ECOLOGICAL FUNCTION ANALYSIS OF URBAN GREEN OPEN
SPACE FOR THE SUSTAINABILITY OF BEKASI CITY
ARIZONA STATE UNIVERSITY
ABS 370 – ECOLOGY
SPRING 2024
Introduction:
The challenges of population problems faced by every country, both developing and developed,
are population growth, urbanization, and uneven population distribution. These population problems
are also experienced by Indonesia, especially in the Jabodetabek area. Jabodetabek continues to grow
and urbanize along with the increase in population and residential areas. Population growth followed
by housing development and economic activities in Jabodetabek has expanded the built-up area and
increased urbanization in this region (Aritenang 2023). Population growth in the Jabodetabek region is
rapidly spreading to suburban areas that have large rural areas.
The denser the population, the smaller the space available. The need for land, both residential
and non-residential, increases with the increase in population. Along with the increasing need for land,
more and more open land is converted into built-up land (Akhirul et al. 2020). Land use change is a
common occurrence in the process of urban development, but it does not occur evenly in every region
because each land has different potentials and strategies. These actions are not solutions, but
destructive actions that can disrupt the balance of the environment. So the level of environmental
damage will increase along with the increase in population growth. Land use, land use change and
forestry affect the global carbon cycle. The Intergovernmental Panel on Climate Change (IPCC)
estimates that about 1.6 billion tons of carbon are released annually due to land use change activities
(Köhl et al. 2009).
In addition to the increasing need for housing, population growth
This is also always accompanied by an increase in the standard quality and quantity of living needs.
This has an impact on the increasing number of motorized vehicles, reduced Green Open Space,
lifestyle changes that encourage increased energy consumption, increased use of fuel oil as an energy
source, and low public awareness of air pollution and efforts to control it. According to Cahyono
(2016), global warming is caused by too much pollutant gas in the air. In urban areas, the main sources
of pollutants that affect air quality come from industries and motor vehicles. Some human activities in
urban areas, especially industry and transportation, cause changes to the atmosphere. Pollution in
urban areas also impacts visibility and the amount of solar radiation absorbed by the atmosphere.
Solar radiation is the main determinant of climate in a region. Microclimate is the weather in a
small area, which affects humans, plants and animals directly, making it one of the essential forms of
weather (Lakitan 2002). Urban climatic conditions are influenced by a variety of natural and man-
made factors. Air pollution, materials used as pavement, heat-generating human activities, as well as
natural influences, contribute to climatic differences between neighborhoods urban and non-urban.
According to Laurie (1986), t h e perfect environmental condition for humans is an environment with
fresh air and has an ambient temperature of 27ºC to 28ºC, and humidity ranging from 40% to 75%.
The correlation between industrialization as a driver of economic development and environmental
pollution is one of the main factors causing the decline in environmental quality. It is feared that the
environment and natural resources will not be able to meet human needs in the present and future. The
biggest challenge for natural resource managers is to balance human needs with environmental
sustainability. This balance can be achieved by increasing the positive interaction between natural
resources and human activities through land use or land cover in an area.
(Naiman et al. 1992).
Green Open Space (RTH) has an important role in maintaining the sustainability of a big city.
RTH can at least reduce the problems that arise in urban areas. Based on its function, green open space
has the main function of balancing the environment, regulating microclimate, providing shade,
producing oxygen and absorbing pollution, storing rainwater, protecting animal habitats and
functioning as a windbreak. The benefits of RTH are very diverse, including providing a place for
socializing, recreational activities, improving aesthetics and comfort, and contributing to the economy.
Based on the provisions of Law No. 26 of 2007 concerning Spatial Planning, the provision of Green
Open Space in an area is at least 30% of the area, with a division of 20% for public green space and
10% for private green space. Urban growth accompanied by changes in land use has caused
environmental damage that can limit the carrying capacity of land for urban life. Therefore, it is very
important to create and maintain enough green space to improve environmental quality (Silas 2014).
Several efforts have been made by the government to increase space
green city to build environmental stability and improve the quality of the cityscape. One such effort is
the Green City Development Program (P2KH). This program was established to realize a higher
quality urban space, with eight attributes, including green planning and design, green open space,
green community, green transportation, green waste, green water, g r e e n building, and green
energy. The Green City Development Program (P2KH) is an initiative initiated by the Ministry of
Public Works and the Directorate General of Spatial Planning as a joint effort between the central,
provincial, and local governments to meet the requirements of the UUPR, especially those related to
urban green spaces.
Bekasi City is one of the metropolitan cities with a high population density. The population in
2022 reached 2.6 million people (BPS Bekasi City 2023), with a population growth rate over the last
four years (2018-2022) of 1.6%. The location of Bekasi City, which is directly adjacent to DKI Jakarta
Province, has resulted in dense activities in Bekasi City. The increasing rate of urbanization in Bekasi
City makes the phenomenon of land conversion into residential areas and supporting facilities
inevitable. Bekasi City has a total area of 213.13 km2 , then the public green space that must be owned
by Bekasi City is 42.09 km2 . Currently the area Public RTH in Bekasi City has only reached 8.35 km2
or only 3.9% of public RTH available in Bekasi City, so there is still 16.1% of public RTH area that
must be fulfilled to reach the ideal amount. This public green space has increased since 2018 by 4%.
Increasing public green spaces in Bekasi City is being pursued by the local government by making it a
regional program that is implemented in stages until 2035.
The factor of low public awareness of the benefits of green spaces affects the quality of existing
green spaces. Urban green spaces must be able to improve the quality of the surrounding environment
and provide a balance for the life of living things. So public awareness of the importance of green
spaces for life can be an important factor for the development of green spaces in Bekasi City.
Sustainability between government programs and public awareness must be created to realize the
sustainability of Bekasi City.
Apart from the availability of RTH, the function of RTH is also important to be considered so
that the existence of RTH can provide sustainable benefits. One function that is important for the
sustainability of the city is the ecological function of RTH. So that in the planning of green spaces,
especially in Bekasi City, it must focus on ecological functions to achieve a sustainable Bekasi City.
One form of Green Open Space in Bekasi City is the city park. The limited area of city parks in Bekasi
City can be maximized by optimizing the functions of city parks, especially ecological functions.
Therefore, this research was conducted to determine the magnitude of ecological value and to find out
people's perceptions regarding Bekasi City Park, Bekasi City Government Park, and Patriot Bina
Bangsa City Forest in Bekasi City. The results are expected to be used to improve the ecological
functions of existing parks in Bekasi City and achieve a sustainable Bekasi City.
1.1 City Park
According to Bekasi City Regional Regulation No. 13 of 2011, city parks are an important part
of the city's Green Open Space. Located in the middle of city buildings and infrastructure, these parks
facilitate various community activities. The parks have three functions, namely ecological, aesthetic,
and social functions that are interrelated. In terms of ecology, urban parks help absorb pollution
caused by high population activity, reduce noise levels, and absorb dust particles. It also helps regulate
the microclimate. In addition to providing aesthetic functions by beautifying the city, the park also
serves as a place for people to conduct social activities, such as sports, recreation, and discussions.
Gallion and Eisner (1994) say that urban parks are usually a link between urban and rural areas,
located away from crowded places. Urban parks are created as grassy barriers to separate different
types of land in the city. Urban parks are defined as designated open spaces. It is mostly dominated by
vegetation and water, and is generally reserved for public use. City parks are usually large, but can
also be smaller pocket parks. Urban parks are usually defined locally by the government as 'parks'
(Konijnendijk 2013).
1.2 Urban Forest
According to Regional Regulation No. 63 of 2003 on Urban Forests, an urban forest is an
expanse of trees that grow densely on state-owned or private land in urban areas. Its purpose is as an
environmental buffer, regulator of water and air cycles, habitat for flora and fauna, and has aesthetic
value. Authorized officials designate the area as an urban forest, and the area must have green open
space densely packed with trees. Marini (1996) categorizes urban forests into several types based on
their purpose and designation, namely conservation urban forests, industrial urban forests, residential
urban forests, tourist urban forests, and other types of urban forests, such as urban forests for animal
protection. Dahlan (1992) categorizes urban f o r e s t s into six types, namely urban forests for
settlement, industry, recreation and beauty, germplasm preservation, protection, and security.
