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| Author | : T. BIRKEMOE |
| Publisher | : |
| Total Pages | : |
| Release | : 2000 |
| Genre | : |
| ISBN | : |
| Author | : A.N. Rai |
| Publisher | : Springer Science & Business Media |
| Total Pages | : 357 |
| Release | : 2007-05-08 |
| Genre | : Science |
| ISBN | : 0306480050 |
Cyanobacterial symbioses are no longer regarded as mere oddities but as important components of the biosphere, occurring both in terrestrial and aquatic habitats worldwide. It is becoming apparent that they can enter into symbiosis with a wider variety of organisms than hitherto known, and there are many more still to be discovered, particularly in marine environments. The chapters cover cyanobacterial symbioses with plants (algae, bryophytes, Azolla, cycads, Gunnera), cyanobacterial symbioses in marine environments, lichens, Nostoc-Geosiphon (a fungus closely related to arbuscular mycorrhiza fungi) symbiosis, and artificial associations of cyanobacteria with economically important plants. In addition, cyanobiont diversity, sensing-signalling, and evolutionary aspects of the symbiosis are dealt with. Renowned experts actively involved in research on cyanobacterial symbioses deal with ecological, physiological, biochemical, molecular, and applied aspects of all known cyanobacterial symbioses. This volume on cyanobacteria in symbiosis complements the two earlier volumes on cyanobacteria published by Kluwer (Molecular Biology of Cyanobacteria, edited by D.A. Bryant and Ecology of Cyanobacteria, edited by B.A. Whitton and M. Potts). Together, the three volumes provide the most comprehensive treatment of cyanobacterial literature as a whole. The book will serve as a valuable reference work and text for teaching and research in the field of plant-microbe interactions and nitrogen fixation.
| Author | : Bettina Weber |
| Publisher | : Springer |
| Total Pages | : 540 |
| Release | : 2016-05-21 |
| Genre | : Nature |
| ISBN | : 3319302140 |
This volume summarizes our current understanding of biological soil crusts (biocrusts), which are omnipresent in dryland regions. Since they cover the soil surface, they influence, or even control, all surface exchange processes. Being one of the oldest terrestrial communities, biocrusts comprise a high diversity of cyanobacteria, algae, lichens and bryophytes together with uncounted bacteria, and fungi. The authors show that biocrusts are an integral part of dryland ecosystems, stabilizing soils, influencing plant germination and growth, and playing a key role in carbon, nitrogen and water cycling. Initial attempts have been made to use biocrusts as models in ecological theory. On the other hand, biocrusts are endangered by local disruptions and global change, highlighting the need for enhanced recovery methods. This book offers a comprehensive overview of the fascinating field of biocrust research, making it indispensable not only for scientists in this area, but also for land managers, policy makers, and anyone interested in the environment.
| Author | : Gerardo Perillo |
| Publisher | : Elsevier |
| Total Pages | : 1130 |
| Release | : 2018-11-02 |
| Genre | : Science |
| ISBN | : 0444638946 |
Coastal Wetlands, Second Edition: An Integrated and Ecosystem Approach provides an understanding of the functioning of coastal ecosystems and the ecological services that they provide. As coastal wetlands are under a great deal of pressure from the dual forces of rising sea levels and the intervention of human populations, both along the estuary and in the river catchment, this book covers important issues, such as the destruction or degradation of wetlands from land reclamation and infrastructures, impacts from the discharge of pollutants, changes in river flows and sediment supplies, land clearing, and dam operations. Covers climate change and its influence on coastal wetland form and function Provides a fully updated and expanded resource, including new chapters on modeling, management and the impact of climate change Contains full-color figures of wetlands and estuaries in different parts of the world
| Author | : Turid Liengen |
| Publisher | : |
| Total Pages | : 131 |
| Release | : 1997 |
| Genre | : |
| ISBN | : 9788257503024 |
| Author | : |
| Publisher | : |
| Total Pages | : 662 |
| Release | : 2001 |
| Genre | : Entomology |
| ISBN | : |
| Author | : Katherine J. Stewart |
| Publisher | : |
| Total Pages | : 0 |
| Release | : 2010 |
| Genre | : Cyanobacteria |
| ISBN | : |
"Atmospheric N2-fixation by cyanobacteria is a key source of newly fixed N in nutrient-poor arctic ecosystems. To further determine the causes of N limitation and predict long-term responses to climate change the controls of biological N2-fixation must be better understood. Using acetylene reduction assays we evaluated the spatial and temporal variation in N2-fixation by associative cyanobacteria in various ecosystem types in both the low and high Canadian Arctic. The direct and indirect effects of soil moisture, plant community functional composition, and bryophyte and lichen abundance on rates of N2-fixation were examined at sites varying in latitude and vegetation type. The linkages between N and C cycling processes in arctic systems were examined through paired measurements of N2-fixation, inorganic soil N with surface greenhouse gas fluxes, including CO2, N2O and CH4. Total growing season N2-fixation input across a low arctic landscape was estimated at 0.68 kg ha−1yr−1, which is slightly less than twice the estimated average N input 0.39 kg ha−1yr−1 via precipitation. N2-fixation by bryophyte-cyanobacterial associations appear to be very important across the Canadian Arctic. Increasing soil moisture was strongly associated with an increasing presence of bryophytes and increasing bryophyte abundance was a major factor determining higher N2-fixation rates at all sites. Shrubs had a negative effect on bryophyte abundance; competition from vascular plants, potentially through shading, may negatively influence N2-fixation. Soil N status was linked to rates or N2-fixation in both the high and low Arctic indicating that these N2-fixing associations act as important point sources of soil N. Higher rates of nitrification may be associated with warmer and drier vegetation types; however, increasing NO3-N availability does not appear to increase rates of denitrification. Loss of N through denitrification was not a significant factor in the N cycle at the high arctic sites examined. We found many factors control both the spatial and temporal variability of N2-fixation, including topography, microtopography, vegetation characteristics, microclimatic conditions, nifH abundance and availability of other nutrients, such as phosphorus. Moisture, however, appears to be a key factor not only in determining N2-fixation but also by influencing related nutrient cycling processes."--P. ii-iii.
