Chapter 5: Identifying Tree Species with Maximum Carbon...

Climate Change Impacts: Vegetation And Plant Responses In Gujarat

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Chapter 5: Identifying Tree Species with Maximum Carbon Sequestration Capabilities as Future Sinks of Carbon in the Scenario

of Changing Climate.

Azadirachta indica A Juss tree with a girth of 4.1 m

Bombax ceiba L with a girth of 3 m

Figure-32: Largest trees of Gujarat University Campus


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Introduction

CO2 emissions

Anthropogenic activities, especially fossil fuel burning and land use changes

(Pandey, 2002) are currently responsible for an annual emission of 9 Gt C (33 Gt

CO2). Terrestrial and oceanic systems manage to absorb 3 and 2 Gt of this

anthropogenic C release, respectively, but the rest, 4 Gt, remains in the atmosphere

(Kumar et al., 2009; Jansson et al., 2010) which have resulted in an increase in the

concentration of GHGs particularly CO2 (Jina et al, 2008). Since the beginning of the

industrial revolution, carbon dioxide concentration in the atmosphere has been rising

alarmingly. Prior to the industrial revolution carbon concentration was around

270ppm which increased to 372ppm in 2005 (Kumar et al., 2006; Ramachandran et

al., 2007). The rising level of atmospheric CO2 is believed to cause global warming

at an alarming rate of 0.2°C per decade with an estimated average rise in global

temperature of 3°C by 2100 (Hamburg et al., 1997; Phani Kumar et al., 2009; Jana et

al., 2009; Lavania and Lavania, 2009; Chavan, 2010). Impact of climate change on

the ecology, economy and society is increasing (Pandey, 2002).

CO2 mitigation options

Carbon dioxide is among the most important anthropogenic greenhouse gases

(Houghton et al., 1991). Potential actions to mitigate fossil fuel emissions include

increased energy conservation and efficiency, employment of renewable energy

systems and use of alternative fuels. Other greenhouse gas mitigation options include

sequestration of CO2 in biologic sinks such as plant biomass. For example, C can be

sequestered in trees and durable forest products, in agronomic crops, in halophytes

(salt-tolerant plants), as organic matter in soil, and in marine plants such as

microalgae for decades or centuries (Wisniewskil et al., 1993; Moura-Costa et al.,

1994).

The problem of anthropogenic carbon dioxide accumulation in the atmosphere can

be addressed either by reducing CO2 emission or by developing carbon sinks. The

Kyoto Protocol of the UN framework convention on climate change (UNFCCC) was


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the first step taken by the international community in this direction. For developing

carbon sinks, much of the emphasis was given at Kyoto pertained to afforestation

and reforestation programmes (Ravindranath et al., 1997; Jina et al., 2008). Large

scale reforestation can offset fossil fuel based CO2 emissions. It is suggested that the

global climate problem could be solved by planting a total of 500 million hectares of

plantations even without parallel efforts to minimize carbon emissions from fossil

fuel combustion. CO2 emissions from deforestation are about 2 billion tC/year over

three times the emission from motor cars (Baral and Guha, 2004).

Jansson et al., (2010) has included the statement of Freeman Dyson (2008) which

states that, “If we can control what the plants do with carbon, the fate of the carbon

in the atmosphere is in our hands.”

Forests as carbon sinks

Global carbon is held in a variety of different stocks. Natural stocks include oceans,

fossil fuel deposits, the terrestrial system and the atmosphere. In the terrestrial

system carbon is sequestered in rocks and sediments, in swamps, wetlands and

forests, and in the soils of forests, grasslands and agriculture. About two-thirds of the

globe’s terrestrial carbon, exclusive of that sequestered in rocks and sediments, is

sequestered in the standing forests, forest under-storey plants, leaf and forest debris,

and in forest soils (Warran & Patwardhan, 2001).

Global carbon (C) cycling depends largely on the photosynthetic uptake of

atmospheric carbon dioxide (CO2). The total C stock (i.e., organic and inorganic C)

in terrestrial systems is estimated to be around 3170 gigatons, 2500 Gt in the soil and

560 Gt and 110 Gt in plant and microbial biomass, respectively. Total C in the

oceans is 38,000 Gt (Tuskan and Walsh, 2001; Lal, 2004, 2008; Houghton, 2007).

The soil C pool, which is 3.3 times the size of the atmospheric C pool of 760 Gt,

includes about 1550 Gt of soil organic carbon (SOC) and 950 Gt of soil inorganic

carbon (SIC) (Lal 2004, 2008). Of the C present in the world’s biota, 99.9% is

contributed by vegetation and microbial biomass; animals constitute a negligible C

reservoir (Jana et al., 2009; Jansson et al, 2010).


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Forests play a significant role in climate change as it emits as well as sequesters CO2.

Trees absorb atmospheric CO2 for their growth and also increase the carbon content

in the soil as well. Revitalizing degraded forest lands and soils in the global

terrestrial ecosystem can sequester 50-70% of the historic losses. Forests play a

profound role in reducing ambient CO2 levels as they sequester 20-100 times more

carbon per unit area than croplands (Karky and Banskota, 2006).

