The Western Ghats, also
known as the Sahyadri Hills, are well known for their rich and unique assemblage
of flora and fauna. Norman Myers included the Western Ghats amongst the 25
biodiversity hot-spots identified in the world. Geologically the Western Ghats
may be divided into two segments. The hills north of the Krishna basin (largely
Maharashtra and Gujarat) with fragile basaltic rocks are results of the same
processes that gave rise to the Deccan trap. Isolated, conical, flat-topped
hills occur here with steep sides, marked with striations. They seldom rise
beyond 1500 m. South of the Krishna basin is the region of precambrian archean
crystalline hard rocks (nearly 2000 million years old granites, schists,
gneisses, quartzites, etc). Soils vary from humus rich peat in the montane areas
to laterite in the lower elevation and high rainfall belts. Soils are generally
Arising abruptly from the
narrow Konkan and Malabar coasts, these hills run 1600 km north-south between
the river Tapti in Gujarat and Kanyakumari in Tamilnadu covering an area
approximately equal to 160,000 sqkm. In the east, they slope gently towards the
Deccan Plateau. The northernmost segment that extends into Gujarat merges in the
east with the Surat Dangs. In the Nilgiris, Palanis and parts of Karnataka, the
Western Ghats extend considerably eastwards, locally merging with the Eastern
Ghats. Towards the south, the hill chain is divided into two by the Palghat Gap
(a mere 13 km gap at its narrowest) rendering a physically homogeneous high
altitude plateau into two rather distinct biogeographic units viz., the Nilgiris
complex in the north and the Anaimalai-Palnis complex in the south. Here are
found the highest peaks viz., Anaimudi (Anaimalai Hills) and Doddabetta (Nilgiri
Hills), reaching well over 2695 and 2637m ASL respectively. Apart from these, a
number of peaks reaching heights of over 2000 m are present in the southern half
as that in Tamilnadu (Palnis) and Kerala (eg. Highy Wavy Mountains and Grass
Climatic conditions in the
Western Ghats vary with the altitude and physical proximity to the Arabian Sea
and the equator. Although the Western Ghats experience a tropical climate -
being warm and humid during most of the year with mean the temperature ranging
in the south to 24oC
in the north, the higher elevations experience subtropical climates and on
occasions frost. Further, it has been observed that the coldest periods in the
southern Western Ghats coincide with the wettest.
Whereas rainfall peaks of
9000 mm and above per year, are known locally, annual rainfall as low as 1000 mm
are frequent in the east bringing the average to around 2500 mm. Interestingly,
the total amount of rainfall received and the spread are not often correlated.
Areas in the northern Western Ghats (in the State of Maharashtra) receiving the
highest rainfall (locally over 9000 mm) experience dry weather over more than
half the year. On the contrary, areas receiving much less rainfall in Kerala and
closer to the equator experience rain almost all through the year. Much of the
rainfall is received during the southwest monsoon season. Peak period of
rainfall is July-August.
Origin and Prehistory
Peninsular India was part
of the Gondwana land till about 150 million years ago, from which it split and
started moving north. The northward drift which lasted about a 100 million years
finally ended with the peninsula colliding with the Asian mainland 45 million
years ago. Major geologic transformations took place as the peninsula moved
northwards. Soon after detachment from the Gondwanaland, the Indian peninsula
drifted over the Reunion Hotspots - localised volcanic centres in the earth’s
lithosphere, 200-300 km across, which have remained active for several million
years. It was this event that happened some 120-130 million years ago that
resulted in the uplift of the Western Ghats. Subsequently, there were a series
of volcanic eruptions until around 65 million years ago giving rise to the
extensive Deccan Traps. These volcanic episodes to a large extent moulded the
northern third of the Western Ghats. Since the Western Ghats are the result of
domal uplift, the underlying rocks are ancient - around 2000 million years old.
