NB
This was an assignment done in 2007 at the Wildlife Institute of India. I missed a medal by one mark but I realized that "A miss is as good as mile".
Dams provide drinking water, irrigate the
land, produce hydro-electricity and prevent floods and it is understood that
over 48,000 large dams are in operation worldwide. Despite of such an alarming
number of dams being in operation, WWF report that one billion people do not
have access to safe drinking water today and more than double that number lack
basic sanitation and two billion people have no access to electricity which is
expected to rise. With the ever fast growing population of people it is
expected that by 2050 at least 1 in 4 people will be living in a country
affected by water shortages. An alarming scenario of seven billion people in 60
countries is expected to face water scarcity and to meet the demand for water,
more large dams are proposed as a key solution. But will such idea solve the
problem of those whose needs are growing by days at largest? Dams more than
often have brought benefits at the cost of environmental and society as they
destroy ecosystems and cause people to lose their homes and livelihoods.
Of the total area submerged which is about 54.57 km2, 75% of the submergence area falls within the Park boundaries covering about 17.24 km2 in Karmajhiri Range and 37.27 km2 in Gumtara Range and remaining 25% (19.93 km2) falls in Jawaharlal NP in Maharastra. The details of the different water levels of the dam are as follows;
This was an assignment done in 2007 at the Wildlife Institute of India. I missed a medal by one mark but I realized that "A miss is as good as mile".
ABSTRACT
Acclaimed as
the cataclysmic event, damming of river has been known to bring about change in
local ecosystem. Damming results in fragmentation of wildlife population into
genetically isolated sub-populations, affect prey population, less diversity
downstream due to lowered nutrient availability and limited dispersal of
aquatic fauna between river systems. This study envisages changes in wildlife
habitat brought by the construction of Pench Reservoir over the Pench River at
Todladoh. The impact assessment of submergence on wildlife values was done by
comparing the past scenario through literature survey and existing situation by
conducting field study on floristic composition and use of reservoir by
wildlife. The data were collected by laying circular plots at targeted areas.
Due to the construction of this reservoir around 72 km2 of prime
teak forest was lost leading to the loss of prime tiger habitat. However, the
reservoir has also contributed significantly by creating new wildlife habitat
and by providing water and recharging the aquifers in this semiarid region. The
results of the study revealed that the cheetal Cervus axis are using the drawdown areas most. The sambar Cervus unicolor
and neelgai Boselaphus tragocamelus
are using the fringe forests more than the drawdown areas. The other animals
using the drawdown areas are gaur Bos
gaurus and wild boar Sus scrofa.
Discussion with the park management indicated higher biomass production in
these areas resulting in enhanced prey biomass for tiger and other carnivores.
At least 24 species of migratory and 36 species of resident water birds
belonging to 15 families are using this reservoir. In recent years the drawdown
areas are getting infected with weeds such as Parthenium, Cassia tora
and Argemone mexicana leading to decreased wildlife values. Human activities such as
fishing and movement of people are disturbing wildlife. At the moment the
management intervention is limited to terrestrial wildlife habitat. Improvement
of aquatic species habitat for migratory and resident water birds and other
species such as mugger Crocodylus
palustria and otter Lutra perspicillata
is suggested.
1. Introduction
A dam or
a reservoir is created
when people need water
for irrigation or the rivers
are dammed to generate
hydroelectric power or to control
flood. Pench River has been dammed to generate power for the public of Madhya
Pradesh and Maharastra. By a simple logic, such reservoir severely can affect
virtually everything from abiotic to biotic components of a wetland ecosystem.
The reservoir can over
the period change the soil
structure, temperature and rainfall pattern of the adjoining
areas creating a new environment
and ecosystem. It can affect the land use pattern of animals such as birds,
mammals, fishes, reptiles etc.
In the light
of above affect that a dam can bring to wildlife, some specific loss and
benefit to wildlife are discussed below.
1.1. Habitat Loss or Alteration
In some
cases reservoirs are helpful to wildlife. For example, some dam projects
produce wetlands, which can provide feeding and breeding areas for many types
of waterfowl depending on the reservoir operation. This is an example for the
case of Pench Reservoir. Although some wildlife species benefit from the
development of reservoirs, most studies have reported habitat loss to be a
major concern for wildlife. Reservoir clearing and flooding can result in
extensive loss of riparian and valley bottom habitats. Because of their
abundant food supplies and sheltered micro-climate, these habitats often support
a much higher diversity of wildlife than adjacent upland habitats. Many wildlife
species depend on these habitats for breeding or over wintering.
Wildlife can
also be adversely affected by more subtle changes in habitat quality. Changes
in the flow regime of rivers that are regulated by dams can change the natural
succession in downstream vegetation communities and affect the suitability of
these habitats for wildlife. (Succession is the gradual process of replacement
of vegetation and wildlife communities with time. Once an area is mature it
takes an event like fire or flood to start the process over again.) Dam
operations can reduce the incidence of flooding of riparian habitat, which is
often necessary to maintain early-successional communities that are important
for certain wildlife species.
The
long-term effects of flow regulation on downstream ecosystems are often complex
and may be difficult to predict.
1.2. Effects on Wildlife Movements
Affects can
also occur when dams or reservoirs change movements of wildlife between
seasonally important habitats. Large reservoirs can permanently alter the
traditional movement patterns of migratory species. Some reservoirs facilitate
wildlife movements and open new territory but wildlife may experience
difficulty crossing reservoirs or reaches of rivers downstream of dams.
Operation of some reservoirs, particularly those used for hydroelectric
generation, may result in unstable ice conditions or the formation of ice
shelves along shorelines, which can restrict wildlife movements and increase
the risk of injury or mortality of wildlife. Direct mortality of large ungulate
is possible due to drowning, either by falling in the unseen gullies in the
ground cover by water or by attempting to cross downstream reaches of rivers
during the pinch period when they are forced to travel far and wide in search
of food.
1.3. Wildlife Mortality
During
facility construction and reservoir flooding, large numbers of birds, mammals,
amphibians and reptiles can be lost. Risks are greatest to nestlings and
smaller, less mobile species, as larger animals are displaced into adjacent
habitats. Fluctuating water levels in reservoirs can also cause the accidental
mortality of nesting birds. If the construction of the dam creates easier
access, then collisions with vehicles on transportation corridors and increased
hunting pressure can also increase the mortality of wildlife.
2. World
scenario on Dams
Dams provide drinking water, irrigate the
land, produce hydro-electricity and prevent floods and it is understood that
over 48,000 large dams are in operation worldwide. Despite of such an alarming
number of dams being in operation, WWF report that one billion people do not
have access to safe drinking water today and more than double that number lack
basic sanitation and two billion people have no access to electricity which is
expected to rise. With the ever fast growing population of people it is
expected that by 2050 at least 1 in 4 people will be living in a country
affected by water shortages. An alarming scenario of seven billion people in 60
countries is expected to face water scarcity and to meet the demand for water,
more large dams are proposed as a key solution. But will such idea solve the
problem of those whose needs are growing by days at largest? Dams more than
often have brought benefits at the cost of environmental and society as they
destroy ecosystems and cause people to lose their homes and livelihoods.