Irwan (1994) categorizes urban forest forms into three, namely clustered or grouped, dispersed,
and irregular spacing. Clustered urban forests have a centralized population of vegetation with a
minimum of 100 trees. Spreading urban forests are not clustered or piled up. Urban forests with
spreading vegetation have no particular pattern. Vegetation grows in clumps or small groups. It can
also grow in a path-shaped pattern, following the formation of rivers, roads, beaches, channels, etc.
The shape and structure of the urban forest is designed to cope with the reduction of available land,
while still balancing its functions. To improve the function of the urban forest, it is necessary to
improve its structure to resemble a natural forest. This not only involves providing forest land In
addition, the structure of urban forest vegetation is also being improved. Marini (1996) divides urban
forests into four forms, namely parks, gardens and yards, greenways, and forests located in
conservation areas, one of which is forests located in urban conservation areas.
The structure of the urban forest relates to the number and diversity of vegetation communities
that make up the urban forest. To achieve a stratified and multilevel urban forest that resembles a
natural forest, it is important to plant a variety of vegetation types. Plant communities can be classified
into several types of urban forests. The urban forest plant community can be a two-strata community,
consisting only of trees and grass or other ground cover. Stratified communities, which consist of
trees, shrubs, epiphytes, saplings and ground cover. In stratified communities, the irregular distance
between strata mimics the conditions of natural forest plant communities (Irawan 1994).
Urban forests have several benefits (Dahlan, 1992). These benefits make the urban forest an
important part of a city. The urban forest helps to identify the city, conserve germplasm, filter solid
particles from the air, absorb lead particles and cement dust, reduce noise, reduce the danger of acid
rain, absorb carbon monoxide, retain wind, absorb and filter odors, improve climate/climate
amelioration, waste management, groundwater conservation, filter glare, add beauty, bird habitat,
coastal abrasion control, improve the tourism industry, and hobby and recreation places.
1.3 Green Open Space
Open space is defined as part of land use in urban areas whose use is intended to meet open
space needs, which can be in the form of Green Open Space, fields, cemeteries, ponds, rice fields, and
others. Urban Green Open Space (RTH) is the open space of an urban area that contains plants, crops,
and vegetation that provide benefits both directly and indirectly in the form of security, comfort,
welfare, and beauty of the urban area (Ministry of Public Works 2008). Green Open Spaces in urban
areas have various forms, functions, and purposes, ranging from simple playgrounds to natural
landscapes or well-maintained neighborhoods. Green Open Space serves as a place for recreation,
exercise, socializing, and relieving fatigue from work routines. Most are public facilities, although
some can be privately owned (Panduro and Veie 2013). The existence of green areas in urban areas
aims to provide ecological, social, cultural, economic, and aesthetic benefits. Ecologically, green
spaces function to create a microclimate (providing oxygen, cleaning the air, and ensuring the
availability of clean water), conserve soil and water, and preserve animal habitats (Nurisjah and
Pramukanto 1995).
1.4 Functions of Vegetation in the Landscape
Vegetation is a biotic component in the form of plants as part of the ecosystem. Changes in the
size, shape, texture, and color of plants during the growth process will affect the character of open
space. Similarly, the quality and quantity of open space will continue to increase along with the growth
of the ecosystem (Hakim and Hardi 2004). Thus, the selection of appropriate plant species can affect
the effectiveness of open space functions, such as its ability t o suppress air pollution, absorb dust,
reduce noise, reduce soil erosion, and resist wind and rain as a whole.
Vegetation can function as a natural sound absorber. The right combination of vegetation can
create a barrier that can reduce noise. According to Carpenter et al. (1998), vegetation in parks can
reduce noise by 25-80%, depending on the height, width, type of plant, and distance from the noise
source. Planting different types of plants with different levels is more effective in reducing noise
because the noise that can be reduced by plants can be influenced by the intensity, frequency, and
direction of the sound. The ability of plants to reduce noise is influenced by leaf shape and crown
density. Wide leaves, rough leaf texture, and dense leaves are the characteristics of plants that are most
effective in reducing noise.
Vegetation can also reduce pollution levels by absorbing, decomposing, storing or regulating the
rate at which air pollution occurs. Hence, air quality can be improved by releasing oxygen
(Shannigrahi et al. 2010). Azzahro et al. (2019) mentioned that tree crowns can reduce pollutants
released into the environment by deflecting them and absorbing particles with the surface of leaves,
stems, and twigs. Therefore, the selection of vegetation that is suitable and has characteristics in
absorbing pollutants must be considered. Characteristics of plants that are good at absorbing pollutants
include having a dense crown with a large number of leaves. Plantings consisting of a combination of
trees, shrubs, bushes, and ground cover can increase the absorption of pollutants.
Trees with high canopy density may block light from entering.
sun well. This is because little solar radiation enters and is passed through the empty spaces between
the leaves. The types of trees that provide an effective shading effect are large trees with wide crowns,
because the leaves of these trees can hold, reflect, absorb and filter solar radiation (Gray and Deneke
1978). In addition to controlling temperature, vegetation also has the function of controlling air
humidity. Humidity that is too high or too low can cause reduced thermal comfort for humans.
1.5 Sustainability City
According to Cappon's (1990) description, a city is an identifiable set of buildings and streets
where people live, work, and engage in social and cultural activities. The minimum population for a
city is
10,000 inhabitants. The term 'urban' has various meanings related to factors such as population
density, land use, and cultural behavior. These processes can have negative impacts on the
environment, such as changing air temperatures, disrupting the water cycle, and altering ecological
processes. Urban areas are referred to as ecosystems where natural and social processes function in
harmony with each other. Urbanization, on the other hand, is the process of cities growing larger and
expanding into the countryside. Sustainability means being able to cope with disturbances and changes
without losing the function, structure, identity and efficiency of the system (Folke et al. 2004).
The United Nations (UN) defines a sustainable city as one in which social, economic and
physical development takes place over a long period of time. This implies that the city's development
is sustainable and continues to rely on natural resources, taking into account their capacity and
sustainability. According to the World Commission on Economic Development (1987) document,
sustainable development must meet current needs without disturbing the balance. Sustainable
development is a positive socio-economic change without neglecting the ecological and social aspects
that are the needs of society. Successful sustainable development requires appropriate policies,
planning and learning processes, as well as full support from the community through the government
and its businesses (Soemarwoto 2004).
1.6 Perceptions and Preferences
Perception is how a person organizes and understands information from their senses to give
meaning to the environment around them. Factors that influence how a person perceives something
include personal characteristics or factors related to the perceiving individual (such as attitudes,
motives, interests, experiences, and hopes or expectations), situational factors (such as time,
situation/workplace, and social conditions), and factors of the perceived thing (such as novelty,
movement, sound, size, background, distance, and similarity). A person can see an object in a different
way from other people, because several factors can shape and influence a person's perception. How to
observe and understand an object is strongly influenced by the personal traits of the individuals
involved (Simbolon 2008).
According to Mc Shane and Von Glinow (2000), there are several distortions in the
perceptions that need to be considered, among others:
1. Primary Effect which refers to a person's tendency to form an opinion quickly based on the first
information received.
2. Recency Effect, which occurs when the most recent information dominates one's perception of
something.
3. Hallo Error occurs when we rely on only one characteristic to evaluate a person or situation as a
whole. This is known as overall bias.
4. Projection Bias occurs when we attribute qualities of ourselves to others. This means projecting
something we see in ourselves onto others.
Preference is a person's process of choosing information or something that is preferred by the user.
User preference is defined as a person's choice of likes or dislikes for a product of goods or services
consumed. This preference shows a person's preference for a product from a variety of existing
product choices (Kotler and Armstrong 2004). It can be concluded that choosing something based on
personal pleasure and rational thinking is known as preference.
Tools and Materials
The tools used in this research include a smartphone camera as a documentation tool to assist in
the site inventory process, stopwatch and Sound Level Meter as tools to measure noise levels, Thermo
Hygrometer used to measure microclimate (temperature and humidity) on the site, questionnaires as a
tool to obtain visitor perceptions, and various supporting software such as AutoCAD, Photoshop, and
Microsoft to process data and compile research results. While the materials used, namely the location
base map to support spatial data.
