Journal of Arboriculture 18(5): September 1992 22 7 SSESSI NG THE BENEFIT S N D COS TS OF THE URB N FOREST by John F. Dwyer E. Gregory McPherson Herbert W. Schroeder and Rowan A. Rowntree Abstract. With effective planning and management, urban trees and forests will provide a wide range of important benefits to urbanites. These include a more pleasant, healthful, and comfortable e nvironment to live, work, and play in, savings in the costs of providing a wide range of urban services, and substantial improvements in individual and community well- being. Urban forestry plans should begin with consideration of the contribution that trees and forests can make to people's needs. Planning and management efforts should focus on ho w the forest can best meet those needs. Past planning and management efforts have not been as effective as they might have been because planners and managers have underesti- mated the potential benefit s that urban trees and forests can provide, and have not understood the planning and manage- ment efforts needed to provide those b enefits, particularly the linkages between benefits and characteristics of the urban forest and its management. Urban forests are a significant and increasingly valuable component of the urban environment. However, with the limited information on the ben- efits and costs of urban trees and forests currently available to decision makers, management of these valuable assets continues to be inadequate. Urban forest resources are declining in many cities, and the resulting benefits are only a fraction of what they could be. In many instances costs are higher than necessary. We are just beginning to learn about the extent and magnitudes of the many benefits and costs associated with urban trees and forests, as well as the many ties between urban forest resources and the quality of urban life. Research in a number of areas suggests that we have vastly underestimated the many ways that t he urban forest touches the li ves of urbanites, as well as the deep significance that many people attach t o trees. Furthermore, we often lack reliable information on how to most effectively manage urban forests to provide many of these benefits. A sound understanding of the full range of benefits and costs associated with urban forests, as well as how various management practices, programs, and policies influence those benefits and costs, is essential for action to enha nce urban forests and the associated well-being of urban- ites. Benefits to consider include the goods and services produced by urban trees and forests that are valuable to people. These benefits vary over space and time according to changes in the urban environment, it s inhabitants, and their needs. Some benefits are easily expressed in dollars or other numbers, while others are difficult to quantify using such measures; but in the aggregate they are highly significant to urbanites. The long life of urban trees and forests man- dates planning with a view to future needs. In- vestments in the planting and care of trees rep- resent a long term com mitment of scarce dollars, and improper plantings can increase costs and reduce benefits. Therefore, it is important to do it right and plan for future management. The effec- tiveness of urban trees and forests in providing benefits to people depends on their species composition, diversity, age, and location with re- spect to people and other elements in the land- scape. An ecosystem approach that recognizes people as the central component offers the best means to assess t he complex interactions between urban trees and forests and the well-being of urbanites, linking management actions with their effects on urban forests and the associated ben- efits and costs. The following discussion begins with the influ- ence of urban trees and forests on the physical and biological environment and continues with th e socio-economic importance of urban trees and the environments that they create.
Journal of Arboriculture 18(5): September 1992 227
SSESSING THE BENEFITS N D C O S TS OF THE
URB N FOREST
by John F. Dwyer E. Gregory McP herson Herbert W. Schroeder and Rowan A. Rowntree
Abstract. With effective planning and m anageme nt, urbantrees and forests will provide a wide range of important b enefitsto urbanites. These include a more pleasant, healthful, andcomfortable e nvironment to live, work, and play in, savings inthe costs of providing a wide range of urban services, andsubstantial improvements in individual and community well-being. Urban forestry plans should begin with consideration ofthe contribution that trees and forests can make to people'sneeds. Planning and manageme nt efforts should focus on howthe forest can best meet those needs. Past planning andmanagem ent efforts have not been as effective as they mighthave been because planners and managers have underesti-mated the p otential benefits that urban trees and forests canprovide, and have not understood the planning and manage-ment efforts needed to provide those b enefits, particularly thelinkages between benefits and characteristics of the urbanforest and its management.
