The Role Of Physical And Biological Soil Crusts On The Water Balance In Semiarid Ecosystems
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The Role Of Physical And Biological Soil Crusts On The Water Balance In Semiarid Ecosystems
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Author : Sonia Chamizo de la Piedra
language : en
Publisher: Universidad Almería
Release Date : 2014-11-06
The Role Of Physical And Biological Soil Crusts On The Water Balance In Semiarid Ecosystems written by Sonia Chamizo de la Piedra and has been published by Universidad Almería this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-11-06 with categories.
In arid and semiarid areas, the interplant spaces are usually covered by physical and biological soil crusts. These crusts, though representing an almost negligible portion of the soil profile, have a number of crucial roles. Soil crusts form the boundary between soil and atmosphere and therefore control gas, water and nutrient exchange into and through soils. Concretely, in the last decade, the study of biological soil crusts (BSCs) (complex communities of cyanobacteria, algae, fungi, lichens, mosses and other microorganisms in intimate association with soil particles) has drawn the attention of a growing number of researchers due to the key role they play in numerous processes in the ecosystems where they appear. Unlike physical crusts, BSCs protect soils against erosion by water and wind, and increase soil fertility by fixing atmospheric C and N, synthesising polysaccharides and reducing nutrient losses by runoff and erosion. Through their influence on numerous properties that affect how water moves though soils such as roughness, porosity, hydrophobicity, cracking, and albedo, BSCs play a key role in water processes, such as infiltration and runoff, evaporation and soil moisture. It is widely known the role of physical crusts in decreasing soil porosity and hydraulic conductivity, thus decreasing infiltration. However, there is controversy regarding the role of BSCs in infiltration and runoff processes. Some studies indicate that BSCs increase infiltration, and consequently, decrease runoff, whereas others have reported that they decrease infiltration and increase runoff or that they have no effect on either of them. In addition, the influence of BSCs on other soil water balance components such as evaporation and soil moisture has hardly been studied and the scarce existing studies also show contradicting results. With the aim of enlightening the role that BSCs play in the water balance in semiarid areas, in this thesis it has been analysed the influence of different soil crust types, physical crusts and various developmental stages of BSCs, on key soil water balance components such as infiltration-runoff, evaporation and soil moisture, at plot scale. Furthermore, to better understand how these crusts affect hydrological processes, the influence of the type of crust and developmental stage of the crust on different properties that affect water movement and retention in soils has been analysed. Last, spectral characteristics of the different crust types, as well as of vegetation, have been examined with the aim of developing a spectral classification system for differentiation of these common ground covers in semiarid areas that allows their mapping and the modelling of the effects of the crusted areas on hydrological and erosion processes on larger spatial scales (hillslope and catchment). To conduct this research, two areas where BSCs are widespread and that represent key spatial distributions of BSCs in semiarid ecosystems were chosen in the province of Almeria (SE Spain): El Cautivo (in the Tabernas Desert), a badlands catchment with silty-loam textured soils, and Las Amoladeras (in the Cabo de Gata-Níjar Natural Park), a flat area with sandy-loam textured soils. Our results show that BSCs increase aggregate stability, water retention capacity, and organic carbon and total nitrogen content compared to physical crusts and, within BSCs, these properties increase in the crust and the underlying soil as the crust is more developed (in terms of greater biomass and later-successional species composition). The increase in soil properties with the presence of BSCs is especially noticeable in the top layer of soil (0.01 m) and decreases with depth (0.01-0.05 m) (Chapter I). Through their effect increasing surface roughness and physico-chemical soil properties, BSCs increase infiltration and decrease runoff compared to physical crusts. In general, infiltration increases with greater BSC development (Chapter II). However, there are exceptions to this general pattern that are conditioned by other factors such as the spatial scale under study or the type of rainfall. At small plot sizes (0.25 m2) and after 1h-high intensity simulated rainfall (50 mmh-1), we found that well-developed BSCs such as lichens, generate higher runoff rates than less developed BSCs as cyanobacteria, and similar runoff rates to physical crusts (Chapter II). Thus, at microplot scales and under extreme events, the effect of well-developed BSCs in enhancing infiltration due to their greater roughness can be overcome by their ability to clog soil pores when wet, thus increasing runoff. However, when the influence of BSCs on infiltration and runoff is analysed under natural rain events and at larger spatial scales (1-10 m2), we found that, in low intensity rainfalls, runoff decreases with the cover of well-developed BSCs (lichens) and this effect is higher as the plot size increases (Chapter III). Such decrease in runoff with the presence of well-developed BSCs is due to the microtopography that these crusts confer to soils. Under high intensity rainfalls, BSC cover has no significant effect on runoff yield and the main factor acting to determine runoff generation is rainfall intensity (Chapter III). The removal of the crust initially causes infiltration to increase. But this effect diminishes over time as raindrop impact reseals the surface and a new physical crust is formed that increases runoff (Chapter II). Moreover, crust disturbance by trampling but, especially by removal, causes a dramatic increase in erosion (Chapter II). Erosion also depends on the type of BSC. Well-developed crusts as lichens and mosses generate lower erosion rates than less developed crusts as cyanobacteria. Regarding the influence of BSCs on soil