World's
largest and most important rivers like Yangtze in China, the La Plata in South
America, and the Tigris and Euphrates in the Middle East are likely to suffer
most from indiscriminate dam buildings, warns a WWF report. WWF report, Rivers at Risk, has recognized
top 21 rivers at risk from dams being planned or under construction. The report
shows that over 60% of the world's 227 largest rivers have been fragmented by
dams, which has led to the destruction of wetlands, a decline in freshwater
species - including river dolphins, fish, and birds - and the forced
displacement of tens of millions of people. The Yangtze River has been
identified as the river at most risks with 46 large dams planned or under
construction and includes the Danube and Amazon rivers.
The
World Commission on Dams (1998) provides recommendations and
guidelines to allow balance between the destruction and benefit which however
has been neglected by the governments and are not applying these
recommendations to their dam projects as a result of which, the benefits that
dams provide - such as hydropower, irrigation, and flood control services - are
often overtaken by negative environmental and social impacts.
For
instance, inefficient agriculture irrigation system is known to waste to 1,500
trillion litres of water annually which is equivalent to 10 times the annual
water consumption of the entire African continent. The downstream communities
suffer most from dams, with rivers running dry and fish stocks decimated. Dams
disrupt the ecological balance of rivers by depleting them of oxygen and
nutrients, and affecting the migration and reproduction of fish and other
freshwater species. For example,
China - the country with the most number of dams planned or under construction
in the world - may lose endangered species such as the Yangtze River Dolphin
and many water birds if indiscriminate dam-building continues to destroy their
habitats.
Picture 1: Lesotho’s Mohale dam is one of the world's highest rock fill dams. US$2 trillion has been spent constructing 45,000 such large dams around the globe
since 1900.
So, it is
not just important that we get it right. It's critical that we get it Dam
right!
3. Indian
version of the Dam story
In 1947 there were about only 300 large dams in India.
But by 2000 the number of dams increased over 4000, more than half of them
being built between 1971 and 1989. India is next only to US and China in terms
of dam building and ranks third in the world. While about 96% of Indian dams
serve the purpose of irrigation some of these dams were built primarily for
flood control, water supply, and hydroelectric power generation. Large dam
construction has been the main form of investment in irrigation undertaken by
the government of India. By 1980 controversy on investing on dam construction
started with the Sardar Sarovar Project - centering on the balance between the
social, environmental, and economic costs of dams and their benefits,
encouraging the question of support to communities and the environment.
Most irrigation dams in India are embankment dams.
That is, they consist of a wall built across a river valley to impound water so
as to form a reservoir upstream and a system of spillways and gates to bypass
the wall so as to maintain normal river flow and convey water to a network of
canals feeding irrigated regions downstream. Power is generated but in majority
of the cases there has been loss to wildlife in the form of obstriuction of
their movement and creation of sub population.
4. The Case of
Pench Tiger Reserve – Todladoh Dam
The Pench
River was dammed at Todladoh with the main objective of generating hydro power
electricity as joint venture between the two states of Maharastra and Madhya
Pradesh. The project started in 1973. The dam is located south of Pench Tiger
Reserve in Compartment No. 229c in Chindwara district. Before the completion of
the dam, the area projected to be submerged had to be cleared thrice due to
delay in construction. Every time the trees were felled, coppicing would be
there and felling was required repeatedly. The felling work continued till the
year 1985, '86 and '87.
5. Objectives
of the study on the Todladoh Dam in Pench Tiger Reserve
a. Examine type and extent of
vegetation/forest submerged.
b. Assess the status of wildlife and their
habitat in the submergence area.
c. Examine the impacts of the reservoir on
wildlife values.
d. To suggest remedial measures on the
basis of the findings of the above objectives.
6. Scope of the study
Due to time constraints, the scope of this study is limited to;
- Examination of
the past and present scenario through literature survey.
- Assessment of
status of wildlife through field data collection and discussion with the
Park Management.
- Identification
of problems on wildlife caused by the reservoir through discussion
with the Park Officials and
subsequently, the field visit.
- Make suggestions for enhancement of wildlife value on the basis of this study and the discussions with the Park Officials, and the faculty members of the Institute.
7. Methodology
7.1. Literature
review
A thorough
review of literature on Pench Tiger Reserve especially pertaining to the
Reservoir was made. Alfred and Chandra (2002) have reported the use of the
reservoir area by faunal elements such as insects, fishes, reptiles and
amphibians. Based on these studies, conservation status and distribution of
rare and endangered animals were drawn and illustrative field guides were
developed for the museum collection of fauna occurring in Pench Tiger Reserve.
Study on wetlands and riparian Areas in Pench Tiger Reserve were conducted with
a focus on the diversity and status of fishes, waterfowls and mammals by Alfred
and Chandra (2002). Shrivastava (2002) has discussed in detail the floristic
composition, vegetation structure, conservation status and the distribution of
rare and endangered plant and plant communities in Pench Tiger Reserve.
Management plans of Pench Tiger Reserve for the year 1990 and 2005 were also
consulted.
7.2. Field
Survey
To assess
the terrestrial habitat use by various animals and to compare the habitat
condition of the draw down areas and the fringe forest a circular plot of 10 m
radius were laid at compartment 9 (Teak Forest), compartment 12 (Mixed Forest),
compartment 5 (Fringe forest area) and compartment 2 (Drawdown area) at
Karmajhiri Range.
To find out
the use of fringe habitat all pellet/dung groups for all animals that were
found in the plots were counted irrespective of freshness or the dryness. By
ocular estimation the percentage of canopy cover was made in two plots of
compartments 9 and 12 (fringe area plots). In order to compare the ground cover
in the fringe forest and the draw-down area and to assess the habitat use by
animals the following data were recorded in all the plots;
a) % of grass
(dry and wet)
b) % litter
c) % barren
soil
d) % weeds
e) Number of
pellets in each plot of individual animal species.
Grass
species where noted to find the difference in species composition if any
between the fringe forest and the draw-down areas. The number of pellet/dung
groups for all animals were counted and compared for the two different habitats
to asses the habitat use by animals.
8. Results
and discussions
Literature
survey revealed the following results;
8.1. Extent
of submergence
A
considerable area in Pench Tiger Reserve comes under submergence during 4 - 5
months commencing with the monsoon. After water recedes, Compartment No. 1, 2
and 3 comes under drawdown area and gets covered extensively with Parthenium hysterophorus. The Parthenium cover over the years has led
to suppression of natural flora and vast hectares of land are deprived of
forage on which the herbivores depend. The decaying logs and woods carried by
water studded along the banks of the reservoir have made the bank unproductive.