The oldest of these rocks are found in the Nilgiris and the high ranges of the
The uplifted crust of the
earth bears a central axial region of weakness coinciding with the track of
upliftment. Peninsular India broke along its line of weakness, and the western
segment drifted westward into the sea (a process known as faulting), giving rise
to the present day hill chain, the Western Ghats and the west coast. This
happened during the Eocene (between 45 and 65 million years ago), even before
India became part of the Asain mainland. At this time the peninsula also
experienced a marked eastward tilt permanently changing the pattern of drainage.
The western faulting led to ‘river capture’ and diversion of the easterly
drainage to the west in many instances. The rivers Sharavathy and Kali in
Karnataka are two classical examples of westerly diversion of drainage due to
uplift and faulting. The Western Ghats thus represent a tectonically active
region with high rates of uplift, high summit altitudes, steep slopes, deep
gorges and large potential energy for erosion and correspondingly high sediment
Modern biogeographers feel
that the sp species of all vertebrates are endemic. Amongst vertebrates,
endemism is the highest in amphibians (78% species), followed by reptiles (62%),
fish (53%), mammals (12%) and birds (4%) (Table 1).
Table 1: Endemic species of the Western Ghats
Very little fossil
evidence exists to reliably reconstruct the prehistoric biodiversity of the
Western Ghats. What we do know is that the flora of the Western Ghats share
elements with Africa, Madagascar and South America (eg., Family Bignonaceae;
Vinca rosea, etc). Many species of invertebrates including a few species of
butterflies are also shared with South America and Africa. Amongst freshwater
fishes there are a few genera (Notopterus, Barilius, Rasbora, Puntius, Labeo,
Clarias, Aplocheilus, Mastacembelus, Garra, Aphanius) that are common
to India and Africa represented by one or more species in the Western Ghats.
Species of amphibians (especially caecilians) and reptiles (snakes in the genus
Boiga for instance) may well have been there ever since the Western Ghats
came into existence. Most species of land birds and mammals that are seen in
the Western Ghats today are those essentially derived from the eastern
Himalayan-Malayan complex after peninsular India became part of Asia.
Table 2: Vegetation types of the Western Ghats
As early as 1904 Hooker
had drawn attention to the distinct flora of the Western Ghats, which he called
the ‘Malabar’ floristic region. The presence of Bambusae, Dipterocarpaceae,
Guttiferae, Myristicaceae and Palmae (Arecaceae) has contributed to its
distinctness. The various major vegetation types are tropical evergreen forests,
moist deciduous forests, dry deciduous forests, scrub jungles, sholas, savannas
including high rainfall savannas, peat bogs and Myristica swamps (Table
Four thousand species of
flowering plants are known from the Western Ghats. The gymnosperm flora is
represented by Cycas circinalis (Cycadales), Decussocarpus
wallichianus (Coniferales) and Gnetum ula and G. contractum (Gnetales).
Amongst the lower plants around 320 species of pteridophytes, 200 species of
bryophytes, 300 species of algae and 800 species of lichens are known. There are
600 species of fungi known from the Western Ghats.
Fifty-six genera of
flowering plants are considered endemic to the Western Ghats. Recent studies
have suggested that there could be 1500 species of flowering plants endemic to
the Western Ghats. Although the exact number keeps varying with the author and
time, what is of interest is that nearly 38% of all species of flowering plants
in the Western Ghats are endemic. Sixty three per cent of India’s evergreen
woody plants are endemic to the Western Ghats.
Scientific research on the invertebrates of the Western
Ghats has largely been restricted to a few groups of organisms. As with any
other tropical regions, the Western Ghats’ invertebrate diversity is best known
by the butterflies (Table 3). Amongst other insects, ants of the Western Ghats
are better studied for their habits and ecology. While there are a number of
studies undertaken on other invertebrates throughout the Western Ghats, few
really address questions relating to ecology and biodiversity. Most of the
studies on invertebrates are of a checklist nature or taxonomic.
Studies in Uttara Kannada district have suggested that ant
species diversity in forests is linked to the woody plant species diversity.
