Water and landscape in Madrid: Possibilities and limitations

Landscape and Urban Planning, 16 (1988) 6 9 -79 Elsevier Science Publishers B .V . . Amsterdam-Printed in The Netherlands

WATER

AND

LANDSCAPE AND

IN

69

MADRID : POSSIBILITIES

LIMITATIONS

FERNANDO GONZALEZ BERNALDEZ Departamento de Ecotogia, Universidad Autbnmna, Madrid 28049 (Spain)

ABSTRACT Gonzalez Bernaldez, F., 1988 . Water and landscape in Madrid: possibilities and limitations . Landscape Urban Plann ., 16 : 69-79 . Water courses and their riverineforests, zones influenced by ground water, marshlands and ponds of very varied origin are very important sources of landscape diversity in the Madrid area . Evapotranspiration from relatively shallow saturated zones is an important factor in aquifer discharge in the semiarid part of the Madrid area . The following values are ofgreatest importance in the just if cation ofthe interest of water landscape in Madrid : ecological diversity, the wetland habitats representing pockets with biogeographical characteristics contrasting greally with the surrounding territories, mi-

INTRODUCTION It is clear that the level of nature protection or conservation cannot be the same throughout a given territory. Although the philosophy of maintaining only a small fraction of a territory as nature reserves and abandoning the rest of the land to destructive processes should be rejected (but it is . unfortunately, gaining

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croclimatic interest, as the network of humid areas within a relatively dry area give rise to a phenomenon of energy dissipation as latent heat, temperature reduction and increasing humidity, thus improving climatic comfort ; aesthetic-emotional values - vigorous tree growth, the occasional presence of water and a contrast with the surrounding areas ; productive interest, as the influx of ground water in aquifer discharges means that plants avoid the water stress typical of a Mediterranean summer . Conservation and protection policies should not only refer to the maintenance ofan acceptable degree of water quality in surface and underground waters but also be extended to the biocenosis and landscape characteristics of associated ecosystems.

ground in many areas), it is necessary to establish a hierarchy of possible restrictions . This raises the question of the values, attributes, criteria and strategies of nature conservation, which arc of great importance in any rational conservation policy or environmental impact studies . In such studies, in particular, it is often necessary to choose between several options and

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therefore to compare values . However, given the sequential nature of the identification and delimitation of protected areas in practice, it is also necessary to compare values to decide which areas should receive priority treatment . Highly varied criteria have been employed in the past to give priority to the protection of certain territories . In many cases their election seems to have depended on the whims of influential people (such as ministers) . Criteria which can he rationalised are of a completely different nature . There are, for example . protection models based on clearly utilitarian criteria, such as those concerning water resources for domestic or industrial purposes . In other cases the aim has been to create a suitable natural environment for sporting activities, recreation or rest . However, the problem is more difficult in the case of nature conservation, given that the dominant value is that of genetic diversity or educational interest . Usher (1986 ) recently dedicated a book to the discussion of criteria employed in the evaluation of nature conservation and listed diversity, size of territory, rarity (of both species and habitat ), threat of human interference and aesthetic value, among others . Obviously, any conservation policy, and therefore any natural resource policy, must combine several of these criteria . The conservation policy of the Madrid Regional Government concerning water resources is briefly analysed here from the point of view of an important aspect : landscape value in its broadest sense with special attention paid to its connections with nature conservation . Given space limitations, aspects such as those related to the environment have not been included, as these are already well known and are more objective . Comments focus on the visual and perception aspects which are currently causing most problems for both conservation policies and impact studies . The concept of landscape employed here is "the easily perceived part (or phenosystem )" of an ecosystem . It is von UexkUll's human

