Download or read book Variation in Response to a Continuum of Stress and Disturbance in a Salt Marsh Plant Assemblage written by Stuart Keating Allison and published by . This book was released on 1991 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1991 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1992-11 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physiology of Salt Stress in Plants written by Pratibha Singh and published by John Wiley & Sons. This book was released on 2021-10-11 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: PHYSIOLOGY OF SALT STRESS IN PLANTS Discover how soil salinity affects plants and other organisms and the techniques used to remedy the issue In Physiology of Salt Stress in Plants, an editorial team of internationally renowned researchers delivers an extensive exploration of the problem of soil salinity in modern agricultural practices. It also discusses the social and environmental issues caused by salt stress. The book covers the impact of salt on soil microorganisms, crops, and other plants, and presents that information alongside examinations of salt’s effects on other organisms, including aquatic fauna, terrestrial animals, and human beings. Physiology of Salt Stress in Plants describes the morphological, anatomical, physiological, and biochemical dimensions of increasing soil salinity. It also discusses potential remedies and encourages further thought and exploration of this issue. Readers are encouraged to consider less hazardous fertilizers and pesticides, to use safer doses, and to explore and work upon salt resistant varieties of plants. Readers will also benefit from the inclusion of: Thorough introductions to salt stress perception and toxicity levels and the effects of salt stress on the physiology of crop plants at a cellular level Explorations of the effects of salt stress on the biochemistry of crop plants and salt ion transporters in crop plants at a cellular level Practical discussions of salt ion and nutrient interactions in crop plants, including prospective signalling, and the effects of salt stress on the morphology, anatomy, and gene expression of crop plants An examination of salt stress on soil chemistry and the plant-atmosphere continuum Perfect for researchers, academics, and students working and studying in the fields of agriculture, botany, entomology, biotechnology, soil science, and plant physiology, Physiology of Salt Stress in Plants will also earn a place on the bookshelves of agronomists, crop scientists, and plant biochemists.

Download or read book Salt Stress in Plants written by Parvaiz Ahmad and published by Springer Science & Business Media. This book was released on 2013-02-26 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental conditions and changes, irrespective of source, cause a variety of stresses, one of the most prevalent of which is salt stress. Excess amount of salt in the soil adversely affects plant growth and development, and impairs production. Nearly 20% of the world’s cultivated area and nearly half of the world’s irrigated lands are affected by salinity. Processes such as seed germination, seedling growth and vigour, vegetative growth, flowering and fruit set are adversely affected by high salt concentration, ultimately causing diminished economic yield and also quality of produce. Most plants cannot tolerate salt-stress. High salt concentrations decrease the osmotic potential of soil solution, creating a water stress in plants and severe ion toxicity. The interactions of salts with mineral nutrition may result in nutrient imbalances and deficiencies. The consequence of all these can ultimately lead to plant death as a result of growth arrest and molecular damage. To achieve salt-tolerance, the foremost task is either to prevent or alleviate the damage, or to re-establish homeostatic conditions in the new stressful environment. Barring a few exceptions, the conventional breeding techniques have been unsuccessful in transferring the salt-tolerance trait to the target species. A host of genes encoding different structural and regulatory proteins have been used over the past 5–6 years for the development of a range of abiotic stress-tolerant plants. It has been shown that using regulatory genes is a more effective approach for developing stress-tolerant plants. Thus, understanding the molecular basis will be helpful in developing selection strategies for improving salinity tolerance. This book will shed light on the effect of salt stress on plants development, proteomics, genomics, genetic engineering, and plant adaptations, among other topics. The book will cover around 25 chapters with contributors from all over the world. ​​

