Forest water

Water is the basis of life on Earth and establishes one of the basic links between the biosphere and the atmosphere. The long history of the Mediterranean region is marked by the interaction and co-evolution between man and his natural environment, as well as the development of agriculture, livestock and the emergence of urban habitats. For millennia, the Mediterranean Basin has experienced significant changes in land use that have affected and continue to affect biological and biogeochemical processes, including the water cycle and water resources, both in quality and quantity.

On a global scale, and since the origins of our planet, the same body of water flows continuously following the routes that make up the processes of the hydrological cycle. The water cycle in terrestrial ecosystems begins with rain, after which it follows routes that can diverge at certain points: the so-called partition points (PP); the first PP is made up of the treetops, which intercept part of the rainwater that is re-emitted by direct evaporation; in the second PP, precipitation is divided into surface runoff and infiltrated water; in the third PP, the water that reaches the ground is partially evaporated from it, transpired by plants, and a fraction recharges aquifers subways.

Hydrological cycle and rain partition points. Source: Birot & Gracia 2011

A practical accounting method that provides a good framework for understanding hydrological processes is water balance analysis, applicable at various scales. In its simplest form, a water balance analysis is based on a single equation that compares water inputs and outputs while accounting for changes in water storage. Thus, rain in the form of precipitation generates two types of resources: green water in the soil, which is used for plant growth and production and which returns to the atmosphere in the form of vapor flow; and blue water in rivers and aquifers, accessible to man, including irrigation (through which blue water is transformed into green water).

In short, in the language of water resource management, water is divided into two components: green water and blue water. Green Water is the sum of interception, evaporation and transpiration, and is equivalent to the concept known as evapotranspiration. Blue Water is the sum of runoff and deep infiltration; it is what goes to the hydrographic network (springs, streams, rivers, lakes and reservoirs).

Water from precipitation that falls on a forest property and which, therefore, is considered a private domain constitute Forest Water. In Spain, private domain waters are recognized (Article 408 of the Civil Code and Article 10 of the Water Act), establishing that rainwater in the private domain is those that fall on land of that nature until it crosses its boundaries; the owner of a mountain may use for private purposes the rainwater that falls on the forest lands he owns until it leaves his property. This volume of water, when it falls on forest vegetation and crosses it, can be transformed into Blue Water, which passes into the hydrographic network or aquifers through runoff or infiltration, or into Green Water, which is transformed into plant matter or is used by it (Transpiration and Evaporation).

The multifunctionality of forest and forest masses has been proven, with the provision of water and the regulation of the water cycle being the most valuable environmental service in our forest ecosystems. It is clear that through silviculture and the management of forest masses, it is possible to influence the destinations of Forest Water and, therefore, the optimization of the two concepts that compose it. The management carried out on vegetation will affect the greater proportion of one type of water or another, of the elements that compose them, the quantity and distribution of their flows and their quality. With proper management, significant increases or decreases in the volume of Blue Water can be managed and obtained, which will result in variations in the available surface flows. The same applies to the volume of Agua Verde, which in some cases will make it possible to vary the productivity of the mass by the same proportion or to guarantee its survival in phases of implantation and restoration.

To this, we must add knowledge in Mediterranean Spain of traditional techniques and actions for the management of water and fertile and productive soils in mountain areas, which make it possible to use runoff water as useful water for plant production, contributing in many cases to the elimination of erosion and soil loss. This is the case of terraces and albarradas, reservoirs, cattle ponds, etc.

Traditional terraces in La Gomera. Source: www.aidergomera.es

Traditional albarrada in Monte de Bercho (Pegalajar, Jaén) Source: Www.pegalajar.org

In short, Forest Water is a productive factor whose management and use are possible, always within an environmentally and economically sustainable framework. Optimizing the balance point between the two concepts and carrying out actions to achieve it, always based on the annual rainfall in the field of action, constitutes a possible niche for business services.

Based on these principles, the National Association of Forestry Companies (ASEMFO) began in 2013 a line of action aimed at achieving the placing on the market of a charter of business services associated with the management of the water cycle from forest masses, through the Project”Forest Water: water production on forest land”, chosen by the EmpleaVerde 2007-2013 program, managed by the Biodiversity Foundation and subsidized by the European Social Fund. As part of this Project, ASEMFO provided two distance training courses on actions and tasks for the design of forest water management actions, products and services; and then offered business advice to a selection of companies and professionals from among those who completed the courses mentioned above, for the creation and implementation of lines of business in this regard, with IDEAS MEDIOAMBIENTAL being one of the companies selected and participating in this Project.

The fruit of the participation of Ideas MedioAmbiental S.L. in the “Forest Water: Water Production on Forest Lands” Project, it is the addition to its environmental services portfolio of a new line of business for Forest Water actions.