Urban forests are a significant and increasinglyvaluable component of the urban environment.However, with the limited information on the ben-efits and costs of urban trees and forests cu rrentlyavailable to decision makers, management ofthese valuable assets continues to be inadequ ate.Urban forest resources are declining in manycities, and the resulting benefits are only a fractionof what they could be. In many instances costs arehigher than necessary. We are just beginning to
learn about the extent and magnitudes of themany benefits and costs associated with urbantrees and forests, as well as the many ties betweenurban forest resources and the quality of urbanlife. R esearch in a number of areas suggests thatwe have vastly underestimated the many waysthat the urban forest touches the lives of urban ites,as well as the deep significance that many peopleattach to trees. Furtherm ore, we often lack reliableinformation on how to most effectively manage
urban forests to provide many of these benefits.A sound understanding of the full range of
benefits and costs associated with urban forests,as well as how various management practices,programs, and policies influence those benefitsand costs, is essential for action to enha nce urbanforests and the associated well-being of urban-ites. Benefits to consider include the goods andservices produced by urban trees and forests thatare valuable to people. These benefits vary overspace and time according to changes in the urbanenvironment, its inhabitants, and their needs. Somebenefits are easily expressed in dollars or othernumbers, while others are difficult to quantifyusing such measures; but in the aggregate theyare highly significant to urbanites.
The long life of urban trees and forests man-
dates planning with a view to future needs. In-vestments in the planting and care of trees rep-resent a long term com mitment of scarce dollars,and improper plantings can increase costs andreduce benefits. Therefore, it is important to do itright and plan for future m anagem ent. The effec-tiveness of urban trees and forests in providingbenefits to people depends on their speciescomp osition, diversity, age, and location w ith re-spect to people and other elements in the land-scape. An ecosystem approach that recognizespeople as the central component offers the bestmeans to assess the complex interactions betweenurban trees and forests and the well-being ofurbanites, linking man agement actions with theireffects on urban forests and the associated ben-efits and costs.
The following discussion begins with the influ-ence of urban trees and forests on the physicaland biological environment and continues with thesocio-economic importance of urban trees and
Urban and community forests can strongly in-fluence the physical/biological environment andmitigate many impacts of urban development bymoderating climate, conserving energy, carbondioxide, and w ater, imp roving air quality, control-ling rainfall runoff and flooding, lowering noiselevels, harboring wildlife, and enhancing the at-tractiveness of cities. These benefits may bepartially offset by problems that vegetation canpose such as pollen production, hydrocarbonemissions, green waste disposal, water consum p-tion, and displacement of native species by ag-
gressive exotics(15). U rban forests can be viewedas a "living technology," a key component of theurban infrastructure that helps maintain a healthyenvironment for urban dwellers.
Energy and carbon dioxide conservation.Trees can contribute to energy conservation be-cause they help to reduce the cost of heating andcooling buildings. Projections from computersimulations indicate that 100 million mature treesin U.S. cities (three trees for every other singlefamily home) could reduce annua l energy use by30 billion kWh, saving about 2 billion dollars inenergy costs (1). Savings associated with avoidedinvestment in new power supplies could augm entthese savings considerably. Also associated withthis energy savings is a 9 million ton per yearreduction in carbon dioxide em issions from powerplants. At present, U.S. urban forests are estimatedto store approximately 800 million tons of carbon ,nearly 5 percent of live tree carbon storage in allUS forests (19). Recent studies by scientists and
energy utilities show that when the costs of planting,watering, and maintaining trees are considered,tree planting is a more cost-effective energy andcarbon dioxide conservation strategy than manyother fuel-saving measures (13).
As with most urban forest benefits, energysavings can only be realized through appropriatemanagement strategies. With poor management,important be nefits can be lost and increased costsincurred. For example, annual space air condition-ing and heating costs for a typical home in Madi-son, Wisconsin increase from 671 for an ene rgy-efficient planting design, to $700 for no trees, to
$769 for trees that block winter sunlight and pro-vide little summer shade (11). Costs for water,pruning, removal, litter clean-up, pollen, health-related problem s, and liability can also offset ben-efits, particularly if the wrong tree is planted in thewrong place.
Air quality. Trees exchange gases with theatmosphere and capture particulates that can beharmful to people. The rate at which trees removegaseous pollutants such as ozone, carbon mon-oxide, and sulphur dioxide depends primarily onthe amoun t of foliage, number and condition of thestomata, and meteorological conditions. Resultsfrom computer studies indicate that trees can
reduce appreciably the amount of ozone in pollutedair. Pine trees in Los Angeles were projected toremove from the atmosphere (under 400 m eters)about 8% of the ozone and decrease the concen -tration around the leaves by 49 % (18).