"Umwelt", or the existing sensorial part of the environment with which humans have interacted for centuries and which is responsible for numerous adaptations and predispositions still in force today . This long evolutionary history explains the important resources that the landscape, "green areas" etc ., suppose for humans today and the fact that they are one of the most important social demands currently made in developed countries, as all politicians should know (Gonzalez Bernaldez, t985) . Water . and the different components of its cycle, condition the presence of very important landscape characteristics in Madrid : a highly developed tree cover, special microclimates and the presence of water itself. WA'I'ER LANDSCAPES IN MADRID AND CRITERIA OF NATURE PROTECTION The following basic landscapes related to water exist in Madrid . ( I ) Water courses and their riverine forests or those zones influenced by ground water near water courses (in the terrace systems, especially on the lowest terraces and in the steps between each), in ecosystems derived from the alteration of riverine areas, such as reed banks, meadows, tree plantations and irrigated croplands . (2) Marshlands, lagoons and ponds of very varied origin . Evaporative discharge from aquifers is of particular importance in Madrid : in other words, those areas in which the groundwater level is near enough to the soil surface for water to reach the atmosphere as vapour (particularly through plant transpiration), although it does not appear in liquid form or in water courses . ( 3) Large reservoirs or artificial lakes . There arc many variants of these aquatic or semiaquatic territories and they present complex zonation and segmentation with diverse ecological origins and mechanisms . The following values are those of greatest importance in the justification of the interest

of riverine, reservoir and marshland landscapes in the province of Madrid . BIOLOGICAL INTEREST The main conservation criteria emphasized by Usher in his discussion of those attributes to be employed in the evaluation of territories Eor their protection was diversity (Usher, 1986, Chap . 1 ) . This could be assessed employing various mathematical expressions, such as the Shannon equation . This equation is sensitive to both the number of different species and the number of individuals within each species when applied to animal or plant species (high values imply a balanced distribution of individuals between species) . When applied correctly, diversity is an index of complexity generally related to stability, absence of fluctuations, organization of the ecological system, its "good state of conservation" and of the value of an area in terms of genetic conservation . With regards to ecological diversity, the wetland habitats of the Madrid province are of great interest as they represent pockets of which the biogeographical characteristics contrast greatly with those of the surrounding territories . It is typical for the drought period to coincide with the hot season in Mediterranean climates . But in many wetland habitats, valley, marshes, flooded areas etc . within the Iberian Peninsula, the absence of precipitation in the hot season is compensated for by the availability of ground water that permits the existence of flora (and to a certain degree, fauna) that are not typically Mediterranean . For example, certain tree species that cannot support the drought typical of tableland areas of the Madrid province may survive in areas in which ground water is close to the soil surface : two poplar species (white and black), ash, elm, alder (which requires permanently humid conditions), and various large willow species (Salix alba and Salix fragilis) . In severe drought areas and in sandy soils, even trees

such as the Mediterranean oak take refuge in valleys. Many small trees, shrubs and creepers also grow in riverine areas, taking advantage of the more humid conditions : the Montpellier maple, alder buckthorn, dogwood, several willows (mainly Salix salvifolia and Salix atrocinerea ), hawthorn, several species of wild rose, brambles, blackthorn and honeysuckle etc . Many of the plants taking refuge in such humid pockets belong to communities generally typical of more humid macroclimates (such as those of the north of the peninsula, or of the mountainous zones of the Madrid province which receive more precipitation) or are related to these . For example. the ash found in Madrid, Fraxinus angustifolia (the "country ash"), is a miniature species of the ash found in northern woodlands (Fraxinus excelsior) . Wetland or marshland areas therefore represent pockets in which water is made available to the vegetation through various mechanisms, the major one being upward flow of ground water within the saturated zone . Given that most water courses in the Madrid region are discharge areas (in other words, they receive ground water from the large aquifer on which they rest), both riverine plants and those of marshy and flooded areas depend on aquifer discharges (GonzalezBernaldezetat ., 1985 . 1986) (Fig . I) . Many other vegetation formations such as reed banks and meadows (which are the most common formations replacing destroyed riverine vegetation) also demonstrate groundwater flow towards the surface, as do peatlands, springs and marshy areas in the Guadarrama and Somosierra mountains (Fig . 2) . The high biological diversity that these formations confer on the territory as a whole is due to their ecotone effect or "grain" diversity . This arises from their complex intersection with the rest of the territory of uniform macroclimatic characteristics . The lineal and complex branching nature of riverine areas and liquid or vapour (evaporative) discharge zones