Download or read book Inter and Intraspecific Variation in Carbon and Nutrient Pools of Salt Marsh Plants written by Tracy Elsey-Quirk and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examined both inter- and intraspecific variation of four dominant salt marsh macrophytes, a high marsh shrub, Baccharis halimifolia, a high marsh rush, Juncus roemerianus, a mid-marsh grass, Spartina patens, and the low marsh grass that is ubiquitous in wetlands along the Atlantic and Gulf coasts of the United States, short-form S. alterniflora. Chapter One evaluates the seasonal C pool dynamics of the four species including the seasonal allocation of above- and belowground C pools, C pool loss through decomposition, and soil C concentration in a wetland fringing Little Assawoman Bay, one of Delaware's Coastal Bays. To determine whether the rate of vertical accretion and organic matter accumulation differed between the low, S. alterniflora and high, J. roemerianus zones, soil cores from the two zones were used to measure 137 Cs and 210 Pb activity. Total plant C pools of the mid- and low marsh grass species, Spartina patens (4360 g C m -2) and Spartina alterniflora (4197 g C m -2), were similar and almost two and three times larger than total pools of Juncus roemerianus (2508 g C m -2) and Baccharis halimifolia (1490 g C m -2), respectively. Moving from the high to low marsh zones, the C pool shifted from primarily aboveground to belowground. Baccharis had the greatest aboveground C storage (1140 g m -2) and the slowest rate of C loss. Chapter Two examines interspecific variation in N pool dynamics in the four species including seasonal allocation of N pools above- and belowground, N loss through decomposition, N resorption efficiency, and soil N concentration. The seasonal fluctuation in the total N pools of the herbaceous species was due to belowground N pool dynamics, particularly fine root and dead large and small-sized macroorganic matter fluxes. Comparisons among the species revealed that the location, magnitude and timing of N storage and dispersal differed, which is important in the context of how species will shift in response to environmental change. Chapter Three describes the above- and belowground species associations in the fringing wetland and whether or not species shifts have occurred. Accurate productivity measurements in fringing wetlands may be dependent on species-specific organic matter separation, particularly belowground. Vegetation change in salt marshes may also become apparent when comparing above- and belowground species-specific live and dead organic matter. We surveyed species richness, frequency, and percent cover and measured above- and belowground biomass in three vegetation zones. Our study illustrates the importance of species-specific belowground biomass estimates to provide evidence of species shifts in both the low and high marsh zones. Chapter four examines intraspecific variation in morphological characteristics and carbon, nutrient, and mineral concentration and allocation within B. halimifolia, J. roemerianus, S. patens, and S. alterniflora. Ecotypic variation in morphology and composition and allocation of C, nutrients, and minerals in wetland plants may influence ecosystem functions such as the deposition and trapping of sediments, detritus production, secondary productivity, the cycling and storage of organic and inorganic nutrients, belowground organic matter production, and long-term C storage. We examined the expression of morphological traits and C, nutrient, and mineral composition and allocation among southern ecotypes, a tissue-culture regenerant, and a native mid-Atlantic ecotype for each of four salt marsh species after two growing seasons within natural stands in a mid-Atlantic salt marsh. Overall, we found that the expression of phenotypic variation was greatest in the low marsh, Spartina alterniflora than in the higher marsh species likely due to both the greater spatial variation in elevation and soil conditions in the higher marsh and potentially a lower tolerance of higher marsh species to environmental stress. The differences that we found among ecotypes have important implications for enhancing and developing ecosystem processes in restoration and creation projects. Chapter Five characterizes carbon pool dynamics of the salt marsh species, J. roemerianus, S. patens, and S. alterniflora using a STELLA model. The model was developed to examine the relationships between C pools and fluxes within species, to simultaneously compare the timing and magnitude of seasonal fluxes of C of each of the three species within a square meter, and to examine how changes to model parameters influence C pool dynamics and the accumulation of C belowground. (Abstract shortened by UMI.).

Download or read book The Ecology of a Salt Marsh written by L. R. Pomeroy and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecologists have two long-standing ways to study large ecosystems such as lakes, forests, and salt-marsh estuaries. In the first, which G. E. Hutchinson has called the holological approach, the whole ecosystem is first studied as a "black box," and its components are investigated as needed. In the second, which Hutchinson has called the merological approach, the parts of the system are studied first, and an attempt is then made to build up the whole from them. For long-term studies, the holological approach has special advantages, since the general patterns and tentative hypotheses that are first worked out help direct attention to the components of the system which need to be studied in greater detail. In this approach, teams of investigators focus on major func tions and hypotheses and thereby coordinate their independent study efforts. Thus, although there have been waves, as it were, of investigators and graduate students working on different aspects of the Georgia salt-marsh estuaries (personnel at the Marine Institute on Sapelo Island changes every few years), the emphasis on the holo logical approach has resulted in a highly differentiated and well-coordinated long-term study. Very briefly, the history of the salt-marsh studies can be outlined as follows. First, the general patterns of food chains and other energy flows in the marshes and creeks were worked out, and the nature of imports and exports to and from the system and its subsystems were delimited.