Of the total area submerged which is about 54.57 km2, 75% of the submergence area falls within the Park boundaries covering about 17.24 km2 in Karmajhiri Range and 37.27 km2 in Gumtara Range and remaining 25% (19.93 km2) falls in Jawaharlal NP in Maharastra. The details of the different water levels of the dam are as follows;
- Maximum Flood Level - 493.60 meters
- Minimum Reservoir Level - 464.00 meters
- Level at heavy rainfall (FTL) - 490.00
meters
- Reservoir after heavy rainfall - 2 - 3
meters (Data source; Management Plan 1990)
- Maximum depth of water at FTL - 68.10
meters
- Expected life span of the dam - 100 yrs
- The extent of draw down area 11.74 km2 (Data source; Management Plan 2005)
Figure 1. Map
of study sites depicting the location of sampling plots in different habitat
types.
8.1.1. Range
and compartment wise area under submergence
The dam
has submerged at least three
categories of land
viz. reserve forest,
protected forest and
revenue land covering
two Ranges of Gumtara and Karmajhiri in the Madhya Pradesh part
of the Tiger
Reserve. The extents of coverage
are detailed below compartment wise.
Table 1. Details of submergence areas in the Karmajhiri
Range in Pench Tiger Reserve
Compartment
No.
|
Area in
hectare
|
Area
under submergence
|
Total
area
|
1
|
115.40
|
510.10
|
625.50
|
2
|
153.80
|
143.70
|
297.50
|
3
|
228.70
|
414.60
|
643.30
|
4
|
346.10
|
277.40
|
623.50
|
5
|
681.40
|
53.00
|
734.40
|
6
|
517.40
|
4.00
|
521.40
|
7
|
547.80
|
16.20
|
564.00
|
9
|
322.30
|
42.50
|
364.80
|
26
|
287.90
|
72.80
|
360.70
|
27
|
283.40
|
117.40
|
400.80
|
29
|
313.40
|
72.90
|
386.30
|
1724.60
|
Table 2.
Details of submergence areas in the Gumtara Range in Pench Tiger Reserve
Compartment.
No.
|
Area in
hectare
|
Area
under submergence
|
Total
area
|
172
|
200.00
|
10.50
|
210.50
|
173
|
190.60
|
47.00
|
237.60
|
174
|
155.10
|
42.50
|
197.60
|
175
|
225.00
|
22.70
|
247.70
|
176
|
217.10
|
35.60
|
252.70
|
177
|
249.30
|
32.40
|
281.70
|
194
|
222.20
|
6.10
|
228.30
|
195
|
185.00
|
6.50
|
191.50
|
196
|
318.50
|
54.60
|
373.10
|
197
|
96.70
|
105.20
|
201.90
|
198
|
189.40
|
102.40
|
291.80
|
199
|
87.40
|
226.60
|
314.00
|
200
|
152.40
|
35.60
|
188.00
|
201
|
265.50
|
53.80
|
319.30
|
202
|
218.40
|
11.70
|
230.10
|
203
|
199.50
|
4.00
|
203.50
|
209
|
271.40
|
2.40
|
273.80
|
210
|
253.30
|
24.70
|
278.00
|
211
|
104.80
|
170.00
|
274.80
|
213
|
162.00
|
57.50
|
219.50
|
214
|
209.60
|
29.20
|
238.80
|
215
|
181.70
|
45.30
|
227.00
|
216
|
193.00
|
34.40
|
227.40
|
222B
|
11.30
|
11.30
|
|
223B
|
114.50
|
114.50
|
|
224
|
177.50
|
177.50
|
|
225
|
287.30
|
287.30
|
|
226
|
285.10
|
285.10
|
|
227
|
227.00
|
227.00
|
|
228
|
179.20
|
53.80
|
233.00
|
229
|
107.70
|
293.70
|
401.40
|
237
|
226.10
|
35.60
|
261.70
|
238
|
3.20
|
226.70
|
229.90
|
239
|
212.20
|
116.10
|
328.30
|
Total
|
2989.3
|
Table 3.
Total area of Protected forest under submergence in the Pench Tiger Reserve
P 84
|
-
|
270.60
|
270.60
|
P 85
|
17.20
|
189.10
|
206.30
|
Total
|
459.70
|
Table 4. Total
area of Revenue land under submergence in the Pench Tiger Reserve
Paraspani - Khurd and Umrighat
|
-
|
278.10
|
278.10
|
Total
|
278.10
|
Table 5. Total
land categories with their extent at various Ranges and Revenue areas below:
Gumtara
Range
Reserve forest
|
-
|
2989.30
|
Protect forest
|
-
|
459.70
|
Revenue level
|
-
|
278.10
|
Total
|
3727.10
|
Karmajhiri Range
Reserve forest
|
-
|
1724.6
|
Grand Total of area coming under
submergence
Grand total
|
-
|
5451.70
|
Table
6. Split up of area coming under Submergence
Karmajhiri
|
Gumtara
|
Total
|
|
Forest Land
|
1724.60
|
3449.00
|
5173.60
|
Revenue Land
|
-
|
278.10
|
278.10
|
Total
|
1724.60
|
3727.10
|
5451.70
|
8.1.2. Total submergence area based on digital data
Based
on LISS III digital data twelve different vegetation and land cover categories
have been delineated in PTR in which the submergence accounts to about 11.74
km2 of which 1.55% is Land cover category. While the
extent submergence area
has been well
documented, the total
volume of timber
extracted from this
area has not been maintained
making it very difficult
to guesstimate the
biomass content of the
zone of submergence 34 years back when the
felling operation started with
the launch of Todladoh
Dam for generating hydroelectric power for
the two states
of Maharashtra and
Madhya Pradesh over
the River Pench.
8.2. Types
of forest submerged
An over view of Vegetation in Pench Tiger
Reserve
As per
Rodger's and Panwar's classification, Pench Tiger Reserve is in Bio-geographic zone 6A (Deccan
Peninsula) and SFRI, Jabalpur, report of the flora of Pench Tiger Reserve
confirms the following categories of forest based on the revised classification of forest by Champion
and Seth (1968):-
5BC1c - South Indian Tropical Moist Deciduous
(slightly moist) Teak Forest
5A/C1b (iv) - Southern Tropical Dry Deciduous
Teak bearing forests
5A/C3 - Southern Tropical Dry Mixed Deciduous
forest
5BC1c - South Indian Tropical Moist Deciduous
(slightly moist) Teak Forest
All the teak
forests of southern slopes of Satpura range, stretching from southwest Kandlai
to Karmajhiri along the Pench River have been classified under this category
based on the average rainfall received in Soeni district over the past 95 years
which is 1308.16mm. The Pench National Park and Pench Sanctuary area cover mainly two sub types of forest as described
below:-
Sub type 5A/C 1b - Southern Tropical Dry
Deciduous Teak Bearing Forest
Sub type 5A/C 3 - Southern Tropical Dry Mixed
Deciduous forest
Type 5A/C1b
covers about 29% of the Park and 35% of the Sanctuary area, the rest of the
area falls under Southern Tropical Mixed Deciduous forests - 5A/C3 type. There
is no sharp demarcation line between the above two types in the Pench National
Park and Sanctuary area.
