Drylands are the largest terrestrial biome on the planet, and the critically important systems that produce approximately 40% of global net primary productivity to support nearly 2.5 billion of global population. Climate change, increasing populations and resulting anthropogenic effects are all expected to impact dryland regions over the coming decades. Considering that approximately 90% of the more than 2 billion people living in drylands are geographically located within developing countries, improved understanding of these systems is an international imperative. Although considerable progress has been made in recent years in understanding climate change impacts on hydrological cycles, there are still a large number of knowledge gaps in the field of dryland ecohydrology. These knowledge gaps largely hinder our capability to better understand and predict how climate change will affect the hydrological cycles and consequently the soil-vegetation interactions in drylands. The present study used recent technical advances in remote sensing and stable isotopes, and filled some important knowledge gaps in the understanding of the dryland systems. My study presents a novel application of the combined use of customized chambers and a laser-based isotope analyzer to directly quantify isotopic signatures of transpiration (T), evaporation (E) and evapotranspiration (ET) in situ and examine ET partitioning over a field of forage sorghum under extreme environmental conditions. We have developed a useful framework of using satellite data and trend analysis to facilitate the understanding of temporal and spatial rainfall variations in the areas of Africa where the in situ observations are scarce. By using a meta-analysis approach, we have also illustrated that higher concentrations of atmospheric CO2 induce plant water saving and the consequent available soil water increases are a likely driver of the observed greening phenomena. We have further demonstrated that Leuning's modified Ball-Berry model and RuBP limited optimization model can generally provide a good estimate of stomatal conductance response to CO2 enrichment under different environmental conditions. All these findings provide important insights into dryland water-soil-vegetation interactions.

Ecohydrology emerges as a new field of research aiming at furthering our understanding of the earth system through the study of the interactions between the water cycle and vegetation. By combining the analysis of biotic and abiotic components of terrestrial ecosystems, this volume provides a synthesis of material on arid and semiarid landscapes, which is currently spread in a number of books and journal articles. The focus on water-limited ecosystems is motivated by their high sensitivity to daily, seasonal, and decadal perturbations in water availability, and by the ecologic, climatic, and economic significance of most of the drylands around the world. Conceived as a tool for scientists working in the area of the earth and environmental sciences, this book presents the basic principles of eco-hydrology as well as a broad spectrum of topics and advances in this research field. The chapters collected in this book have been contributed by authors with different expertise, who work in several arid areas around the World. They describe the various interactions among the biological and physical dynamics in dryland ecosystems, starting from basic processes in the soil-vegetation-climate system, to landscape-scale hydrologic and geomorphic processes, ecohydrologic controls on soil nutrient dynamics, and multiscale analyses of disturbances and patterns.

This book presents recent lessons learned in the context of research and development for various dryland ecosystems, focusing on water resources management, land and vegetation cover degradation and remediation, and socioeconomic aspects, as well as integrated approaches to ensuring water and land security in view of the current and predicted climate change. As water and land are the essential bases of food production, the management of these natural resources is becoming a cornerstone for the development of dryland populations. The book gathers the peer-reviewed, revised versions of the most outstanding papers on these topics presented at the ILDAC2015 Conference in Djerba, Tunisia.

^iEco-Hydrology is the first book to offer an overview of the complex relationships between plants and water across a wide range of terrestrial and aquatic environments. Leading ecologists and hydrologists present reviews of the eco-hydrology of drylands, wetlands, temperate and tropical rain forests, streams, and rivers and lakes. Contents include: * background information on the water relations of plants, from individual cells to strands of plants * the role of mathematical models in eco-hydrology * explanations of how plants affect patterns and rates of water movement and storage in a range of terrestrial and aquatic ecosystems.

This book is open access under a CC BY-NC 2.5 license. This book provides an unprecedented synthesis of the current status of scientific and management knowledge regarding global rangelands and the major challenges that confront them. It has been organized around three major themes. The first summarizes the conceptual advances that have occurred in the rangeland profession. The second addresses the implications of these conceptual advances to management and policy. The third assesses several major challenges confronting global rangelands in the 21st century. This book will compliment applied range management textbooks by describing the conceptual foundation on which the rangeland profession is based. It has been written to be accessible to a broad audience, including ecosystem managers, educators, students and policy makers. The content is founded on the collective experience, knowledge and commitment of 80 authors who have worked in rangelands throughout the world. Their collective contributions indicate that a more comprehensive framework is necessary to address the complex challenges confronting global rangelands. Rangelands represent adaptive social-ecological systems, in which societal values, organizations and capacities are of equal importance to, and interact with, those of ecological processes. A more comprehensive framework for rangeland systems may enable management agencies, and educational, research and policy making organizations to more effectively assess complex problems and develop appropriate solutions.