The goal of this research topic was to motivate innovative research that blurs traditional disciplinary and geographical boundaries. As the scientific community continues to gain momentum and knowledge about how the natural world functions, it is increasingly important that we recognize the interconnected nature of earth systems and embrace the complexities of ecosystem transitions. We are pleased to present this body of work, which embodies the spirit of research spanning across the terrestrial-aquatic continuum, from mountains to the sea. Publisher’s note: In this 2nd edition, the following article has been updated: Sawakuchi HO, Neu V, Ward ND, Barros MdLC, Valerio AM, Gagne-Maynard W, Cunha AC, Less DFS, Diniz JEM, Brito DC, Krusche AV and Richey JE (2017) Carbon Dioxide Emissions along the Lower Amazon River. Front. Mar. Sci. 4:76. doi: 10.3389/fmars.2017.00076

Rivers around the world are threatened by changes in land use, climate, hydrologic cycles, and biodiversity. Global changes in rivers include, but are not restricted to water flow interruptions, temperature increases, loss of hydrological connectivity, altered water residence times, changes in nutrient loads, increasing arrival of new chemicals, simplification of the physical structure of the systems, occurrence of invasive species, and biodiversity losses. All of them affect the structure and functioning of the river ecosystem, and thereby, their ecosystem services. Understanding the responses of river ecosystems and their services to global change is essential for protecting human well being in all corners of the planet. Rivers provide critical benefits by providing food from fisheries and irrigation, regulating biogeochemical balances, and enriching our aesthetic and cultural experience. Predicting responses of rivers to global change is challenged by the complexity of interactions among these man-made drivers across a mosaic of natural hydrogeomorphic and climatic settings. This book explores the broad range of determinants defining global change and their effects on river ecosystems. Authors have provided thoughtful and insightful treatments of specific topics that relate to the broader theme of global change regulation of river ecosystems.

The international journal Ecohydrology & Hydrobiology (E&H) has been created to promote the concept of Ecohydrology, which is defined as the study of the functional interrelations between hydrology and biota at the catchment scale. Ecohydrology extends from the molecular level to catchment-scale processes and is based on three principles: • framework (hydrological principle) - quantification and integration of hydrological and ecological processes at a basin scale; • target (ecological principle) - necessity of enhancing ecosystem absorbing capacity and ecosystem services; and • management tool (ecological engineering) – the use of ecosystem properties for regulation the interplay between hydrology and biota. The journal encourages the submission of manuscripts which adopt an integrative approach to aquatic sciences, explaining ecological and hydrological processes at a river-basin scale or propose practical applications of this knowledge. It will also consider papers in other hydrobiological fields. Especially welcome are papers on regulatory mechanism within biocenosis and the resistance and resilience of freshwater and costal zones ecosystems. There is no page charge for published papers. All submitted papers, written exclusively in English, should be original works, unpublished and not under consideration for publication elsewhere. All papers are peer-reviewed. The following types of papers are considered for publication in E&H: • original research papers • invited or submitted review papers, • short communications

Soil degradation is a widespread problem in Africa resulting in decreased agricultural productivity while demand for food continues to increase. Degradation is caused by accelerated erosion, acidification, contamination, depletion of soil organic matter and plant nutrients, and salinization. The major cause of soil degradation in Africa is uncontrolled and excessive grazing in the savanna regions followed by deforestation and the use of inappropriate and extractive farming practices. Perpetual neglect of the health of soils in Africa can exacerbate the already serious problems of food and nutritional insecurity and environmental degradation. Food and nutritional security of the growing population of Africa can only be achieved if degraded soils are restored and soils of agroecosystems are managed prudently and sustainably. Ignoring soils and taking the fragile, finite and precious soil resources for granted is the principal cause of poverty, hunger, and environmental degradation. The downward spiral must be reversed through soil restoration measures based on translating science into action. This book describes the soils of Africa, processes of soil degradation, extent and severity of soil degradation, and the impacts of degradation processes on food and nutritional security. Features: Explores the extent and severity of soil degradation in Africa Analyzes the cause–effect relationship between anthropogenic activities and soil degradation Reviews processes of soil degradation in Africa including erosion, salinization, nutrient depletion, and decline of soil organic matter Addresses the effect of climate change on soil degradation in Africa. Explains how soil degradation causes food and nutritional insecurity Part of the Advances in Soil Sciences series, this volume is specifically devoted to the processes and factors that cause soil degradation and the challenges and potential for remediation and restoration of soil health in Africa.

Estuaries are among the most biologically productive ecosystems on the planet--critical to the life cycles of fish, other aquatic animals, and the creatures which feed on them. Estuarine Ecology, Second Edition, covers the physical and chemical aspects of estuaries, the biology and ecology of key organisms, the flow of organic matter through estuaries, and human interactions, such as the environmental impact of fisheries on estuaries and the effects of global climate change on these important ecosystems. Authored by a team of world experts from the estuarine science community, this long-awaited, full-color edition includes new chapters covering phytoplankton, seagrasses, coastal marshes, mangroves, benthic algae, Integrated Coastal Zone Management techniques, and the effects of global climate change. It also features an entriely new section on estuarine ecosystem processes, trophic webs, ecosystem metabolism, and the interactions between estuaries and other ecosystems such as wetlands and marshes