Fig . I . E , aporative discharge from aquifers or evaporation from relatively shallow saturated zones is an important landscape factor in Madrid . Very often water passes from the aquifer to the atmosphere through transpiration by phreatoplrytic trees . These are larger and more active in creating meroe] intatic conditions than the tree species growing outside discharge areas .

in general . that often follow lineal structures, provides a long contact line between pockets of hygrophytic vegetation and the rest of the territory characterised by more xerophytic vegetation . The effect of this fine alternation of humid areas on the degree of general diversity is the result of the great territorial heterogeneity it provides, and this is even more pronounced in Madrid and other dry Mediterranean areas because of the great biogeographical differences existing between them . (These are less pronounced in more humid regions .. in which differences between humid pockets and the surrounding territory are less marked . ) Biogeographical differences are even clearer in animals . Various groups of animals may be considered as visual and/or audible components of the landscape . birds and butterflies

being the most important in Madrid (Sterling . 1986) . Birds inhabiting humid zones in Madrid differ notably from those of surrounding territories, whether these be woodlands or other vegetation formations, and particularly in dry tableland areas . Birds such as the nightingale, blackbird . mistle thrush, long-tailed tit, robin, golden oriole, sparrow hawk, chiffchatf etc__ constitute "hygrophilous" fauna that differ from those of surrounding dry green oak woods, matorral or fields . However, this contrast is not so great in the hiocenosis of mountain areas, which are more closely related to those of humid pockets than the dry ones . There are also very clear differences between butterfly communities (Galiano et af, 1985) . The following hygrophilous species. green-veined white butterfly, peacock butter-

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Fig. 2 Road cut across the aquifer produces discharge near Madrid . The limit of the saturated soil is clearly seen by the growth of reeds (Scirpus hotoschoenus) . Road trenches, underground conducts . etc, are sources of impact in aquifer discharge landscapes .

fly, southern white admiral, comma butterfly, gatekeeper, speckled wood and holly blue contrast with other species that are not related to either the plants or special microclimate of the humid pockets . In mountain areas, however, the butterfly fauna observed in both riverinc areas and in the surrounding territory are similar . Some species use both zones but for different purposes (for example, riverine areas for refuge and rest ) . As a result, the biological diversity of areas enclosing many humid pockets is very high when overall heterogeneity is considered . It is therefore easy to appreciate that the destruction or alteration of humid areas has imporrepercussions the biological tant on impoverishment of a whole territory, and that the level of alteration does not bear a direct relationship to the size of the humid pockets affected .

MICROCLIMATIC INTEREST

The network of humid areas within a relatively dry area such as Madrid also represents an interesting phenomenon of energy dissipation as latent heat, giving rise to the reduction in ambient temperatures and the increase in humidity in given locations . This phenomenon is due, basically, to ground-water movements from recharge zones located in the higher parts of the territory, to discharge zones from which water evaporates from liquid streams or ponds, or directly to the atmosphere through transpiration (for a comment on the role of recharge and discharge zones on the landscape, see Gonzalez Bernaldcz et al ., 1985, 1986) . As is well knowr, evaporation causes an important fall in temperatures or a refrigeration effect which is observed to a much lesser degree