5A/C1b (iv) - Southern Tropical Dry Deciduous
Teak Bearing Forest
This type of
forest is found along the Pench River as well as on the hill slope of the
Bodanala and Kalapahad area. Most of this type of forest in Soeni and Chindwara
(within the Park boundary) has gone under submergence of the Pench
Hydroelectric Project. The density of such crop varies from 0.6 to 0.8 and teak
forms about 25% to 50% of the total crop.
i. Over-wood
The
associates of Teak (Tectona grandis)
such as Dhawra (Anogeissus latifoilia),
Lendia (Lagerstroemia parviflora),
Saja (Terminalia tomentosa), Salai (Boswellia serrata), Moyan (Lannea coromandelica), Mahua (Madhuca indica), Dhoban (Dalbergia paniculata), Mokha (Schrebera swietenioides), Siras (Albezzia lebbec), Tendu (Diospyrus melanoxylum), Bija (Pterocarpus marsupium), Tinsa (Ougeinia oojeinensis) and Haldu (Adina cordifolia). The trees of Koha (Terminalia arjuna) and Jamun (Syzygium cumini) are found along the
large water bodies, riverbanks and small islands in the riverbed.
ii. Underwood
There could
have been an under wood of middle density comprising of Anola (Emblica officinalis), Dhaman (Grewia tiliaefolia), Kumbhi (Cassia fistula), Ghont (Zyzyphus xylopyra), Baranga (Kydia calycina), Amaltas (Cassia fistula), Ashta (Bauhinia racemosa), Dainkamali (Gardenia resinifera), etc. Bamboo (Dendrocalamus strictus) occurs sparsely
restricted to some valleys of Compartment No. 25, 27, 41, 42, 21, 22, 230, 331
and 232.
iii. Shrubs
Shrubby
species such as Seharoo (Bauhinia retusa),
Bekal (Gymnosporia spinosa), Dhawai (Woodfordia fruticosa), Karonda (Carissa carandas), Jhau (Tamarix ericoides) that occurs in river
beds could have been submerged.
iv. Grasses
that could have been submerged
Apluda mutica, Digitaria setigena,
Heteropogon contortus, Eragrostis tenella, Themedia quadrivalvis, Themedia
triandra, Setaria glauca, Sorghum nepalense and Schima nervosum that usually occur in the ground floor along with
many other less prominent grass species.
v. Climbers
Chilati (Acacia pinnata), Mahulbel (Bauhinia vahlii), Palabel (Butea superba) that are common along the
riverbed and water bodies could have been submerged.
vi. Weeds
Lantana camera and Van
Tulsi (Deadalacanthus purpurascens)
are present in most of the area especially in the compartment located on the
periphery of PA.
5A/C 3 - Southern Tropical Dry Mixed
Deciduous forest
Mixed
forests are found in small patches. Generally the forests containing less than
25% teak had been recognized as mixed forests. This type of forests covers
large tracts of National Park and Sanctuary. It can be recognized as the
prominent vegetation type in the National Park and Sanctuary.
The floristic composition of 5A/C3 type of
forests in Pench
i. Overwood
Lendia (Lagerstroemia parviflora), Saja (Terminalia tomentosa), Dhaora (Anogeissus latifolia), Salai (Boswellia serrata), Garari (Cleistanthus collinus), Bhirra (Chloroxylon sweitenia) together form 60%
of the crop. Dhaora (Anogeissus latifolia)
is plentiful on deep loamy soil in better quality forest. Salai (Boswellia serrata) and Bhirra (Chloroxylon sweiitenia) become prominent
in poor quality soil. Patches of Garari (Cleistanthus
collinus) can be seen near Bodanala area adjoining Ambadi village and as
well as compartment 26, 37, 29, 30 and 4 near Chindwara.
ii. Underwood
Khair
(Acacia catechu), Aonla (Emblica
officinalis), Bhirra (Chloroxylon
sweitenia) and Palsah (Butea
monosperma) form the major components of the under - forests.
iii. Bamboo
Locally
present in some areas but their proportion is very low in mixed forests.
iv. Shrubs
The shrubby
layer compose of Siharoo (Baihinia retusa),
common in compartment 36; growing gregariously
in open areas are Ber (Zizyphus
jujuba), Marorphali (Helicteres isora),
Adusa (Adatoda vasica), Mainpal (Randia dumentorum), Kakai (Flacourtia indica), Dhawai (Woodfordia fruticosa) and Karonda (Carissa carandas)
v. Herbs
Herbaceous
flora consists of few seasonal herbs growing sparsely. The most common herbs
are Jangli Tuar (Moghania semialata),
Chirayata (Andrographis paniculata),
Van Tulsi (Daedalacanthus purpurascens),
Jangli baigan (Solanum spp.), Kali
Musli (Curculigo orchioides) and
alike.
vi. Grasses
A wide
variety of grasses cover most of the ground area. Some of the common species
are Heteropogon contortus, Digitaria
ciliaris, Apluda mutica, Dicanthium annulatum, Themedia triandra, Themedia
quadrivalvis, Euliopsis binata etc. The grass growth is noticed profusely
under slightly open crop and in clear patches.
vii. Climbers
The
important climber species are Makoi (Zizyphus
oenoplia), Palabel (Butea superba),
Ramdaton (Smilax zeylanica), Satawar
(Asparagus racemosa), Gunj (Abrus precatorius), Gurar (Milletia
auriculata), Kevanch (Mucuna prureins)
and Mahulbel (Bauhinia vahlii).
viii. Weeds
Weeds are
prevalent in the over grazed area in most of the forest compartments in both
Soeni and Chindwara part of the Park. The common weeds are Gokhru (Xanthium strumarium), Gulmehandi (Lantana camara), Chirota (Cassia tora) and Parthenium species. The Parthenium
species occurs in open areas near Alikata and Chedia forest areas as well
as along the submergence area if the Pench River. Thick Lantan camara can be seen in areas within low density forests near
habitation. The following associations of various grass species have been
recognized in the Park and Sanctuary area:-
a)
Heteropogon contortus - Themedia triandra Community
This
community comprise of Rottboellia
exltata, Apluda mutica, Seteria glauca. Paspalidium flavidum and Bothrichloa
odorata, Digitaria granularis, Sorghum nepalensis as associates. This can
be seen in compartment along Allikata - Karmajhiri road, near Mannu talab along
Gurshalghat - Baghdeo Road.
