5. A Second Example: Vertical Migration and Reproductive Effort in Daphnia

2020 ◽  
pp. 52-72
Keyword(s):  
Vertical Migration ◽  
Reproductive Effort

A Second Example: Vertical Migration and Reproductive Effort in Daphnia

2020 ◽  
pp. 52-72
Keyword(s):  
Population Dynamics ◽  
Vertical Migration ◽  
Biological System ◽  
Population Model ◽  
Reproductive Effort ◽  
Reproductive Allocation ◽  
Dynamic State ◽  
Trade Off ◽  
State Variable ◽  
Almost All

This chapter demonstrates the application of state- and prediction-based theory (SPT) to a real biological system, but a system that has been simplified enough to also be addressed by dynamic state variable modeling (DSVM). The Daphnia vertical migration (VM) system allows one to explore ways to use SPT for an adaptive trade-off behavior that clearly is important to population dynamics, and to compare the behavior it produces to behavior predicted by a DSVM model and observed in real organisms. The chapter reproduces the three patterns of observed behavior, in almost all their details, while converting Øyvind Fiksen's DSVM model into a population model that includes mortality and reproduction and could easily include processes that make DSVM intractable—like interaction and variation among individuals. One lesson is that SPT can readily represent contingent decisions, such as Daphnia choice of both depth and reproductive allocation. This is not surprising because such decisions have also been modeled with DSVM.

High Reproductive Effort and Low Recruitment Rates of European Beech: Is There a Limit for the Superior Competitor?

2015 ◽  
Vol 63 (2) ◽  
pp. 198-212 ◽  
Author(s):  
Jerzy Szwagrzyk ◽  
Georg Gratzer ◽  
Hanna Stępniewska ◽  
Janusz Szewczyk ◽  
Bojana Veselinovic
Keyword(s):  
Reproductive Effort ◽  
European Beech ◽  
High Reproductive Effort

scholarly journals Response of Vertical Migration and Leaching of Nitrogen in Percolation Water of Paddy Fields under Water-Saving Irrigation and Straw Return Conditions

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 868 ◽  
Author(s):  
Chengxin Zheng ◽  
Zhanyu Zhang ◽  
Yunyu Wu ◽  
Richwell Mwiya
Keyword(s):  
Vertical Migration ◽  
Growth Stage ◽  
Nitrogen Leaching ◽  
Water Saving ◽  
Paddy Fields ◽  
N Leaching ◽  
Leaching Losses ◽  
Leaching Loss ◽  
Straw Return ◽  
Percolation Water

The use of water-saving irrigation techniques has been encouraged in rice fields in response to irrigation water scarcity. Straw return is an important means of straw reuse. However, the environmental impact of this technology, e.g., nitrogen leaching loss, must be further explored. A two-year (2017–2018) experiment was conducted to investigate the vertical migration and leaching of nitrogen in paddy fields under water-saving and straw return conditions. Treatments included traditional flood irrigation (FI) and two water-saving irrigation regimes: rain-catching and controlled irrigation (RC-CI) and drought planting with straw mulching (DP-SM). RC-CI and DP-SM both significantly decreased the irrigation input compared with FI. RC-CI increased the rice yield by 8.23%~12.26%, while DP-SM decreased it by 8.98%~15.24% compared with FI. NH4+-N was the main form of the nitrogen leaching loss in percolation water, occupying 49.06%~50.97% of TN leaching losses. The NH4+-N and TN concentration showed a decreasing trend from top to bottom in soil water of 0~54 cm depth, while the concentration of NO3−-N presented the opposite behavior. The TN and NH4+-N concentrations in percolation water of RC-CI during most of the rice growth stage were the highest among treatments in both years, and DP-SM showed a trend of decreasing TN and NH4+-N concentrations. The NO3−-N concentrations in percolation water showed a regular pattern of DP-SM > RC-CI > FI during most of the rice growth stage. RC-CI and DP-SM remarkably reduced the amount of N leaching losses compared to FI as a result of the significant decrease of percolation water volumes. The tillering and jointing-booting stages were the two critical periods of N leaching (accounted for 74.85%~86.26% of N leaching losses). Great promotion potential of RC-CI and DP-SM exists in the lower reaches of the Yangtze River, China, and DP-SM needs to be further optimized.

