Plant zonation in a brackish tidal marsh: descriptive verification of resource-based competition and community structure

1990 ◽  
Vol 68 (8) ◽  
pp. 1689-1697 ◽  
Author(s):  
Michael J. Pidwirny
Keyword(s):  
Soil Nitrogen ◽  
Tidal Marsh ◽  
Resource Competition ◽  
Plant Biomass ◽  
Soil Surface ◽  
Tidal Marshes ◽  
High Marsh ◽  
Plant Zonation ◽  
Total Species ◽  
Total Soil Nitrogen

This study examined the hypothesis that the zonal patterns of dominant species in brackish tidal marshes may be explained by resource competition for soil nitrogen and light. This hypothesis was tested by analyzing abiotic and biotic field data collected from a brackish tidal marsh located at Brunswick Point, British Columbia. Biotic data revealed that this tidal marsh is dominated by two species that occupy distinct separate zones correlated to marsh elevation. In particular, sites whose elevation was from −0.80 to 0.20 m (geodetic datum) were dominated by Scirpus americanus, while sites with an elevation 0.20 m were dominated by Carex lyngbyei. Analysis of the relationships between measured variables indicated that total species biomass, species height, and total soil nitrogen were all positively correlated to sample site elevation. Further, the availability of light at the soil surface was found to be negatively correlated to plant biomass and site elevation. These results may suggest that S. americanus is dominant in the low marsh because it is a better competitor for soil nitrogen. Carex lyngbyei may be competitively dominant in the high marsh because its greater biomass and height make it a superior competitor for light. Key words: competition, light, nitrogen, tidal marshes, zonation.

scholarly journals RGB Indices and Canopy Height Modelling for Mapping Tidal Marsh Biomass from a Small Unmanned Aerial System

2021 ◽  
Vol 13 (17) ◽  
pp. 3406
Author(s):  
Grayson R. Morgan ◽  
Cuizhen Wang ◽  
James T. Morris
Keyword(s):  
Remote Sensing ◽  
Tidal Marsh ◽  
Explanatory Power ◽  
Canopy Height ◽  
Tidal Marshes ◽  
Biomass Estimation ◽  
Unmanned Aerial Systems ◽  
High Marsh ◽  
Environmental Biology ◽  
Marsh Vegetation

Coastal tidal marshes are essential ecosystems for both economic and ecological reasons. They necessitate regular monitoring as the effects of climate change begin to be manifested in changes to marsh vegetation healthiness. Small unmanned aerial systems (sUAS) build upon previously established remote sensing techniques to monitor a variety of vegetation health metrics, including biomass, with improved flexibility and affordability of data acquisition. The goal of this study was to establish the use of RGB-based vegetation indices for mapping and monitoring tidal marsh vegetation (i.e., Spartina alterniflora) biomass. Flights over tidal marsh study sites were conducted using a multi-spectral camera on a quadcopter sUAS near vegetation peak growth. A number of RGB indices were extracted to build a non-linear biomass model. A canopy height model was developed using sUAS-derived digital surface models and LiDAR-derived digital terrain models to assess its contribution to the biomass model. Results found that the distance-based RGB indices outperformed the regular radio-based indices in coastal marshes. The best-performing biomass models used the triangular greenness index (TGI; R2 = 0.39) and excess green index (ExG; R2 = 0.376). The estimated biomass revealed high biomass predictions at the fertilized marsh plots in the Long-Term Research in Environmental Biology (LTREB) project at the study site. The sUAS-extracted canopy height was not statistically significant in biomass estimation but showed similar explanatory power to other studies. Due to the lack of biomass samples in the inner estuary, the proposed biomass model in low marsh does not perform as well as the high marsh that is close to shore and accessible for biomass sampling. Further research of low marsh is required to better understand the best conditions for S. alterniflora biomass estimation using sUAS as an on-demand, personal remote sensing tool.

Effect of Prescribed Burning of Forest Litter on Total Soil Nitrogen

1962 ◽  
Vol 26 (2) ◽  
pp. 200-202 ◽  
Author(s):  
J. O. Klemmedson ◽  
A. M. Schultz ◽  
H. Jenny ◽  
H. H. Biswell
Keyword(s):  
Soil Nitrogen ◽  
Prescribed Burning ◽  
Forest Litter ◽  
Total Soil ◽  
Total Soil Nitrogen

scholarly journals Cross-Feeding of a Toxic Metabolite in a Synthetic Lignocellulose-Degrading Microbial Community

