THE VALUE OF OPEN LANDSCAPES AS LIFE-SUPPORTING SYSTEMS
by Zev Naveh
Professor Emeritus, Lowdermilk Faculty of Agricultural Engineering, Technion – Israel Institute of Technology, 32000 Haifa, Israel
Editor’s Note: Prof. Zev Naveh has written extensively on the subject of ecodiversity conservationthe holistic conservation of biological and cultural diversity of landscapes. He has continuously warned, in both papers and scientific presentations, that pressures on open landscapes, largely driven by population growth and urban, industrial and tourist development, are threatening the biological, ecological and cultural diversity, or in short the over-all "landscape ecodiversity" of our planet. In his numerous studies on the future of Mediterranean forest landscapes, Prof. Naveh has contended that integrative and transdisciplinary methods and strategies for holistic landscape conservation must be developed in order to halt creeping extinction and ensure continued evolution. Prof. Naveh calls for the development of semi-natural, human-managed landscapes where the dynamic flow equilibrium between biodiversity, ecological heterogeneity and land uses at different scales and intensities will be maintained and restored. To help bridge the communication gap between researchers, on the one hand, and land managers, the public and decision makers, on the other hand, more efficient tools for scientific and technical information transfer should be developed. These may include "Red Books" or "Green Books" for the conservation of threatened landscapes. These would help translate the results of integrated research and management projects into practical information and make recommendations for implementation.
Prof. Naveh’s vision of an environmental revolution whereby the expansion of technospheric and agro-industrial landscapes will be replaced by their total integration with the natural and cultural biosphere landscapes is described in Landscape Ecology – Theory and Applications by Z. Naveh and A.S. Lieberman (Second edition, Springer-Verlag, New York, 1994).
The following is excerpted from a presentation made by Prof. Naveh within the framework of a Hadassah Panel on "The Race for Open Space" which was held in February 1997.
If we look at any older land-use map of Israel, we will realize that all the open and mostly untillable landscapes which are neither cultivated nor designated as nature reserves or planted forests, are marked as wasteland. This reflects the conception of planners that land is wasted if it is not converted into more profitable purposes. This term has been used in the evaluation of open spaces, such as sand dunes, wetlands and uplands, for housing and highway construction by economic and political decision makers. Decisions are guided almost exclusively by short-sighted economic cost/benefit considerations. They ignore the fact that we live in the higher, super system of our total human ecosystem in which humans and all other living organisms are integrated with their total physical, natural and socio-economic and cultural environmental.
If this total human ecosystem is taken as a yardstick for land use decisions, then all open, non-cultivated land covered by a natural vegetation mantle which has not yet been destroyed completely, or whose original structure and function cannot be at least partly restored, should be marked as natural life support systems fulfilling vital multiple functions for our physical, social and cultural well-being. In addition to their non-instrumental, intrinsic values (i.e., values for their own sake as the last remaining refuge of nature and wildlife in our small and crowded country), their unique value lies in the fact that they provide free services of nature for human society, without need for further inputs, because these are part of their natural function. They are maintained solely by the biological conversion of high grade solar energy through photosynthesis and assimilation into chemical and kinetic energy, and by the recycling and bio-regeneration of living and non-living material. In contrast to our intensive agricultural fields which are subsidized heavily by fossil energy and chemicals and have detrimental environmental impacts similar to urban-industrial technosphere landscapes, these last islands of the biosphere are regulated by complex natural feedback mechanisms of self-organization and self-recreation.
A detailed list of the multiple functions of natural systems is given by De Groot (1992) in an important study on the "Functions of Nature" and their evaluation. Their efficiency depends on the integrity of the living sponge of soil and vegetation and their supporting physical air, water and rock systems. These function together as ecosystems, but their actual tangible sites are the three-dimensional patches of nature, namely the smallest, mappable landscape cells known as "ecotopes" which together form closely interlaced puzzles of landscape mosaics. The living sponge of natural and semi-natural landscapes is irreplaceable, and the loss of their life-supporting functions is irreversible.