Download or read book Response of Salt Marsh to Anthropogenic Disturbance written by S. Y. Lee and published by . This book was released on 2004 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Species Diversity in Northern California Salt Marshes written by Brenda Joy Grewell and published by . This book was released on 2004 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Abiotic and Biotic Drivers of Spatial Variation in Salt Marsh Species Interactions and Community Dynamics written by Akana Noto and published by . This book was released on 2016 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interactions among members of ecological communities often vary spatially in response to environmental differences. Yet interactions can also vary spatially as a result of biotic factors such as differences in species traits or variation in other species interactions. It is necessary to understand the conditions under which each of these drivers of variation has an effect in order to predict how species interactions will be affected both by changes in the environment and in biotic communities. In this thesis, I explore mechanisms that may cause species interactions to vary across space at local, regional and continental scales in salt marsh plant communities. Chapter 1 investigates the relationship between the environment (means and variability) and community diversity and stability in time-series data from the east and west coasts of North America. Chapter 2 experimentally investigates the effect of sea-level rise on species interactions within a marsh. Chapter 3 seeks to understand geographic variation in plant interactions among six sites spanning the California coast. Chapter 4 uses a common garden experiment to test whether spatial variation in species interactions are driven by differences among plant populations or the environment. Finally, Chapter 5 describes geographic patterns of variation in herbivore pressure to determine whether herbivory drives regional differences in interactions among plants. I found that changes in mean conditions, including sea level, can affect community diversity, stability and strength of species interactions. Environmental variability only affects community stability and diversity when it is relatively large, so increases in variability with climate change may cause plant community dynamics to become affected by both variability and means. Species interactions vary geographically along the west coast, but unlike on the east coast, do not show consistent trends with latitude. Rather, interaction strengths may differ due to trait variation among plant populations and differences in herbivore pressure. My thesis demonstrates that environmental conditions and local factors, including intraspecific phenotypic variation and herbivory, both determine the nature of species interactions in salt marshes, and that the west coast of North America shows geographic patterns in interactions that are distinct from those found on the east coast.

Download or read book Underground Biomass Dynamics and Substrate Selective Properties of Atlantic Coastal Salt Marsh Plants written by John L. Gallagher and published by . This book was released on 1977 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: An intensive study was made of the dynamics of the underground portion of selected salt marsh plants along the U.S. Atlantic Coast. The plants studied included: Borrichia frutescens, Carex paleacea, Distichlis spicata, Eleocharis obtusa, Juncus gerardi J. roemerianus, Phragmites communis, Salicornia virginica, Spartina alterniflora, S. bakeri, S. cynosuroides, S. patens, and Sporobolus virginicus. The study provides information applicable to marsh development on dredged material, particularly methodologies that can be used for determining which marsh plants will be likely to do well on various kinds of dredged material and when a marsh, which has been established on dredged material, approaches natural conditions. The overall study focuses on: an investigation of underground biomass dynamics; characterization of soils supporting the salt marsh plants; and experimentation on the substrate selective properties of several of the marsh plants studied. The following topics are included: underground biomass profiles and dynamics in Atlantic coastal marshes; comparison of some tidal marsh soils along the Atlantic Coast; response of salt marsh plant stands to a pulse of ammonium nitrate; salt marsh plant growth on three types of dredged material; and a bioassay approach to studying marsh plant root growth in natural soil and dredged material.

