An Estimation of Oxygen Release from Green Surfaces in Durres City
OSMAN METALLA1, MARSIDA KLEMO2, AZEM HYSA2, ELVIS CELA3,
ABDULLA DIKU3, MIGENA NAKO3
1 Marine and Engineering Science Department, “Aleksander Moisiu” University,
Durres, ALBANIA
2 Applied and Natural Sciences Department, “Aleksander Moisiu” University,
Durres, ALBANIA
3 Environmental Center for Protection, Education and Rehabilitation,
Tirana, ALBANIA
Abstract: - Due to urbanization trend in Durres city, distance between city inhabitants and nature is increasing.
Urban greenery is one of the methods to bridge this gap between people and nature.
The study results were performed with the cooperation of EPER Center, professors and students of Durres
“Aleksander Moisiu” University. It was focused in the estimation of O2 release from green surfaces at different
areas of Durres city. The results achieved were carried out by field visits, the use of the GIS method and
calculations performed based on various standard manuals.
According to the results, it was concluded that the total amount of O2 release from green surfaces was 64420
kg/year or 64.4 t /year. It was also calculated that the available green surface for a resident in Durres city is
only 1.05 m2 out of required 9 m2 per capita.
Based on the needs of the population and the EU standards, this study suggests that the amount of O2 release
should be 1.49∙ 108 kg/year or 1.49. 5∙ 105 t/year. The needed costs to be invested to achieve this O2 amount, is
about 47 .65 billion ALL.
Finally, it can be concluded that the low number of trees in Durres city, requires urgent provisions to improve
air, and life quality of Durres citizens.
Key-Words: - Oxygen release, Public green surface, Lost green surface, Air quality
Received: May 12, 2021. Revised: November 15, 2021. Accepted: December 14, 2021. Published: January 11, 2022.
1 Introduction
The transformation of natural and agricultural lands
into urban areas is increasing every year. It is
estimated that 66% of the world’s population will
live in cities by 2050, compared to 30% in 1950 [1].
In those areas, humans, animals, and plants coexist
together. Dense buildings, heavy traffic,
construction works with deep excavation, and the
common use of concrete and glass materials leads to
the degradation of the environment in relation to
plant growth [2].
Urban vegetation, particularly trees, provides
numerous benefits that can improve environmental
quality and human health in and around urban areas.
These benefits include improvements in air and
water quality, building energy conservation, cooler
air temperatures, reductions in ultraviolet radiation,
and many other environmental and social benefits
[3, 4].
According to statistics, people spend 80%-90% of
their time indoors, so indoor air quality, whether at
home or in the office, has a significant impact on
people's quality of life, health status and work
efficiency. [5]
Vegetation absorbs CO2 through the processes of
photosynthesis, releases O2 into the air, and
consequently helps to mitigate urban air pollution
[6, 7].
Increasing energy consumption, soil sealing and the
high competition for surface between green and grey
infrastructure in densifying urban areas may lead
locally to a lack of urban greening [8] and the loss
of biodiversity. Climate change will potentially lead
to a decline of quality of life in cities [9].
Planting trees remains one of the cheapest, most
effective means of drawing excess CO2 from the
atmosphere [10].
A single mature tree can absorb carbon dioxide at a
rate of 48 lbs./year and release enough oxygen back
into the atmosphere to support 2 human beings [11].
Trees remove gaseous air pollution primarily by
uptake through the leaves, though some gases are
removed by the plant surface. Trees also remove
pollution by intercepting airborne particles. Many of
WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT
DOI: 10.37394/232015.2022.18.14
Osman Metalla, Marsida Klemo,
Azem Hysa, Elvis Cela,
Abdulla Diku, Migena Nako
E-ISSN: 2224-3496
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the particles that are intercepted are eventually
resuspended back to the atmosphere, washed off by
rain, or dropped to the ground with leaf and twig fall
[12].
Net oxygen production by trees is based on the
amount of oxygen produced during photosynthesis
minus the amount of oxygen consumed during plant
respiration [13, 14]:
Photosynthesis: n(CO2) + n(H2O) + light →
(CH2O)n + nO2
Respiration: (CH2O)n + nO2 → n(CO2) + n(H2O) +
energy
The purpose of this paper is to:
- evaluate the state of green surfaces and the
amount of O2 release in Durres City;
- recommend measures to be taken for
improving air quality
2 Materials and Methods
The object of the monitoring methodology used in
this paper is the accurate inventory of urban
greenery, the assessment of its condition and the
creation of a digital platform to assist the dynamic /
alternative environmental monitoring process.