Work Procedure
This research was conducted in several stages, including preparation, inventory, analysis, and
synthesis in the form of a descriptive presentation of the role of parks for the sustainability of Bekasi
City and recommendations for implementing green planning. Data collection was carried out by field
observations, interviews with managers, literature studies, and distributing questionnaires. The data
collected consisted of climate data, physical data, biophysical data, geographical location, and
vegetation data.
1.1.1 Preparation
The preparation stage includes discussing research topics and titles, making research proposals,
collecting secondary data through literature studies, pre-research surveys to research locations, and
obtaining the necessary licenses from relevant agencies.
1.1.2 Inventory
Inventory is done by collecting data and information about the research location. The
information needed at this stage is the location of the site, vegetation, climate, noise, and visitor
perception. The data collected consists of primary and secondary data obtained by conducting surveys
and literature studies. The survey was conducted by directly observing the location, taking
documentation, interviewing the manager, and distributing questionnaires to visitors. Literature study
was conducted by finding information from journals, books, and data from related agencies.
Observations made at the site include observation of vegetation, measurement of microclimate
(air temperature and humidity), and measurement of the level of air pollution noise. Questionnaires
were distributed in each park used as a research site to obtain data on visitor perceptions.
a. Microclimate Measurement
Microclimate observations were made in several locations in the park, including areas with
shaded pavement, pavement areas without shade, and shaded areas without pavement. Measurement of
temperature and humidity data was carried out with three repetitions at three different times
representing morning, afternoon, and evening, as for the time, namely, 8-9 hours for the morning, 12-
13 for the afternoon, and 15-16 for the afternoon. Measurements were taken using a Thermo
Hygrometer. The results of temperature and humidity data measurements were recorded in each of
these segments.
Margaretha's (2007) research shows that areas with extensive pavement without shade have high
temperatures with low relative humidity. This suggests that land covered by vegetation that provides
shade has a more comfortable temperature compared to pavement areas.
b. Noise Measurement
Noise levels were measured in the parks using a device called a Sound Level Meter, measured in
each park at one-minute intervals with readings taken every five seconds in the morning, afternoon,
and evening. Noise data sampling points were selected based on their distance from the highway,
which is the noise source. Point S is represented as the noise source. Point number one is located near
the noise source with a distance to point S of five meters and is the outermost point. Point number two
is between the nearest and farthest point from the noise source. Point number three is located in the
middle of the park. Based on its distance, point number three is the farthest point from the noise source
from the noise source. The distance between points 1, 2, and 3 is about 30 meters. The determination
of the distance between points refers to research conducted by Anggraini et al. (2020). This is depicted
in the illustration below.
c. Community Perception
Data collection related to things that park visitors feel and by giving questionnaires to visitors
(Appendix 2). Sampling was carried out by accidental sampling method where samples were taken
from individuals who were accidentally encountered at the research location. The total number of
samples observed was 150 people with the provision of a minimum number observed of 52 people.
The groups selected as samples in this study were visitors aged between 15 and 65 years and had
visited the park at least once.
1.1.3 Analysis
a. Ecological Function Analysis
The ecological function of the green space was analyzed by reviewing the condition of the
vegetation on the site and conducting an analysis of the data collected. The analysis focused on the
functions of noise cancellation, shading, humidity control, particle trapping and pollutant absorption.
The analysis used a descriptive approach involving an assessment of each identified tree element
(Appendix 1). The analysis was conducted by comparing the quality and condition of plants in the
field with standards obtained from several sources. T h e following is a list of assessment criteria used
in identifying vegetation conditions:
4.1 General Condition of the Park
4.1.1 Bekasi City Park
The establishment of Bekasi City Park is a form of government concern for its people. Bekasi
City Park was established with the aim of providing space for the community so that people can relax
and enjoy the view from the Green Open Space (RTH). Apart from meeting the needs of the
community, Bekasi City Park also aims to preserve the heritage of Bekasi City. There is a monument
erected on July 5, 1955 with a five-square shape made of bricks as a symbol of the struggle of the
people of Bekasi City. This monument is located in the traffic park, this park is adjacent to the Bekasi
City square and opposite the Bekasi City park. In the past, on February 17, 1950, this area was used as
a demonstration site by 40,000 Bekasi people who proposed that Jatinegara Regency be converted into
Bekasi Regency. Based on Law No. 14 of 1950, Bekasi Regency was formed, which is symbolically
expressed in the symbol of Bekasi Regency with the motto "Swatantra Wibawa Mukti". This history is
the forerunner of the establishment of Bekasi City.
Bekasi City Park has facilities such as signage, toilets, dome, bench, management office,
pergola, pond, and children's play facilities that are no longer used. This park is usually used to relax,
take a break from work, wait for prayer time, sit around, look for inspiration, and some online
motorcycle taxi drivers use it to wait for orders. The intensity of visitors i s higher in the afternoon to
evening than in the morning, while on holidays it is quieter than on weekdays. Bekasi City Park has a
focal point in the form of a dome in the center of the park with the road as the axis line to the dome.
Maintenance carried out in the city park in the form of cleaning leaf litter scattered on the road and
replanting trees. This city park is surrounded by a 1 (one) meter high fence, but visitors can still access
the park from the north, south, east and west sides because there are several missing parts of the fence.
4.1.2 Bekasi City Government Park
Bekasi City Government Park is present because of the availability of vacant land around the
Bekasi mayor's office, so that the land is utilized to preserve vegetation and animals and to provide
comfort for employees and the wider community when in this location. The Bekasi City government
park consists of several small parks located scattered around the office. These parks have names,
including deer park, cape forest park, water park, and medicine park. Based on history, there used to
be many deer in the deer park so it is now called the deer park. Facilities in Bekasi City Government
Park include benches, ponds with fountains, plazas, parking lots, toilets, jogging tracks, sports
facilities, mosques, management offices, and security posts. The pond in the water park has a fountain
installation that is turned on 3 times a day for 3 hours at certain times.
On weekdays, visitors to the park are dominated by employees work in local offices. Employees
who visit the park usually utilize the park to rest, chat, exercise, or just sit around. The park is open to
the public, but the general public usually visits the park on Sundays because on those days a car free
day is routinely held on Ahmad Yani street. There are several gates to access the park. On weekdays,
motorcycles can enter through the door on Jalan Rawa Tembaga 1 and cars can enter through the door
on Jalan Ahmad Yani, while the door on Jalan Insinyur is on Jalan Insinyur. H. Juanda is only used for
exit access. On holidays, cars and motorcycles can enter through the doors on Jalan Ahmad Yani and
Jalan Insinyur H. Juanda.
The garden is in very good condition due to regular maintenance which includes sweeping,
watering, fertilizing, replacing plants, replanting, pruning parts of trees that are dangerous and
eyesores, and pruning for the purpose of shaping plants. Maintenance on aquatic plants includes lotus
pruning and cleaning of dried leaves. Pruning of tall tree branches must be done with the approval of
the Environmental Agency for safety reasons.
The Urban Forest was established based on a decree by the mayor of Bekasi in 2012. Before the
urban forest was established, this land was a grassland that was part of a sports facility that was not
used by the local government. The land was used as a campground and trees were planted since the
1990s. Of the many trees planted, only a few trees survived to grow on this land, including ketapang
trees, teak trees, and mahogany trees. The land was converted into an urban forest in 2012 and the
camp was moved to Jatisari. Before it was renamed the patriot urban forest, this area was called
Taman Tugu Perjuangan (Struggle Monument Park) because there is a monument that symbolizes the
struggle of the Bekasi people in defending their territory from invaders. There are five bamboo-shaped
struggle monuments and each is 17 meters high. It is a replica of the five precepts in Pancasila and
illustrates the commitment to always maintain "National Unity and Unity" which is now the logo of
Bekasi City. The monument stands in the middle of a pond with 18 fountains, the back of which has a
relief depicting the people's struggle to seize and defend independence and a strong community life.
The patriot urban forest was established to fulfill regulations on the area of Green Open Space
(RTH) in Bekasi City. However, due to several reasons such as road widening, the area of urban forest
and other RTH in Bekasi City has not met the minimum limit of Green Open Space that should exist
in Bekasi City. In addition to road widening, the construction of facilities in the urban forest is also a
factor in the reduction of RTH. In addition to fulfilling the RTH area in Bekasi City, the patriot urban
forest also prioritizes other functions by building facilities to support the needs of the community.
