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There is a long history of describing communities in ecology. It is now time to develop a general predictive framework for this discipline. The goal is to simultaneously provide a consistent theoretical framework to guide research and a practical framework to guide conservation of wild landscapes. We propose that this framework has four key elements: the species pool vector P, the local community vector C, a vector of environmental filters E, and a vector of functional traits T. The central challenge of community ecology is to predict the species composition of any community C, using prior knowledge of P, E and T. Common filters include flooding, fire and herbivory. Each community C is a subset of the regional species pool P and is the result of filtering that matches species’ traits to the local environmental conditions. Dispersal, competition and time are also important in community assembly.
This chapter singularly focuses on the impacts of dikes (levees), including their design, management, and influence on hydrologic and fluvial sedimentary processes. Floodplain embankment commonly removes ~75% of the natural floodplain from annual flood pulse dynamics. Flood control by embankment fundamentally alters fluvial processes between, along, and beyond dikes. Over longer timescales dikes result in a unique floodplain environment characterized by distinctive morphologic, hydrologic, and sedimentary features that do not exist on natural floodplains. Dike breach ponds are distinctive hydrologic features along dikes that provide valuable ecosystem services. Embanked floodplains trap flood deposits that results in thicker and somewhat coarser flood deposits, which buries natural wetlands and infills floodplain lakes. This results in a channel belt ‘perched’ above low-lying flood basins, which increases the risk of avulsion. The chapter closes by integrating concepts related to channel engineering (Chapter 5) and floodplain embankment to arrive at an evolutionary model for engineered rivers, which provides a segue to flood basin management (Chapter 7).
This book addresses an important problem in ecology: how are communities assembled from species pools? This pressing question underlies a broad array of practical problems in ecology and environmental science, including restoration of damaged landscapes, management of protected areas, and protection of threatened species. This book presents a simple logical structure for ecological assembly and addresses key areas including species pools, traits, environmental filters, and functional groups. It demonstrates the use of two predictive models (CATS and Traitspace) and consists of many wide-ranging examples including plants in deserts, wetlands, and forests, and communities of fish, amphibians, birds, mammals, and fungi. Global in scope, this volume ranges from the arid lands of North Africa, to forests in the Himalayas, to Amazonian floodplains. There is a strong focus on applications, particularly the twin challenges of conserving biodiversity and understanding community responses to climate change.
Pressure on large fluvial lowlands has increased tremendously during the past twenty years because of flood control, urbanization, and increased dependence upon floodplains and deltas for food production. This book examines human impacts on lowland rivers, and discusses how these changes affect different types of riverine environments and flood processes. Surveying a global range of large rivers, it provides a primary focus on the lower Rhine River in the Netherlands and the Lower Mississippi River in Louisiana. A particular focus of the book is on geo-engineering, which is described in a straight-forward writing style that is accessible to a broad audience of advanced students, researchers, and practitioners in global environmental change, fluvial geomorphology and sedimentology, and flood and water management.
The sixth chapter examines how Native communities and haciendas adopted livestock rearing and, in particular, cattle ranching as a new economic activity within the lakes. Responding to the rise of the urban market for meat as well as the demographic decline within Native communities, residents of the chinampa districts expanded into the waters of the lakes in new and destabilizing ways. Alongside the chinampas, many of which survived and retained their value, haciendas and Native communities now fashioned pastures from the swamps. As they pushed further into the lake, pastoralists instituted new environmental management practices and constructed new hydraulic engineering works of their own. At the same time, the colonial administration, responding to renewed fears of flooding in the capital, increasingly intervened in the southern lakes’ hydrology. These new forces for change, when combined with higher rates of rainfall because of renewed climate extremes, undermined both the ecological autonomy and the flood defenses of the Nahua communities, portending of wholesale environmental transformation if not ruination on the eve of Mexico’s Independence.