outside humid areas . Under the drought conditions typical of Mediterranean climates, plants outside phrcatophytic habitats soon use up their water reserves and must then reduce or terminate transpiration and therefore soil water extraction . Green oaks . prickly juniper, cistus and other xerophytic plants may survive the dry season with very low or even non-existent transpiration . Riverside areas are several degrees cooler in summer than the surrounding dry woodlands (Sterling, 1986), not only because of their dense shade, but also because of the greater energy dissipation involved in the phase change of water from liquid to vapour (water constantly reaches soil and roots from recharge zones) . This microclimatic effect is observed not only in riverine vegetation but also in meadows and other habitats located in aquifer discharge areas and the fresh nature of such areas is directly related to this process . AESTHETIC-EMOTIONAL INTEREST Aesthetic and emotional aspects of the natural environment, green areas or the landscape in general form one of the less known but one of the most important topics in resource management . The lack of methodological procedures has often led environmental design and natural resource management experts to consider this aspect insufficiently . However, the need to respond to the growing social demand for this type of resource has recently been recognised . Research to identify those components of landscape attributes responsible for aesthetic evaluations has revealed the existence of a series of universally appreciated constants (see . for example . Gonzalez Bernaldez, 1985 ; Abe116 and Gonzalez Bernaldez, 1986) . Among these, healthy and vigorous vegetation, especially trees, and clean water appear to stand out . Apparently, a view of trees and the various forms in which natural water is found have psychophysical effects (which may be measured oh-

jectively) and leads to an increase in psychological well-being and a reduction in stress. Formal characteristics such as the location, legibility and structure of a scene's elements are other important aspects of subjective landscape appraisal and vary from subject to subject (according to age, culture and personality ; see Abe116 and Gonzalez Bernaldez, 1986), but among these formal aspects related to information theory, there is one of high universality : the existence of a certain degree of environmental diversity within a scene . These universally appreciated visual landscape characteristics (vigorous tree vegetation, water and a contrast with surrounding areas) are clearly related in Madrid to humid and phreatophytic areas, water courses and large water bodies such as reservoirs . It is not strange, therefore, that these characteristics, in association with other values (basically, activities undertaken and the comfortable nature of the microclimate) make streams, rivers and reservoirs favourite points of attraction in the Madrid landscape . It is clear that the combination of vegetation (above all, trees) and water formations are the fundamental elements of landscaping and gardening . In fact . aquifer discharge zones (either evaporative with no water courses, or river terraces) offer the best conditions in most of the Madrid region for use as green zones . Such areas have been employed for centuries, the gardens of Aranjuez and the Casa del Moro being examples . PRODUCTIVE INTEREST As already mentioned, the influx of ground water in humid pockets of aquifer discharge zones means that plants avoid the water stress typical of the Mediterranean summer drought period . River banks . meadows and evaporative discharge zones therefore constitute pockets of at least potentially high primary production . This effect is particularly noticeable in the case of discharge in granitic zones of

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Fig . 3 . Recharge (upper part of the photograph) and discharge (lower part) areas are used as complementary units by Madrid livestock raisers . The discharge area ("barn") is more productive in summer but remains too wet in winter, and so it is late in grass production . The recharge land ("cerrillo") is better drained in winter and early in the grass-production cycle . Complementarity allows the buffering of seasonal fluctuation typical of Mediterranean temperature and rainfall patterns .

mountainous areas and conditions the presence of woods and pastures in hygrophytic pockets . Data concerning grass productivity in arkosic areas in Monte de El Pardo collected by Diaz Pineda and colleagues (Gonzalez Bernaldez et al.. 1985, 1986), revealed a delay in the peak of maximum productivity from March-April to April-May and an increase from 200°k to 300% in biomass production . It is precisely in this alternation of local recharge and discharge zones in the granitic area (and in certain arkosic areas) that one of the keys to traditional livestock raising may be found in Madrid (Ruiz and Gonzalez Bernaldez, 1983) . Livestock graze local recharge zones in winter, these being well drained and of early growth ; in summer the livestock move to local discharge zones which remain humid longer but

which are flooded in the winter season (Fig . 3) . In other regions of differing ground-water conditions, such as the shale areas of the Sierra Morena (southern Spain), this duality is reflected in the adret-ubac (southern-northernm slope) relationship . Similar relationships appear to exist in the alternation of fauna, although no studies exist on this point . The importance of lower river terraces for irrigation purposes (case, flatness, fertility and depth of alluvial deposits) is well known in Madrid (and in general throughout the Mediterranean area) and reference has already been made to their potential as low-cost wooded green zones . As is already known, numerous woody Mediterranean plants are adapted to use ground water (for example, the southern nettle-tree, vitex, oriental plane, white poplar, elm