Urban ozone concentrations go up with in-creases in am bient temperatures. One study foundthat the incidence of smoggy days increased 1 %for each 1°C increase in temp erature (26). Be-cause urban forests can reduce sum mertime tem-peratures they provide a nother m eans of improv-ing air quality.
By extrapolating from studies for non-urbanforests we can infer that a m ature urban tree canintercept up to 50 pounds of particulates per year.Planting of 500,00 0 trees in Tucson was projectedto reduce air-borne particulates by 6,500 tons peryear. The annua l implied value of paniculate mattercontrol was estimated at $4.16 per tree per year onaverage or $1.5 million for all trees each year (12).
Citizens spend millions of dollars annually to
control gaseous and particulate pollutants throughprograms for vehicle inspection and maintenance ,oxygenated fuels, rideshare, and street pavingand sw eeping. To the extent that trees can controlpollutants there is potential for improved air qualityand substantial cost savings. Urban forests can beviewed as components of an overall strategy torestore airqua lity in our cities. Improved airqualitywill enhance physical and mental health, resultingin substantial savings in expenditures for healthcare. Improvements in air quality also reduce thecosts of repairing damage to buildings, statuary,etc. that poor air quality causes.
, flooding dam age, stormwater treatment cos ts,y p roblems. Runoff estimates for
ve storm event in Day ton, Ohio showed
By reducing runoff, trees function like reten tion/
Tucson we re calculated
runoff
in many com munities.
Water use by landscape veg etation is an impor-
resources are increasingly scarce; but also
ulberry (14). However, energy
set by water con served at the power plant duerovided by the tree.
Because of recent regulations by the Environ-Protection Agency aimed at improving the
rvation, these hydrologic b enefits willease in importance over time.
Noise reduction. Field tests have shown
on from p lantings along
. Buffer plantings
eening views than reducing n oise.Ecological benefits. Urban forests promote
ecolog ical stability by providing habitat for wildlife,conserving soil, and enhancing biodiversity. Al-though the value of these benefits is seldomquantified, they are important to many urbandwellers and to the long term stability of urbanecosystems. Surveys have found that most city-dwellers enjoy and appreciate w ildlife in their day-to-day lives (25). To enhance wildlife habitat,numerous comm unities havedeveloped programsto preserve valuable existing natural areas and torestore the habitat on degraded lands. For ex-ample, restoration of urban riparian corridors andtheir linkages to surrounding natural areas havefacilitated the m ovement of wildlife and dispersal
of flora. Usually hab itat creation and enhancementincreases biodiversity and complements manyother bene ficial functions of the urban forest (10 ).Because of the growing environmental awarenessand concern for qua lity of life in our cities, ecologi-cal benefits such as these w ill increase in signifi-cance over time. There can also be problems orcosts associated with urban wildlife, includingdamage plants and structures, droppings, threatsto domestic pets, disease, etc.
Social Dimensions
All of the b enefits associated with the physical/biological environment and p rocesses discussedabove have significant implications for peoplewho live in urban areas. We now turn our attentionto critical people/forest interactions.
Desirable environments. The presence ofurban trees and forests can make the urbanenvironment a more pleasant place to live, work,and spend leisure time. Studies of urbanites'
preferences and behavior confirm the strong con-tribution that trees and forests make to the qualityof life in urban areas. Trees and forests are aprominent component of the landscape in mosturban areas. Urban forests provide significantoutdoor leisure/recreation opportunities for ur-banites. Based on nine visits per year to localparks per person, and $1.00 per visit in valueadded by the presence of well managed urbanforest resources, the total contribution of urban
trees and forests in park and recreation a reas tothe value of recreation experiences provided inthe USA could exceed $2 billion (8). These are
both conservative estimates based on studies inthe Midwest (6,7), and do not include benefits fromtrees on residential lots and other "non-desig-nated" areas.
The Forest Preserve District of Cook County,Illinois provides more than 40 million visits peryear from a base of 66,000 acres of urban forests.In addit ion to parks and preserves, urbangreenways provide a wide range of recreationalopportunities. Bicycle trails in river corridors in theChicago Metropolitan area support up to 5,000
bicycles per day passing a given point on a singletrail. To the extent that urban trees and forestsincrease the quality of the urban environment and
make spend ing leisure time there more attractive,there will be substantial savings in fuel consumedbecause people will not drive to distant recreationsites as often. At $1.25 per g allon, the savings toindividuals across the U.S. total $300 million peryear if just one gallon per individual is saved byreduced leisure trips. It would seem that the po-tential savings in fuel costs from an urban envi-ronment that is enhanced by well managed treesand forests might be five times that am ount or $1.5billion per year (8). Reduced fuel consumption
wou ld substan tially reduce air pollution and relatedproblems.