A substantial amount of C can be sequestered in plant biomass. As about 90% of the

world’s terrestrial C is stored in forests, forest plantations and the preservation of old

forests are of chief importance in controlling the size of the overall terrestrial C sink

(Jansson et al., 2010). Carbon capture and sequestration through forests can play an

important role in reducing India’s GHG emissions. Managing forests to sequester

carbon has a combined advantage of producing woods and conserving biodiversity

while preventing soil erosion. Absorbing CO2 from air and transferring it into the

biomass could be a cost effective and practical way of removing large volumes of

GHGs from the atmosphere. It has been estimated that managing the world’s

vegetation could turn the terrestrial biosphere from a source of carbon (0.1-4.2 Pg

carbon per year) to a carbon sink (1.3-3 Pg carbon per year) (Mohapatra, 2008).

Forest ecosystem plays very important role in the global carbon cycle. It stores about

80% of all above-ground and 40% of all below-ground terrestrial organic carbon

(Houghton et al., 2001, Sulistyawati et al., 2007). During productive season, CO2

from the atmosphere is taken up by vegetation (Losi et al., 2003) and stored as plant

biomass (Samalca et al., 2007). However the global forest cover is declining at an

alarming rate as about 13 million hectares of global forests are lost annually (Singh

and Lodhiyal, 2009)

Current estimate of annual terrestrial plant uptake of C due to CO2 fertilization are

within the range 0.5-2.0×1015g, which is about 8-33% of annual fossil fuel

emissions. Currently, total aboveground biomass in the world’s forest is 421×109

tonnes distributed over 3869 Mha. Of this, 3682×106 ha or 95% is natural forest and

187×106 ha or 5% is plantation area. Forests store 1200 GtC in vegetation and soil

globally. C in forest constitutes 54% of the 2200 Gt of the total C pool in terrestrial

ecosystem. Forests sequester 1-3 GtC annually through the combined effect of


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reforestation, regeneration and enhanced growth of existing forest, offsetting the

global CO2 emissions from deforestation. Terrestrial and marine environment are

currently absorbing about half of the CO2 that is emitted by fossil fuel combustion

(Pandey, 2002). The total aboveground and below ground biomass in the Indian

forest has been estimated as 6865.1 and 1818.7 Mt contributing 79 and 21% to the

total biomass respectively. The C pool for the Indian forest has been estimated to be

2026.72 Mt for the year 1995. Further mitigation of about 3.32 Gt in the next 50

years at an annual reduction of about 0.072 Gt of C is possible (Pandey, 2002).

Lal et al. (2000) reported that estimated annual carbon uptake increment by Indian

forests and plantations have been able to remove about 0.125 Gt of CO2 from the

atmosphere in the year 1995. Ravindranath et al. (1997) reported the Indian forests

based on the forest sector of the year 1986 could sequester around 5 Tg C (1 Tg

=Tera gram, 10-12 g). Haripriya (2003) noted on the average biomass carbon of the

forest ecosystems in India for the year 1994 was 46 Mg C ha-1, of which nearly 76%

was in aboveground biomass and the rest was in fine and coarse root biomass (Jana

et al., 2009).

Vegetation as Carbon Sink

Carbon sequestration involves the capture and storage of the carbon from the

atmosphere which would otherwise go on accumulating in the atmosphere. Carbon

dioxide is captured and stored naturally by the plants by the process of

photosynthesis where they take in CO2 and sequester it in the form of sugars and

finally contribute to organic matter in the soil (Kumar et al., 2006; Phani Kumar et

al., 2009). Hence, estimation of this C content both in vegetation and in soil becomes

imperative to access the Carbon sequestration potential. Later on, the glucose in trees

gets converted to other forms of food material, i.e. starch, lignin, hemicelluloses,

amino acids, protein, etc. and is diverted to other tree components for storage. It is a

well-established fact that food is stored either in the roots or bole and branches.

Generally, the plants allocate more of the energy in the root system under stress

conditions and in the aboveground components in normal conditions (Negi et al.,

2003). This results in an increase in their biomass, indicative of an increase in carbon


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sequestered by them (Kumar et al., 2006; Ramachandran et al., 2007; Jana et al.,

2009; Jeff and Hill, 2009). In the case of carbon sequestration in a permanent stand,

the C accumulation rate in above ground biomass is linear initially but declines due

to saturation effect. Carbon sequestered in soil and litter over 100 years represents

about 20% of carbon sequestered in aboveground biomass in the case of direct

sequestration (Baral and Guha, 2004). Soil-vegetation systems play an important role

in the global carbon cycle. Soil contains about three times more organic carbon than

vegetation and about twice as much carbon than is present in the atmosphere.

Vegetation stands next only to soil in sequestering carbon (Dinakaran et al., 2008;

Kumar et al., 2006; Batjes & Sombroek, 1997). Plants can contribute to mitigate

GHE and global warming. Terrestrial vegetation and soil currently absorb 40% of

global CO2 emission from human activities (Sheikh and Kumar, 2010).

Carbon sequestration by trees

Tree, shrub, soil and sea water play crucial role in absorbing atmospheric carbon

dioxide (Chavan, 2010). Trees act as a sink for CO2 by fixing carbon during

photosynthesis and storing excess carbon as biomass. The net long term CO2

source/sink dynamics of forests change through time as trees grow, die and decay. In

addition, human influences on forests can further affect CO2 source/sink dynamics of

forests through such factors as fossil fuel emissions and harvesting/utilization of

biomass (Nowak and Crane, 2002). As the tree biomass experience growth, the

carbon held by the plant also increases carbon stock. The rate of carbon storage

increases in young stands, but then declines as the stand ages. An observation from a

study on pine species planted on cropland in the southeastern U.S., the rate of carbon

storage begins to decline at approximately age 20 and is close to zero by 100.

