Horizons in Earth Science Research : Volume 1

Rangelands are confined to the tropic and sub-tropic regions, and cover about 4.5 billion hectares of the world''s dry lands or one fifth of the earth''s land surface. In spite of their hostile environment, they are important biodiversity conservation landscapes and support livelihoods of nearly 135 million people, yet they are some of the most neglected and abused biomes. This book examines the degradation of rangelands, and its potential ecological and socio-economic implications. Also discussed are the traditional management of dehesa systems, with a focus on the problems and advantages of the livestock diversification which characterise them. A brief description of the Surface Renewal (SR) method and research is given, and performance observed for estimating sensible heat, latent heat and C02 fluxes against the more expensive EC measurements over grasslands are looked at as well. This book also gives an overview of the widespread isotopic techniques applied to study connectivity between streams and groundwater; assumptions, advantages and drawbacks of the isotopic methodologies are reported. In addition, human impact is arguably the most important issue confronting mountain ecosystems today across the world. This book outlines the trajectory of mountain studies in anthropology, from early studies to the peak of mountain anthropology in the 1980s, highlighting major theoretical and research foci. Other chapters in this book review the current threats to inland desert rangelands, ranging from groundwater depletion, habitat fragmentation, exotic species introductions and overgrazing. Recommendations on how to improve the state of irrigated soils and to eliminate anthropogenic desertification are also discussed.