scholarly journals Porewater salinity in a southeastern United States salt marsh: controls and interannual variation

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5911 ◽  
Author(s):  
David Miklesh ◽  
Christof Meile
Keyword(s):  
Surface Waters ◽  
Coastal Marsh ◽  
Soil Conditions ◽  
Spatially Explicit ◽  
High Marsh ◽  
Tidal Inundation ◽  
Marsh Soil ◽  
Spatially Explicit Model ◽  
External Forcings ◽  
Porewater Salinity

In coastal marsh ecosystems, porewater salinity strongly affects vegetation distribution and productivity. To simulate marsh porewater salinity, an integrated, spatially explicit model was developed, accounting for tidal inundation, evaporation, and precipitation, as well as lateral and vertical exchanges in both surface waters and the subsurface. It was applied to the Duplin River marsh, Sapelo Island, USA, over a 3-year period, which covered both drought and wet conditions. Simulated porewater salinity in the low and high marsh correlated with Duplin River salinity, with evapotranspiration and precipitation leading to substantial variations in porewater salinities across seasons, in particular in the high marsh. The model revealed substantial interannual variability in marsh soil conditions, and—due to its process-based approach linked to external forcings—can be used to explore effects of sea level rise and changes in hydrological forcings on marsh soil conditions.

scholarly journals Comparing Phylogeographic Hypotheses by Simulating DNA Sequences under a Spatially Explicit Model of Coalescence

2014 ◽  
Vol 31 (12) ◽  
pp. 3359-3372 ◽  
Author(s):  
Simon Dellicour ◽  
Chedly Kastally ◽  
Olivier J. Hardy ◽  
Patrick Mardulyn
Keyword(s):  
Dna Sequences ◽  
Spatially Explicit ◽  
Explicit Model ◽  
Spatially Explicit Model

scholarly journals Spatiotemporal dynamics of soil phosphorus and crop uptake in global cropland during the 20th century

2017 ◽  
Vol 14 (8) ◽  
pp. 2055-2068 ◽  
Author(s):  
Jie Zhang ◽  
Arthur H. W. Beusen ◽  
Dirk F. Van Apeldoorn ◽  
José M. Mogollón ◽  
Chaoqing Yu ◽  
...  
Keyword(s):  
Crop Production ◽  
Soil Phosphorus ◽  
Fertilizer Application ◽  
P Uptake ◽  
Vital Role ◽  
Spatially Explicit ◽  
Explicit Model ◽  
Spatially Explicit Model ◽  
Soil P ◽  
Crop Uptake

Abstract. Phosphorus (P) plays a vital role in global crop production and food security. In this study, we investigate the changes in soil P pool inventories calibrated from historical countrywide crop P uptake, using a 0.5-by-0.5° spatially explicit model for the period 1900–2010. Globally, the total P pool per hectare increased rapidly between 1900 and 2010 in soils of Europe (+31 %), South America (+2 %), North America (+15 %), Asia (+17 %), and Oceania (+17 %), while it has been stable in Africa. Simulated crop P uptake is influenced by both soil properties (available P and the P retention potential) and crop characteristics (maximum uptake). Until 1950, P fertilizer application had a negligible influence on crop uptake, but recently it has become a driving factor for food production in industrialized countries and a number of transition countries like Brazil, Korea, and China. This comprehensive and spatially explicit model can be used to assess how long surplus P fertilization is needed or how long depletions of built-up surplus P can continue without affecting crop yield.

scholarly journals Resource-Driven Encounters and the Induction of Disease Among Consumers

2016 ◽  
Author(s):  
Rebecca K. Borchering ◽  
Steve E. Bellan ◽  
Jason M. Flynn ◽  
Juliet R.C. Pulliam ◽  
Scott A. McKinley
Keyword(s):  
National Park ◽  
Interaction Model ◽  
Spatially Explicit ◽  
Encounter Rate ◽  
Model Parameters ◽  
Expected Number ◽  
Spatially Explicit Model ◽  
Consumer Population ◽  
Using Data ◽  
The Relationship

AbstractSubmitted Manuscript 2016. Territorial animals share a variety of common resources, which can be a major driver of conspecific encounter rates. We examine how changes in resource availability influence the rate of encounters among individuals in a consumer population by implementing a spatially explicit model for resource visitation behavior by consumers. Using data from 2009 and 2010 in Etosha National Park, we verify our model's prediction that there is a saturation effect in the expected number of jackals that visit a given carcass site as carcasses become abundant. However, this does not directly imply that the overall resource-driven encounter rate among jackals decreases. This is because the increase in available carcasses is accompanied by an increase in the number of jackals that detect and potentially visit carcasses. Using simulations and mathematical analysis of our consumer-resource interaction model, we characterize key features of the relationship between resource-driven encounter rate and model parameters. These results are used to investigate a standing hypothesis that the outbreak of a fatal disease among zebras can potentially lead to an outbreak of an entirely different disease in the jackal population, a process we refer to as indirect induction of disease.

scholarly journals A Spatially Explicit Model to Predict the Relative Risk of Golden Eagle Electrocutions in the Northwestern Plains, USA