( Ulmus minor), the country ash and numerous species of Tcnnari.x etc .), some of which have been used traditionally in gardens in these areas . POSSIBILITIES The importance of these humid "islands" in the Madrid province is therefore clear . As noted, it is the result of the contrasting and complementary nature they present with the rest of the territory, especially in lowland areas of the Madrid province, and their lineal layout which permits the development of many contacts and ecotones . These reach their maximum importance in semiarid Mediterranean areas where intense contrasts exist between the phreatophytic habitat (aquifer discharge area) and the recharge lands (or areas of parallel water flows) . The possibility of encountering abundant and non-saline discharge areas decreases with aridity . It is logical, therefore, for aquifer discharge areas and the phreatophytic ecosystems related to them, and all the water formations in the Madrid province, to be priority zones in any protection programme . The same conclusion was reached by the authors of successive versions of the Plan for the Protection of the Environment of COPLACO in the 1970s (although pressure from lobbies imposed a reduction in the level of protection afforded to river terraces in the final document) . Conservation and protection policies should not only refer to the maintenance of an acceptable degree of water quality in the surface and underground waters but also be extended to the biocenosis and landscape characteristics of associated ecosystems . It seems that the administration has included such an idea in studies of defence of water courses but this should he extended to all ecosystems related to discharge aquifers . At least two possible policies exist from the landscape point of view . (A) Conservation and reconstruction . There

are probably few well-conserved valley or riparian woods (or perhaps none) in the Madrid province . Many factors contribute to their deterioration and destruction and a specific conservation policy must be formulated if it is to function efficiently . The ecological reconstruction of a certain number of degraded pockets could then be initiated (Montes . 1986) . Reconstruction should be based on an adequate knowledge of the ecological structure and characteristics of each phreatophytic habitat (Sterling, 1986) and supposes the provision of infrastructure and applied ecophysiological knowledge . Such reconstruction may "stimulate" progressive succession . Colonization by animals of visual interest (basically birds and insects such as dragonflies and butterflies would occur spontaneously once the vegetation was established (Gonzalez Bernaldez, 1981, p . 168) . Emphasis should be placed, however, on the need for a precise understanding of species and ecotypes, of their position along the gradient of depth of the water table, adaptation to fluctuations of the water table and type of mineralization. For example, different shrub species vary in their adaptation to such fluctuations : Sally salvitolia is more tolerant than S . atrocinerea (neither thrive under the shade of large ash or elm trees) and, as in the case of the reed Scirpus holoschoenus, they only appear to a limited degree in cleared riparian woods . Naturally, such conservation and reconstruction policies should provide for frequent public access to such types of landscapes, adequately combining maximum recreation value with conservation needs . Programmes should therefore be adopted which include both technical and educational aspects . (B) Transformation - developing potentially phreatophytic habitats as green zones . A policy for the creation of green areas should exist alongside that of recuperation of natural ecosystems (Gcpp, 1983), taking advantage of the potential fertility and humidity of the type

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of humid "islands" considered here . Ease of installation and maintenance, microclimatic effects etc ., offer many possibilities for the development of highly varied programmes . Some years ago, attention was drawn to the possibility of converting the terraces of large rivers into recreation zones . In Madrid, certain completely degraded phreatophytic pockets offer adequate characteristics for transformation into socially interesting green zones through programmes incorporating technical, ecological and anthropological criteria (for the subjective factors, see GonzAlez Bernaldez and Gallardo, 1986) . IMPACTS AND RESTRICTIONS There is no need to emphasize the depressingly deteriorated state of the humid habitats considered in the Madrid province . Sufficient knowledge and awareness exists about the phenomena of water pollution, but there are many factors causing the specific deterioration of qualities of aquifer discharge and phreatophytic areas (valleys, fluvial riverine areas, meadows, reed banks, marshy spots, ponds etc . ) . The arbitrary destruction of trees undertaken with impunity, fires (which frequently affect humid pockets situated between fields of stubble) and the influence of sand and gravel extraction (abundant literature exists concerning the landscape impact of the latter) are also well-known influences . Sterling (1986) outlined the possibility of systemizing anthropogenic degradation in riverine areas following a series of characteristic norms, beginning with the disappearance of certain liana species (which act, therefore, as indicators of the degree of conservation of these ecosystems) . It is worthwhile briefly considering other specific reasons for the deterioration of riverme and other hygrophytic pockets in Madrid . Various works employing heavy machinery, undertaken to "improve" such zones, are having adverse effects on riverine and humid zones in marry parts of Spain and, naturally, in Mad-