Navua sedge [Cyperus aromaticus (Ridl.) Mattf. & Kuek.], is a hard to control C4 perennial weed species in tropical regions of Australia. Knowledge of its seed biology could help to develop integrated weed management programs for this species. This study was conducted under laboratory and screenhouse conditions to evaluate the effect of alternating day/night temperatures, light, pretreatment high temperatures, burial depth, and flooding depth on the germination and emergence of two populations (Ingham and Tablelands) of C. aromaticus. Both populations germinated at temperatures ranging from 20/10 to 35/25 C; however, the Ingham population germination (76%) was greater than the Tablelands population (42%) at the highest temperature regime (35/25 C). None of the populations germinated at 15/5 C. Darkness completely inhibited germination in both populations, suggesting that the seeds are positively photoblastic. Seeds (dry and wet) of both populations germinated after exposure to pretreatment temperatures of up to 100 C for 5 min. After pretreatment at 150 C, only the Ingham population germinated, and germination was greater for dry seeds (62%) than for wet seeds (1%). Neither population germinated after exposure to 200 C. For both populations, maximum germination was observed for seeds at 0 cm; a burial depth of 0.5 cm completely inhibited emergence of the Tablelands population, and a burial depth of 2.0 cm completely inhibited germination of the Ingham population. A flooding depth of 10 cm greatly reduced emergence in both populations compared with 0 cm (62% and 78%) but 12% to 14% of seedlings still emerged, suggesting the need to integrate flooding with other management tools. The results also suggest that the Ingham population may have a greater potential to spread into new areas or become more invasive than the Tablelands population. Knowledge gained from this study can be used to manage C. aromaticus by fire/burning, tillage, and flooding.
Richard Wright’s relationship with African American music was fundamentally paradoxical: he was both thoroughly immersed in and profoundly detached from such genres as blues and jazz. While he listened to black music avidly, its presence in his fiction is minimal, and—like other progressives and literary figures of his time—he tended to see blues and jazz not as art in themselves, but as vital and raw folk material out of which the literati might create art. What is more, Wright emerged as an author and produced his most canonical works during a relative hiatus in blues history, as well as at a moment when jazz existed primarily as mainstream entertainment in the form of big-band swing. Although critics conventionally focus upon the few fleeting references to African American music in Wright’s fiction, revisionist scholarship might bring the music to bear on the author’s work instead. There are, for example striking parallels of topic, theme, language, and imagery between Wright’s “Down by the Riverside” (1938) and Charley Patton’s song about southern flooding, “High Water Everywhere” (1930). Critics, then, can fill in the blues and jazz gaps in Wright’s work that he was unable to complete himself.
Rising flood damages have prompted local communities to implement buyout and property acquisition programmes to eliminate repetitive losses for at-risk properties. However, buyouts are often costly to implement and are reactionary solutions to flooding. This study quantifies the benefits of acquiring vacant private properties in flood-prone areas rather than acquiring such properties after they are built up. Using a geodesign framework that integrates concepts and analytical approaches derived from geographical, spatial and statistical-based disciplines, we analyse vacant properties with high development potential that intersect current and future floodplain areas in Houston (TX, USA). We use geospatial proximity analysis to select candidate properties, land-use prediction modelling to estimate future development and sea-level rise and benefit–cost analysis to assess the economic viability of buyouts. The results indicate that cumulative avoided flood losses exceed the cost of vacant land acquisition by a factor of nearly two to one, and up to a factor of ten to one in selected areas. This study emphasizes the benefits of proactive property buyouts that focus on acquiring parcels before they are built up, while also avoiding the social and institutional problems associated with traditional buyout programmes.
Scientific advances of the nineteenth and early twentieth century meant climate began to be understood as something to be measured and described technically; yet the supposed objectivity of this scientific discourse became inseparable from the subjectivity of social comment and prejudice. With its interest in putting different discourses in tension, Modernist writing is well suited to challenge these conceptions, and the growing literary recognition of under- or unrepresented communities saw a diversity of cultures being written. While Modernist writers such as Stein and Stevens complicated easy assertions about the social effects of climate, Southern and African-American writers including Faulkner, Hurston and Hughes contested generalized or racially inflected climatic theories. It is the economy rather than environment that places the figures of American Modernist literature in their privileged or precarious positions, which only then determines whether they can exploit or are subject to the climate. Such writing reveals the limitations and failures of technical and economic understandings of the environment, troubling them with personal and bodily experience of weather.
Atrazine applied at planting is commonly used for weed control in corn. With global climate change causing an increase in river flooding in the United States over the past decade, producers need information to determine the best course of action in flooded fields treated with atrazine into which they wish to immediately plant soybean. Studies were designed to understand the effect of flooding on atrazine residual activity including atrazine concentration, soybean injury, and soybean yield. In 2012, soybean yield in flooded treatments was reduced by prior atrazine application. In 2014, soybean injury was <10% in all plots, and nonflooded, atrazine-treated soils had yields equal to the nontreated. Findings from this research indicated that it is possible for producers to consider replanting soybean after atrazine application, with appropriate changes to product labeling.