Until they are impaired, we remain unaware of most of the free gifts of nature, such as flood prevention, soil protection, filtering and breakdown of pollutants, water collecting, cleaning and draining. But if our decision makers would have as much ecological wisdom as they have political and technological power to destroy these landscapes, they would be willing to consider at least the economic "replacement values" of these functions before they are lost. For their replacement they would need costly engineering and technological devices whose production and maintenance would require the use of polluting fossil energy and non-biodegradable material and skilled technical supervision which would be otherwise used for economic production. Thus, for example, Westman calculated that it would cost $122 million to remove from an area of 4000 hectares the amount of sediments of eroded soil causing the siltation of water collecting ponds and lakes. This erosion was prevented by the ponderosa pine tree cover on these slopes before these trees were damaged by ozone air pollution and by the dense shrub cover before its conversion into open grassland for pasture and for highway construction.
In Israel, as in California, the protection and regulation function of the vegetation covered mountainous areas are of vital importance in the narrow, densely populated coastal strip. It would be worthwhile to calculate the replacement value of the conversion of this living sponge of soil and vegetation and their supporting physical air, water and rock systems into asphalt highways. This includes not only the actual loss of clean rain water for the coastal aquifer, but also the direct economic damage caused by the accelerating floodings which affect urbanized coastal plains almost every winter. These costs should be included in environmental impact statements and in the cost/benefit calculations of highway construction, along with the damages caused by air and water pollution which would have been prevented by these natural vegetation covered lands. In such calculations, we have to take into consideration that each patch of land covered by grass increases by 10 times the physical absorption and infiltration capacity of bare land or asphalt, each patch of shrubland about 100 times and each patch covered by trees 1000 times. Moreover, these figures have to be raised by several powers in order to calculate the biological and physico-chemical surface activity of the canopy of shrubs and trees, functioning as powerful biological filters and "green lungs." (Petsch, 1972).
According to Bernatzki (1968), an 80-year old huge oak tree in Germany, covering an area of 160 square meters had a photosynthetic surface of 160,000 square meters. It absorbed during its lifetime 40 million cubic meters of air-equivalent to the contents of 80,000 two-family houses. Using only 6 calories of solar radiation each hour, it absorbed 2352 kg of CO2 and contributed 1712 kg of O. When this tree was to be sacrificed for the sake of "more comfortable car transportation," it was calculated that its free services would have to be replaced by planting 2700 young trees at a cost of 150,000-160,000 DM.
The contribution of trees to the supply of clean oxygen is of special importance in polluted urban-industrial conurbations such as Haifa and Haifa Bay because they can replace the oxygen consumed by cars. Thus, a 6 ton truck, driving 10,000 km may consume the oxygen requirement of 8-10 years of a physically active person. A small private car consumes about 400 cubic meters of oxygen-equivalent to 600 people (Berge, 1970).
Of no less importance are the air filtering and dust and pollution absorption functions on this living sponge. Thus, a single chestnut tree, 30-years old, absorbed 120 kg of dust and 80 kg of microscopic particles or aerosols and cleaned a polluted area of 100,000 cubic meters. A pine forest in the Ruhr region absorbed 26 times more aerosols than in the bordering bare area. A green strip of 2-3 km reduced SO2 concentrations from the adjacent industrial area from 0.26 to 0.11 mg (Knabe, 1973). In Russia, a green strip of 500 meters reduced the SO2 concentration by 75% and NO2 by 67%. An ambient ozone concentration of 150 ppb was reduced by an 1/8 in one hour and was undetected in the air after 8 hours. Trees were found to be the only effective removers of CO in polluted areas and along highways (Dochinger, 1980).
Vester (1985) calculated the economic replacement value of all biological, ecological, socio-economical and cultural services provided in Germany by an average single tree as worth 1675 DM. This is 200 times higher than its value for timber alone. The German economy would have to spend 4230 billion DM every year in order to replace these functions and free services. In another independent study carried out by a team of foresters and planners, the multiple benefit values-also known as "social functions"-of the forest near Baden-Baden were found to be 280 times higher than the wood and timber products of this forest (Pabst, 1971).