Increasing the atmospheric CO2 concentration stimulates the photosynthetic rate of

trees and can result in increased growth rates and biomass production. Results from

free air CO2 enrichment (FACE) experiments show a 25% increase in growth in

twice normal concentrations of CO2. Growth is therefore almost always higher in air

with an elevated concentration of CO2 (Burley et al., 2004). Scientific evidence

suggests that increased atmospheric CO2 could have positive effect such as improved


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plant productivity (Schaffer et al., 1997; Pan et al., 1998; Centritto et al., 1999; Idso

and Kimball, 2001; Keutgen and Chen, 2001; Jana et al., 2009)

Biological fixation of CO2 is an attractive option because plants naturally capture

and use CO2 as a part of the photosynthetic process. Terrestrial plants sequester vast

amounts of CO2 from the atmosphere (Khan, 2008). Meanwhile, plants have the

ability to absorb carbon dioxide for carbonxylation and subsequently for production

of carbohydrates (especially by the tuberous plants) and for production of woods and

fibres (by trees) through photosynthesis. Photosynthesis is the major process by

which plants produced carbohydrates, and the major ingredient in this process is

carbon dioxide (Abdulrahaman and Oladeley, 2008). As trees grow and their

biomass increases, they absorb carbon from the atmosphere and store it in the plant

tissues (Mathews et al., 2000) resulting in growth of different parts. Active

absorption of CO2 from the atmosphere in photosynthetic process and its subsequent

storage in the biomass of growing trees or plants is the carbon storage (Baes et al.,

1977). In terms of atmospheric carbon reduction, trees in urban areas offer the

double benefit of direct carbon storage and stability of natural ecosystem with

increased recycling of nutrient along with maintenance of climatic conditions by the

biogeochemical processes (Chavan, 2010). Plants can play two fundamentally

different roles as C sinks. By capturing atmospheric CO2 through photosynthesis

plants store large amounts of organic C in above and belowground biomass. This is

particularly relevant for perennial trees and herbaceous plants with extensive root

systems (Jansson et al., 2010). Biological growth involves the shifting of carbon

from one stock to another. Plants fix atmospheric carbon in cell tissues as they grow,

thereby transforming carbon from the atmosphere to the biotic system (Warran &

Patwardhan, 2001).

Trees take atmospheric CO2 during photosynthesis and fix it in woody (branches,

stem and woody roots) and non-woody (foliage and fine roots) parts (Baral and

Guha, 2004). The trees act as major CO2 sink which captures carbon from the

atmosphere and acts as sink, stores the same in the form of fixed biomass during the

growth process. Therefore, growing trees in urban areas can be a potential


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contributor in reducing the concentration of CO2 in atmosphere by its accumulation

in the form of biomass (Chavan, 2010).

Factors influencing carbon sequestration capacity of trees

Forests are the large terrestrial reservoir for atmospheric carbon. They remove CO2

from the atmosphere and store it in the organic matter of the soil and trees. The

amount of carbon stored in the forest depends on its age and productivity (Sheikh

and Kumar, 2010). The concept of sequestering atmospheric carbon by forestry is

based on the principle that trees extract CO2 from the atmosphere in the process of

photosynthesis, and use it to produce structural compounds for their growth. The

amount of carbon stored in trees in a forest can be calculated by determining the

amount of biomass in the forest and applying a conversion factor. As longer-lived,

high density trees store more carbon than short-lived, low density, fast-growing trees

or other vegetation, enrichment planting logged forests with hardwood trees make it

possible to obtain dense stands which accumulate higher amounts of carbon per area

than logged forests which are left untreated (Moura-Costa et al., 1994).

The rate of carbon sequestration depends on the growth characteristics of the tree

species, the conditions for growth where the tree is planted, and the density of the

tree’s wood (Jana et al., 2009). Ability of the terrestrial biosphere to sequester and

store atmospheric CO2 has been recognized as an effective and low cost method of

offsetting carbon emissions. C sequestration potential differs with the kind of land

use. It is a proven fact that forest ecosystems are the best way to sequester carbon.

Carbon sequestration depends upon the biomass production capacity, which in turn

depends upon interaction between edaphic, climatic and topographic factors of the

area (Koul and Panwar, 2008). The potential of individual trees to act as a C sink

may be highly dependent on response to soil nutrition and environmental stress

rather than to atmospheric CO2 concentration (Norby et al., 1992; Wisniewskil et al.,

1993). Carbon storage is linked with the site quality, nature of the land use, choice of

species and other crop management practices adopted (Koul and Panwar, 2008). The

variation in carbon sequestration capacity of plantations depended on DBH, height,

number of branches and crown canopy of individual plants. Increase in annual


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productivity of plantations directly indicates an increase in forest biomass and hence

higher carbon sequestration potential (Phani Kumar et al., 2009). The amount of

carbon sequestered by trees depends on the biomass accumulation rate and rotation

length (Baral and Guha, 2004). The carbon sequestration capacity of a tree species

depends upon its age, height, girth size, biomass accumulation capacity, canopy

diameter and most important wood specific density (Rathore and Jasrai, 2013).