| Author | : Katherine Stewart |
| Publisher | : |
| Total Pages | : |
| Release | : 2011 |
| Genre | : |
| ISBN | : |
Atmospheric N₂-fixation by cyanobacteria is a key source of newly fixed N in nutrient-poor arctic ecosystems. To further determine the causes of N limitation and predict long-term responses to climate change the controls of biological N₂-fixation must be better understood. Using acetylene reduction assays we evaluated the spatial and temporal variation in N₂-fixation by associative cyanobacteria in various ecosystem types in both the low and high Canadian Arctic. The direct and indirect effects of soil moisture, plant community functional composition, and bryophyte and lichen abundance on rates of N₂-fixation were examined at sites varying in latitude and vegetation type. The linkages between N and C cycling processes in arctic systems were examined through paired measurements of N₂-fixation, inorganic soil N with surface greenhouse gas fluxes, including CO₂, N₂O and CH₄. Total growing season N₂-fixation input across a low arctic landscape was estimated at 0.68 kg ha⁻~yr⁻~, which is slightly less than twice the estimated average N input 0.39 kg ha⁻~yr⁻~ via precipitation. N₂-fixation by bryophyte-cyanobacterial associations appear to be very important across the Canadian Arctic. Increasing soil moisture was strongly associated with an increasing presence of bryophytes and increasing bryophyte abundance was a major factor determining higher N₂-fixation rates at all sites. Shrubs had a negative effect on bryophyte abundance; competition from vascular plants, potentially through shading, may negatively influence N₂-fixation. Soil N status was linked to rates or N₂-fixation in both the high and low Arctic indicating that these N₂-fixing associations act as important point sources of soil N. Higher rates of nitrification may be associated with warmer and drier vegetation types; however, increasing NO₃-N availability does not appear to increase rates of denitrification. Loss of N through denitrification was not a significant factor in the N cycle at the high arctic sites examined. We found many factors control both the spatial and temporal variability of N₂-fixation, including topography, microtopography, vegetation characteristics, microclimatic conditions, nifH abundance and availability of other nutrients, such as phosphorus. Moisture, however, appears to be a key factor not only in determining N₂-fixation but also by influencing related nutrient cycling processes.
| Author | : John Dighton |
| Publisher | : CRC Press |
| Total Pages | : 982 |
| Release | : 2005-05-24 |
| Genre | : Science |
| ISBN | : 9781420027891 |
The Fungal Community: Its Organization and Role in the Ecosystem, Third Edition addresses many of the questions related to the observations, characterizations, and functional attributes of fungal assemblages and their interaction with the environment and other organisms. This edition promotes awareness of the functional methods of classification over taxonomic methods, and approaches the concept of fungal communities from an ecological perspective, rather than from a fungicentric view. It has expanded to examine issues of global and local biodiversity, the problems associated with exotic species, and the debate concerning diversity and function. The third edition also focuses on current ecological discussions - diversity and function, scaling issues, disturbance, and invasive species - from a fungal perspective. In order to address these concepts, the book examines the appropriate techniques to identify fungi, calculate their abundance, determine their associations among themselves and other organisms, and measure their individual and community function. This book explains attempts to scale these measures from the microscopic cell level through local, landscape, and ecosystem levels. The totality of the ideas, methods, and results presented by the contributing authors points to the future direction of mycology.
| Author | : Jordi Catalan |
| Publisher | : Springer |
| Total Pages | : 413 |
| Release | : 2017-08-03 |
| Genre | : Nature |
| ISBN | : 3319559826 |
This book provides case studies and general views of the main processes involved in the ecosystem shifts occurring in the high mountains and analyses the implications for nature conservation. Case studies from the Pyrenees are preponderant, with a comprehensive set of mountain ranges surrounded by highly populated lowland areas also being considered. The introductory and closing chapters will summarise the main challenges that nature conservation may face in mountain areas under the environmental shifting conditions. Further chapters put forward approaches from environmental geography, functional ecology, biogeography, and paleoenvironmental reconstructions. Organisms from microbes to large carnivores, and ecosystems from lakes to forest will be considered. This interdisciplinary book will appeal to researchers in mountain ecosystems, students and nature professionals. This book is open access under a CC BY license.