Download or read book Impacts of Extreme Drought Eutrophication and Plant Invasion on Salt Marshes and Blue Carbon written by Megan Amanda Kelso and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal salt marshes are ecologically rich, productive systems that provide many benefits including flood protection, water filtration, and habitat for coastal fish, invertebrates, and shorebirds. In addition, they are one of the most effective natural systems at sequestering carbon, storing it three times as densely as most forest systems per unit area. These valuable ecosystems are increasingly threatened by anthropogenic stressors such as invasive species, eutrophication, and climate change. Each of these stressors can have large independent impacts on ecosystems and may also have important interactive effects. In this dissertation, I explore the interacting effects of extreme drought associated with climate change, eutrophication, and invasion by an aggressive non-native plant called Lepidium latifolium on tidal salt marshes and their ability to sequester carbon. In chapter 1, my collaborators and I explored how the combined stress of extreme drought and elevated nutrients altered invasion dynamics of L. latifolium in tidal salt marshes of San Francisco Bay, CA, USA. From 2012-2015, California experienced an unprecedented drought that stressed tidal salt marsh ecosystems. In a three-year field experiment from 2014 to 2016, we tracked the effects of this extreme drought on L. latifolium invasion using field experiments to test how nutrient addition altered invasion dynamics at four salt marsh sites along a salinity gradient in San Francisco Bay. We documented a dramatic die-back of invasive L. latifolium during the extreme drought, including large reductions in stem density (52%-100%) and height (17%-47%) that were more severe at low salinity sites than high salinity sites. We found nutrient addition lessened the effect of drought on L. latifolium stem density, but not height. In native salt marsh plots, extreme drought reduced native plant percent cover (4%-24%), but nutrient addition strongly mitigated this impact. Interestingly, we found native plants in areas invaded by L. latifolium did not suffer reductions in percent cover due to drought, perhaps because they were simultaneously benefitting from the die-back of the invader. Further, native plant percent cover actually increased during the drought in plots that were both invaded by L. latifolium and received nutrients. These results indicate extreme drought is an important driver of change in salt marsh plant communities and may impede the invasion and spread of L. latifolium. Further, nutrient loading appears to help both native and invasive plants cope with extreme drought stress. In chapter 2, we examined the physical mechanisms and temporal scale underlying the dramatic die-back of L. latifolium documented in chapter 1. Extreme drought affects estuarine tidal salt marshes both by reducing local rainfall and by raising estuarine salinity through reduced fresh-water inflows. We tested the impact of local rainfall on L. latifolium by experimentally manipulating rainfall for one year in plots at a salt marsh in south San Francisco Bay. Surprisingly, we did not detect a significant impact of local rainfall on density of the invader, despite diverting 100% of the rainfall that would have fallen into experimental plots during the rainy season (January to mid-May). Next, we explored the relationship between bay salinity and invasion using eight years of monthly water column salinity data and five years of L. latifolium density field data at three salt marsh sites. We found a significant time-lagged (three years) effect of bay salinity on L. latifolium density across our three sites, with high salinities preceding reductions in L. latifolium densities and low salinities preceding increases. The most dramatic change in stem density, a 54% reduction in 2015, was preceded by a salinity increase of 43% from 2011 to 2012. Our finding that water column salinity was a major driver of L. latifolium invasion dynamics suggests sea level rise, like extreme drought, may hinder L. latifolium invasion, since rising sea levels will also raise estuarine salinities. Further, our study highlights the importance of temporal lags in climate change impacts on biological invasions, which has received very little study to date. In chapter 3, we examine the effects of L. latifolium invasion and eutrophication on the valuable ecosystem service of carbon storage provided by coastal salt marshes, known as “blue carbon” storage. Specifically, we measured standing stock of carbon and rates of decomposition, an important underlying process driving future rates of carbon storage. We found invasion by L. latifolium overall decreased blue carbon, a surprising result that contradicts the general assumption that invasive plants store more carbon than native communities. We identified a synergistic interaction between invasion and nutrient addition on rates of below-ground decomposition, where nutrient addition amplified the accelerating effect of invasion on below-ground decomposition. We found nutrient addition increased carbon in above-ground and below-ground biomass. Our results demonstrate that anthropogenic stressors can alter blue carbon in independent and interactive ways. Taking a multi-stressor approach to studying blue carbon ecosystems will improve predictions of the permanence of blue carbon storage and might explain some of the observed variability in carbon storage among sites, two of the largest technical hurdles impeding the development of comprehensive blue carbon policy. Coastal wetland ecosystems are under threat from multiple concurrent stressors and understanding their combined impacts on these ecosystems and the valuable carbon storage service they provide is critical for effective management and policy development.

Download or read book Decomposer Community Response to Sea Level Rise in a California Salt Marsh written by Ellie Jo Wenger and published by . This book was released on 2019 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Salt marshes are highly productive ecosystems which perform many valuable services including carbon sequestration, nutrient transformation, and mitigation of rough waters generated by storms. Coastal salt marshes currently face threats resulting from global climate change, including sea level rise (SLR). Coastal marshes have kept pace with historical SLR through elevation gain via sediment precipitation from tidal waters. In the coming century, sea level is expected to increase 5x-8x faster than the previous century. Since the rate of sedimentation is unlikely to increase with SLR, marshes are in danger of habitat loss via drowning and subsidence. The decomposing organisms in salt marsh sediments are essential to maintaining marsh plant health. The response of decomposing organisms to longer periods of inundation is unclear. To determine how the prokaryote and invertebrate communities may change in response to SLR, mesocosms were designed, which simulated different inundation intensities within the marsh. A gradient developed over the 10-month sampling period in which the most inundated sediments had significantly different communities than the driest sediments. The high inundation treatments were dominated by anaerobic prokaryotes and insect larvae, and sulfate reduction was the predominant decomposition processes. The ambient mesocosms (driest sediments) were dominated by aerobic prokaryotes and oligochaete worms. Aerobic processes such as leaf litter decay became the key decomposition processes in these sediments.