These facilities include a roller skating track, sports hall (GOR), basketball court, toilet, prayer room,
multipurpose plaza, and guard post. The facilities provided in this urban forest can be used by the
community, both individuals and groups from Bekasi City and its surroundings. Activities that can be
carried out range from environmental activities, to sports and recreation. Similar to the Bekasi City
Government Park, this urban forest is also used by visitors to rest after completing car free day
activities, because there are several sellers selling their wares in the urban forest.
4.2 Identification of Plant Types and Functions
The research was conducted in three parks in Bekasi City, namely Bekasi City Park, Bekasi City
Government Park, and Patriot Bina Bangsa City Forest in Bekasi City. Each park has different
vegetation types and planting patterns. In general, the three parks have several types of vegetation in
common, which are endemic to Bekasi City. Based on Bekasi City Regional Regulation Number
13/2018 Article 11 concerning Protection and Management of Biodiversity, some of the endemic
vegetation found in one or all three parks include durian (Durio zibethinus), jamblang (Syzygium
cumini), buni (Antidesma bunius), belimbing wuluh (Averrhoa bilimbi), rambutan (Nephelium
lappaceum), jackfruit (Artocarpus heterophyllus), randu (Ceiba pentandra), breadfruit (Artocarpus
altilis), petai (Parkia speciosa), and sawo (Manilkara zapota).
4.2.1 Bekasi City Park
Vegetation in this city park is dominated by randomly planted vegetation. There is no specific
theme applied to the design or planting pattern in this park. Vegetation in this park consists of 36
species and 515 individuals dominated by trembesi trees (Samanea saman). The majority of the
vegetation in this park has grown to its full potential.
4.2.2 Bekasi City Government Park
Bekasi City Government Park has various types of vegetation. The planting pattern in Bekasi
City Government Park is quite regular in each park. The planting pattern in the cape forest is linear,
while the planting pattern in the deer park tends to be spread and irregular. Based on the results of
observations, Bekasi City Government Park has 24 species and 654 individuals. which are generally
dominated by cape trees (Mimusops elengi) as shade vegetation with a total of 352 individuals.
4.2.3 Patriot Bina Bangsa City Forest Bekasi City
Vegetation in this urban forest is dominated by large trees planted randomly. There is tea-tehan
(Acalypha siamensis) vegetation as a barrier planted along the edge of the park directly adjacent to the
sidewalk and road. There is no specific theme applied to the design or planting pattern in this park.
Based on observations, the vegetation in this park consists of 24 species and 1118 individuals that
have grown to their full potential, dominated by mahogany trees (Swietenia macrophylla).
4.3 Ecological Function Analysis
Urban green spaces provide a variety of ecosystem services, including recreational and
educational values, ecological processes such as pollination and seed dispersal, and other services such
as air filtration, microclimate regulation, noise suppression, stormwater drainage, and waste treatment
(Daily 1997). This study divides the ecological functions of plants into five categories, including noise
suppression, temperature modification (shading), humidity control, particle trapping, and pollutant
absorption.
4.3.1 Noise Cancellation Function
Noise is often referred to as 'pollution' and has been the subject of environmental regulations
(Ingard 2010). According to the Decree of the Minister of Environment No.
Kep.Men48/MEN.LH/11/1996, noise is unwanted sound from a business or activity in a certain level
and time that can cause disturbance and discomfort that disturbs human health and the environment.
Noise can be produced by various sources, including human activities such as vehicle traffic, industrial
activities, and even small activities such as talking. Plants can reduce noise pollution in several ways,
one of which is that their leaves and trunks can bend sound waves. When sound waves pass through
plants, they are refracted and bent, reducing the amount of sound that enters the garden. The sound
produced by the leaves and branches is also useful for masking unwanted noise (Maeril 2012). Their
effectiveness in reducing noise depends on several factors. Here are the criteria for plants as noise
absorbers:
K1 = Tight crown and leaf mass (DPU Bina Marga 1996) K2 = Thickly leafed (Gray and Deneke
1978)
K3 = Large branch and stem structure (Gray and Deneke 1978) K4 = Needle-leaved (Gray and Deneke
1978)
K5 = Forms a mass with a density of 75-80% (DPU Bina Marga 1996)
There are four types of good category vegetation with a score of 70% in Bekasi City Park,
including acacia (Acacia mangium), sengon (Albizia falcataria), beautiful violin (Ficus lyrata), and
angsana (Pterocarpus indicus). The total types of vegetation with good categories as noise absorbers
in Bekasi City Park are 10 types. Most of the vegetation in Bekasi City Park falls into the medium
category and some vegetation falls into the poor category. Irregular planting and the lack of a
combination of planting between shrubs and trees cause the function of vegetation in reducing noise in
this park to be less than optimal, so that noise from outside can still enter the park to inside park. So
efforts that can can be done to optimize the noise dampening function in this park is t o plant
vegetation that forms a high-density mass. To reduce noise, efforts to improve the vegetation planting
pattern will be more effective in reducing noise if planted close to the source noise.
Noise measurements at Bekasi City Park were conducted in the morning, afternoon, and
evening. Based on the measurement results (Table 12), the average noise intensity in Bekasi City Park
in the morning to afternoon is more than 53 dBA. This shows that Bekasi City Park does not meet the
noise standard for Green Open Space. The inside of the park or at measurement point number three
has a low average noise and is close to the noise standard for Green Open Space, so visitors can utilize
the inside of the park for activities.
TThe observation results show that the vegetation found in the Bekasi City Forest is mostly in the
medium category with a total of 10 species or 733 individuals. The highest value obtained was 75%
for rubber banyan (Ficus elastica) vegetation (Table 15). There are still some vegetation with poor
category in reducing noise in Bekasi City Forest. These include teak (Tectona grandis), petai (Parkia
speciosa), and bintaro (Cerbera manghas).
Rubber banyan gets the best score because it has a tight crown and thick leaves, as well as a high
planting density. The rubber banyan is located in the center of the park, so its function as a noise
reducer has not been maximized. A combination of plantings with different height strata, such as
shrubs and trees, planted at the edge of the park can improve the existing conditions and increase the
noise dampening function in Bekasi Urban Forest.
Most of the vegetation in the Bekasi Urban Forest has a function as a noise reducer. The amount
of vegetation in the Urban Forest is sufficient to reduce noise, but the planting pattern is not yet
suitable t o fulfill its function as a noise reducer. The vegetation that is categorized as good is located
inside the park, so there is no vegetation on the edge of the park that is able to reduce noise coming
from outside the park. The strategic location of Bekasi City Forest with high vehicle mobility causes a
lot of noise pollution that pollutes the Bekasi City Forest environment. So this condition can be
optimized by adjusting the vegetation planting pattern.
The noise standard for Green Open Space is 50 dBA with a tolerance of 3 dBA. Bekasi City
Forest does not meet the noise standard because based on the measurement results, the noise intensity
in Bekasi City Forest is greater than 53 dBA (Table 16). The measurement conducted at point three
obtained the lowest average value among the other two measurement points, but it is still not in
accordance with the noise standard for Green Open Space because the noise figure is more than 53
dBA.
Based on the results of vegetation assessment and noise intensity measurement, the Urban Forest
has good vegetation in reducing noise. However, there are several things that cause the noise intensity
in the Urban Forest to not match the noise standard for Green Open Space. The things that affect the
intensity level in the Bekasi Urban Forest include the geographical condition of the Bekasi Urban
Forest which is flanked by two primary arterial roads, the high noise level in the Bekasi Urban Forest,
and the high noise level in the Bekasi Urban Forest mobility of motorized vehicles, and vegetation
planting that has not considered the ecological function in reducing noise. The lack of vegetation
planting on the sides of the park causes noise coming from the highway to not be reduced properly.
Vegetation assessment data is processed to determine the percentage of plants that are influential
in reducing noise. Based on the percentage of plant assessment, Bekasi City Park obtained a score of
224.07 in reducing noise with a percentage dominance of total individuals in the moderate category of
68.54%. Bekasi City Government Park scored 212.38 with the dominance of the percentage of
individuals in the medium category of 85.16%. Bekasi City Forest obtained a park value of 209.92
with the dominance of the percentage of total individuals in the moderate category of 65.56% (Table
17).