2020 ◽  
Vol 54 (2) ◽  
pp. 110 ◽  
Author(s):  
Geoffrey Bedrosian ◽  
Jason D. Carlisle ◽  
Brian Woodbridge ◽  
Jeffrey R. Dunk ◽  
Zach P. Wallace ◽  
...  
Keyword(s):  
Relative Risk ◽  
Spatially Explicit ◽  
Explicit Model ◽  
Golden Eagle ◽  
Spatially Explicit Model ◽  
Northwestern Plains

scholarly journals Information use during movement regulates how fragmentation and loss of habitat affect body size

2018 ◽  
Vol 285 (1884) ◽  
pp. 20180953 ◽  
Author(s):  
Jasmijn Hillaert ◽  
Martijn L. Vandegehuchte ◽  
Thomas Hovestadt ◽  
Dries Bonte
Keyword(s):  
Body Size ◽  
Evolutionary Dynamics ◽  
Information Use ◽  
Spatial Arrangement ◽  
Habitat Choice ◽  
Spatially Explicit ◽  
Spatially Explicit Model ◽  
Feedback Effects ◽  
Body Sizes ◽  
Movement Ability

An individual's body size is central to its behaviour and physiology, and tightly linked to its movement ability. The spatial arrangement of resources and a consumer's capacity to locate them are therefore expected to exert strong selection on consumer body size. We investigated the evolutionary impact of both the fragmentation and loss of habitat on consumer body size and its feedback effects on resource distribution, under varying levels of information used during habitat choice. We developed a mechanistic, individual-based, spatially explicit model, including several allometric rules for key consumer traits. Our model reveals that as resources become more fragmented and scarce, informed habitat choice selects for larger body sizes while random habitat choice promotes small sizes. Information use may thus be an overlooked explanation for the observed variation in body size responses to habitat fragmentation. Moreover, we find that resources can accumulate and aggregate if information about resource abundance is incomplete. Informed movement results in stable resource–consumer dynamics and controlled resources across space. However, habitat loss and fragmentation destabilize local dynamics and disturb resource suppression by the consumer. Considering information use during movement is thus critical to understand the eco-evolutionary dynamics underlying the functioning and structuring of consumer communities.

Links between hydrological patterns and lateral carbon fluxes: a comparison between a wet and a drained site on a Siberian permafrost floodplain tundra

2021 ◽  
Author(s):  
Sandra Raab ◽  
Mathias Goeckede ◽  
Jorien Vonk ◽  
Anke Hildebrandt ◽  
Martin Heimann
Keyword(s):  
Organic Carbon ◽  
Water Table ◽  
Surface Waters ◽  
Carbon Fluxes ◽  
Flow Patterns ◽  
Control Site ◽  
Water Levels ◽  
Soil Conditions ◽  
Transport Patterns ◽  
Carbon Transport

<p>As a major reservoir for organic carbon, permafrost areas play a pivotal role in global climate change. Vertical carbon fluxes as well as lateral transport from land to groundwaters and surface waters towards the ocean are highly dependent on various abiotic and biotic factors. These include for example temperature, groundwater depth, or vegetation community. During summer months, when soils thaw and lateral carbon transport within suprapermafrost groundwater bodies and surface waters occurs, flow patterns and therefore carbon redistribution may differ significantly between dry and wet conditions. Since dry soil conditions are expected to become more frequent in the future, associated shifts in carbon transport patterns play an important role in quantifying the carbon input into the water body linked to permafrost degradation.</p><p>This study focuses on hydrological and carbon transport patterns within a floodplain tundra site near Chersky, Northeast Siberia. We compared a wet control site with a site affected by a drainage ring built in 2004 to study the effect of water availability on carbon production and transport. Water table depths at both sites were continuously monitored with a distributed sensor network over the summer seasons 2016-2020. At several locations, water samples were collected in 2016 and 2017 to determine organic carbon concentrations (DOC) as well as carbon isotopes (e.g. ∆<sup>14</sup>C-DOC). Suprapermafrost groundwater and surface water from the drainage ditch and the nearby Ambolikha river were included in the analysis.</p><p>Our results focus on the physical hydrological conditions as well as on DOC and ∆<sup>14</sup>C-DOC observations. The spatio-temporal dynamics of water table depth revealed systematic differences between control and drained sites. The drained area showed a stronger decrease in water tables towards peak summer season in July and stronger reactions to precipitation events. The control area responded less pronounced to short-term changes. At the drained site, the main groundwater flow direction was stable throughout the measurement period. The control site was characterized by a shift in water flow confluence depending on increasing and decreasing water levels. DOC and ∆<sup>14</sup>C-DOC data showed that the highest concentrations of organic carbon and oldest DOC can be found in late summer. DOC concentrations were higher at the drained site compared to the wet site. We will show that the distribution of dissolved carbon can be directly related to hydrological flow patterns, and that understanding of these redistribution processes is essential for interpreting the carbon budget in disturbed permafrost.</p><p> </p>

scholarly journals A spatially explicit model of postdisaster housing recovery

2019 ◽  
Vol 35 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Ali Nejat ◽  
Roxana J. Javid ◽  
Souparno Ghosh ◽  
Saeed Moradi
Keyword(s):  
Spatially Explicit ◽  
Explicit Model ◽  
Spatially Explicit Model ◽  
Housing Recovery
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