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Literature Review

Carbon sequestration

Concern about an enhanced greenhouse effect has prompted several attempts to

calculate the net release of CO2 to the atmosphere resulting from deforestation

(Emanuel et al., 1984; Houghton et al., 1991; Houghton 1991). Similar efforts have

been made to calculate the amount of CO2 that can be sequestered by planting trees

(Cooper, 1983; Cropper and Ewe1, 1984; Thompson and Matthews, 1989). Workers

have variously concentrated on the amount of carbon stored in the living trees

(Cooper, 1983; Johnson and Sharpe, 1983; Matthews et al., 1991), the wood

products (Row and Phelps, 1990), the tree-soil ecosystem (Cropper and Ewe1, 1984),

or the trees and wood products (Thompson and Matthews, 1989). Few studies have

encompassed the entire tree-soil-products system, and few have tracked the flow of

carbon from the trees to soils and products in a dynamic fashion, as outlined in a

model proposed by Dewar (1991).

Carbon sequestration involves the capture of carbon dioxide from the atmosphere

and storage in the plant tissue in the form of carbohydrates by the process of

photosynthesis (Kumar et al., 2006; Phani Kumar et al., 2009). The biomass of the

tree also increases and can be computed to know the amount of carbon sequestered.

There are many destructive and non-destructive methods to compute it which have

been developed through centuries.

Moura-Coasta (1996) worked on the carbon sequestration potential of the

Dipterocarp forest ecosystem in tropical forestry practices in New Jersey.

MacDicken (1997) analysed and constructed a guide for monitoring carbon storage

in forestry and agroforestry, USA. Ramachandran et al., (2007) estimated the carbon

stock of wood biomass and soil in natural forest using geospacial technology in the

Eastern Ghats of Tamil Nadu, India. Phani Kumar et al., (2009) analysed the carbon

stock of willow and poplar species by non-destructive method and also organic

carbon in soil samples in the Nubra valley, Ladakh, India. Jana et al., (2009)

measured the carbon sequestration rate and above ground biomass carbon potential

of four young species of Shorea robusta, Albizzia lebbek, Tectona grandis and


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Artocarpus integrifolia by the non destructive method in West Bengal and observed

that carbon sequestration rate of Albizzia lebbek was higher than Shorea robusta

followed by A. integrifolia and T. grandis.

Chan (1982), Chaturvedi and Singh (1987) and Rawat and Singh (1988) determined

the below ground biomass to be 25% of the above ground biomass. Of the total

carbon stored in the 8-year-old Poplar plantation, 78.68% carbon was allocated in the

above ground components whereas 21.32 % carbon was allocated in the below

ground components of the trees.

Total carbon stock of a tree has been evaluated by adding all the carbon contents of

stems, branches and leaves of the tree (Jana et al., 2009; Phani Kumar et al., 2009).

Trees are important sinks for atmospheric carbon i.e. carbon dioxide, since 50% of

their standing biomass is carbon itself (Ravindranath et al., 1997; Warran &

Patwardhan, 2001). Most of the information for carbon estimation described in the

literature suggests that carbon constitutes between 45 to 50 percent of dry matter

(Schlesinger, 1991; Chan, 1982) and it can be estimated by simply taking a fraction

of biomass as C = 0.475 × B. Where C is the carbon content and B is oven dry

biomass (Singh and Lodhiyal, 2009).

Chan (1982), Pettersen (1984), Losi et al., (2003), Koul and Panwar, (2008) analysed

the carbon percentage of the wood to be 50% of the total biomass. Work of Losi et

al., (2003) obtained that measured carbon content of dry sample was 47.8% for A.

excelsum and 48.5% for D. panamensis. West (2003) reported in his paper that

extensive studies in Australia recently of a variety of tree species showed that above

ground dry biomass generally contain 50% carbon. These proportions of carbon in

aboveground biomass agreed closely with values of 49% and 47% reported from

other parts of the world for Pinus taeda (Kinerson et al., 1977) and Populus spp.

(Deraedt and Ceulemans, 1998) (Jana et al., 2009). The carbon content of vegetation

is surprisingly constant across a wide variety of species.

A field experiment conducted by Mutanal et al., (2007) to assess the performance of

10 multipurpose tree species (viz., Casuarina equisetifolia, Eucalyptus tereticornis,

Grevillea robusta, Tectona grandis, Dalbergia sissoo, Anogeissus latifolia, Albizia

lebbek, Hardwickia binata, Azadirachta indica and Acacia nilotica) suitable for


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agroforestry system in degraded gravelly soils at Main Agricultural Research Station,

University of Agricultural Sciences, Dharwad during the year 1990.

The observations of Negi et al., (2003) revealed that the wood, which constitutes

maximum portion of total biomass, stored maximum amount of carbon. While

comparing the different life forms, it was observed that the maximum carbon is

stored in the order of conifers > deciduous > evergreen > bamboos. Thus it can be

said that the conifers are more efficient in carbon sequestration.