In wetlands, dormancy may be a key functional trait enabling seeds to avoid underwater germination, which could be lethal for seedling establishment. Our objectives were to find out (i) if shallow dormant (i.e. conditionally dormant) Echinochloa crus-galli seeds from an anaerobic germination resistant accession can break dormancy under hypoxic submergence and (ii) if underwater germination can be restored in scarified, non-dormant seeds. Shallow dormant E. crus-galli seeds perceived diurnally alternating temperatures (AT) and red light (R) pulses (i.e. dormancy-breaking cues) under hypoxic submergence; however, an inhibitory far-red light pulse given at the end of the 4-d inundation period demonstrated that most of the seeds (85%) were unable to break dormancy. Scarified E. crus-galli seeds, which did not express dormancy under drained conditions, were unable to germinate under hypoxic submergence, despite being exposed to dormancy-breaking cues (AT + R). Lastly, the temporal window for germination sensitivity to the inhibitory action of hypoxia, once dormancy-breaking signals have been applied, is progressively lost and bounded to approximately 18 h for half of the seed lot. These results highlight the importance of dormancy as a trait enabling E. crus-galli seeds to avoid underwater germination, a risky scenario for seedling emergence and establishment in this facultative hydrophyte.
Environmental information from place-names has largely been overlooked by geoarchaeologists and fluvial geomorphologists in analyses of the depositional histories of rivers and floodplains. Here, new flood chronologies for the rivers Teme, Severn, and Wye are presented, modelled from stable river sections excavated at Broadwas, Buildwas, and Rotherwas. These are connected by the Old English term *wæsse, interpreted as ‘land by a meandering river which floods and drains quickly’. The results reveal that, in all three places, flooding during the early medieval period occurred more frequently between AD 350–700 than between AD 700–1100, but that over time each river's flooding regime became more complex including high magnitude single events. In the sampled locations, the fluvial dynamics of localized flood events had much in common, and almost certainly differed in nature from other sections of their rivers, refining our understanding of the precise nature of flooding which their names sought to communicate. This study shows how the toponymic record can be helpful in the long-term reconstruction of historic river activity and for our understanding of past human perceptions of riverine environments.
Our study is located in northern Beni and aims to improve knowledge on regional landscape changes from the last 8600 years, based on pollen and charcoal analyses from a lacustrine sediment core from Lake Ginebra. Our results showed that gallery forest and lacustrine sediment were observed from 8645 until 3360 cal yr BP. After a change from a lacustrine to a swamp environment at 1700 cal yr BP, the Cerrados and the Mauritia swamp became installed 1000 years ago on our study site. The environmental changes we observed over the last 8600 years in the Ginebra record reinforce the evidence of a west–east climatic gradient with the persistence of rain forest throughout the Holocene on the western side and the presence of the Cerrados until the late Holocene on the eastern side. Moreover, the persistence of a wet forest in the early to mid-Holocene in southwestern Amazonia highlighted some local responses to the global trend that could be related to the distance from the Andes; while in the late Holocene, both an increase in insolation and strengthening of the South American summer monsoon system enabled the installation of a seasonal flooded savanna in northern Beni and of the rain forest in eastern Beni.
This chapter looks empirically at the field of health technology assessment (HTA) and argues that it is possible to identify the ‘defence’ style of hyper-active governance posited in the previous chapter. HTA is the crucial expert policy area, involving deciding which drugs and other medical treatments are safe and cost-effective to be prescribed by a local doctor or hospital. HTA has been described by international organisations promoting its use as ‘the systematic evaluation of the properties and effects of a health technology, addressing the direct and intended effects of this technology, as well as its indirect and unintended consequences, and aimed mainly at informing decision making regarding health technologies’ (www.inahta.org). It is a process for making delicate decisions about whether a country will fund a medicine, often based on variants of cost–benefit analysis. In this sense, HTA is a classic arena of expert governance: it is the attempt to turn highly emotive decisions about life and death – about who gets access to new potentially life saving drugs and medical treatments – into rational, evidence-based questions of medical science.