Elsewhere in the forests of Karnataka studies on ant communities have indicated
that the common weaver ant Oecophylla smaragdina regulates the behaviour
of other terrestrial ants that share its habitat. Whether such dominance by the
weaver ant also has a bearing on the ant species diversity in the habitat is not
yet clear. It has been observed that ants in the genus Leptogenys
dominate ant communities in the Western Ghats.
Butterflies in the Western Ghats belong to five families,
166 genera and 330 species. Of these, 37 species are endemic. These 330 species
of butterflies depend on over 1000 species plants for feeding and breeding.
Diversity of butterflies in the Western Ghats is thus related to not only adult
feeding habitats, but also larval food plants. Comparative studies on
butterflies using selectively logged and unlogged forests in
Kalakkad-Mundanthurai Tiger Reserve has suggested that butterfly diversity tends
to increase in selectively logged habitats. However, it has been pointed out
that this increase is due to the invasion by ubiquitous species at the expense
of habitat specialists such as Idea malabarica.
Distribution of butterflies in the Western Ghats
Many parts of the Western
Ghats are still poorly explored for their invertebrate biodiversity. At the
workshop on ‘Research priorities in tropical rainforests’ held in Coimbatore
(February 27-28, 2001) the status of malacological studies in the Western Ghats
was reviewed. It was apparent that most of the earlier works in the Western
Ghats have under-represented the number of species of land and aquatic snails.
A few studies in the
Western Ghats have paid attention to aquatic invertebrates including molluscs.
During the early 1980s, a study of aquatic insects in the Nilgiris indicated
that human interference in the upper Nilgiris has apparently reduced the
diversity of species in seemingly undisturbed areas as Silent Valley. A decline
in the diversity of aquatic invertebrates has also been noticed elsewhere in the
Western Ghats. Habitat loss and pollution in Pune City have been attributed as
reasons for the decline of aquatic insects and molluscs.
There are around 218
species of primary and secondary freshwater fishes in the Western Ghats. 53% of
all fish species (116 species in 51 genera) in the Western Ghats are endemic
(Table 4). Patterns of distribution and diversity of freshwater fishes in the
Western Ghats are rather poorly understood. This is mainly due to the widespread
construction of lakes, reservoirs and dams and the subsequent introduction of
food and sport fish during the past 200 years. Despite the human interference of
freshwater habitats in the Western Ghats, there are still some discernable
patterns of fish distribution and diversity.
In general, the small and
rapidly flowing hill streams support only a few species of specialised fish.
Species poor fish communities are also seen in the higher elevation streams of
the Western Ghats. Deep waters that are slow moving tend to support the highest
diversity of fishes in the Western Ghats. Very deep waters as that in lakes,
reservoirs and dams tend to be ideal for large sized and introduced species of
fishes. They are not suitable for many smaller species that inhabit shallow,
clear and rocky pools and streams.
Table 4: Diversity of endemic fishes in the
From what little has been
understood of the distribution and diversity of freshwater fishes in the Western
Ghats, it is apparent that the streams and rivers in the south are more diverse,
including a larger number of endemic species, than those in the north. A study
of the freshwater fishes in the Kerala part of the Nilgiri Biosphere Reserve has
suggested that the east and west flowing rivers in the region do not
significantly differ in the number of species and those species exclusive to
them – 69 species, 24 being exclusive in the east flowing rivers as against 68
species and 23 being exclusive in those flowing west.
One hundred and twenty one
species of amphibians are known from the Western Ghats. The 121 species fall
under 24 genera, six families and two orders. The family ranidae (true frogs)
has the largest number of species (49) amounting to 42% of the amphibian fauna
of the Western Ghats. The next largest family is rhacophoridae (treefrogs) with
30 species (25% of the amphibian fauna) (Table 5). In general, there are more
species of terrestrial and arboreal amphibians in the Western Ghats than aquatic
There is a remarkable
diversity of caecilians in the Western Ghats. 16 out of 20 species known in
India occur in the Western Ghats; all 16 being endemic. Caecilians prefer moist
soils rich in organic carbon (essentially derived from rotting wood and leaf
litter). The highest diversity of species in any given landscape is noticed in
the southern half of the Western Ghats.