The study investigated by Sheikh and Kumar (2010) with respect to the species

composition and tree carbon stock in two different aspects (northern and southern) of

sub-tropical regions in the Garhwal Himalayas showed that northern aspect have

more carbon sequestration potential especially conifers (Pinus dominant) than that of

broadleaved forest (dominant Anogeissus latifolia) on the southern aspect.

Utilization of biomass as a substitute for fossil fuels is one method to minimize

greenhouse gas emissions Trees also can be used to help conserve energy in urban

areas. Strategic planting of shade trees in cities with substantial air condtioning

requirements can reduce energy use and fossil fuel CO2 emissions. Similarly, trees

may also serve as wind breaks and reduce winter heating needs by 4 to 22%. Akbari

et al., (1988) asserted that urban trees are 15 times more important in reducing CO2

build-up than rural trees. It has been estimated that improving the existing urban

forests in the United States could result in lowering total C emissions by 1 to 3 %

(Sampson et al., 1992; Wisniewskil et al., 1993).


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Significance of the study

In the present day scenario, the enhancement of atmospheric CO2 coupled with the

rise in temperature is the main reason behind the global climate change which has

evidently raised the global mean temperature by 0.5°C during the last hundred years

and 0.4°C in the last 70 years for the Indian sub-continent (Negi et al., 2003). Global

warming risks from emissions of greenhouse gases (GHGs) by anthropogenic

activities have increased the need for the identification of ecosystems (Phani Kumar

et al., 2009; Chavan, 2010) and classifying the plant species for their efficient

responses to enhanced CO2 to climate change in terms of high carbon sink capacity

as an alternative mitigation strategy of terrestrial carbon sequestration (Negi et al.,

2003).


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Material and Method

Study area

Figure-33: Google image of Gujarat University Campus, the study site

Gujarat University, situated in Ahmedabad (Fig-33) has a campus which spreads

over an area of 1.1km2. It is situated between 23°02'11.44"N latitude and

72°32'46.63"E longitude at an elevation of 180 feet. It is subjected to a dry semi-arid

type of the climate according to the Koppen system of classification. The average

summer minimum to maximum temperature varies from 23 to 45°C. The south-

western monsoon results in a humid climate from mid-June to mid-September and

the average annual rainfall is about 76cms.

Methods of tree biomass computation

Trees of ≥ 30cm dbh were considered for the biomass computation.

For the carbon stock estimation, each tree was measured for its height, bole, GBH

(girth at breast height) and diameter of the canopy.

The height of the tree was measured using Haga’s Altimeter. The GBH and canopy

diameter were measured using a measuring tape (Fig-34).

Total sequestered carbon stock of the trees was therefore measured by non-

destructive method using equations involving the total volume, total biomass,

percentage of carbon sequestered and wood density of the plants studied.


The total biomass was determined by analyzing both the above ground biomass

(AGB), below ground biomass (BGB) and tree canopy biomass values specific to

each tree species.

The AGB was measured by calculating the volume of the above ground plant and

wood density (Phani

BGB was determined as per the method of

accordance with the work and result of

Singh (1988).

The biomass of foliage cover of each tree was determined with the he

volume calculation (

The total volume is then multiplied by the specific density of the tree to get the total

biomass (Chowdhury

The carbon percentage of the trees was calculated by

by 50% (Chan 1982;


ass was determined by analyzing both the above ground biomass


each tree species.


Phani Kumar et al., 2009).

was determined as per the method of MacDicken,

the work and result of Chaturvedi and Singh (1

The biomass of foliage cover of each tree was determined with the he

volume calculation (Phani Kumar et al., 2009).


(Chowdhury and Ghosh, 1958, 1963).

The carbon percentage of the trees was calculated by multiplying the total biomass

Chan 1982; Pettersen, 1984; Jina et al., 2008).


158

ass was determined by analyzing both the above ground biomass



MacDicken, (1997) which is in

Chaturvedi and Singh (1987) and Rawat and

The biomass of foliage cover of each tree was determined with the help of crown


multiplying the total biomass


159

Terminalia chebula Retz Pithecellobium dulce (Roxb) Bth

Limonia acidissima L Ficus benghalensis L

Tamarindus indica L Ailanthus excelsa Roxb

Syzygium cumini (L) Skeel Azadirachta indica A Juss

Figure-35 a): Trees of Gujarat University campus


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Ficus religiosa L Albizia lebbeck (L) Bth

Terminalia arjuna (Roxb) W & A Eucalyptus globulus Labill

Cassia fistula L Casuarina equisetifolia L

Mimusops elengi L Peltophorum pterocarpum (DC) Baker

Figure-35 b): Trees of Gujarat University Campus


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Result and Discussion

The Gujarat University campus has a rich floral diversity. The main tree species

comprise of Azadirachta indica (neem), Peltophorum ferrugineum (copper pod tree),

Alianthus excelsa (arduso), Ficus sps., Cassia fistula (amaltas), Polialthia longifolia

(asopalav), Limonia acidissima (wood apple) and Pongamia pinnata (karanj).

The total number of trees in the Gujarat University was counted to be 3379

belonging to 60 species comprising 28 families and 47 genera (Fig-35a,b) and their

carbon stock was measured. Azadirachta indica A Juss (910) trees were most

dominant followed by Peltophorum pterocarpum (DC) Baker (752), Polyalthia

longifolia (Sonner) Thwaites (504), Pongamia pinnata (132), Eucalyptus globulus

Labill (97) and Ailanthus excelsa Roxb (89).