2021 ◽  
Vol 9 (2) ◽  
pp. 321
Author(s):  
Jessica A. Lee ◽  
Alyssa C. Baugh ◽  
Nicholas J. Shevalier ◽  
Brandi Strand ◽  
Sergey Stolyar ◽  
...  
Keyword(s):  
Resource Competition ◽  
Plant Biomass ◽  
Lignocellulose Degradation ◽  
Toxic Metabolite ◽  
Growth Requirements ◽  
Mutualistic Interaction ◽  
Metabolite Exchange ◽  
Future Work ◽  
Biomass Transformation ◽  
Complex Organic

The recalcitrance of complex organic polymers such as lignocellulose is one of the major obstacles to sustainable energy production from plant biomass, and the generation of toxic intermediates can negatively impact the efficiency of microbial lignocellulose degradation. Here, we describe the development of a model microbial consortium for studying lignocellulose degradation, with the specific goal of mitigating the production of the toxin formaldehyde during the breakdown of methoxylated aromatic compounds. Included are Pseudomonas putida, a lignin degrader; Cellulomonas fimi, a cellulose degrader; and sometimes Yarrowia lipolytica, an oleaginous yeast. Unique to our system is the inclusion of Methylorubrum extorquens, a methylotroph capable of using formaldehyde for growth. We developed a defined minimal “Model Lignocellulose” growth medium for reproducible coculture experiments. We demonstrated that the formaldehyde produced by P. putida growing on vanillic acid can exceed the minimum inhibitory concentration for C. fimi, and, furthermore, that the presence of M. extorquens lowers those concentrations. We also uncovered unexpected ecological dynamics, including resource competition, and interspecies differences in growth requirements and toxin sensitivities. Finally, we introduced the possibility for a mutualistic interaction between C. fimi and M. extorquens through metabolite exchange. This study lays the foundation to enable future work incorporating metabolomic analysis and modeling, genetic engineering, and laboratory evolution, on a model system that is appropriate both for fundamental eco-evolutionary studies and for the optimization of efficiency and yield in microbially-mediated biomass transformation.

scholarly journals Biogeomorphic modeling to assess resilience of tidal marsh restoration to sea level rise and sediment supply

2021 ◽  
Author(s):  
Olivier Gourgue ◽  
Jim van Belzen ◽  
Christian Schwarz ◽  
Wouter Vandenbruwaene ◽  
Joris Vanlede ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Marsh ◽  
Model Performance ◽  
Suspended Sediments ◽  
Sediment Supply ◽  
Tidal Marshes ◽  
Marsh Restoration ◽  
Tidal Marsh Restoration ◽  
Increasing Demand

Abstract. There is an increasing demand for creation and restoration of tidal marshes around the world, as they provide highly valued ecosystem services. Yet, tidal marshes are strongly vulnerable to factors such as sea level rise and declining sediment supply. How fast the restored ecosystem develops, how resilient it is to sea level rise, and how this can be steered by restoration design, are key questions that are typically challenging to assess. In this paper, we apply a biogeomorphic model to a planned tidal marsh restoration by dike breaching. Our modeling approach integrates tidal hydrodynamics, sediment transport and vegetation dynamics, accounting for relevant fine-scale flow-vegetation interactions (less than 1 m2) and their impact on vegetation and landform development at the landscape scale (several km2) and on the long term (several decades). Our model performance is positively evaluated against observations of vegetation and geomorphic development in adjacent tidal marshes. Model scenarios demonstrate that the restored tidal marsh can keep pace with realistic rates of sea level rise and that its resilience is more sensitive to the availability of suspended sediments than to the rate of sea level rise. We further demonstrate that restoration design options can steer marsh resilience, as it affects the rates and spatial patterns of biogeomorphic development. By varying the width of two dike breaches, which serve as tidal inlets to the restored marsh, we show that a larger difference in the width of the two inlets leads to more diversity in restored habitats. This study showcases that biogeomorphic modeling can support management choices in restoration design to optimize tidal marsh development towards sustainable restoration goals.

scholarly journals Decade-long soil nitrogen constraint on the CO2 fertilization of plant biomass

2012 ◽  
Vol 3 (3) ◽  
pp. 278-282 ◽  
Author(s):  
Peter B. Reich ◽  
Sarah E. Hobbie
Keyword(s):  
Soil Nitrogen ◽  
Plant Biomass ◽  
Co2 Fertilization

Tidal marsh restoration at Blackwater National Wildlife Refuge, Maryland: A case study in thin-layer placement

Shore & Beach ◽  
2021 ◽  
pp. 13-20
Author(s):  
Albert McCullough ◽  
David Curson ◽  
Erik Meyers ◽  
Matthew Whitbeck
Keyword(s):  
Thin Layer ◽  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Marsh ◽  
Climate Adaptation ◽  
Thin Layers ◽  
High Marsh ◽  
National Wildlife Refuge ◽  
Saltmarsh Sparrow ◽  
Wildlife Refuge