However, we should not overestimate our ability to transfer the many intangible "soft" values provided by natural and semi-natural landscapes into hard money and market goods. Not everything which can be counted counts, and many things which cannot be counted, count. De Groot, a Dutch landscape ecologist, states that a change in the attitude of economic and political decision makers in favor of long-term sustainability is more important than constructing an artificial yardstick for measuring all economic benefits of environmental functions. We may never be able to measure the experience of nature, but at least we should attempt to consider all the values of the natural environment in the economic decision making process.
In our book on Landscape Ecology (Naveh and Lieberman, 1994), we distinguish between "hard" landscape values which provide marketable goods or can be evaluated in money terms, and "soft" values of economic non-richness values. We conclude that there is an urgent need for a new, post-industrial reconciliation, and even symbiosis between human society and nature. In the terms of the great Jewish cultural philosopher and teacher Martin Buber, our present estranged I-IT relation with nature should be transformed into a new reciprocal I-THOU relation. An essential part of these relations is the spiritual experience gained from these landscapes and their intrinsic, amenity and aesthetic values. These are far too rich to be reduced to dollar terms in markets and are more than complementary to the aesthetic values attached to human art objects. Therefore, they should not be viewed merely as a source for our materialistic satisfaction, but also as a source of enlightenment and enjoyment, as a vital source of mental health.
This can be realized only if the narrow and short-sighted monetary evaluations in environmental cost/benefit calculations and land-use decisions would be replaced by much broader ecological and socio-economic functional evaluations of the soft and hard values provided by these landscapes. Of great significance, in this respect, is the emergence of a new synthetic field of ecological economy, aimed at achieving ecologically and economically sustainable development. It has therefore, like landscape ecology, a transdisciplinary goal which requires transcending the realm of natural sciences into that of the humanities for a new, post-industrial reconciliation between humans and nature.
In order to account for the full value of our natural and semi-natural landscapes as life-supporting systems we have to include the following three major domains in all land-use decisions:
1) The bio-ecological domain, related to those physical, chemical and biological processes which ensure ecosystem function and structure, and thereby also highest attainable biological and cultural diversity and integrity.
2) The socio-cultural domain, related to environmental quality, socio-hygienic, psychological and cultural requirements which ensure the greatest possible overall benefit for the largest possible human populations from a national and regional point of view.
3) The socio-economic domain, related to the direct economic benefits to be derived from these landscapes as pastures, forests and recreation parks or otherwise, under rational management, which will not endanger the sustainability of these landscapes and the multiple benefits derived from the other two domains.
In order to implement sustainable holistic land uses, regional masterplans should be prepared which will ensure healthy, viable and attractive natural and agricultural, rural and urban landscapes which provide combined biological, ecological, cultural and socio-economic services. This can only be achieved through an optimization of soft, intangible values with non-economic riches and hard monetary landscape values.
– Berge, H. 1969. Journal Vitalstoffe-Zivilisationkrankenheite 4/69.
– Bernatzky, A. 1968. Baum-Zitung 2:37-47.
– Buber, M. 1970. I and Thou. Scribner’s, New York.
– De Groot. R.S. 1992. "Functions of Nature." Evaluation of Nature in Environmental Planning, Management and Decision Making. Wolters-Noordhoff, Amsterdam.
– Dochinger, L.S. 1980. "Interception of airborne particles by tree planting". J. Environmental Quality 9:265-268.
– Kellert, R.S. 1996. "The Value of Life." Biological Diversity and Human Society. Island Press/Shearwater Books. Washington, D.C.
– Naveh, Z. and A. Lieberman. 1994. Landscape Ecology, Theory and Application. Springer-Verlag, New York.
– Pabst, H.R. 1971. Schriftenreihe der Landesforstverwaltung Baden Wuertenberg, 35.
– Petsch, G. 1972. Schriftenreihe Siedlungsverband Ruhrkohlenbezirk 41, 27-30.
– Roszak, T. 1992. "The Voice of the Earth." An Exploration of Ecopsychology. A Touchstone Book, Simon & Schuster, New York.
– Vester, F. 1985. Ein Baum is mehr als ein Baun (One tree is more than just one tree). Koesel Verlag, Munchen.
– Westman, W.E. 1985. Ecology, Impact Assessment and Environmental Planning. John Wiley and Sons, New York.