Preface

Water is a fundamental requirement for life and an essential factor for all organisms, from cells to whole body, and from first cell division until death. Globally only 2.5% of water is present as fresh water, of which about 68% is in glaciers and 30% in ground water. The rest is to be found as atmospheric humidity, surface water in the form of rivers and lakes, soil moisture, and in plants and animals. Water has a crucial role as a permanent substance of the central vacuole in plant cells, with the water component ranging from 85-95% in fresh leaves and young tissues, 35-75% in woody parts and stems, and 5-15% in dry seeds.

Water stress is one of the major environmental factors that affects most terrestrial organisms, and in plants leads to readily distinguishable effects on growth parameters, accompanied by changes in biomass ratios and physiological and biochemical alterations. Stress symptoms are visible morphologically and as biomass reduction depending on the severity and duration of drought exposure. Water stress (drought) decreases plant water potential and turgor, causing physiological difficulties, inhibition of photosynthesis and respiration, effects on metabolic and biochemical processes, changes in carbohydrate content, quantity and quality of nutrients, translocation, lipid composition in leaves, and plant hormone regulation.

Water stress not only effects plant-animal community interactions but also human societies, as a result of impacts on horticultural systems and agricultural lands, as well as natural ecosystems. Every year many cultivated areas of the world experience drought, particularly in arid and semi-arid climates. Water loss and lack of water availability from soil is therefore of considerable importance in agricultural and horticultural areas, where crop production mostly depends directly on precipitation regimes, since use of irrigation is limited on a world scale. It is well known that drought can cause more than 50% of yield reduction in most crop plants. The United Nations' FAO states that by 2025, 1.9 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under water-stress conditions. Since about one-third of potential arable land is facing water scarcity, and yield production in the remainder may be adversely affected by periodic drought, FAO reports state that more than half of the world population could be negatively affected by 2025.

The editor hopes that this wide-ranging book, with seven chapters, will be beneficial for all those interested in plant-water research, including students, researchers from scientific institutions and universities, and other professionals. The editor cordially extends his thanks to the authors, who are from all over the world, for their valuable contribution to the book. He also would like to express his appreciation particularly to Ms. Daria Nahtigal, Ms. Maria

#### XII Preface

Jozipovic and Ms. Iva Lipovic from InTech Open Access Publisher for their great effort and support throughout this whole processes of publishing the "water stress" book.

> **Dr. Şener AKINCI** University of Marmara Turkey

**Chapter 1**

**Quantification of Stress Arisen from Freshwater**

Masaharu Motoshita

http://dx.doi.org/10.5772/54237

**1. Introduction**

aged appropriately.

sessment model.

context of life cycle thinking.

Additional information is available at the end of the chapter

**Consumption in the Context of Life Cycle Assessment**

Freshwater is one of the most essential resources for living things on the earth. In‐ creasing water demand due to population and economic growth in the world may threat the balance of freshwater supply and demand. Consequently, almost 30% of world population is expected to be suffering from water scarcity in 2025 according to the UNESCO's prospects [1]. Physical scarcity of freshwater will cause several kinds of stress on human and ecosystem. In order to avoid or minimize the effects of freshwa‐ ter scarcity, the balance of freshwater demand and resource amount should be man‐

Freshwater is consumed not only directly but also indirectly in our activities. For instance, a cup of coffee directly requires freshwater for dripping coffee and washing a cup and drip equipment. In addition, freshwater is indirectly consumed for making a cup of coffee through the life cycle (growing coffee plants, processing coffee beans, producing packaging and so on) [2-3]. Thus, freshwater consumption should be analyzed and managed in the

As a tool for accounting stress of freshwater consumption based on life cycle concept, water footprinting has attracted high attention in recent years. Water footprinting generally ac‐ counts both the volume of consumed freshwater and the impact resulting from freshwater consumption. The stress of freshwater consumption will be different among regions. In this context, to quantify the impact of freshwater consumption with the consideration of regional differences has been seemed to be of significance and several researches on this topic have been performed for modelling the impact of freshwater consumption as life cycle impact as‐

> © 2013 Motoshita; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 Motoshita; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and reproduction in any medium, provided the original work is properly cited.