Tidal marsh loss at Blackwater National Wildlife Refuge (NWR) has been a major concern of refuge managers in recent decades. The approximately 2,035 hectares (5,028 acres) of tidal marsh that have converted to open water in Blackwater NWR since 1938 (Scott et al. 2009) represent one of the most significant areas of marsh conversion within the Chesapeake Bay. In 2013, a suite of climate adaptation strategies focused on sea level rise was developed for Blackwater NWR and surrounding areas of Dorchester County by the Blackwater Climate Adaptation Project (BCAP). The BCAP is a collaboration of The Conservation Fund, Audubon Maryland-DC, and the U.S. Fish and Wildlife Service, assisted by the Maryland Department of Natural Resources (MD DNR), U.S. Geological Survey, and others. In 2016, the BCAP implemented a thin-layer placement (TLP) project at Shorter’s Wharf in Blackwater NWR on 16 hectares (40 acres) of subsiding and fragmenting tidal marsh dominated by Schoenoplectus americanus, Spartina alterniflora, and Spartina patens. The purpose of the project was to increase the 16 hectares’ (40 acres’) resiliency to climate-driven sea level rise and storm impacts. The project built up the marsh elevation by applying thin layers of sediment dredged from the adjacent Blackwater River. The sediment enhancement was designed to extend the longevity of the marsh and increase its resiliency by raising its surface elevation in relation to the tidal regime and to return the habitat to its prior high-marsh condition with S. patens dominating. The colonization of this site by saltmarsh sparrow would be an indicator of success in reaching this goal. Dredging operations in November and December 2016 placed approximately 19,900 cubic meters (26,000 cubic yards) of sediment on the project site. Post-restoration elevations obtained one year after material placement indicated that, although the target elevations were achieved in 78% of the surveyed placement area, the material was not distributed uniformly. Coarser material tended to stack up at the discharge location while the grain size declined and the slopes flattened toward the periphery of the discharge area. In 2017, natural vegetation had regenerated through the placed sediment with vigorous regrowth of S. americanus and S. alterniflora . This regrowth was supplemented with hand-planting of more than 200,000 plugs of S. patens. Vegetation monitoring is ongoing to determine the plant composition evolution within the placement site. Pre-dredge and post-dredge bathymetric surveys reveal 70% accretion nearly two years after dredging within the borrow area footprint.

The effects of some grazed tropical grass-legume mixtures and nitrogen fertilized grass on total soil nitrogen, organic carbon, and subsequent yields of Sorghum vulgaris

1967 ◽  
Vol 7 (24) ◽  
pp. 66 ◽  
Author(s):  
RJ Jones
Keyword(s):  
Organic Carbon ◽  
Soil Nitrogen ◽  
Crop Yields ◽  
Low Fertility ◽  
Apparent Lack ◽  
Carbon And Nitrogen ◽  
Total Soil ◽  
Significant Difference ◽  
Nitrogen Treatments ◽  
Total Soil Nitrogen

Mixtures of some tropical legumes and Paspalum plicatulum (Michx) cv. Hartley, and stands of P. plicatulum were fertilized with urea at 100 and 200 lb nitrogen an acre a year, and were intermittently grazed by cattle over a period of four years. Soil analyses for organic carbon and for total soil nitrogen in the fourth year of the pasture phase revealed large treatment effects in three of the five replicates. These three replicates which were on a podsolic soil were lower in fertility than the remaining two on a latosolic soil. Soil nitrogen at the 0-3 inch depth in the high nitrogen treatment, and in two Phaseolus atropurpureus D.C. treatments was significantly higher than the control (P<0.05). Organic carbon at the 0-3 inch depth was significantly higher than the control (P<0.05) in the nitrogen treatments and in one of the P. atropurpureus treatments. For both soil nitrogen and organic carbon the Lotononis bainesii Bak. treatment did not differ from the control. There was no significant difference between treatments for soil nitrogen or organic carbon at the 3-6 inch depth though trends were similar to those at 0-3 inches. Organic carbon and nitrogen were closely correlated for all treatments at both depths, and there were no significant differences in the C : N ratio in any treatment. Yields of sorghum grown as a test crop after the pastures were significantly correlated with soil nitrogen values in the three low fertility replicates. A high correlation (r = +0.976) also existed between yields of nitrogen obtained in the pasture phase and test crop yields of nitrogen for all treatments except L. bainesii. Reasons for the apparent lack of improvement in soil nitrogen and carbon on the higher fertility replicates and for the poor test crop yields following L. bainesii are discussed.

Sign in / Sign up

Export Citation Format

Share Document