Medical. Reduced stress and improved physi-cal health for urban residents have been associ-ated with the presence of urban trees and forests.Studies have shown that landscapes with treesand vegetation produce more relaxed physiologicalstates in humans than landscapes that lack thesenatural features. Hospital patients with windowviews of trees recover significantly faster and with
fewer complications than comparable patientswithout access to such views (27). Future researchwill identify specific situations (e.g., urban com-muting) in which urban forests can offset stress,and m easure the amount of stress reduction thatoccurs. The benefits to public health from usingtrees to reduce urban stress are potentially verysignificant. In addition, cleane r air can be expectedto improve health. There may be health-relatedcosts as well, such as allergies to plants, pollen, orassociated animals and insects.
ment of everyday life, and a greater sense ofmeaningful connection between people and thenatural environment. Trees are among the mostimportant features contributing to the estheticquality of residential streets and comm unity parks(21). Perceptions of esthetic quality and personalsafety are very sensitive to features of the urbanforest such as number of trees per acre and viewdistance (22). Park and arboretum visitors havereported that trees and forests provide se ttings forsignificant emotional and spiritual experiences(3,23,24). These experiences are extremely im-portant in peop le's lives, and can lead to a strongfeeling of attachment to particular places and
trees (9). An improved understanding of the emo-tional and symbolic meanings of trees will enablemanagers to provide the kind of settings thatcontribute to a m eaningful and satisfying sense ofplace in the urban environment. Costs include fearof trees, forests, and associated environm ents.
Real estate values. The sales value of realestate reflects the benefits that buyers attach tothe attributes of that property, including the treesand forest resource found on the property, alongthe street, and in neighboring parks and greenways.An individual's willingness to pay for a residentialproperty is likely to reflect the value of benefits thatthey expect from these forest environments, in-cluding opportunities for leisure out in the yard orin the neighborhoo d, reduced heating and coolingcosts, privacy, and the lack of a need to constructfences or screens. The variation in sales pricesover a large number of residential properties withdifferent forest resources on the property andnearby can be used to infer the willingness of
users to pay for those urban forest resources (2).These increases in property values are not aseparate category of value that is distinct from thegoods and services provided; but rather one meansof reflecting or capturing the values of the manyimportant services that urban residents receivefrom urban forests.
The ties between trees and property valuesprovide an incentive for homeowners to invest intrees since increased revenues can be received atthe time of sale of that home (i.e., an advertise-
ment mentioning well landscaped yard, shadedpatio, close to parks and bicycle trails, and an
d tree care on public and private landsinvestment that achieves an
a 5 percent increase in property values
erty tax $500, and quickly adds up to $1.5 billion per
in the USA. A more realistic estimatetwo to three times that amoun t.
Parks and greenways have been associatedents in the value of nearby real estate
tial and it appea rs that parks with an "open
estate. We have yet to identify the increments
Residential properties are not the only real
environment that will attract shoppers, therebyeasing the value of businesses a nd the shop-
ch that documents the increased business
s, trees and forests m ay make an importantomic vitality of these busi-
s, and the private sector is currently making in this area—far in excess
is required, to enhance
areas
In short, trees and forests can make a sub stan-tial contribution to property tax revenues, thereby
providing annual returns on municipal investmentsin urban trees and forests. These benefits areoffset, in part, by the costs of managing the forestsand repairing damages that may be associatedwith them , such as disruption of sidewalks, sew-ers, pow erlines, etc.
Local economic development. Urban forestresources also make a broad contribution to theeconomic vitality of a city, neighborhood, or sub-division. While this is particularly d ifficult to quan -tify, it is apparently no accident that many cities
and towns are nam ed after trees a nd forests (i.e.,Elmhurst and Oak Park) as are subdivisions (i.e.Tall Timbers and Timber Trails) and many areasstrive to be designated as a "Tree City USA."Many neighborhoods select tree planting as acomm unity improvement project. Trees can domi-nate the urban environment and contribute muchto its character. In the Chicago area, comm unitiessuch as Evanston, Oak Park, and Elmhurst arewell known for their mature forest environme nts.