rid . Two basic aims motivate such work : the dredging or "clearance" of water courses to ease water flow in streams, rivers etc . (destroying riverine vegetation and excavating new profiles), and the drainage of phreatophytic and flooded areas . The "clearance" or dredging of water courses is causing widespread and arbitrary destruction with no consideration whatsoever of ecological, landscape or impact aspects . Occasionally, attempts are made to justify the works by reference to the fight against floods, but these operations (and many others) are really the result of economic pressure to employ machinery that becomes unprofitable if left idle, to undertake projects, to propose programmes or other works etc . Sometimes the excuse has been the fight against pollution : given that the river smells, it must be dredged to allow water to flow faster (hoping that in this way it will smell less) . One can see terrible examples of waterway destruction in certain areas at the foot of the Sierra de Guadarrama : for example, the Guadarrama river as it leaves Villalba (in the past, this was a rural landscape : now it is a chaotic mass of tumbled earth and stone) . Water-course works affect an important part of our heritage and should therefore be subject to detailed studies which must include the design and assessment of ecological and landscape impacts . The pressurized and frivolous manner in which these are considered today is irresponsible . The advances made in research in this field by a special programme of the Deutsche Forschungsgemeinschaft concerning hydrodynamics of waterway vegetation and their effects on flood levels, integrating landscape conservation with water management policies, should be mentioned here . It is clear that the effects of flood flows are worsened if no precautions are taken to avoid urbanization of flood plains, or if other regulatory measures are not taken as part of an integrated policy in which landscape factors should be present . It is sad to think that there is an anti-riverine

campaign currently under way in Spain just as the Council of Europe has launched its own pro-river-bank programme . Another important consequence of pressure to use heavy machinery and undertake "projects" is the dessication that has destroyed and is still destroying numerous Spanish wetlands, despite the recent growth in awareness of the administration and numerous interventions to defend these zones . The administration, nature associations and all individuals should insist that implicit values be taken into consideration in such works (in which public money is spent) and not only the economic interests of a few individuals, given that even changes in production may he negative . New dispositions concerning impact and water will he a test of the credibility of the Public Administration precisely in a difficult moment given that EEC credits may be diverted towards an increase in such degradation in the name of "improvement works" . In Madrid, problems of the latter type affect discharge areas above all . particularly in lower areas of the provinceOver-exploitation of ground water presents another potential threat to phreatophytic landscapes. Its results are already visible in many zones including Doiiana (in which lowering of the water table is threatening the viability of phreatophytic dune vegetation (heathers and matorral) ; see Rodriguez and Llamas, 1986) : the sad story of the Tablas de Daimiel (Lopez Camacho and Cabrera Mendez, 1985) and the less well known story of the sandy areas in the Duero river basin in which marshy zones, ancient lagoons and even pinewoods are suffering effects similar to those registered in Donana . In the centre of the Iberian Peninsula . evaporative discharge zones, or those in which there are no water courses to compensate for local depression cones, are those most vulnerable to alterations in natural flows . Given the complex nature of the most important aquifer in Madrid (located on arkoses), it is even more difficult to clarify the current situation, but, as in any other area, it is