Based on the measurement results, the difference in noise level between the point outside the
park and the point inside the park in the government park is very large, reaching 16.03 dBA. Then
followed by the urban forest which has a difference of 11.23 dBA. The city park has the smallest noise
level difference among the three parks, which is 4.29 dBA (Table 18). This small difference is due to
the fact that the intensity of vehicles traveling on the road around the city park is less compared to
vehicles traveling on the main road around the government park and urban forest. In addition, the final
park score of the city park is smaller than the other two parks. This causes the noise difference
between outside and inside the city park to be smaller.
Based on the graph of respondents' perception of noise (Figure 11), the graph shows the results
for each park. More than 50% of respondents felt that the noise in the three parks fell into the
moderate category, a few percent felt that the noise in the parks was very quiet, and 4-6% of
respondents felt that it was very noisy. The noise intensity in some parks is not yet in accordance with
the predetermined standards, but the majority of respondents consider that the noise level is in the
moderate category which can still be tolerated by the sense of hearing and does not interfere with the
respondents' activities when in the park.
4.3.2 Temperature Modification Function
Trees can modify temperature by blocking the sun's heat. The dense leaves on trees can block
sunlight from reaching the ground and release heat through evapotranspiration by the plants.
Evapotranspiration is one of the hydrological cycles in which water contained in plants is lost to the
atmosphere through evaporation. As the temperature increases, more water evaporates. But when the
humidity in the air increases, evaporation decreases. This water vapor absorbs heat from the air, which
can help cool the surrounding area, causing the temperature under the tree to be lower than outside the
tree (Pratama 2013).
The amount of cooling that vegetation can provide depends on a number of factors, including
vegetation type, vegetation density, and climate. The following are criteria for vegetation with a
temperature modification function:
K1 = Branching height > 2 m above the ground (Ernawati 2003) K2 = Spreading crown shape
K3 = Canopy width > 2 m
K4 = Dense leaf mass (80% dense) K5 = Planted in rows < 3 m
Vegetation with a temperature modification function in Bekasi City Park is dominated by good
category vegetation with a total of 20 types of vegetation and a total of 290 individuals. Bekasi City
Park is classified as a park that is quite old so that the vegetation in the park is in good condition.
Existing vegetation has grown optimally and meets the criteria for temperature modification (shading).
There are 6 types of vegetation that have very good criteria in modifying temperature. Vegetation with
excellent categories in temperature modification (shading) in this park include acacia (Acacia
mangium), sengon (Albizia falcataria), angsana (Pterocarpus indicus), and mahogany (Swietenia
macrophylla) with 95% each, guava bol (Syzygium malaccense) with 90%, and breadfruit (Artocarpus
altilis) with 85% (Table 19).
The results of the ideal temperature analysis show that Bekasi City Park is included in the hot
enough category with an index value of 28.92°C (Table 20). Neutral temperatures or temperatures that
are considered comfortable for people living in tropical environments range from 25.8°C - 27.1°C
(Kotta 2008). In the current condition of the city park, the ideal temperature in the city park is close to
comfortable conditions for the community. To achieve comfortable climate conditions, it is necessary
to plant vegetation with excellent categories, such as acacia, sengon, and angsana. Planting appropriate
vegetation can reduce the temperature in the park more optimally.
The results of temperature measurements at three points show that the temperature measured at
the tree point without pavement has the lowest value compared to the other two points (Table 20). At
this point, measurements were taken in the morning, afternoon, and evening. The figures were 34.9°C,
34.4°C, and 33.6°C, respectively. This condition shows that the presence of trees in the park is needed
to reduce temperature and create comfort for people who move in it. Measurements taken at points
with pavement tend to have high temperatures. This happens because the pavement in the park can
reflect heat and cause an increase in surface temperature.
Based on the results of the vegetation assessment, this park provides sufficient temperature
comfort for visitors. However, there are several things that can be improved to achieve ideal
temperature standards, including adding plants that have a very good category and changing the
pavement to permeable pavement. Permeable pavement is recommended to reduce Urban Heat Island
(UHI) by cooling the environment. In wet conditions, the pavement can reduce the temperature
through evaporative cooling. In dry conditions, voids in the pavement will increase its surface area.
Under these conditions permeable pavement will limit heat transfer to the underlying pavement
structure and soil, so that heat remains on the pavement surface but reduces the storage of large
amounts of heat (Lin 2013).
Most of the vegetation in the assessment of the temperature modification function aspect in
Bekasi City Government Park is in the medium category, with a total of 11 species or 486 individuals.
The highest value obtained is 95% with an excellent category owned by angsana (Pterocarpus indicus)
and 85% with an excellent category owned by randu trees (Ceiba pentandra). There is still one type of
vegetation that is categorized as poor, namely Balinese pandanus (Cordyline australis) with a value of
40% (Table 21). Overall, the condition of shade vegetation in this park is not evenly distributed. So
there are locations that are very shady, such as in the cape forest, and there are locations that are very
hot, such as in the plaza.
The ideal temperature calculation results show that the climate in this park is quite hot with a
temperature index of 29.05°C (Table 22). Temperature measurements at three points did not show
significant differences. However, measurements taken at the tree point without pavement obtained the
smallest number among the other two measurement points. Meanwhile, measurements taken in the
afternoon obtained an average temperature of 33.93°C. Temperature conditions in the City
Government Park in the afternoon are the smallest when compared to measurements taken in the
afternoon and evening.
The results of the vegetation assessment with a good category of 11 species have a total number
of individuals of 272, a moderate category with a total of 6 species have a total number of individuals
of 158, and a very good category with a total of 5 species have a total number of individuals of 688
(Table 23). Vegetation with a very good category in modifying the temperature in this park include
sengon (Albizia falcataria), breadfruit (Artocarpus communis), mahogany (Swietenia macrophylla),
water guava (Syzygium aqueum), and salam (Syzygium polyanthum) with a range of values between
85-95%. It can be seen that vegetation in the very good category has the highest number of
individuals.
Most of the temperature-modifying vegetation in the urban forest is located in areas that are not
accessible to visitors. Meanwhile, people who visit the urban forest usually do their activities in
locations that have little shade, such as plazas and rollerblading areas. This has an impact on the
experience of urban forest users.
Based on the results of the ideal temperature calculation (Table 24), this park has an ideal
temperature of 28.71°C which is included in the moderately hot category. The results of the ideal
temperature calculation in this urban forest are almost close to the comfortable temperature based on
the perception of people living in areas with tropical climates. The temperature measurements at the
three points have significant differences, especially at the measurement point of the unshaded
pavement. Measurements taken at this point showed the highest results in the morning and evening,
when compared to the measurement results at the other two points. Based on the results of
measurements taken at the unshaded pavement point, the temperature reached 35.3°C.
The air temperature at the three points in the morning is still low because the influence of solar
radiation is still small and the duration of radiation is short. Likewise, in measurements taken in the
afternoon and evening, there is a difference in temperature difference between points with shade and
without shade. This is because open spaces without shade will receive direct solar radiation. The solar
radiation will then warm the pavement surface, which in turn warms the air temperature above it.
The existing vegetation in this urban forest is considered quite good at modifying temperature,
it's just that some locations that are the center of visitor activity in the park are not well shaded. In
addition, the amount of vegetation categorized as good and very good is less than the vegetation
categorized as moderate. Planting vegetation with very good categories by paying attention to the
pattern of the vegetation planting can reduce the temperature in the urban forest by blocking solar
radiation from reaching the surface.
The three parks have a value of 305.63 for Bekasi City Park, 226.29 for Bekasi City
Government Park, and 347.40 for Patriot Bina Bangsa Urban Forest Bekasi City. The percentage of
total individuals in city parks is dominated by vegetation in the good category with a total of 56.31%.
In government parks, the percentage of total individuals is dominated by moderate category vegetation
at 74.31%. The urban forest has a total percentage of individuals dominated by vegetation in the
excellent category of 61.53% (Table 25).
The difference between the average temperature outside the park and the average temperature
inside the park is not too large. The lowest temperature difference is found in Bekasi City Park with an
average temperature outside the park of 35.4 ° C and an average temperature inside the park of 34.42 °
C, resulting in a difference between the two of 1.07 ° C. Government parks with an average
temperature outside the park of 36.9 ° C and an average temperature inside the park of 34.74 ° C
obtained a temperature difference of 2.16 ° C. The average temperature outside the Patriot Bina
Bangsa Urban Forest is 37.1 ° C and the average temperature inside is 34.8 ° C. The average
temperature difference in the urban forest is 3.01 ° C (Table 26). Of the three parks, Patriot Bina
Bangsa Urban Forest Bekasi City is the best park in modifying temperature because it is able to reduce
the temperature by 3.01°C. In addition, the existing vegetation conditions in this urban forest are quite
good at modifying the ambient temperature with a final park score of 347.40 and the ideal temperature
in the urban forest is almost close to the comfortable category.