b) Themedia
quadrivalvis - Apluda mutica - Rottboellia exaltata community
This
community has been seen associated with Iseilema
laxum, Bothrichloa pertusa, Eragrostis tenella, Rottboellia performata and
can be seen in compartments along Kala Pahar - Piorthari - Chhindimata road.
c)
Heteropogon contortus - Digitaria granularis community
Associated
with Apluda mutica, Aristida adsensionis,
Sorghum nepalense and Eragrostis
tenella - seen in compartment 42, 41, 10 and 6
d) Heteropogon contortus - Bothriochloa pertusa community
Associted
with Eragrostis tenella, Dactyloctenium
aegypticum, Chloris barbata, Hackelochloa granularis, Echnochloa colonum,
Paspalidium flavidum, Brachiaria ramosa, Eragrostis bifaria, Setaria tomentosa,
Oplismenus burmanni, Alloteropsis cimicina and Cynodon dactylon. It can be seen in open forest areas of Turia,
Khamrith and Satosha beats.
e) Saccharum
spontaneum community
Associated
with Coix gigantea, Eragrostis diarrhena,
Imperata cylindrica along the river Pench near Raiyakassa, Chhedia,
Bodanala and other moist localities.
f)
Eragrostis tenella community
In some areas on shallow soils, pure extensive patches
of Eragrostis tenella are present mostly visible
at compartment 26, 27 and 3 of Alikatta
circle.
8.2.1. Impact
of submergence on vegetation: What could have been submerged?
To come to
the conclusion of what could
have been submerged is an important question that has
to be answered in a closest
possible way so as to understand the pre-reservoir habitat for the
animals of Pench Tiger Reserve. To the best of the information available
and to the best of the understanding
made possible by field visits and as per
the various survey records
on the Pench vegetation, the forest type, 5A/C1b (iv) - Southern Tropical Dry
Deciduous Teak Bearing Forest (based
on Champion and Seth's revised
forest classification (1968)) must have been the victim of
the Pench Dam. A ecologically
viable riparian forest along the Pench
River which could
have been the primary habitat of
the most endangered big cat the Royal Bengal Tiger have been submerged. Barring the habitat loss to
wild animals a beautiful stretch of this type of forest in Soeni and Chindwara
(within the Park boundary) has gone under submergence of the Pench
Hydroelectric Project. The density of such crop varies from 0.6 to 0.8 and teak
forms about 25% to 50% of the total crop (source management plan).
Large chunk
of Overwood which is mainly
dominated by teak (Tectona grandis)
and its associates of such as Dhawra (Anogeissus latifoilia), Lendia (Lagerstroemia parviflora), Saja (Terminalia tomentosa), Salai (Boswellia serrata), Moyan (Lannea coromandelica), Mahua (Madhuca indica), Dhoban (Dalbergia paniculata), Mokha (Schrebera swietenioides), Siras (Albezzia lebbec), Tendu (Diospyrus melanoxylum), Bija (Pterocarpus marsupium), Tinsa (Ougeinia oojeinensis) and Haldu (Adina cordifolia) and the trees of Koha (Terminalia arjuna) and Jamun (Syzygium
cumini) which are found along the large water bodies, riverbanks and small
islands in the riverbed have come under submergence and it is now totally gone.
In the form
of Underwood a middle density
comprising of Anola (Emblica officinalis),
Dhaman (Grewia tiliaefolia), Kumbhi (Cassia fistula), Ghont (Zyzyphus xylopyra), Baranga (Kydia calycina), Amaltas (Cassia fistula), Ashta (Bauhinia racemosa), Dainkamali (Gardenia resinifera), etc. have been
submerged. A chunk of Bamboo (Dendrocalamus strictus) that could have been growing along the riparian zone
providing food to animals has been submerged.
Shrubby species such as Seharoo (Bauhinia retusa), Bekal (Gymnosporia spinosa), Dhawai (Woodfordia fruticosa), Karonda (Carissa carandas), Jhau (Tamarix ericoides) that occurs in river
beds could have been submerged.
Grasses such as Apluda mutica, Digitaria setigena, Heteropogon contortus, Eragrostis
tenella, Themedia quadrivalvis, Themedia triandra, Setaria glauca, Sorghum
nepalense and Schima nervosum
that usually occur in the ground floor along with many other less prominent
grass species could have gone under submergence although records do not speak
much about the grasses that occurred along the Pench River.
Similarly, Climbers like Chilati (Acacia pinnata), Mahulbel (Bauhinia vahlii), Palabel (Butea superba) that are common along the
riverbed and water bodies could have been submerged.
8.3. Status of wildlife and their habitat in the
submergence area
Literature survey on fishes and water fowl and the field visits (survey
for ungulates) indicated the following result;
8.3.1. Fishes
50 species
recorded of which 17 known earlier and 33 added later (ZSI Report). Most
species are local while some species such as Labeo, Cirrhina and Catla
are introduced. Tor putitora, a game
fish is known to exist in the but not yet recorded by PTR and ZSI. The largest
number of fish belongs to carp group and includes species of Puntius, Labeo, Cirrhinus, Rasbora, Catla,
Barilius, Chela, Danio, Esomus, Aspidopariya, Garra, Salmostoma and Tor. The second largest group is catfish
represented by Wallago, Ompok, Mystus,
Rita, Clarias, Bagarius, Pseudeutropius and Heteropneustes. Besides these, miscellaneous other species include Channa, Mastacembelus, Chanda, Xenentodon,
Nototerus, Oreochromis, Glossogobius, Noemacheilus and Lepidocephalichthys.
The
Reservoir in PTR was created by the construction of dam over Pench River. The
construction of a dam interferes with the riverine environment, inevitably
affecting the fishery resources. The effects of the interference may be
variously armful, beneficial or indifferent. The effects of dam construction on
populations can be categorized into two headings viz. obstructional and ecological.
Figure 2. Compartments
in Pench Tiger Reserve affected by submergence
The dam acts
as a physical barrier to migration and tends to prevent access of the fish to
their usual breeding, rearing and feeding grounds. The denial of migration may
result in permanent and irrevocable reduction of fish stocks ranging from
lowering the levels of abundance to complete extermination.
The
ecological changes brought about by dam construction adversely affect both the
migratory and non - migratory species of fishes. The ecological changes include
the conversion of running water body into a water body of slow discharge
characteristics, fluctuations in water levels,, inundation of spawning grounds,
alterations in the physico-chemical conditions of spawning areas in upper
reaches, disappearance of marshlands constituting the spawning and silting
patterns. These changes may result in the failure of spawning or ineffective
spawning of many fishes of commercial importance.
The impact
of the obstructional effects would be felt only by local migratory fishes like
the Mahseer, major carps and some catfishes which are monsoon breeders,
generally migrating upstream in search of breeding grounds where as the impact
of ecological changes will be felt by almost all the species.
In recent
years, some commercially important species such as Catla, Cirrhinus and Labeo have been introduced in the waters
of Pench. The commercial varieties generally are fast breeding while the local
species cannot breed as fast as them.