Vegetation and urban ecosystem, through their
services, are indicators for air quality monitoring
according to European standards (EU directives
008/50 / EC and 2004/107 / EC).
The basic service that was evaluated through
measurements, digitalization and analysis was the
amount of O2 emitted from green surfaces.
The main component of the methodology was the
creation of the urban tree database in GIS (similar to
the i-Tree platform) realized through field visits and
consultations with specialists in the field. Elements
identified in the field included: type, diameter of
wood (via a strip meter), height of trees (by
comparing the floors of nearby buildings or urban
lighting poles), tree cavity - measured as the product
of their two dimensions.
There were 5 steps followed for this study:
a) Division of study areas with clear boundaries and
area between 7-20 ha per study region. The areas
were named according to main neighborhoods or
streets.
b) Detailed inventory and digitalization of the
vegetation area (identification of each tree, medium
and high shrubs, as well as green areas and gardens).
c) Specific measurements like trunk diameter, cavity
surface, type of vegetation, ordinal nomenclature,
estimated height, approximate age, condition of
vegetation, trunk cover, condition of cover, green
area.
Through these data, the use of "Tree age calculator"
and "Tree benefit calculator" were then identified
the age of the tree and was calculated the amount of
oxygen (kg/year) that it was released in
environment.
d)Identification of infrastructural and environmental
problems.
This methodology followed has a high degree of
accuracy compared to other alternative methods
such as orthophoto in geoportal [15].
3 Results and Discussion
Monitoring of urban green surfaces in Durres city
was carried out in three areas, zone A (commercial
zone), zone B (industrial zone), zone C (residential
zone) as shown in the following map (Map 1),
during the period January 2019 - February 2021.
Each of them was divided into subzones and in total
was composed of 44 subzones.
Fig. 1: Number of trees for each subzone
Area A includes the “Volga” area, the “trade road”,
the “Egnatia” road, the “Court” road, the “Museum
of the Martyrs”, and part of the amphitheater. There
were identified 2292 trees in this area.
Zone B includes “Adria” street from the train station
to Dajlani bridge, the road from the sports palace to
“Niko Dovana” stadium, “Glaukia” street to the big
industrial market, “Aleksander Goga” street to the
Durres police directorate. There were identified
2333 trees in this area.
Zone C includes the area of "Niko Dovana" stadium,
, Durres regional hospital, the area of the swamp, the
park near “Vaso Pasha” Street and surroundings.
There were identified 1775 trees in this area.
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From the monitoring and calculations of each urban
tree of Durres city, 64.4∙ 103 kg of oxygen were
released.
In the three monitored areas of Durres city were
identified 212.3∙103 m2 of existing green surfaces
and 66.1∙103 m2 lost as well as 6400 urban trees,
which were mainly of Tilia Cordata, chestnut, palm,
maple, poplar, oak, pine, plane, Ligustrum lucidum
etc. Each of them had a diameter (from 10 to 15 cm)
and a certain age (up to 100 years).
The table below shows a summary of urban
greenery monitoring (tab 1).
Table 1. Summary table of urban greenery
monitoring
Public
green
surface
(m2)
Total
number
of trees
Total O2
released
(kg/year)
212.3 ∙ 103
6400
64.42∙103
The maps of each area with green surfaces are
presented below (map 2, map 3, map 4).
Fig. 2: Green surfaces of A zone
Fig. 3: Green surfaces of B zone
Fig. 4: Green surfaces of C zone
As we see from Table 1, the total amount of O2
released per year from green surfaces is 64.42∙ 103
kg or 64.42 t.
Based on [16] a human breathes about 740 kg of
oxygen per year. If we rely on Durres city
population (202 000 inhabitants) [17] we can
calculate the amount of O2 needed for this
population which is about 1.49.5∙ 108 kg/year or
1.49∙ 105 t/year.
Comparing the amount of O2 released by actual
green surfaces and what is standard, it is far from
meeting these standards.
It is estimated that for the amount of O2 released
actually in Durres city the cost goes somewhere
around 20.5 million ALL.
To improve air quality in Durres city, local
authorities have to increase green surfaces. Based on
population size the cost to be invested is about 47
.65 billion ALL.