Respondents in all three parks rated the temperature in the park as cool with the percentage of
respondents who chose cool being 32% in city parks, 68% in government parks, and 60% in urban
forests. A total of 22% of respondents in Bekasi City Park considered that the temperature in the park
was very cool. This also happened to respondents in the urban forest, 15% of respondents in the urban
forest said that the urban forest was very cool.
4.3.3 Air Humidity Control Function
Humidity is the amount of water vapor in the air. The higher the humidity, the more water vapor
there is in the air. There are two types of humidity, including absolute humidity and relative humidity.
Absolute humidity is the total amount of water vapor in a given volume of air. Absolute humidity is
measured in grams of water vapor per cubic meter of air. In contrast to absolute humidity, relative
humidity is the amount of water vapor in the air compared to the maximum amount of water vapor that
the air can hold at a given temperature. Relative humidity is measured as a percentage (Green and
Dyer 2009). The amount of water vapor that air can hold depends on its temperature. Warmer air can
hold more water vapor than colder air. This is why the air feels more humid on hot days. High
humidity can make visitors uncomfortable, and low humidity can make visitors feel uncomfortable. In
terms of garden conditions, high humidity can encourage the growth of moss on garden pavement, but
low humidity can also cause pavement or soil to dry and crack.
Vegetation factors that can affect humidity in These include the criteria below:
K1 = Low leaf density (Bianpoen et al. 1989)
K2 = Needle-leaved or rough (Gray and Deneke 1978)
K3 = Rough stem texture (Gray and Deneke 1978) K4 = Many leaves (Carpenter et al. 1975)
Based on the assessment of the ability of vegetation to control humidity carried out in Bekasi
City Park, vegetation with a moderate category was found to be 18 species with a total of 142
individuals, vegetation with a good category was 15 species with 355 total individuals, and an
excellent category was 3 species with 18 total individuals. Vegetation that obtained an excellent
category included rambutan trees (Nephelium lappaceum), Japanese bamboo (Pseudosasa japonica),
and king palm (Roystonea regia) with a score of 81.25% each (Table 27).
The ideal relative humidity for green spaces is between 40% and 60%, according to the US
Environmental Protection Agency (EPA). This range of humidity is considered comfortable and can
prevent the growth of mold and mildew. This level of humidity can also vary, according to individual
preferences and climate. The results of relative humidity measurements in Bekasi City Park show that
the average humidity in the morning, afternoon, and evening ranges from 48-55% (Table 28).
Referring to the EPA statement above, this city park has an ideal humidity level.
The high ambient temperature measurement results affect the comfort value in this city park.
Even though this park has an ideal humidity level, it falls into the uncomfortable category because it
has a relatively high temperature. After evaluating the temperature comfort level using the
Temperature Humidity Index (THI) in Bekasi City Park, the results show that the comfort level of the
park is included in the uncomfortable category. This is because the THI value is above 27 in the
morning, afternoon, and evening.
In addition to affecting the level of temperature comfort in the park, changes in ambient
temperature can have an impact on the body temperature conditions of visitors who are on the move.
Thirst will arise in response to the loss of fluid in the body caused by increased body temperature.
When the level of heat generated is equivalent to the heat lost, the body temperature will stabilize
(Tortora and Derickson in McCallum 2012). When human body temperature adapts to high ambient
temperatures, the skin responds by producing surface sweat, increasing the size of skin pores, and
causing thirst. This condition can cause a decrease in the performance of the human body and affect
the activities it performs. If this condition lasts long enough, heat stroke, heat exhaustion, heat
asthenia, and even heart attack will occur. Shashua and Hoffman (2000) state that, about 80% of the
temperature increase in hot and humid climates is due to tree shading. Shading is also considered a
major factor in the magnitude of temperature reduction and relative humidity increase. Adding trees
with a shading function can help lower the ambient temperature in the garden. Optimal temperature
will create ideal humidity. The balance between ambient temperature conditions and relative humidity
in the park will create comfort for visitors.
Based on the assessment of vegetation's ability to control humidity carried out in Bekasi City
Government Park, vegetation with excellent categories were obtained as many as 2 species with a total
of 12 individuals, vegetation with good categories were 11 species with 135 individuals, and
vegetation with moderate categories were 10 species with 507 individuals. Vegetation that obtained an
excellent category included king palm trees (Roystonea regia) and norfolk cypress (Araucaria
heterophylla) with a score of 81.25% and 87.5% respectively (Table 29).
Norfolk spruce is considered to be able to control humidity because it has a low leaf density,
needle-shaped leaves, rough stems, and a large number of leaves. These vegetation criteria allow
norfolk cypress to control humidity by allowing evaporation to occur without being blocked by a
dense tree canopy.
In the condition of trees that have dense crowns, it can cause retention of evaporation by tree
canopies. This condition can result in high humidity in government parks. A humid park will have an
impact on the comfort level of visitors. When planting plants to control humidity, it is necessary to
consider the conditions of the planting location. If planting vegetation with dense crowns is done in a
location that has soil with low permeability, it can increase the humidity in the area and have an
impact on the growth of moss and mold. The condition of trees with sparse leaves is also incompatible
with the function of moisture control. Trees with sparse leaves are not able to withstand evaporation,
so the site conditions will be dry and can affect the comfort of park visitors.
Relative humidity measurement results at Bekasi City Government Park
showed that the average humidity in the morning, afternoon, and evening was between 47 to 55%
(Table 30). Referring to the EPA statement, this city park has ideal humidity levels. Ideal humidity
conditions in government parks cannot ensure temperature comfort in good conditions. This is because
the high air temperature in this park affects the comfort score in the park.
Temperature comfort based on THI calculated using temperature and humidity data in
government parks shows an average THI of more than 30, the THI number is included in the
uncomfortable category. THI in government parks is usually higher during the day when the sun is
shining brightly. This is because when there is heating of the ground surface, the humidity can
decrease rapidly. In addition, seasonal conditions can also affect the high THI values. THI values are
higher in summer compared to the rainy season. Vegetation that can block and reflect sunlight can
help keep the air temperature cool and lower THI values. Vegetation can also release water vapor
through the transpiration process and help moisturize the air and make the air temperature feel cooler.
Efforts that can be made to achieve a comfortable temperature level A good way to reduce ambient
temperature in government parks is to lower the ambient temperature. Lowering the ambient
temperature can be done by planting vegetation that is good at modifying temperature. Planting
vegetation must pay attention to planting locations, prioritizing the planting of shade vegetation in
places that have low humidity levels. In addition, it is recommended to avoid planting s h a d e
vegetation in locations that have high humidity conditions. Paying attention to the planting location
can help maintain ideal garden humidity conditions and can optimize temperature comfort in the
garden.
Based on the assessment of the ability of vegetation to control humidity carried out in the Patriot
Bina Bangsa City Forest in Bekasi City, vegetation with a good category was found to be 3 types with
a total of 629 individuals, vegetation with a medium category was 16 types with 337 individuals, and a
poor category was 3 types with 89 individuals. Vegetation that obtained a good category included
white teak (Gmelina arborea) with a score of 65%, mahogany (Swietenia macrophylla) with a score of
60%, and teak (Tectona grandis) with a score of 60% (Table 31).
Vegetation in the good category has twice as many individuals as vegetation in the moderate
category, even though it only consists of three types of vegetation. There are still some vegetation in
the poor category. Vegetation i n the poor category included breadfruit (Artocarpus communis),
bintaro (Cerbera manghas), and glodokan tiang (Polyalthia longifolia).
The results of relative humidity measurements in Bekasi City Park show that the average
humidity in the morning, afternoon, and evening ranges from 54-59% (Table 32). Referring to the
EPA statement, this city park has an ideal humidity level. The variation in taking the measurement
points does not have a significant impact, as there is no large difference in humidity between the three
points. The significant difference in humidity is seen in the time difference of humidity measurement.