So, it is to be seen that in a matter of time the fast breeding species would
replace the local species.
8.3.2. Status
and diversity of waterfowls
Of the 242
species of birds recorded from PTR 60 species of them are waterfowls that
directly depend on the wetland for their survival. 36 out of them are residents
while 24 are winter migrants. The wetland serves as feeding and resting station
for the migrant species and their seasonal influx serves to increase the
diversity of the wetland site. The
waterfowls recorded from PTR belongs to 15 families viz. Podicipitidae,
Phalacrocoracidae, Ardeidae, Ciconiidae, Threskiornithidae, Anatidae, Gruidae,
Rallidae, Jacanidae, Charadridae, Rostratulidae, Recurvirostridae, Burhinidae,
Glareolidae, and Laridae. Besides waterfowls, a large number rof other bird
species such as osprey, fishing eagle and kingfishers visit the reservoir and
are totally or casually dependent on it for survival. Although resident species
found in the wetland area do not take very long flights like migratory birds,
they do undertake local movements depending on drought/water conditions.
The
waterfowls are valuable and highly visible part of the wetland environment
where they rest, feed and chatter before resuming their journey. Without
nesting territory, wintering grounds and resting areas between the two,
waterfowl populations would simply not exist. In the last few decades waterfowl
populations have diminished markedly, a direct result of the reduction in the
amount of suitable habitat clearly establishing the fact that the wetlands are
important for their conservation. Major factors affecting the waterfowls
adversely are: (i) Depletion and change in habitat on account of anthropogenic
pressure and (ii) poaching or hunting of waterfowls for meat, eggs and
feathers. Development and restoration of wetland habitat and effective check on
poaching are essential for their conservation.
8.3.3. Mammals
in riparian areas
Although, no
aquatic mammals are recorded in PTR, still, its wetland and riparian area
attracts most of the 38 species of mammals recorded from the reserve, so far.
These animals differ from small sized species like rodents and hares to larger
one like Wild pigs (Sus scrofa) and
Chital (Cervus axis). A large number
of grazing and browsing animals like Blue Bull (Bosalephus tragocamelus) and Sambar (Cervus unicolor) are supported by the riparian areas. These animals
frequent the riparian area mainly in search food, water and protective cover,
which also act as limiting factors affecting distribution.
The
vegetation growing around the riparian area provides food to the herbivores and
protective cover to both herbivores and carnivores. The growth of vegetation is
directly related to the availability of water. During the monsoon, the
vegetation is at its luxuriant best and there is no shortage of food plant.
However, with the advent of winter, water level starts plunging and by
mid-summer, when the temperature remains very high, there is acute shortage of
water, vegetation dries creating such a condition that the animals are in
difficult position. Population of both the herbivores and carnivores shrink in
size only reviving with the onset of rains. In this manner, variations in
climatic conditions act as limiting factors controlling the distribution of
mammalian species.
The wild
animals of Pench are known to congregate nearby the reservoir between the month
of May and last week of June as the water level is known to drop drastically.
By the second week of June, pre-monsoon showers are received in the area and
the animals disperse into inner reaches of the forest as the food become
plentiful with the onset of rains bringing the life back to the jungle. The
post monsoon season brings about a period of abundance when food, shelter and
water are plenty resulting into growth and multiplication of all forms of life
(Maximum biomass period). The coolest month being December with a minimum
temperature being 11.80C and this marks the onset of food and water
scarcity for many animals which becomes acute by the winter season. The mean
normal annual rainfall of the area is 1319.75mm. The maximum water is received
between Junes - Septembers.
The data
that was collected revealed that the Chital used the drawdown areas the most
owing to growth of plenty of Cyonodactylon
grass. Heteropogon contortus grass
that was found in maximum in the fringe forest where the plots were laid could
be the good food source for the Sambar and Nigai that were found to use the
fringe forest more than the drawdown areas. The dung/pellet/dropping count
showed Langur and the Wild Pigs use the submerged lesser than Sambar, Chital
and the Nilgai.
Figure 3. Habitat use by ungulate species in
Pench Tiger Reserve
Figure 4. Grass
availability in sampling plots in different habitat types in Pench Tiger
Reserve.
Figure 3
above indicate Chital using both the habitat but more towards the drawdown
areas where the opening is more and also indicate that the Chital dominate the
ungulate population. The ungulate concentration is high towards the reservoir.
Figure 4
shows the grass coverage in all the plots almost equal indicating that the
fringe forest are as good as the drawdown and open areas which tells that
the drawdown areas used more than
fringe forest not because
of food but for other reasons
which could be easy escape, availability of water
and good breeding ground.
8.3.4. Reptiles
By way of reptiles, it is learnt that Mugger (Crocodylus palustris) is the top
carnivore in the reservoir and three testudines Indian flap shell turtle (Lissemys punctata), Indian soft shell
turtle (Aspideretes gangeticus) and
Peninsular black shell turtle (Melanochelys
trijuga) which are omnivorous are found.
8.3.5. Amphibians
By way of Amphibians, seven species of order
Anura has been recorded from PTR so far that use the aquatic habitat. The most
common is Indian bull frog (Rana tigerina), painted frog (Kaloula pulchera), common tree frog (Polypedates maculatus), Ornate
Microhtlid Frog (Microhyla ornata -
Dumeril & Bibron), cricket frog (Rana limnocharis), burrowing frog (Tomopterna breviceps) and common toad (Bufo melanostictus).
8.3.6. Invertebrates
The ZSI
report on lower animals have recorded that there are; Odonata 10 species, Plecoptera 1 species
Orthoptera 44 species Dermaptera 6 species Isoptera 5 species Hemiptera 14
species Coleoptera 32 species, Lepidoptera 45 and 56 species of moths and
butterflies.
8.4. Examination of the impacts of the reservoir
on wildlife values
8.4.1. Negative
Impacts
- About 54 km2 of prime tiger
and other animal habitat lost to submergence.
- Loss of prey base because of which
predators must have been lost
- A chunk of riparian habitat with lots of
nesting places and food source lost impacting the wildlife. It needs to be
seen if the indigenous fishes are not affected by introduced ones
8.4.2. Positive
Impact
- New habitat of open grassland in the
draw-down areas
- Water availability round the year for
wildlife because of collection in the reservoir
- Increased congregation of ungulate near
the reservoir
- The peripheral shallow area of the
reservoir has gradually been colonized by hydrophilic vegetation, grasses
and sedges, which provide adequate food for the waterfowls that increased
migratory waterfowl visit.
- Increased fish species diversity because of 33 species introduction
8.4.3. Future
impacts of the Reservoir on the wildlife
The future
impact of the Dam is obviously visible very positively. With the management
manipulations on the vegetation composition on the drawdown areas and the
management of aquatic ecology through management intervention, Pench reservoir
is expected provide water to a large population of ungulate that will support a
good number of tigers. While future of so many protected areas may be grim,
Pench may survive better than others with the partial support of water supply
to wild animals which is must.