necessary to formulate a plan of optimum location of ground-water extraction, bearing in mind ecological and landscape criteria (already under way in many countries .. reference being made once again to the Deutsche Forschungsgemeinschaft research) . The unification of farm units has also given rise to the destruction and alteration of numerous landscape and ecological values . It is essential for the teams undertaking such work to be adequately informed about nature conservation and landscape values . Once again, the application of a new directive and the promises made by IRYDA to representatives of nature conservation groups and scientific researchers (invoked by the Public Participation Committee of the lnterministerial Advisory Group) should be examined from the point of view of their applicability and credibility. It is impossible to include all the adverse consequences of many other actions . The situation is even more complex in Madrid, given the scarcity of water resources in relation to its population and activities, and the resulting modifications of the water cycle and related material cycles . Within the complex catalogue of problems, one example may he noted : the effect of polluted water on stream flows that arc incremented by waste water . Such streams that were formerly effluent (fed by ground water from aquifers) have become losers (the - polluted - water flow is now towards the ground water reserve), Polluted water has been detected in the root zone of riverine areas in El Pardo, derived from wastewater influxes from outside the park area . There has been a significant increase in chloride in ground water which undoubtedly leads to changes in the vegetation (presumably the loss of riverinc vegetation and conversion into tamarisk thickets) . There are also, without doubt . many cases of increases in nitrogen (which causes vegetation evolution towards nitrogen-loving plants, although it may favour elm species in the initial stages) .

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ACKNOWLEDGEMENT The research summarized in this paper was financed by Research Project 1559-92 of the Spanish Scientific Research Council (CAICYT) . REFERENCES Abello, R .P . and Gonzalez Bernaldez, F ., 1986 . Landscape preference and personality . Landscape Urban Plann ., 13 : 19-28 . Galiano . E .F., Sterling, A . and Viejo . J .L ., 1985 . The role of riparian forests in the conservation of butterflies in a Mediterranean area. Environ . Conserv ., 12 : 361-362 . Gepp, J., 1983 . Natur in Meinem Garten . Oesterreichischer Naturgesetzbund . Graz . Gonzalez Bernaldez, F . . 1981 . Ecologia y Paisaje . H . Blume . Madrid . Gonzalez Bernaldez, F ., 1985 . Invitaci6n a la Ecologia Humana. Technos . Madrid . Gonzalez Bernaldez, F . and Gallardo, D., 1986 . Factores subjetivos en el diseno de las zonas verdes publicas. PARJAP 86 . XIX Congreso de Parques y Jardines Publicos, November, 1986, Las Palmas de Gran Canaria, Spain .

Gonzalez Bernaldez, F., Perez Perez, C . and Sterling Carmona A ., 1985 . Areas of evaporative discharge from aquifers: little known Spanish ecosystems deserving protection . J . Environ . Manage . . 21 : 321-330 . Gonzalez Bernaldez. F ., Herrera, ., P Levassor, C ., Peco . B . and Sastre, A ., 1986 . Las aguas sublerraneas en el paisaje . Investigacidn y Ciencia . 127 : 8-17Lopez Camacho, B . and Cabrera Mendez, E . . 1985 . Evoluci6n del acuifero de la Llanura Manehega en el periodo 1981-1984 . Direcci6n General deObras Hidraulicas . Servicio GeolOgico S-231 700 3C, MOPU. Madrid . Montes . C ., 1986 . Directrices para la restauracibn ecol6gica del tramo medto del no Manzanares . Direcci6n General de Obras Hidraulicas . Comunidad de Madrid y Canal de Isabel 11, Madrid. Rodriguez Arevalo, J . and Llamas, M .R ., 1986 . Groundwater development and water table variation in the Donana Park . 19th Congr. Int . Assoc . Hydrologists . Karlovy Vary . Ruiz, J .P. and Gonzalez Bernaldez, F ., 1983 . Landscape perception by its traditional users : the ideal landscape of Madrid livestock raisers . Landscape Plann ., 9 : 279-297 . Sterling, A . . 1986 . Tests doctoral en preparacibn . Universidad Aut6noma de Madrid, Facultad de Ciencias . Usher . M .B . (Editor) . 1986. Wildlife Conservation Evaluation. Chapman and Hall . London .