3
other words, trees are major environment
capital assets in cities that require care and
maintenance. The majority of the cities in the
western world have patches of forest or blocks
of tree plantations in addition to adequate
number of trees along streets and in gardens. In
Gujarat, Gandhinagar and Bhavnagar have such
patches of forest which ameliorate the urban
environment and provide recreational value to
the people.
Carbon store and sequestration:
Urban areas in
the world account over three fourth of Carbon
emission and a significant source of pollution
1
.
Expanding developmental activities such as
industries, constructions, transports, vehicles
and power plants in cities are causing a serious
pollution
3
. As a result, the quality of air has
become matter of concern for human health.
Several newcities in thecountry likeGandhinagar
in Gujarat and Chandigadh have been developed
in a planned manner after developing tree
cover in the town planning areas. In a few other
cities, tree cover dominates over the concrete
jungle but situation is reverse in majority of the
cities. The concrete jungles with negligible tree
cover have a high level of pollution. People in
such cities have poor quality of life due to the
presence of harmful gases and dust particles,
and very high temperature during summers. To
reduce net emission of Carbon gases, forest or
tree covers in the urban area are considered a
main source of Carbon sequestration. There
are several cities in the world where tree cover
provides services to reduce Carbon gases by
sequestering it. For example, about 14.7 lakh
trees in Portlands city, Oregon, USA reduce 2.4
crore kg of Carbon annually
4
.
Similarly, over two
lakh tone Carbon is stored in 24 lakh trees in the
central part of Beijing, China where the average
size of trees is small. The Carbon store and
sequestration have increased during the recent
year due to increase in tree cover in Beijing
5
.
The carbon store in the tree cover in the Capital
city of Gujarat, Gandhinagar may be about 1.79
lakh tones. The Carbon sequestration rates are
high in large trees and it is up to 90 times greater
for healthy large trees than healthy small trees.
In Chicago’s urban forest, the average annual
carbon sequestration by individual trees ranged
from 1.0 kg/yr for a tree less than 8 cm in trunk
diameter to 93 kg/yr for a tree greater than 77
cm
6
.
The
Green India Mission (GIM), one of the
missions under India’s National Action Plan on
Climate Change (NAPCC), hopes to sequester
4.3 crore tones of greenhouse gases each year
by 2020 and absorb 6.35 percent of annual
emissions. This action plan mentions about
enhancing tree cover in over 2 lakh hectares
in urban and peri-urban areas. It has been
estimated that about 2.21 percent of the
carbon stocks are stored in through urban tree
cover, and the mission will promote greening
forest patches threatened by expanding urban
development, diffused planting and planting on
institutional lands. The carbon enhancement is
estimated about 2.2 lakh tones per year. This
programme includes urban areas in Gujarat
also. Thus, development of urban forestry may
result into one tenth of above enhancement in
Gujarat (MoEF, 2011)
7
.
Temperature moderation
: Concrete structures
absorb heat, increase temperature of the
structures and radiate heat, which increases air
temperature during the summer. The vegetation
absorbs heat and use light in photosynthesis,
reducing the availability of the sunlight that
amount heating atmosphere and the local areas.
In summer, temperatureof Gandhinagar remains
below the temperature normally recorded
in Ahmedabad at same time. Tree canopies
normally reduce air temperatures significantly
3
.
A study in the United States of America reports