8.5. Problems
of the submergence zone
8.5.1. Weed
growth
Growth of weeds, like Parthenium, Cassia tora, Dhatura and Argemone mexicana in the draw down area of the submergence which
leads to the elimination of the native flora, mainly Cynodon dactylon. Survey revealed at least 10 - 20 percent of
the plot to be occupied by weeds as shown below.
Figure 5. Percentage
occurrence of weeds in sampling plots in different habitat types in Pench Tiger
Reserve.
8.5.2. Degradation of soil condition
Literature
survey and field visit reveal that the erosion of soil in the nalas and streams
feeding the reservoir is a cause of concern as this is leading to excessive
silting in the wetland.
8.5.3. Illegal fishing in the reservoir
Illegal
fishing used to be a major problem in the tiger reserve. While this problem has
been tackled effectively, the threat from illegal fishing still persists.
Picture 2. Cheetals
drinking water in the soon going to be drawn back water (Photo: Management of PTR
Picture 3. Most
of the trees in the submergence zone were felled prior to the filling up of the
reservoir. The existing trees serve as roosting sites but are rapidly decaying (Photo: Author)
Picture 4. Terns
recently exposed due to lack of proper habitat (Photo courtesy: Park Management of PTR)
8.5.7. Inadequate
knowledge about the wetland
The ZSI study
provides a faunal list but the wetland dynamics and detailed inventory of the
insect, arachnid, fish and amphibian fauna is required for proper scientific
management of the wetland. But the effect of agricultural pollutants including
the use of pesticides in the areas upstream before the river enters the park
has to be studied.
Picture 5. This could
have been a continuous stretch before the reservoir was built
Picture 6. Pench
submergence area now with the back water flow of the Dam (Photo: Author).
9. Suggestions
to mitigate the problem after the creation of Dam
9.1. Construction of earthen dykes
To retain receding water; a series of dykes in each major nallah flowing
into the Pench River is proposed in order to retain water and reduce siltation
in the reservoir. This will include anicuts and earthen dykes in the
submergence area. This will result in;
i. Stable
water bodies for waterfowl, especially migratory ones and also provide easily
accessible water to the wildlife during the pinch period.
ii. Stable
and permanent water that will lead to growth of vegetation in suitable areas of
these reservoir leading to provision of green fodder and cover for the animals
including ambush cover to the predators.
iii. Trees of suitable native species can be planted along the
upper margins of these water bodies to provide nesting and roosting sites to
the water fowl. The available roosting and nesting sites in the reservoir are reducing with the dying & decaying of original trees.
Figure 6. Proposed sites for construction of earthen dykes on feeder nallahs to retain water for pinch period in Pench Tiger
Reserve.
9.2. Erection of temporary ex-closures
To
initiate growth of fodder for pinch period, Blocks of ex-closures, about 10
hac. each are proposed to be erected each year and efforts made to help the
growth of native grass and fodder species. This will be especially useful for
the herbivores during the summer pinch period when in the resource of weeds,
the natural grass growth of Cynodon
dactylon is affected and there is a shortage of fodder for the herbivores.
These ex-closures will be cleared of weeds by manual uprooting and the native
grasses and other vegetation will be encouraged. These
exclosures will be taken out every year before submergence and erected soon
after water recedes from the area.
9.3. Development
of perching, roosting and nesting sites for birds
As almost
the entire tree growth of the submergence area was cleared, only a few trees
along the banks and the main original river course remain. There are also dying
and disappearing; slowly leading to a shortage in nesting and roosting trees,
especially for waterfowl like Darters, Cormorants and Painted Starks. In order
to mitigate this shortage and provide for new roosting and nesting trees to be
adopted and protected with the help of erection of tree guard and soil working
of native tree species like Jamun, (Syzygium
cumini) Ber (Zygiphus ssp) and
Arjun (Terminalia. arjuna).
9.4. Soil and
moisture conservation in streams feeding the submergence area
The
health of the wetland in Pench Tiger Reserve depends to a large extent, on the
quality of water fixing into the submergence. In order to ensure the health of
the wetland the silt load of the streams feeding the Pench river has to be
reduced. While some amount soil moisture conservation activities has been done
in the preceding years, one comprehensive sequence of treatment measures needs
to be implemented. For this the nala feeding the Pench River & their
Catchment needs to be treated urgently; for this the sequence of operations is
proposed in following areas (compartments with pink colour).
Figure 7. Soil
and moisture conservation, boulder Check-dam in Pench Tiger Reserve.
9.5. Protection
of nesting sites of water fowl
In
addition to birds like the Cormorants, Darter and Painted storks nesting on the
margins of the submergence area, several species of birds use the islands in
the reservoir for nesting. Most prominent amongst these is the Little Tern
(Sterna albifrons) the Indian River Turn and the Small Indian pantincole. These
birds use the islands in the reservoir for nesting. As their egg laying time is
well into the dry season, most of the islands used by these birds develops a
land bridge with the mainland as the water recedes. This leads to serious
problems with predators like Jackal and Jungle Cat destroying the eggs of these
ground nesters. This is especially true of an island located near Sambar matta,
which is the favoured nesting ground of the highly endangered Little Tern.
These islands are proposed to be protected from such predators by erecting a
temporary fencing structure every year during egg laying season and taking out
the chain link fencing as the season over and area submerged.
9.6. Patrolling of wetland
The
submergence area is subjected to grave threat from illegal fishermen. As the
submergence straddles two states protection requires coordination and fast
response. The reserve has 4 motor boats without board motors. These have their
limitations especially in areas where the depth of water is low as is the case
from November to June. It is therefore proposed that for effective patrolling
of the reservoir 2 swamp boats are to be acquired. These will cost about Rs.9.0
lakhs each, and will be used to effectively eliminate illegal fishing in the
reservoir. Further for effective patrolling; two water scooters are also
proposed to be acquired for quick apprehension of the illegal intruders. In addition for effective patrolling camping
equipments like tents, camp cots, solar lanterns etc and equipments like
wireless, batteries, search lights etc are proposed to be provided to the staff
patrolling the wetland. In addition a provision for the maintenance cost of the
boats and equipments including POL has to be provided.
9.7. Study of the Pench Wetland
In
order to properly understand the wetland dynamics and for the management of the
wetland, a comprehensive study of the wetland is urgently required to be
commissioned. A reputed national institute specializing in such studies needs
to go in to the dynamics of the wetland and a detailed inventory of the insect,
arachnids, fish and amphibian fauna to be done. Further the effect of
agricultural pollutants including the use of pesticides in the areas upstream
before the river enters the park and mitigation measures have to be studied.