Hyper-active governance is about more than just government resisting public demands that they intervene in expert-led agencies. Often intervention is required to protect the status quo. Emergencies are a good example of this. In the event of a terrorist attack, a bush fire or a fire in a nightclub, politicians are expected to be in control of the situation. However, this does not mean that they rely any less on experts and expertise. In fact, during emergencies experts are arguably even more important. Ministers need information on the ground, expert assessments of whether things are going to get better or worse, how the situation is expected to progress and what might be done to alleviate human suffering in a highly contingent and dynamic context. They hence create emergency technocratic agencies staffed with scientists and experts in all aspects of emergency prevention, response and recovery.
Hyper-active Governance is a new way of thinking about governing that puts debates over expertise at the heart. Contemporary governing requires delegation to experts, but also increases demands for political accountability. In this context, politicians and experts work together under political stress to adopt different governing relationships that appear more 'hands-off' or 'hands-on'. These approaches often serve to displace profound social and economic crises. Only a genuinely collaborative approach to governing, with an inclusive approach to expertise, can create democratically legitimate and effective governance in our accelerating world. Using detailed case studies and global datasets in various policy areas including medicines, flooding, water resources, central banking and electoral administration, the book develops a new typology of modes of governing. Drawing from innovative social theory, it breathes new life into debates about expert forms of governance and how to achieve real paradigm shifts in how we govern our increasingly hyper-active world.
The tale of human habitation of the Nile Valley is a long one and includes famine, disaster, global environmental events, and human resolve told against a background of ever-changing landscape. In this volume, Judith Bunbury examines the region over a 10,000 year period, from the Neolithic to the Roman conquest. Charting the progression of the river as it meanders through the region and over the ages, she demonstrates how ancient Egyptians attempted to harness the Nile's power as a force for good. Over the generations, they learned how to farm and build on its banks, and also found innovative solutions to cope in a constantly evolving habitat. Using the latest theories and evidence, this richly illustrated volume also provides a blueprint for the future management of the Nile.
A large and sparse random graph with independent exponentially distributed link weights can be used to model the propagation of messages or diseases in a network with an unknown connectivity structure. In this article we study an extended setting where, in addition, the nodes of the graph are equipped with nonnegative random weights which are used to model the effect of boundary delays across paths in the network. Our main results provide approximative formulas for typical first passage times, typical flooding times, and maximum flooding times in the extended setting, over a time scale logarithmic with respect to the network size.
The resilience of seed quality in rice (Oryza sativa L.) to flooding was investigated. Pot-grown plants of the japonica cv. Gleva, the indica cv. IR64, and the introgressed line IR64-Sub1 were submerged in water, to simulate flooding, for 3‒5 days at different stages of seed development and maturation. Mean seed weight, pre-harvest sprouting, ability to germinate, and subsequent longevity in air-dry storage were assessed. Whereas seed quality in both IR64 and IR64-Sub1 was resilient to submergence, in Gleva the longer the duration of submergence and the later in development when plants were submerged the greater the pre-harvest sprouting. Thousand seed dry weight was reduced more by submergence in Gleva than IR64 or IR64-Sub1. At harvest maturity, few pre-harvest sprouted seeds were able to germinate upon rehydration after desiccation to 11‒12% moisture content. Seed longevity of the non-sprouted seed fraction in air-dry hermetic storage (40°C, 15% moisture content) was not affected greatly by submergence, but longevity of the japonica rice was less than that of the indica rices due to the former's steeper seed survival curves. Longevity of the two indica rices was predicted well by the seed viability equation and previously published estimates of viability constants for rice. The greater dormancy of IR64 and IR64-Sub1, compared with Gleva, enhanced resilience to pre-harvest sprouting and reduced thousand seed dry weight from plant submergence. There was little or no effect of plant submergence on subsequent air-dry storage longevity of non-sprouted seeds in any genotype.
Climatic fluctuation is often cited as a major factor in the collapse of Maya civilisation during the Terminal Classic Period (e.g. Luzzadder-Beach et al.2016). Evidence of how people dealt or failed to deal with it has only recently become a more widespread focus for archaeologists. Investigations at Xcoch in the Puuc Hills show the various ways in which resident populations sought to manage water stores when faced with a climate prone to drought and other meteorological extremes. The study also presents results from the analysis of nearby speleothem laminae, which indicate that severe episodes of flooding and droughts may have contributed to a collapse in the population around AD 850.