The average carbon stock (t) determined for all the 60 tree species (Table-5 and Fig-

36) shows that trees belonging to Terminalia chebula Retz (76.93 t) had the

maximum amount of C stock followed by Pithecellobium dulce (Roxb) Bth (65.88 t)

Limonia acidissima L (61.31 t) , Ficus benghalensis L (54.03 t), Tamarindus indica

L (52.84 t), Morus alba L (47.92 t), Ailanthus excelsa Roxb (43.89 t), Syzygium

cumini (L) Skeel (43.64 t), Azadirachta indica A Juss (43.11 t), F. religiosa L (42.79

t), Albizzia lebbeck (L) Bth (40.57 t) followed by Terminalia arjuna (Roxb) W & A

(38.21 t), Eucalyptus globulus Labill (35.9 t), Mangifera indica L (35.75 t),

Casuarina equisetifolia L (34.59 t) have the maximum carbon sequestration

capability and therefore are ideal selection for sequestering CO2 in the present

scenario to prevent climate change. While the trees like Acacia nilotica (L) Del (2.48

t) and the members of family Palmae like Phoenix sylvestris (L) Roxb (2.18 t),

Roystonea regia (1.24 t), Musa paradisiaca (0.87 t), Dicrostachys cinerea (DC)

(0.63 t) are found to sequester least amount of carbon (Fig-36). Similar work has

been done by Warran and Patwardhan (2001) on trees of Pune city, Mutanal et al.,

(2007) on selected tree species for agroforestry at Dharwad, Karnataka, Jina et al.,

(2008) on the Oak and Pine forest of Central Himalaya, Jana et al., (2009) on

Albizzia lebbek and Shorea robusta trees in West Bengal, Phani Kumar et al., (2009)

on Poplar and Willow tree plantation in Ladakh, Singh and Lodhiyal (2009) on


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Populus tree plantation in central Himalaya, Chavan, (2010) on selected 20 tree

species in the University campus at Aurangabad, Maharashtra, India; Chavan and

Rasal, (2012) for Albizzia lebbek and Delonix regia in Aurangabad, Ullah and Al-

Amin (2012) of trees in natural forest of Bangladesh and Mariappan et al., (2012) on

the urban forest in Chennai.

The carbon stock for each and every tree belonging to the 60 tree species in Gujarat

University campus was calculated. The trees based on their girth sizes and also on

the basis of number of tree species in a particular girth range, were divided into

various girth classes (0-30, 31-40, 41-50, 51-60, 61-70, 71-80, 81-90, 91-100, 101-

110, 111-120, 121-130, 131-140, 141-150, 151-160, 161-170, 171-180, 181-190,

191-200, 201-250, 251-300, 301-350, 351-400 cms).

Table-5: Carbon stock of the selected tree species of Gujarat University

Campus.

Family Scientific name of tree No. of Trees

Avg. Carbon stock (t)