Atlanta's large investment in downtown treeplantings has paralleled an upswing in conventionbusiness and contributed to its image of a pro-gressive, livable city.
Community action program s that start with treesand forests often spread to other aspects of thecommunity and result in substantial economicdevelopment. Often trees and forests on publiclands — and to some extent those on private landsas well — are significant "common property" re-sources that contribute to the economic vitality of
an entire area. The substantial efforts that manycommunities undertake to develop and enforcelocal ordinances and manage urban forest re-sources attests to the substantial return that theyexpect from these investments.
Societal. Stronger sense of community, em-powerment of inner city residents to improveneighborhood conditions, and promotion of envi-ronmental responsibility and ethics can be attrib-uted to involvement in urban forestry efforts. Ac-tive involvement in tree-planting programs hasbeen shown to enhance a community's sense ofsocial identity, self-esteem, and territoriality, and
it teaches residents that they can work together tochoose and control the condition of their environ-ment. Com munity tree planting programs can helpalleviate some of the ha rdships of inner city living,especially for low-income groups. Research onenvironmental education is exploring ways ofteaching children about their responsibility in caringfor trees, and can provide badly needed opp ortu-nities for inner city children to experience nature.Researchers are examining how such early expe-riences with nature influence the willingness toadopt an environmental ethic later in life.
Summary and Conclusions
With effective planning and managem ent, urbantrees and forests will provide a wide range ofimportant benefits to urbanites. These include amore pleasant, healthful, and comfortable envi-ronment in which to live, work, and play, savings inthe costs of providing a wide range of urbanservices, and substantial improvements in indi-vidual and community well-being.
Urban forests can enhance the city environ-ment by influencing tem perature, wind, humidity,rainfall, soil erosion, flooding, air quality, scenicquality, and plant and animal diversity. Each ofthese influences has significant imp lications for thewell-being of urbanites. But there are also envi-ronmental problems that may be associated withthe urban forest, such as the gene ration of pollen,hydrocarbons, and green waste; water and energyconsumption; obscured view s; and displacementof native species of plants.
A well planned and man aged urban forest canreduce costs for heating and cooling, health care,
driving to exurban areas for recreation and leisure,stormwater management, and damage fromflooding, erosion, and polluted air. Substantialincreases in revenues can also be associated withurban trees and forests, including the sale of realestate (individual gains), real estate and businesstaxes (government gains), and tourism (individu-als and government may gain). Costs associatedwith urban forests include establishment and careof the forest; repair of forest-induced damage toother parts of the urban infrastructure (particularlysidewalks and utilities); blocked solar collectors,and foregone opportunities for activities such as
gardening and sports.Many important benefits and costs of urban
forests that contribute significantly to the well-being of urbanites are not easily reflected in dol-lars and cen ts. Psychological benefits associatedwith urban forests include more pleasant envi-ronments for a wide range of activities, improve-ments in the esthetic environme nt (sights, sounds,smells), relief from stress (which can lead toimproved physical health), enhanced feelings andmo ods, increased enjoyment of everyday life, anda stronger feeling of connection between peopleand their environment. Psychological costs caninclude fears of crime, animals, insects, disease
(i.e., Lyme disease), darkness, and falling trees orlimbs; and the displeasure of messiness and clutter.
Benefits attributed to urban trees and forestsextend beyond individuals to society. Societalbenefits include a stronger sense of community,empowerment to improve neighborhood condi-tions, promotion of environmental responsibilityand ethics, and enhanced economic developm ent(business, comm erce, em ployment). Societal costsinclude money a nd other resources that must bediverted from other social programs.
The challenge faced by urban forest resourcemanagers and planners is to balance the manybenefits and costs that are associated with urbantrees and forests. Lack of information about theextent and magnitude of these benefits and thebest approaches for providing them often makesthat task a very difficult on e.
Urban forestry plans should begin with consid-eration of the contribution that trees and forestscan make to people's needs. Planning and man-
agement efforts should focus on how the forestcan best meet those needs. Past planning andmanage ment efforts have not been as effective asthey might have been because planners and ma n-agers have un derestimated the potential benefitsthat urban trees and forests can provide, and havenot understood the planning and managementefforts needed to p rovide those b enefits, particu-larly the linkages betw een ben efits and character-istics of the urban forest and its m anagem ent.