9.8. Weed eradication
The
total submergence area of the Totaladoh dam in PTR is 54.5 sq km. Out of which
about 50% area is under permanent submergence and remaining are opens when
water recedes. The water regime this area is high in compression to surrounding
forest area. There is a lot of silt brought with the debris during rainy
season. Due to change in water regime and supply of seeds of weeds like
Parthanium, Cassia tora, Dhatura metel etc form the catchments area; brought
with silts, a lot of weeds have come up in these areas. These weeds are
suppressing the growth of native vegetation and being unpalatable, bring a lot
of adverse effects on the diets of herbivores.
9.9. Public Awareness and Education
In order to ensure to continued support of the local
population and in order to educate and offer recreational avenues to students,
an intensive public awareness and education programme is absolutely necessary.
In order to achieve this, apart from publicity material like brochures, posters
etc., regular camping and nature camps of school and college going children
including those residing in villages close to the park is proposed. The
existing building at Khawasa will be converted in to a facility that will
enable students to camp. From here they would be conducted in side the park.
They existing mini bus is inadequate for this purpose and there for an
additional vehicle is proposed to be acquired for this purpose. Further,
appropriate training programmes for such students will be organised.
9.10. Community participation
9.10.1. Eco-tourism
The
local community is already involved in eco-tourism. They are at present
involved directly as Park Guides and as boatmen. This association will be
expanded and more local villagers will be involved in future especially in the
promotion of boating facilities for tourists and training of the local youth as
Guides for Bird Watching trips. The boats have already been purchased. A few
rafts for the rafting done in Pench river is proposed. At present there is only
a single raft and rafting is conducted by the Gumtara Eco-development
Committee.
9.10.2. Village Eco-development
Eco-development
is designed to reduce negative impacts of local people of 15 villages 5 Km
around the submergence area on biodiversity and increase collaboration of local
people in conservation by conducting participatory micro planning and providing
implementation support in Ecodevelopment villages. Local people's reciprocal
commitments can be achieved by implementing the alternative livelihoods and
resource used; financed by village ecodevelopment fund. To strengthen the
essential infrastructure of the villages, village ecodevelopment works should
be carried out. From the ecodevelopment fund water harvesting structure,
irrigation facilities, farm improvement, Fuel and fodder programme, capacity
building and poverty elevation programme will be carried out as per the
requirement and Micro-plan of the village.
10. Summary
The present study titled ‘Evaluation of the
impact of submergence on wildlife values in Pench Tiger Reserve and suggesting
remedial measures’ was undertaken with the following objectives:
- Examine type and extent of vegetation/forest submerged.
- Assess the status of wildlife and their habitat in the submergence area.
- Examine the impacts of the reservoir on wildlife values and
- To suggest remedial measures on the basis of the findings of the above objectives
Due to time constraints, the scope of this study was limited to;
- Examination of the past and present scenario through literature survey
- Assessment of status of wildlife through field data collection and discussion with the Park Management
- Identification of problems on wildlife caused by the reservoir through discussion with the Park Officials and subsequently, the field visit and make suggestions for enhancement of wildlife value on the basis of this study and the discussions with the Park Officials, and the faculty members of the Institute.
The Pench
River was dammed at Todladoh with the main objective of generating hydro power
electricity as joint venture between the two states of Maharastra and Madhya Pradesh.
The project started in 1973, however, the dam became functional in 1991. Of the
total area submerged which is about 54.57 km2, 75% of the
submergence area falls within the Park boundaries covering about 17.24 km2
in Karmajhiri Range and 37.27 km2 in Gumtara Range and remaining 25%
(19.93 km2) falls in Jawaharlal NP in Maharashtra.
To assess
the terrestrial habitat use by various animals and to compare the habitat
condition of the draw down areas and the fringe forest a circular plot of 10 m
radius were laid at compartment 9 (Teak Forest), compartment 12 (Mixed Forest),
compartment 5 (Fringe forest area) and compartment 2 (Drawdown area) at
Karmajhiri Range. To find out the use of fringe habitat all pellet/dung groups
for all animals that were found in the plots were counted irrespective of
freshness or the dryness. By ocular estimation the percentage of canopy cover
was made in two plots of compartments 9 and 12 (fringe area plots). In order to
compare the ground cover in the fringe forest and the drawdown area and to assess
the habitat use by animals the following data were recorded in all the plots;
- % of grass (dry and wet)
- % litter
- % barren soil
- % weeds
- Number of pellets in each plot of individual animal species.
Grass
species where noted to find the difference in species composition if any
between the fringe forest and the drawdown areas. The number of pellet/dung
groups for all animals were counted and compared for the two different habitats
to assess the habitat use by animals. The dam
has submerged at least three
categories of land
viz. reserve forest,
protected forest and
revenue land covering
two Ranges of Gumtara and Karmajhiri in the Madhya Pradesh part
of the Tiger
Reserve. The construction of the dam has brought about both negative and
positive impacts on the habitat of Pench Tiger Reserve. About 54 km2
of prime tiger and other animal habitat was lost to submergence. This led to
loss of prey base, nesting sites to grassland avifauna and also affected the
indigenous fish fauna. Growth of
weeds, like Parthenium, Cassia tora,
Dhatura and Argemone mexicana in
the draw down area of the submergence which leads to the elimination of the
native flora, mainly Cynodon dactylon.
Survey
revealed at least 10 - 20 percent of the plot to be occupied by weeds. The
impact has also benefited by creating new habitat of open grassland in the
drawdown areas and with water available round the year there are increased
congregation of ungulate near the reservoir. The peripheral shallow area of the
reservoir has gradually been colonized by hydrophilic vegetation, grasses and
sedges, which provide adequate food for the waterfowls that has resulted in
increased migratory waterfowl visit. The study proposes the following suggestions for the enhancement of wildlife
value along the dam in Pench Tiger Reserve;
·
Construction of earthen dykes
·
Erection of temporary
ex-closures
·
Development of perching, roosting and
nesting sites for birds
·
Soil and moisture
conservation in streams feeding the submergence area
·
Protection of nesting sites of water
fowl
·
Study of the Pench Wetland
·
Weed eradication
·
Public Awareness and Education
·
Community participation
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Acknowledgements
I am very grateful to the Course Director, Sh. A. Udhayan for continuously supporting and boosting my morale all the time and especially so during the tour of Pench to work for this very exercise. Guidance and company given by Sh. N.K. Vasu, Sh. Pratap Singh while on tour is gratefully acknowledged.
The Field Director, Pench Tiger Reserve, Sh. N.S. Duungriyal and handful of his dedicated subordinates needs a special mention for providing all kinds of support ranging from sharing of past photograph to sharing the entire past documents in spite of the heavy documents having to be carried from Soeni to Karmajhiri. Special mention of Sh. K. K. Sahib is hereby made and his contributions to this work gratefully acknowledged.
Back in the Institute, my honest acknowledgements to Dr. S.A. Hussain. Without his support this paper could not have been put into proper shape. Sh. Ashgar Nawab for reading my paper and coming out with brilliant suggestions.
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