Annonaceae Polyalthia longifolia (Sonner) Thwaites 504 9.66

Malvaceae Thespesia populnea (L) Sol ex Correa 6 16.13

Bombacaceae Bombax ceiba L 2 11.64

Sterculiaceae Guazuma ulmifolia Lam 19 9.42

Rutaceae Aegle marmelos (L) Correa 1 15.17

Limonia acidissima L 15 61.31

Simarubiaceae Ailanthus excelsa Roxb 89 43.89

Meliaceae Azadirachta indica A Juss 910 43.11

Rhamnaceae Zizyphus mauritiana Lam 4 27.55

Anacardiaceae Mangifera indica L 3 35.75

Moringaceae Moringa oleifera Lam 44 5.92

Fabaceae Derris indica (Lam) Bennet 132 16.851

Gliricidia sepium (Jacq) Walp 15 9.38

Caesalpinaceae Bauhinia purpurea L 2 11.64

Cassia fistula L 24 28.27

Cassia javanica L var javanica 2 21.75


163

Cassia siamea Lam 29 41.66

Delonix elata (L) Gamble 6 39.74

Delonix regia (Boj) 34 23.2

Peltophorum pterocarpum (DC) Baker 752 28.27

Tamarindus indica L 26 52.84

Mimosaceae Acacia auriculiformis A Cunn ex Benth 8 21.94

Acacia nilotica (L) Del 41 2.48

Albizia lebbeck (L) Bth 102 40.58

Albizia odoratissima (L f) Bth 28 15.69

Albizia procera (Roxb) Bth 64 9.58

Dichrostachys cinerea (DC) 7 0.63

Pithecellobium dulce (Roxb) Bth 10 65.88

Prosopis cineraria (L) Druce 17 10.58

Combretaceae Terminalia arjuna (Roxb) W & A 9 38.21

Terminalia catappa L 7 24.08

Terminalia chebula Retz 5 76.928

Myrtaceae Callistemon citrinus (Curtis) Skeel 3 26.37

Eucalyptus globulus Labill 97 35.91

Psidium guazava L 5 4.23

Syzygium cumini (L) Skeel 10 43.64

Sapotaceae Manilkara hexandra (Roxb) Dub 3 13.52

Manilkara zapota (L) van Royen 1 19.14

Mimusops elengi L 14 32.61

Salvadoraceae Salvadora persica L 9 2.93

Apocynaceae Plumeria alba L 7 4.55

Ehretiaceae Cordia dichotoma Forst f 67 23.38

Cordia gharaf (Forsk) Ehrenb & Asch 5 9.53

Bignoniaceae Kigelia pinnata (Jacq) DC 33 31.17

Euphorbiaceae Emblica officinalis Gaertn 8 43.57

Ulmaceae Holoptelea integrifolia (Roxb) Planch 48 15.45

Moraceae Ficus benghalensis L 3 54.03

Ficus hispida Lf 8 12.07

Ficus drupacea Thunb 8 9.74

Ficus religiosa L 22 42.79

Morus alba L 2 47.92

Streblus asper Lour 1 33.05


Casuarinaceae

Arecaceae

Zygophyllaceae

Nyctagenaceae

Musaceae


Casuarina equsetifolia L

Borassus flabellifer L

Cocos nucifera L

Phoenix sylvestris (L) Roxb

Roystonea regia (H B & K) O F Cook

Zygophyllaceae Balanites roxburghii (L) Del

Bougainvillea spectabilis Willd

Musa paradisiaca L


164

9 34.59

4 17.36

2 28.68

1 2.18

25 1.24

11 2.43

1 8.46

55 0.87


The correlation and regression analysis were then done for all the 60 tree species to

compare the girth class with the carbon stock (t), height (m) and canopy diameter

(m). The average

taken for all the 60 tree species belonging to each girth class. The

plotted showed a linear

vs carbon stock shows a linear positive correlation and regression of R

girth class vs height shows a linear positive correlation and regression of R

Girth class vs canopy diameter also shows a linear positive correlation and

regression of R2= 0.863. The correlation is a little lesser with height than with other

two parameters. But still, t

stock, height and canopy diameter.

Figure-37: Correlation between girth classes and Carbon stock/ height/ canopy

The result shows

increases, resulting in a simultaneous increase in the amount of carbon

tree. The similar work and result has been done by

(2001) found that ther

diameter and leaf area with dbh in San Joaquin Valley street trees.




(m). The average of the carbon stock (t), height (m) and canopy diameter (m) was

taken for all the 60 tree species belonging to each girth class. The

a linear positive correlation in all aspects (Figure

vs carbon stock shows a linear positive correlation and regression of R

girth class vs height shows a linear positive correlation and regression of R

irth class vs canopy diameter also shows a linear positive correlation and

= 0.863. The correlation is a little lesser with height than with other

parameters. But still, the girth classes are positively correlated with the carbon

stock, height and canopy diameter.

: Correlation between girth classes and Carbon stock/ height/ canopy

diameter

that as the girth increases the height and canopy of a tree also

resulting in a simultaneous increase in the amount of carbon

The similar work and result has been done by some researchers. Peper

(2001) found that there was strong correlation (R2 > 0.70) for total height, crown

diameter and leaf area with dbh in San Joaquin Valley street trees.


165



(m) and canopy diameter (m) was

taken for all the 60 tree species belonging to each girth class. The scatter graph

(Figure-37). The girth class

vs carbon stock shows a linear positive correlation and regression of R2= 0.903. The

girth class vs height shows a linear positive correlation and regression of R2= 0.798.

irth class vs canopy diameter also shows a linear positive correlation and

= 0.863. The correlation is a little lesser with height than with other

he girth classes are positively correlated with the carbon

: Correlation between girth classes and Carbon stock/ height/ canopy

eight and canopy of a tree also

resulting in a simultaneous increase in the amount of carbon stock of the

some researchers. Peper et al.,

> 0.70) for total height, crown

diameter and leaf area with dbh in San Joaquin Valley street trees. Alamgir and Al-


166

Amin (2008) in Chittagong forest division of Bangladesh also developed models

using height alone; DBH alone; height and DBH together; height, DBH and wood

density but found poor correlation. A stratified random sample of street trees was

drawn by Peper and McPherson (2012) from 22 U.S. cities municipal tree inventory

and measured to establish relations between tree age (number of years after planting)

and DBH; DBH and tree height, crown height, average crown diameter, and leaf area

and average crown diameter and DBH. Using DBH to predict tree height and crown

diameter showed the strongest correlations of more than 0.8.

From the various girth classes formed, the maximum number of tree species (37) was

found to be in the girth class of 60-70 cm. Hence, the carbon stock, height and

canopy diameter were compared for all these 37 tree species for that particular girth

class (Fig-38).

The carbon stock (t) determined for all the 37 tree species (Fig-38) in the girth class

of 60-70 cms showed that Limonia acidissima L (50.28 t) had the maximum amount

of C stock followed by Terminalia chebula Retz (45.49 t), Mimusops elengi L

(45.28), Morus alba L (43.75 t), Holoptelea integrifolia (Roxb) Planch (37.4 t),

Cassia fistula (37.22 t), Emblica officinalis Gaertn (36 t), Terminalia arjuna (Roxb)

W & A (34.39 t), Albizia lebbeck (L) Bth (33.65 t), Tamarindus indica L (33.4 t),

Pithecellobium dulce (Roxb) Bth (33.39 t), Syzygium cumini (L) Skeel (32.88 t),

Casuarina equisetifolia L (30.25 t), Mangifera indica L (26 t), Ailanthus excelsa

Roxb (23.19 tC), Azadirachta indica A Juss (20.67 t), followed by Eucalyptus

globulus Labill (13.64 t) and F. religiosa L (11.19 t).