Research continues to document new ways inwhich trees and forests can be nefit urbanites, aswell as the magnitudes of these benefits. The
Journal of Arboriculture 18(5): Septemb er 1992 233
efforts of urbanites to protect and preserve treesas well as their enthusiastic involvement in treeplanting programs reflects their high regard for
urban forest benefits.Urban trees and forests promise to be evenmore consequential in the years ahe ad. Increas-ing interest in cost-effective and "minimum im-pact" approaches for improving the quality of theurban environment suggests that trees will playincreasingly important roles in efforts to enhanceairquality and improve urban hydrologic processes.Worldwide con cern for "global warming " suggestsincreasing interest in trees for sequestering car-bon and reducing carbon dioxide emissions. As-
sociated concern for efficient use of energy re-sources will bring increasing attention to trees asa m eans of reducing heating and cooling costs aswell as for encourag ing urbanites to spend leisuretime in the urban environment rather than drivingto more rem ote areas. As we learn m ore about thefunctioning of the urban ecosystem and the role oftrees and forests in that system, it is likely thatthese resources will assume new roles in efforts tomanage the urban environment.
With increasing emphasis on improving thequality of life for urbanites and in "wellness" pro-grams overall, increasing atten tion will be given totrees and forests as a means for enhancing thequality of urban life. This is likely to include effortsaimed specifically at stress reduction and im-proved public health. As we learn m ore about thedeep psychological ties between urbanites andtrees and forests, it is likely that urban trees andforests will assume new roles in efforts to increasethe quality of urban life.
As we learn more abo utthe contribution of treesand forests to the value of residential and com-mercial real estate it is likely that ow ners will m akeincreasing investments in their trees and forests.Local governments and energy utilities will under-
take programs to encourage such efforts, due inpart to the increased tax revenues that will result,and to avoid energy costs.
Education regarding the planting and care ofapprop riate tree species in desirable loca tions will
be critical to the long term cost-effectiveness ofthese programs.With increased evidence of the boost that trees
and tree planting can give to local economicdevelopment and the sense of community, morecomm unity organizations will become involved in
tree planting and tree care and tree and forest-related projects will be increasingly sponsored asa m eans of enhancing comm unity spirit and orga-nization. These projects will also be increasinglyseen as a m eans of providing a sense of empow-ermen t of inner city residents to improve neighbor-hood conditions and for promoting environmentalresponsibility and ethics
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An earlier version of this paper was prepared as background forthe Fifth National Urban Forest Conference: Forging Alliances
for Com munity Trees, in Los Angeles CA November 12-17,19 91
Resume. Les arbres et les forets urbaines sont descomposantes s igni f icat ives et de grandes valeurs pourI'environnement urbain et peuvent pourvoir un large eventail debenefices pour les citadins. Ceux-ci incluent un environnem entplus agreable, sain et confortable dans lequel vivre, travailler et
jouer; des economies dans les couts de fourniture d une largegamm e de services urba ins; et des ameliorations substantiellesde laquali tede vie individuelleetcommuna utaire.Ces beneficeset couts sont analyses en debutant avec I influence des arbreset des forets urbaines sur I'environnement physique et biologiqueet se poursuit avec I importance socio-economique des arbresurbains et la multitude d'environnements qu'ils creent pour lesindividus et les communautes..
Zusammenfassung. Stadtbaume und Stadtwalder sindwichtige und wertbestimmende Komponenten der stadtischenUmwelt und konnen zahlreiche Wohlfahrtswirkungen fur dieStadt haben. Diese beinhalten eine schonere, gesundere und
komfortablere Umwelt zum Leben, Arbeiten und Spielen,Kostenerspamis auf vielen Gebieten stadtischer D ienstleistungenund substant iel le Verbesserung beim indiv iduel len undgemeinschaftlichen Wohlbefinden. Diese Vorteile und Kostenwerdendiskutiert, angefangen mitdem EinfluB der Stadtbaumeund Stadtwalder auf die physikalische und biologische U mwe lt,und fuhren fort mit der soziookonomischen Bedeutung derStadtbaume und die Umgebung, die sie schaffen fur den