The humidity level in the morning is greater than the humidity level in the afternoon and evening. This
is because conditions in the morning have a lower ambient temperature than during the day.
The high temperature measurement results affect the comfort value in this city park, so that even
though this park has an ideal humidity level, it is still included in the uncomfortable category with an
average THI value of more than 30. Similar to Bekasi City Government Park and Bekasi City Park,
the urban forest also has ideal humidity with a relatively high ambient temperature which causes the
temperature comfort level in this urban forest to fall into the uncomfortable category. Of the three
parks, Patriot City Forest has the highest average humidity level. The high level of humidity in the
urban forest is due to the vegetation in the urban forest is dominated by a large number of trees. The
trees in the urban forest can block solar radiation from reaching the ground surface. High humidity
levels that exceed optimal humidity can have a negative impact on visitors. High humidity can
increase the growth of moss so that it covers the surface of the park pavement. Moss-covered
pavement surfaces can harm visitors, giving an unsafe impression to visitors who are in that location.
Planting trees in urban areas can improve microclimate
by providing shade and releasing water vapor into the air. The use of plants to reduce urban heating is
now considered one of the most popular ways (Sailor 1998). In addition to having a positive impact on
the local climate, vegetation can also add moisture to the air, thereby increasing the cooling efficiency
of the environment. Urban areas without sufficient vegetation cannot cool their environment
effectively through heat evaporation. Urban areas often reflect less solar radiation than rural areas. The
difference in characteristics between urban and rural areas is due to the large amount of waste heat
generated from electricity consumption in urban industrial, commercial, and residential environments
(Karl et al. 1988).
4.3.4 Particle Absorber Function
Vegetation can help improve air quality by reducing the amount of particles in the air. This can
provide a number of benefits to human health and the environment. Vegetation can absorb airborne
particles through a process called filtration. Plant leaves and stems act as filters, trapping particles as
air passes through them. The size of particles that can be trapped depends on the size of the leaves and
stems. Larger particles, such as dust and pollen, are more easily trapped than smaller particles, such as
smoke and soot. The amount of particles that can be absorbed by vegetation depends on a number of
factors, including vegetation type and vegetation density. Vegetation can also absorb particles through
a process called deposition. In the deposition process, particles stick to the surface of leaves and stems.
This is more likely to occur when the leaves and stems are wet.
The amount of particles that can be absorbed by vegetation depends on a number of factors,
including vegetation type, vegetation density, and particle size. In general, taller and denser vegetation
is more effective at absorbing particles. Appropriate vegetation can help improve air quality and
reduce the risk of health problems by trapping airborne particles (Gromke et al. 2008). Hosker (1973)
conducted a study by applying a pollen dispersion model over homogeneous grasslands and forests.
The results concluded that the amount of particles deposited on the leaves was much higher in the
forest compared to the grassland. Trees can act as efficient air filters due to their large size, wide leaf
surface area, abundant leaf stems and branches, and often hairy or rough leaf, branch, or bark surfaces.
Wedding et al. (1975) mentioned that particle deposition on rough sunflower leaves is 10 times greater
than that of smooth, waxy tulip leaves.
Research by Yli-Pelkonen et al. (2017) shows that the level of coarse particulate matter in tree
planted areas was 23% lower compared to non-tree planted areas near highways, which means that
tree planting in urban areas can reduce particulate pollution levels to a certain extent. In a study
conducted by Dochinger (1972) in Ohio, rainfall, dust and suspended particles were examined in three
areas (treeless, deciduous canopy and needle-leaved canopy) and it was concluded that trees have the
ability to reduce particulate pollutants in the atmosphere. The following are the criteria for vegetation
that is capable of absorbing particles in the atmosphere:
K1 = Rough leaf surface structure, trichomes (Dahlan 1989) K2 = Needle-leaved or broad-leaved
(Taihuttu 2001)
K3 = Tight crown and leaf mass (Fakuara 1986)
K4 = Rough texture of stems and twigs or thorny twigs (Dahlan 1989) K5 = Dense twigs (Dahlan
1989)
Based on the assessment of the ability of vegetation to absorb particles carried out in Bekasi
City Park, vegetation with an excellent category was found to be 2 types with a total of 26 individuals,
vegetation with a good category was 13 types with a total of 242 individuals, and a medium category
was found 21 species with a total of 247 individuals. Vegetation that received an excellent category
included jabon trees (Anthocephalus cadamba) and ketapang (Terminalia catappa) with a score of
85% each (Table 35).
Some particles may be absorbed into the tree, although most of the absorbed particles will be
trapped on the surface of the plant. Trapped particles will often be released back into the atmosphere,
washed away by rain, or fall to the ground with fallen leaves and twigs. As a result, vegetation is only
a temporary repository for many atmospheric particles (Smith 1990).
Based on the assessment of the ability of vegetation to absorb particles carried out in the Bekasi
City forest, vegetation with an excellent category was found to be 1 type with a total of 121
individuals, vegetation with a good category was 7 types with 260 individuals, a medium category was
13 types with 723 individuals, and a poor category was 1 type with 14 individuals. Vegetation that
obtained an excellent category was the ketapang tree (Terminalia catappa) with a score of 85%. While
the vegetation that obtained a poor category in absorbing pollutants in the urban forest was squirrel tail
palm (Wodyetia bifurcata) with a score of 30% (Table 37).
Similar to the Bekasi City Government Park, Patriot Bina Bangsa Urban Forest Bekasi City also
only has one type of plant with a very good category, namely ketapang trees. Unlike the government
park, the planting pattern of ketapang trees in this urban forest is appropriate because they are planted
at the edge of the park. Trees with good categories in this urban forest also dominate when compared
to plants with other categories. So based on the vegetation assessment conducted, the existing
vegetation in the Patriot Bina Bangsa Urban Forest is quite optimal in absorbing particles.
4.3.5 Pollutant Absorbing Function
Air pollution is the introduction of harmful substances into the atmosphere. These substances
can come from a variety of sources, including cars, trucks, power plants and industrial facilities. In
addition to causing health problems, it can also damage ecosystems, pollute water sources, and
contribute to climate change (Abidin and Hasibuan 2019). Suparwoko and Firdaus (2007) in their
research conveyed that one of the ways that can be done to overcome pollution problems in big cities
is by creating more road greenways, especially planting tree species that have the ability to absorb
pollution.
Tree crowns can function as good pollutant absorbers, especially trees that have many and dense
leaves. This is because the most influential part of vegetation in absorbing pollutants is in the leaves.
Pollutant absorption also affects photosynthesis carried out by leaves because it involves the formation
of oxygen from carbon dioxide.
Vegetation can help reduce air pollution by acting as a natural solution. Vegetation can remove
various harmful pollutants through the absorption process. Through its leaves, vegetation is able to
absorb and store pollutants and absorb lead particles or other pollutants produced by motor vehicles
(Hendrasarie 2007). According to Koeppe and Miller (1970), the ability to absorb pollutants is
strongly influenced by the condition of the plant leaf surface. Plants with hairy (trichome) or rough
(wrinkled) surfaces have a greater ability to absorb pollutants compared to plants with smooth and flat
surfaces.
Vegetation can remove harmful substances in the air by absorbing them through tiny pores
(stomata) in its leaves. The substances then move into the spaces between the cells and mix with water
to create acidic solutions or react with the inner leaf surface. Vegetation absorbs some gases directly
through its surface (Smith 1990). The ability of vegetation to absorb pollutants is influenced by several
factors, including environmental factors, plant arrangement patterns, physiological and morphological
properties of plants. Here are some criteria for vegetation that can absorb pollutants, including:
K1 = Consists of a combination of shrubs, herbs, and trees (Carpenter et al.
1975)
K2 = Dense leaf mass (Carpenter et al. 1975)
K3 = Planted in rows with a density of 75-80% (Carpenter et al. 1975) K4 = Spreading crown shape
(Carpenter et al. 1975)
K5 = Rough leaf edges, serrated/hairy (Carpenter et al. 1975)
Based on the assessment of the ability of vegetation to absorb pollutants carried out in Bekasi
City Park, vegetation with a good category was obtained as many as 11 species w i t h 252 individuals,
a medium category of 20 species with 184 individuals, and a poor category of 5 species with 79
individuals. Vegetation that obtained the good category with the highest score was sengon (Albizia
falcataria) and angsana (Pterocarpus indicus) with a score of 75% each. The vegetation that received
a poor category in absorbing pollutants included coconut ( Cocos nucifera), rubber (Hevea) and rubber
(P te r o c a r p u s ind ic us ). ( brasiliensis), avocado (Persea americana), frangipani (Plumeria sp.),
and king palm (Roystonea regia) (Table 39).