This result when compared to the above results for the average carbon stock of 60

tree species shows similarity, but to a certain extent, owing to the variation in the

factors related to height and canopy diameter. The maximum height was reported in

Emblica officinalis Gaertn (13 m) while, minimum height was measured in

Terminalia arjuna (Roxb) W & A (5 m) and Zizyphus sps (5 m). The largest canopy

diameter was measured in Terminalia chebula Retz (12.5 m) and smallest canopy in

Terminalia cadappa (3.63 m). The result shows that all the trees in a similar girth

class do not have the same height or canopy diameter as well as the specific density


and hence the carbon stock is also not the same.

maximum carbon stock

Bth, Limonia acidissima

Ailanthus excelsa

Azadirachta indica

A, Eucalyptus globulus

come out to be almost

species and hence

recommended for plantations in the scenario of climate change for a tropical state

like Gujarat.

Figure-38: Carbon stock, height and canopy diameter of the 37 tree species

Jana et al., (2009) measured the carbon sequestration rate and above ground biomass

carbon potential of four young species of

grandis and Artocarpus integrifolia

3.33 t C/ha/yr respectively

C stock 5.22, 6.26, 7.97 and 7.28 t C/ha in the state of West Bengal. This can be

observed that carbon sequestration rate of

robusta followed by


and hence the carbon stock is also not the same. But still the first few species

maximum carbon stock like Terminalia chebula Retz, Pithecellobium dulce

Limonia acidissima L, Cassia fistula L, Tamarindus indica

Ailanthus excelsa Roxb, Syzygium cumini (L) Skeel, Emblica officinalis

Azadirachta indica A Juss, Albizia lebbeck (L) Bth, Terminalia arjuna

Eucalyptus globulus Labill, Mangifera indica L and Casuarina equsetifolia

almost the same, as the result above, with respect to the 60 tree

and hence, these tree species can be considered as ultimate tree species to be


: Carbon stock, height and canopy diameter of the 37 tree species

within the girth class of 60-70 cms

(2009) measured the carbon sequestration rate and above ground biomass

of four young species of Shorea robusta, Albi

Artocarpus integrifolia and was estimated to be 8.97, 11.9

respectively; % C content 47.45, 47.12, 45.45 and 43.33


observed that carbon sequestration rate of Albizia lebbek was higher than

followed by A. integrifolia and T. grandis.


167

But still the first few species with

Pithecellobium dulce (Roxb)

Tamarindus indica L, Morus alba L,

Emblica officinalis Gaertn,

Terminalia arjuna (Roxb) W &

Casuarina equsetifolia L

with respect to the 60 tree

imate tree species to be


: Carbon stock, height and canopy diameter of the 37 tree species

(2009) measured the carbon sequestration rate and above ground biomass

Albizia lebbek, Tectona

and was estimated to be 8.97, 11.97, 2.07 and

; % C content 47.45, 47.12, 45.45 and 43.33 respectively;


was higher than Shorea


168

A field experiment conducted by Mutanal et al., (2007) to assess the performance of

10 multipurpose tree species (viz., Casuarina equisetifolia, Eucalyptus tereticornis,

Grevillea robusta, Tectona grandis, Dalbergia sissoo, Anogeissus latifolia, Albizia

lebbek, Hardwickia binata, Azadirachta indica and Acacia nilotica) suitable for

agroforestry system in degraded gravelly soils at Main Agricultural Research Station,

University of Agricultural Sciences, Dharwad during the year 1990. At the end of

tenth year they found that height was significantly higher in C.equisetifolia followed

by E.tereticornis as compared to rest of tree species tried. Diameter of breast height

was higher in E.tereticornis as compared to other tree species. Biomass was

significantly higher in C.equisetifolia (109.18 kg/tree) followed by E.tereticornis

(108.5 kg/tree) and lowest in A.indica (7.54 kg/tree) followed by D.sissoo (12.69

kg/tree).


169

Conclusion

The carbon sequestration capacity of a tree species depends upon its age, height,

girth size, biomass accumulation capacity, canopy diameter and most important

wood specific density. The carbon stock determined for various tree species shows

that trees like Terminalia chebula Retz, Pithecellobium dulce (Roxb) Bth, Limonia

acidissima L, Ficus benghalensis L, Tamarindus indica L, Morus alba L, Ailanthus

excelsa Roxb, Syzygium cumini (L) Skeel, Azadirachta indica A Juss, F. religiosa L,

Albizia lebbeck (L) Bth, Terminalia arjuna (Roxb) W & A, Eucalyptus globulus

Labill, Mangifera indica L and Casuarina equisetifolia L have the maximum carbon

sequestration capability.

So, the trees to be chosen for sequestering maximum amount of carbon in the

scenario of climate change, should be chosen with properties of highest specific

density, they should be fast growing, increasing biomass at a fast rate, should have a

huge canopy and also should have a better climate adaptability, richer litter

productivity, shorter rotation and should be disease resistant.

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Chapter 5: Identifying Tree Species with Maximum Carbon...

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