Diel, lunar and seasonal vertical migration in the deep western Gulf of Mexico evidenced from a long-term data series of acoustic backscatter

2021 ◽  
pp. 102562
Author(s):  
Laura Ursella ◽  
Sara Pensieri ◽  
Enric Pallàs-Sanz ◽  
Sharon Z. Herzka ◽  
Roberto Bozzano ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Vertical Migration ◽  
Acoustic Backscatter ◽  
Data Series ◽  
Term Data

Diel vertical migration of mesozooplankton in the northern Yellow Sea

2021 ◽  
Author(s):  
Ruping Ge ◽  
Hongju Chen ◽  
Guangxing Liu ◽  
Yanzhong Zhu ◽  
Qiang Jiang
Keyword(s):  
Vertical Migration ◽  
Yellow Sea ◽  
Diel Vertical Migration ◽  
Northern Yellow Sea

scholarly journals Role of large-scale advection and small-scale turbulence on vertical migration of gyrotactic swimmers

2019 ◽  
Vol 4 (12) ◽  
Author(s):  
C. Marchioli ◽  
H. Bhatia ◽  
G. Sardina ◽  
L. Brandt ◽  
A. Soldati
Keyword(s):  
Vertical Migration ◽  
Large Scale ◽  
Small Scale ◽  
Scale Turbulence

Seed provenance determines germination responses of Rumex crispus (L.) under water stress and nutrient availability

2019 ◽  
Vol 12 (6) ◽  
pp. 949-961 ◽  
Author(s):  
María Pérez-Fernández ◽  
Carole P Elliott ◽  
Alex Valentine ◽  
José Antonio Oyola
Keyword(s):  
Reproductive Effort ◽  
Agricultural Soils ◽  
Inorganic Nitrogen ◽  
Seedling Emergence ◽  
Plant Mortality ◽  
Rumex Crispus ◽  
Reciprocal Transplantation ◽  
Transplantation Experiment ◽  
Germination Trial ◽  
Western Spain

Abstract Aims Seeds of Rumex crispus from six provenances were studied in relation to their germination under drought and presence of nitrogen in the germination and emergence media. We also investigated whether adaptation to soil increases the ability of the species to colonize and establish in contrasting environments along a longitudinal gradient in western Spain by means of a reciprocal transplantation experiment. Methods We conducted a germination trial in the lab to test for the germination responses to water scarcity along a polyethylene glycol gradient and to varying concentrations of nitrogen compounds. Simultaneously reciprocal transplantations experiment was conducted, where seeds from six provenances were grown in the soils from the very same provenances. Seedling emergence, survivorship and fitness-related variables were measured in all plots. Important Findings We found that R. crispus has a cold-stratification requirement that enhances its germination. Significant differences between the six provenances were detected for time-to-germination, total seedling emergence, plant mortality and reproductive effort in all the experiments. The differences between provenances with respect to germination were confirmed by the significant statistical analyses of the variance, thus providing evidence that seeds from parent plants grown in different environmental conditions have an intrinsically different abilities to germinate and establish. Soil nitrogen content where seed germination and seedlings establish also play an important role in their performance in terms of survivorship and reproduction, being the higher levels of inorganic nitrogen and of microbial biomass those that increased biomass production, enhanced inflorescence formation and reduced plant mortality. We conclude that one of the main reasons for the spread and maintenance of R. crispus would be the increased levels of nitrogen in agricultural soils.

A review of human male field studies of hormones and behavioral reproductive effort

2017 ◽  
Vol 91 ◽  
pp. 52-67 ◽  
Author(s):  
Peter B. Gray ◽  
Timothy S. McHale ◽  
Justin M. Carré
Keyword(s):  
Reproductive Effort ◽  
Field Studies ◽  
Human Male
Sign in / Sign up

Export Citation Format

Share Document