Sengon (Albizia falcataria) and angsana (Pterocarpus indicus) received the highest score
because they meet the criteria for pollutant absorbing functions, because they have a dense leaf mass,
are planted with a high density, and have a spreading crown. These things make sengon and angsana
get high scores in their function of absorbing pollutants in this park. To optimize particle absorption in
the urban forest, these plants can be planted in a stratum with other lower plants.
4.4 Visitor Perceptions and Preferences
Visitors to the park are dominated by Bekasi residents who regularly go to the park with the
intensity of visits in a week can vary, ranging from every day, every week, every month, and
erratically. The length of the respondent's visit in the park is between 30-60 minutes or 1-2 hours
depending on the activities carried out. Some of the activities carried out in the park are dominated by
sitting and looking at the scenery. M o s t respondents go to the park using private vehicles, with an
average distance from their residence of more than 3 km.
Based on the survey results, more than 50% of respondents stated that the presence of parks in
Bekasi City is able to provide coolness in the midst of the heat of Bekasi City. Most respondents also
understand that trees are very important in maintaining a comfortable temperature environment.
Respondents observed the difference in temperature when outside the park and inside the park, thus
respondents realized the importance of trees in efforts to cool the environment.
Public awareness has increased regarding the importance of preserving the environment. More
than 50% of respondents strongly believe that protecting the environment is very important for the
sustainability of Bekasi City. The majority of people who are aware have taken steps to protect the
environment. Environmental maintenance that has been carried out includes throwing garbage in its
place, planting trees, caring for plants, community service, and keeping the surrounding environment
clean. In addition to protecting the environment, each individual supports the sustainability of Bekasi
City by paying taxes and cleaning fees in their neighborhood.
More than 50% of the people surveyed agreed that the community should play a role in making
Bekasi City more sustainable. This is done by encouraging people around them to work together in
preserving the environment. Apart from the community, respondents stated that the government needs
to play a role in maintaining the sustainability of Bekasi City. Some of the efforts that can be made
include making a one house one tree policy, curbing parking in parks, not committing acts of
corruption, repairing damaged facilities, taking action against those who break the rules, making clear
and understandable regulations, supporting the community in carrying out their activities, presenting
more city parks, building green city infrastructure, and other contributions. Comparison of Ecological
Function Analysis
This comparison of ecological function analysis shows overall results based on ecological
functions measured through vegetation assessment with KPIs and visitor perceptions. The comparative
results of the assessment will show the superiority of the park based on its ecological function.
Comparison of ecological function analysis can be seen in tables 43 and 44, based on visitor
perception and vegetation assessment.
Based on the table above, Bekasi City Park has the highest vegetation assessment results in
controlling noise reduction, air humidity, absorb particles, and absorb pollutants. The final park value
obtained based on the vegetation assessment carried out, obtained a value of 244.07 for the function of
noise reduction, 275.92 for the function of air humidity control, 257.08 for the function of absorbing
particles, and 233.59 for the function of absorbing pollutants. Based on visitors' perceptions, the park
excels in temperature modification and humidity control. As many as 68% of visitors assess that
Bekasi City Park has a cool air temperature, besides that 66% of visitors assess the humidity level in
the City Park to be at a moderate level, which means not too dry and not too humid.
Bekasi City Government Park does not excel in vegetation assessment when compared to other
parks. However, based on the five ecological functions analyzed, this park has the highest value in the
particle absorbing function with a park score of 227.82. Based on visitor perceptions compared to the
other three parks, Bekasi City Government Park is good at reducing noise. As many as 27.5% of
visitors rated this park as quiet. Visitors also considered that this park was dust-free, with a percentage
of visitors who considered this park dust-free as much as 45%. In addition, 75% of visitors rated this
park as having good air quality.
Patriot Urban Forest has a superior assessment of the temperature modification function based
on the assessment conducted on the vegetation in the location. This park obtained a score of 347.40 for
temperature modification, which is the highest score compared to the other three parks in the same
function. Based on visitor perceptions, the Urban Forest excels in controlling humidity, just like the
city park, with a percentage of visitors who consider humidity in this park to be in moderate conditions
as much as 66%.
4.5 Recommendation
Recommendations for appropriate vegetation planting patterns for each ecological function must
be supported by the selection of plants that are suitable for the biological conditions of the park.
Vegetation planting can be maximized to reduce noise by arranging vegetation planting at the edge of
the park so that it can reduce noise from the road, as well as increasing the number of trees that are
good at reducing noise and combining them with shrubs so that the noise reduction function is
optimal. Especially in Bekasi City Government Park, which has a small amount of vegetation
categorized as good in reducing noise. Planting vegetation in areas around offices can also help block
noise. Some vegetation that is good in reducing noise include acacia, sengon, beautiful violin,
ketapang, rubber banyan, norfolk cypress, and fan cypress.
Planting trees in the right location is essential for regulating temperature and prevent excessively
humid or dry conditions. The type of vegetation selected should have high quality criteria to ensure
optimal conditions. Humidity in the parks can be controlled by selecting the right type of vegetation
and planting the vegetation in the right location. Humidity conditions in the three parks are already in
the optimal category. However, all three parks have high THI values and do not fit into the
comfortable category. The high temperature in the three parks causes the high THI value. Efforts to
reduce ambient temperature can be an alternative to optimize THI values. Some efforts to reduce
ambient temperature include adding vegetation categorized as good at providing shade, paying
attention to the materials used for park pavement, and considering using ground cover plants or grass
as a substitute for pavement. Especially in government parks and urban forests, efforts to plant
vegetation that is good as a shade need to be optimized, especially in locations that are places of
visitor activity. There are several plants that are good at reducing environmental temperatures,
including acacia, sengon, angsana, mahogany, breadfruit, randu, guava bol, salam, and water guava.
For the comfort and safety of visitors, proper planting patterns can prevent pollution and
particles from entering the park. In addition, the right selection of vegetation must be made to reduce
pollutants and particles. In addition to the criteria mentioned, other things that must be considered
when choosing vegetation include minimal maintenance, minimal plant replacement, and choosing
vegetation that is able to adapt to local environmental conditions. Some vegetation that is good at
absorbing pollutants and absorbing particles are jabon and ketapang. The following is an illustration of
vegetation planting patterns for each function.
5.1 Conclusion
In general, the presence of urban green spaces in the center of Bekasi City has an ecological
influence. The vegetation in the park can function ecologically and has a real influence in each park.
Based on the results of the analysis of vegetation in the three parks, Bekasi City Park and Patriot Bina
Bangsa Urban Forest Bekasi City are most suitable for the temperature modification function because
they have a final value of the park with a good category in modifying temperature. The three parks that
fall into the moderate category still need improvement in ecological functions. Based on respondents'
perceptions, visitors have not felt the ecological benefits provided by these parks, especially in the
function of noise cancellation and particle absorption. Based on the measurement results, these parks
can reduce noise up to 16.03 dBA, can reduce temperature up to 3.01°C, and can control humidity up
to 3.22%.
Based on the standards that have been set, the three parks have a level of
The high noise exceeds the noise standard for Green Open Space, which is 50 dBA. Therefore, the
three parks have not fulfilled their function as noise absorbers. The THI values that have been
calculated in the three parks also have values that are higher than the predetermined standards, so they
are considered uncomfortable for visitors. The high THI value is influenced by the temperature
conditions in the park.
Respondents already understand the sustainability of Bekasi City and their role in realizing the
sustainability of Bekasi City. Not only knowing, respondents are also aware of their actions in
protecting the environment and play an important role in the sustainability of Bekasi City. In addition
to contributions from the community, respondents argue that the government has a very important role
in realizing the sustainability of Bekasi City.
The application of green management related to the five ecological functions of plants in the
three parks needs to be considered to optimize their functions. Some of what can be done in the
application of green management, including regulating planting patterns, choosing the right
vegetation, paying attention to the selection of pavement, considering the selection of ground cover
plants and grass as a substitute for pavement.