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Based at the results, the total public green surface in
Durres city is 212 300 m2 or 21.23 ha. The lost
green surface due to urbanization is 66 100 m2 or
6.61 ha.
According to the World Health Organization
(WHO), every city is recommended to provide a
minimum of 9 square meters of urban green surface
for each person [18, 19] provided that it should be
accessible [20], safe [21] and functional [22]. WHO
also suggest that an ideal amount of urban green
surface can be generously provided as much as 50
square meters per person [18].
If we refer to Durres city population (202 000
inhabitants) and actual green surface (212 300 m2)
we can calculate that to a resident in Durres city is
offered only 1.05 m2 of green surface out of 9 m2
that it should be according to WHO standards.
The comparative tables below shows cities in the
world and the amount of green surface per square
meter per capita. (Table 2, 3).
Table 2. Top 15 cities in the world and amount of
green surface per person [23]
Table 3. The adoption of urban green space
standards in several cities [24]
In comparison with the most cities and required
standards, it is obvious that the existing green
surfaces in Durres city are far from the standards.
3 Conclusions
Urban greenery contributes to the improvement of
air quality and the reduction of noise pollution by:
absorbing gaseous pollutants (NO2, SO2, O3)
through the leaf surfaces; capture PM10 particles
(dust, pollen, smoke); release oxygen through the
process of photosynthesis; enabling the creation of
shadows, which reduce air temperatures; standing as
anti-noise barriers to noise.
Based on the results achieved in this paper we can
conclude that:
- The amount of O2 released per year from green
surfaces in Durres city actually is calculated to be
64420 kg or 64.42 t;
- The amount of 02 released needed for this
population (by standards) is nearly 1.49∙ 108 kg or
1.49 ∙ 105 t (O2/year). The cost to be spent for this
investment goes somewhere to 47 .65 billion ALL;
- For a resident in Durres city is available only
1.05 m2 of green surface from 9 m2 that it should
be;
- The main factors that may have influenced the
loss of green areas are the occasional and
indiscriminate constructions in the city of Durres;
- Durres municipality is working to regenerate
existing green surfaces by replacing them with
young trees. These trees produce less oxygen than
older ones. As a result, we have less oxygen
released to meet vital needs
This study had some limitations. Due to the situation
created by the 2019 devastating earthquake,
followed by the Covid -19 pandemic, it was not
possible to proceed and survey wider areas. For this
reason, few aim that in the future we will monitor
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the entire green area of the city of Durres in order to
have a clearer picture of the entire area of Durres
region.
4 Recommendations
Based on the results of this study the authors
recommend as follows:
- Establishment of a green belt in the hills around
Durres city to prevent urban sprawl, to expand
current green surfaces and to connect the existing
ones.
- Rehabilitation of existing parks (park at the
amphitheater of Durres, villa of Zog, Currila) with
plants resistant to microclimatic conditions of
Durres city and with a significant impact on
improving ecosystem services, such as: maple,
oak, maple, plum, etc.
- Creation of green corridors within the city, based
on the existing path that connects the area of
Durres amphitheater with the port area.
- Creation of a new park in Kallm, 3 km north of
city center center, as part of the general local plan
for the increasement of green areas in Durres
Municipality.
- Establishment of a tree and flower nursery in the
Durres Municipality in long-term cooperation
with existing private nurseries, so that they adapt
to the climate of Durres to guarantee longevity
over the years.
- Rehabilitation and construction of green pockets
in public areas within the residential blocks in
district 15, and 18 of Durres city and later in the
entire Durres Municipality area.
- Expansion of green surfaces in existing areas as
well as in new neighborhoods that are being
consolidated.
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vol 210, ISSN 1743 -3541 (online) ,
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Contribution of Individual Authors to the
Creation of a Scientific Article (Ghostwriting
Policy)
Migena Nako, Elvis Cela, Abdulla Diku have
collected data in the field, their processing and
construction of data in the GIS platform
Osman Metalla, Marsida Klemo, Azem Hysa have
interpreted and evaluated the data
Creative Commons Attribution License 4.0
(Attribution 4.0 International, CC BY 4.0)
This article is published under the terms of the
Creative Commons Attribution License 4.0
https://creativecommons.org/licenses/by/4.0/deed.en
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DOI: 10.37394/232015.2022.18.14
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Azem Hysa, Elvis Cela,
Abdulla Diku, Migena Nako
E-ISSN: 2224-3496
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