Download or read book Functional Traits of Salt Marsh Plants written by Vanessa Minden and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2011-02 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the responses of plant traits on environmental constraints were evaluated and the most responsive plant traits were identified and tested for their applicability to trait-environmental concepts. Trait-trait relationships were investigated and the effects of plant traits on ecosystem properties were assessed. The study was conducted in salt marshes along the mainland coast of Northwest Germany and on the island of Mellum. The most important findings were that nutrient availability and water-related environmental conditions most strongly influence trait expressions of salt marsh plants. Morphology-based traits were partly different from those of other terrestrial plants and trait-trait relationships of elemental-based traits were consistent to the findings of other studies. Different plant traits were found to affect different ecosystem properties. Therefore, multifunctionality of salt marshes can only be ensured by conserving functional diversity via species diversity. engl.

Download or read book Ecophysiology and Responses of Plants under Salt Stress written by Parvaiz Ahmad and published by Springer. This book was released on 2014-12-13 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will shed light on the effect of salt stress on plants development, proteomics, genomics, genetic engineering, and plant adaptations, among other topics. Understanding the molecular basis will be helpful in developing selection strategies for improving salinity tolerance. The book will cover around 25 chapters with contributors from all over the world.

Download or read book The Role of Biotic and Abiotic Processes in the Zonation of Salt Marsh Plants in the Nueces River Delta Texas written by Michael Kevin Rasser and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salt marshes provide critical ecosystem services, such as shoreline stabilization, biogeochemical cycling and habitat for wildlife, to much of the world's population living on the coasts. Emergent vascular plants are a critical component of these ecosystems. This study was a comprehensive effort to gain a better understanding of the ecology of salt marsh plants in the Nueces River delta on the south Texas coast. This knowledge is essential to understand the potential anthropogenic impacts on salt marshes, including sea-level rise, global warming, reduced freshwater inflow and coastal erosion. A combination of remote sensing analysis, field studies and experiments were used to allow analysis across spatial scales ranging from landscape patterns of vegetation to leaf level measurements of the dominant species. A novel method of image classification was developed using high-resolution multi-spectral imagery integrated with ancillary data to map the major plant communities at a landscape scale. This included a high marsh assemblage composed primarily of Spartina spartinae and a low marsh community dominated by Borrichia frutescens and Salicornia virginica. Geospatial analysis determined that the location of these plant communities was related to the distance from the tidal creek network and elevation. The B. frutescens and S. virginica assemblage was more abundant at lower elevations along the waters edge, making it vulnerable to loss from shoreline erosion. At a finer spatial scale, gradient analysis was utilized to examine the relationship between elevation, which creates environmental gradients in salt marshes, and species distribution. I discovered that elevation differences of less than 5 cm can influence both individual species and plant community distribution. One interesting finding was that the two dominant species, B. frutescens and S. virginica, share similar responses along an elevation gradient yet are observed growing in monotypic adjacent zones. I constructed a large reciprocal transplant experiment, using 160 plants at 4 sites throughout the marsh, to determine what causes the zonation between these two species. The results of this study found that S. virginica fared well wherever it was transplanted but was a weak competitor. B. frutescens survival was significantly lower in the S. virginica zone than in its own zone suggesting that abiotic factors are important in determining the zonation of this species. However, high spatial and temporal variability existed in environmental parameters such as salinity. This variability may have been caused by the semi-arid climate and irregular flooding typical in the Nueces Marsh. Therefore, I utilized a greenhouse experiment to directly test the importance of the two dominant physical factors in salt marshes, flooding and salinity. The results found that for B. frutescens the effects of flooding were not significant, however salinity at 30% reduced growth. Salinity did not influence growth of S. virginica. The greater ability of S. virginica to tolerate salinity stress has important implications because reduced freshwater inflow or climate change can increase porewater salinity, thus favoring the expansion of S. virginica, and altering the plant community structure.

Download or read book Saltmarsh Ecology written by Stephen Patrick Long and published by Blackie Academic and Professional. This book was released on 1983 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: