergence and shading stress. Salinity (experiment 2) did not affect seagrass growth or morphology of any of the three populations. The three tested populations differed greatly in morphology but showed no differential response to emergence or salinity level (experiment 2). Our results indicate that the two applied stressors: emergence time (desiccation stress) and shading, simply add-up (no synergistic or antagonistic effect), making the plants still vulnerable to such combination, whereas Z. noltii of different populations seem tolerant to variations in salinity within the tested range. Secondly, our results indicate that the three tested populations show morphotypic rather then ecotypic variation, at least regarding the salinity and emergence, as there were no interactive effects with origin. Intruigingly, North-west European Z. noltii beds generally do not extend downwards to the subtidal, while our study shows that the shorter emergence periods towards the subtidal are more favourable. In our study areas, where light is ample, the lower depth limit may be determined by increasing sediment dynamics.

scholarly journals Soil Texture Alters the Impact of Salinity on Carbon Mineralization

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Ruihuan She ◽  
Yongxiang Yu ◽  
Chaorong Ge ◽  
Huaiying Yao
Keyword(s):  
Soil Texture ◽  
Clay Soil ◽  
Sandy Loam ◽  
Microbial Community Composition ◽  
Clay Content ◽  
Interactive Effects ◽  
Silty Clay ◽  
C Mineralization ◽  
Negative Effect ◽  
Silty Clay Soil

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.

scholarly journals Analysis Methods for Characterizing Salinity Variability from Multivariate Time Series Applied to the Apalachicola Bay Estuary

2012 ◽  
Vol 29 (4) ◽  
pp. 613-628 ◽  
Author(s):  
Steven L. Morey ◽  
Dmitry S. Dukhovskoy
Keyword(s):  
Time Series ◽  
Time Scales ◽  
River Discharge ◽  
River Flow ◽  
High Salinity ◽  
Multivariate Time Series ◽  
Salinity Range ◽  
Apalachicola Bay ◽  
Analysis Methods ◽  
Salinity Variability

Abstract Statistical analysis methods are developed to quantify the impacts of multiple forcing variables on the hydrographic variability within an estuary instrumented with an enduring observational system. The methods are applied to characterize the salinity variability within Apalachicola Bay, a shallow multiple-inlet estuary along the northeastern Gulf of Mexico coast. The 13-yr multivariate time series collected by the National Estuary Research Reserve at three locations within the bay are analyzed to determine how the estuary responds to variations in external forcing mechanisms, such as freshwater discharge, precipitation, tides, and local winds at multiple time scales. The analysis methods are used to characterize the estuarine variability under differing flow regimes of the Apalachicola River, a managed waterway, with particular focus on extreme events and scales of variability that are critical to local ecosystems. Multivariate statistical models are applied that describe the salinity response to winds from multiple directions, river flow, and precipitation at daily, weekly, and monthly time scales to understand the response of the estuary under different climate regimes. Results show that the salinity is particularly sensitive to river discharge and wind magnitude and direction, with local precipitation being largely unimportant. Applying statistical analyses with conditional sampling quantifies how the likelihoods of high-salinity and long-duration high-salinity events, conditions of critical importance to estuarine organisms, change given the state of the river flow. Intraday salinity range is shown to be negatively correlated with the salinity, and correlated with river discharge rate.

Interactive effects of salinity on metabolic rate, activity, growth and osmoregulation in the euryhaline milkfish (Chanos chanos)

1998 ◽  
Vol 201 (24) ◽  
pp. 3355-3366
Author(s):  
C Swanson
Keyword(s):  
Metabolic Rate ◽  
High Salinity ◽  
Swimming Performance ◽  
Interactive Effects ◽  
Routine Activity ◽  
Swimming Velocity ◽  
Activity Levels ◽  
Salinity Adaptation ◽  
Chanos Chanos ◽  
Wide Range

The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities(15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ?salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity(2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ?salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.

scholarly journals Effects of canopy-mediated abrasion and water flow on the early colonisation of turf-forming algae

2007 ◽  
Vol 58 (7) ◽  
pp. 657 ◽  
Author(s):  
Bayden D. Russell
Keyword(s):  
Water Flow ◽  
Interactive Effects ◽  
Light Penetration ◽  
Physical Processes ◽  
Percentage Cover ◽  
Negative Effect ◽  
Flow Through ◽  
Per Se ◽  
Reduced Light ◽  
Reduced Water

Algal canopies form predictable associations with the benthic understorey, and canopy-mediated processes may maintain these associations. Three canopy-mediated processes that are inherently linked are water flow through a canopy, abrasion of the substrate by the canopy, and light penetration. These processes were experimentally reduced to test the hypotheses that turf-forming algae would be: (1) positively affected by reduced abrasion by kelp canopies; (2) positively affected by reduced water flow; and (3) negatively affected by shading (reduced light). Biomass of turf-forming algae was greater when abrasion was reduced, but less when light was reduced. In contrast to predictions, reduced water flow had a negative effect on the percentage cover and biomass of turf-forming algae, rejecting the second hypothesis. It seems, however, that this negative effect was caused by an increase in shading associated with reduced canopy movement, not a reduction of water flow per se. None of the factors accounted for all of the change seen in understorey algae, indicating that it is important to study the interactive effects of physical processes.

scholarly journals Tree-Ring Growth of Larch (Larix decidua Mill.) in the Polish Sudetes—The Influence of Altitude and Site-Related Factors on the Climate–Growth Relationship

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 663 ◽  
Author(s):  
Małgorzata Danek ◽  
Monika Chuchro ◽  
Adam Walanus
Keyword(s):  
Tree Ring ◽  
Climatic Factors ◽  
Negative Relationship ◽  
Thermal Conditions ◽  
Cambial Activity ◽  
Negative Influence ◽  
Larix Decidua ◽  
Related Factors ◽  
Local Conditions ◽  
Negative Effect

In this paper, the first study of a regional character on the influence of climatic factors on the tree-ring growth of European larch (Larix decidua Mill.) growing in the Polish Sudetes is presented. The obtained results indicate the relatively high diversity of the climatic signal observed in the tree rings of larches growing in the Sudetes. The most significant differentiating factor is altitude. The results suggest that the possible influence of local conditions (e.g., summit proximity, soil and bedrock characteristics, and exposure to strong winds) could also be of importance. A positive relationship between tree-ring growth and May temperatures was noted throughout the area; this indicates the principal importance of thermal conditions during the initial stage of cambial activity and tree-ring formation in larches from the Sudetes. The negative effect of the temperatures in the previous summer upon the tree-ring growth of larch in the subsequent year was also observed. The studies also indicate the negative influence of the water stress in summer (particularly in July of the previous year) upon the growth of trees. The negative relationship between tree-ring growth and the previous November temperature could be explained by the need for a late-autumn cooling, which affects the development of assimilation apparatus in spring of the subsequent year, which indirectly affects the tree-ring growth in the same year.

scholarly journals Innovation or Introduction? The Impact of Technological Progress Sources on Industrial Green Transformation of Resource-Based Cities in China

2020 ◽  
Vol 8 ◽  
Author(s):  
Wancheng Xie ◽  
Taihua Yan ◽  
Senmao Xia ◽  
Fengzhang Chen
Keyword(s):  
Technological Innovation ◽  
Industrial Development ◽  
Generalized Method Of Moments ◽  
Estimation Method ◽  
Investment Strategy ◽  
Interactive Effects ◽  
Innovation And Technology ◽  
Technology Introduction ◽  
Negative Effect ◽  
The Impact

With the increasingly prominent problems of global resource consumption and environmental pollution, industrial green transformation has become one of the requirements of China’s industrial development in the new era. However, there is a lack of research on the impact of technological innovation and technology introduction on the industrial green transformation of resource-based cities. To bridge this gap, this study uses the panel data of 115 resource-based cities in China from 2003 to 2016, and uses the dynamic panel generalized method of moments (GMM) estimation method to study the impact of technological innovation and technology introduction on industrial green transformation of resource-based cities. The results show that technology introduction has a negative effect on the industrial green transformation of resource-based cities, while technological innovation can have a positive effect. Meanwhile, technology introduction has imparted a greater role to technological innovation in promoting this transformation. In addition, the interactive effects between technological innovation and technology introduction have obvious heterogeneity on the industrial green transformation of different types of resource-based cities. Therefore, resource-based cities should continue to increase investment in scientific research, to constantly improve and consolidate their technological innovation ability, optimize foreign investment strategy in technology introduction, and strengthen the digestion and absorption of imported technology, while increasing technological innovation and personnel training.

Sulphur and nitrogen nutrition and their interactive effects on Dothistroma infection in Pinusradiata

1986 ◽  
Vol 16 (5) ◽  
pp. 1055-1062 ◽  
Author(s):  
Marcia J. Lambert
Keyword(s):  
Nitrogen Fertilizer ◽  
Nitrogen Nutrition ◽  
Fertilizer Application ◽  
Positive Influence ◽  
Interactive Effects ◽  
Strong Positive Correlation ◽  
Infection Level ◽  
Foliar Nutrition ◽  
Volume Increment ◽  
Negative Effect

Nitrogen and sulphur fertilizers were applied to a 4-year-old Pinusradiata plantation in northern New South Wales and the results were monitored for 7 years. The aim was to study the effects of sulphur and nitrogen nutrition on tree growth and their interactions on Dothistroma infection. Sulphur (300 kg S ha−1), applied as gypsum, elevated foliage sulphate sulphur levels for up to 7 years after treatment, but no direct effects on growth were noted. The low nitrogen fertilizer level (100 kg N ha−1) had a positive influence on volume increment, while the high nitrogen fertilizer application (400 kg N ha−1) significantly depressed volume increment. This latter negative effect was attributed to induced sulphur and phosphorus deficiencies. Sulphur deficiency resulted in highly increased arginine concentrations in current foliage and there was a strong positive correlation between arginine concentration and tree infection level of Dothistroma needle cast fungus, the highest levels of infection being in the nitrogen-treated plots. Relationships between foliar nutrition and foliar fungal infection are discussed.

A time-lagged study on the moderating role of overall satisfaction in perceived politics: Job outcomes relationships

2016 ◽  
Vol 23 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Farooq Ahmed Jam ◽  
Magda B L Donia ◽  
Usman Raja ◽  
Chong Hui Ling
Keyword(s):  
Job Performance ◽  
Job Stress ◽  
Interpersonal Conflict ◽  
High Stress ◽  
Interactive Effects ◽  
Negative Effects ◽  
Negative Effect ◽  
Time Lagged ◽  
Positive Effect ◽  
High Politics

AbstractIn a time-lagged study with independent measures (N=115, paired responses), we examined the interactive effects of perceived organizational politics and overall satisfaction on job stress, interpersonal conflict, job performance, and creativity. The data were collected from a diverse sample of employees from various workplaces in Pakistan. The findings showed that perceived politics had a positive effect on job stress, while overall satisfaction had a negative effect on interpersonal conflict and a positive effect on creative performance. The results also revealed that in the face of high politics, highly satisfied individuals demonstrated higher levels of creativity and job performance. However, in this context of high politics negative effects were also observed, namely that highly satisfied individuals participated in interpersonal conflict and experienced high stress.

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