evaporation, under saturation conditions and warm ambient temperatures, soil water loss is quick in all types of surfaces and no significant differences are found in soils with or without BSCs (Chapter V). However, during long cold wet periods, soil water loss is faster in soils devoid of BSCs than in those covered by them. Thus, BSC-crusted soils maintain more soil moisture at the upper soil layer (0.03 m) than adjacent soils where the BSC has been removed, during wet periods. At deeper soil (0.10 m), soil moisture is similar in both BSC-crusted and uncrusted soils. The removal of the BSC causes a higher decrease in soil moisture in fine-textured soils (Cautivo), where the presence of BSCs has a stronger influence on increasing porosity and infiltration, than in coarse-textured soils (Las Amoladeras). During dry soil periods, soil moisture is similar in soils with or without BSCs (Chapter V). Last, a quantitative analysis of spectral characteristics of vegetation, physical crusts and BSC developmental stages has demonstrated the possibility of classifying these common ground covers in semiarid areas based on distinctive spectral features (Chapter VI). The application of the classification system developed to multi and hiperspectral provides the possibility for future mapping of spatial distribution and temporal dynamics of BSCs, which is crucial to incorporating the effects of crusted surfaces in current hydrological and erosion models. Summarizing, compared to physical crusts, the presence of BSCs increase physico-chemical properties of underlying soils, especially in the first centimeters of soil, and this enhancement is greater as the BSC is more developed. Due to this increase in soil properties and the higher roughness that BSCs provide to soils, BSCs increase water input by increasing infiltration and soil moisture, and soil moisture, and reduce water output by reducing soil evaporation. Hence, compared to physical crusts, the presence of BSCs and, especially the presence of well-developed BSCs, have an overall positive effect on the local water balance in semiarid ecosystems, in addition to having a major role in protecting soils from erosion.
Ecohydrological Response Of Dryland Ecosystems To Aridification The Role Of Runoff Water Redistribution
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Author : Borja Rodríguez Lozano
language : en
Publisher: Universidad Almería
Release Date : 2024-11-25
Ecohydrological Response Of Dryland Ecosystems To Aridification The Role Of Runoff Water Redistribution written by Borja Rodríguez Lozano and has been published by Universidad Almería this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-11-25 with Science categories.
In general, according to our results we may conclude that the effect of runoff water redistribution by increasing water and related nutrients for vegetation and underlying soil microbial communities buffer the expected negative response of drylands to aridification. The magnitude of this effect depends on the interplay with other environmental factors controlling soil hydrology, such as lithology legacy on soil properties. Finally, we found that this positive buffer effect could be counterbalance in areas of high human disturbance, as the negative effects of degradation on soils and vegetation could exacerbate runoff and nutrients losses and limit the capacity of the remaining vegetation to trap and retain the runoff-water and related nutrients. The new set of allometric equations developed in this thesis for the quantification of green biomass and the proposed ecohydrological index can be easily combined to provide a comprehensive coupled assessment of vegetation dynamics and the related processes of water and nutrient transfer from open spaces to plants. Thus, they constitute crucial tools for evaluating the effects of runoff water redistribution across different spatial and temporal scales and for incorporating these effects on Earth System Models (ESMs).
Biological Soil Crusts Spatio Temporal Development And Ecological Functions Of Soil Surface Microbial Communities Across Different Scales
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Author : Shubin Lan
language : en
Publisher: Frontiers Media SA
Release Date : 2024-08-09
Biological Soil Crusts Spatio Temporal Development And Ecological Functions Of Soil Surface Microbial Communities Across Different Scales written by Shubin Lan and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-08-09 with Science categories.
Biological soil crusts (biocrusts) are widely distributed throughout the world, and cover approximately 12% of the terrestrial surface. Biocrusts are composed of cyanobacteria, algae, lichens, mosses, and a great diversity of other microorganisms, which bind soil particles together to form a layer of biological-soil matrix on the soil surface typically of several millimetres thickness. They are important sites of regional and global microbial diversity and perform multiple ecological functions (multifunctionality). During the evolution of terrestrial life on earth, biocrusts are regarded as the main colonising photosynthetic organisms before the advent of vascular vegetation. They not only represent the early stages of terrestrial ecosystems, but also facilitate the ecosystem’s development and succession. Therefore, biocrusts are recognised as ecological engineers in the natural development of ecosystems and for the restoration of degraded terrestrial ecosystems. The development of biocrusts is highly heterogeneous, which is reflected on both temporal and spatial scales, and this heterogeneity is still clearly visible even in a small scale. However, up to now, only limited knowledge is acquired on biocrust temporal and spatial organisation. In particular there still is a large knowledge gap regarding the various biocrust communities under different developmental states and their related physiological metabolisms and ecological functions. Therefore, in-depth studies of these issues will undoubtedly further promote our understanding of the heterogeneous development of biocrusts, as well as their ecological multifunctionality in terrestrial ecosystems. The relevant contributions are expected to provide a scientific basis for the management of biocrusts and technology development (e.g. cyanobacteria-induced biocrust technology) for ecological restoration and the promotion of soil health.
The Role Of Physical And Biological Soil Crusts On The Water Balance In Semiarid Ecosystems
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Author : Sonia Chamizo de la Piedra
language : en
Publisher:
Release Date : 2012
The Role Of Physical And Biological Soil Crusts On The Water Balance In Semiarid Ecosystems written by Sonia Chamizo de la Piedra and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
Arid Dune Ecosystems
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Author : Siegmar-W. Breckle
language : en
Publisher: Springer Science & Business Media
Release Date : 2008-07-19
Arid Dune Ecosystems written by Siegmar-W. Breckle and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008-07-19 with Science categories.
Sand dune dynamics plays a key role in many arid deserts. This volume provides a synthesis of a specific sand dune ecosystem, the Nizzana site in the Negev Desert. Describing its climate and geophysical/geochemical properties of soils, geological history, flora and fauna, and past/present land-use patterns, it elucidates ecological and geomorphological processes and their interrelations, based on long-term monitoring, in situ experiments and satellite imagery. Particular attention is drawn to the impact of the topsoil biological crust in controlling water availability at local/regional scales. The interdisciplinary approach adopted in this case study offers a good example of a highly complex and dynamic system, which could easily be applied to other sandy ecosystems. This is a valuable source of information for soil ecologists and microbiologists, conservation biologists, desert ecologists and geographers, geomorphologists, soil scientists and climatologists, lecturers, policy makers and others interested in deserts and desertification.
Microbial Polymers
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Author : Anukool Vaishnav
language : en
Publisher: Springer Nature
Release Date : 2021-05-03
Microbial Polymers written by Anukool Vaishnav and has been published by Springer Nature this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021-05-03 with Science categories.
This book cover all types of microbe based polymers and their application in diverse sectors with special emphasis on agriculture. It collates latest research, methods, opinion, perspectives, and reviews dissecting the microbial origins of polymers, their production, design, and processing at industrial level, as well as improvements for specific industrial applications. Book also discusses recent advances in biopolymer production and their modification for amplifying the value. In addition, understanding of the microbial physiology and optimal conditions for polymer production are also explained. This compilation of scientific chapters on principles and practices of microbial polymers fosters the knowledge transfer among scientific communities, industries, and microbiologist and serves students, academicians, researchers for a better understanding of the nature of microbial polymers and application procedure for sustainable ecosystem
Soils As A Key Component Of The Critical Zone 5
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Author : Christian Valentin
language : en
Publisher: John Wiley & Sons
Release Date : 2018-11-26
Soils As A Key Component Of The Critical Zone 5 written by Christian Valentin and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-11-26 with Science categories.
One third of the world's soils have already been degraded. The burden on the land continues to grow under the combined pressures of demography, urbanization, artificialization and mining, and there are increased demands on agricultural land: changing dietary preferences, land speculation, as well as new demands for agroenergy, fiber, green chemistry, and more. Resulting issues such as soil crusting, water and wind erosion, soil salinization and soil acidity therefore constitute a major threat. The authors of this book present the main processes and factors of soil degradation, different ways to prevent it and methods of rehabilitation. The book also deals with the origin and processes of metallic and organic soil pollution as well as methods of phytoremediation and restoration. It is one of the few books to explore the issue of soil artificialization and urban soil management and to highlight how agricultural and urban waste can be used to amend and fertilize cultivated soils.
Biological Soil Crusts An Organizing Principle In Drylands
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Author : Bettina Weber
language : en
Publisher: Springer
Release Date : 2016-05-21
Biological Soil Crusts An Organizing Principle In Drylands written by Bettina Weber and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-05-21 with Nature categories.
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.
General Technical Report Pnw Gtr
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Author :
language : en
Publisher:
Release Date : 1999
General Technical Report Pnw Gtr written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999 with Forests and forestry categories.
The Biology Of Arid Soils
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Author : Blaire Steven
language : en
Publisher: Walter de Gruyter GmbH & Co KG
Release Date : 2017-07-24
The Biology Of Arid Soils written by Blaire Steven and has been published by Walter de Gruyter GmbH & Co KG this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-07-24 with Nature categories.
Soils have been called the most complex microbial ecosystems on Earth. A single gram of soil can harbor millions of microbial cells and thousands of species. However, certain soil environments, such as those experiencing dramatic change exposing new initial soils or that are limited in precipitation, limit the number of species able to survive in these systems. In this respect, these environments offer unparalleled opportunities to uncover the factors that control the development and maintenance of complex microbial ecosystems. This book collects chapters that discuss the abiotic factors that structure arid and initial soil communities as well as the diversity and structure of the biological communities in these soils from viruses to plants.