Table 5: Taxonomic breakup of the amphibian
fauna of Western Ghats
Note: This table does not
include the recently discovered amphibians and recent changes in nomenclature of
The north-south ranges of
the 121 species vary from extremely widespread to highly restricted. Some are
patchily distributed, while others show a more continuous distribution.
Interestingly, species restricted to the south of 13o N
latitude are more frequently patchily distributed. There is also a greater
representation of species that prefer moist forests in those with patchy
distribution. When the patterns are analysed on a latitudinal scale, it turns
out that species including Bufo melanostictus, Microhyla ornata, Ramanella
montana, Euphlyctis cyanophlyctis, Limnonectes limnocharis, Hoplobatrachus
tigerinus, Tomopterna breviceps and Polypedates maculatus are found
over the entire range of the Western Ghats. These species (except Ramanella
Montana) are also widespread in the country.
Most species are found in
the altitudinal range of 0-1200 m ASL. Highest diversity of species is at
800-1000 m. Analaysis of the patterns of amphibian distribution in the Western
Ghats has suggested that widespread rainfall, shorter dry season and a more
uniform local climate have contributed to the high levels of diversity and
endemism than elevation per se.
157 species of reptiles
including a crocodile Crocodylus palustris is known from the Western
Ghats. Majority of the reptile species are snakes. In all 97 species,
representing 36 genera (2 genera of turtle/tortoise, 20 snake, 14 lizard) are
endemic (Table 6). Endemism is highest amongst snakes, especially with the
family Uropeltidae alone contributing 33 species. Amongst lizards, dwarf geckoes
(Cnemaspis spp) and skinks (Ristella, Lygosoma, Mabuya and
Scincella) have the maximum number of endemic species.
Table 6: Taxonomic breakup of reptilian
diversity in Western Ghats
Ecological studies of
reptilian communities in the Western Ghats are those limited to the
Kalakad-Mundanthurai Tiger Reserve. Survey-type studies of reptiles in the
Western Ghats have provided the most information on species diversity and
habitat use. Higher diversity of species has been observed in the moist
deciduous forests. As per one study in the Nilgiris, the number of reptilian
species is negatively correlated with altitude, but positively correlated with
number of herbs, number of fallen logs and slope. However, detailed studies in
the Kalakad-Mundanthurai Tiger reserve have suggested that mid-elevations of
1000-1100m ASL in the Western Ghats have the highest diversity of reptiles.
Further, the density of forest floor reptiles in the Western Ghats is generally
low being 0.26 per 25 sqm. It is interesting to note that snakes dominate the
forest floor reptilian communities at altitudes of 1200m ASL and above.
Of all organisms, birds are the best studied in the Western
Ghats. Beginning in the 1860s, British naturalists and planters were busy
surveying the Western Ghats, collecting and describing the avifauna. Subsequent
surveys by the Bombay Natural History Society (then led by Dr Salim Ali), the
various state departments of forests, especially Kerala, many nature clubs and
amateur birdwatchers have suggested that there are 508 species of birds,
represented by nearly 600 forms of resident and migratory birds. Amongst the 508
species, 144 (28%) are aquatic birds including those which are found in the
coastal habitats. A total of 324 species (64%) are resident. These are
predominantly land birds. Nineteen species may be considered endemic to the
Western Ghats (Table 7).
Table 7: Endemic birds of the
Note: Small and isolated populations of the species marked
with an asterisk exist here and there outside the geographical limits of the
Western Ghats in peninsular India.
Broad patterns of
distribution and diversity have been discerned in the birds of the Western Ghats.
In general, most of the resident and typically forest birds are restricted in
distribution to the Western Ghats southwards from Goa. Few endemic species
extend north of Goa. In general, the endemic bird species of the Western Ghats
are primarily birds of the rainforests and the higher elevation shola-grassland
complexes. In Kerala, the presence of some of the endemic birds (Malabar grey
hornbill, Rufous babbler and Crimsonbacked sunbird) is associated with greater
abundance of mammals such as Nilgiri langur, Lion-tailed macaque and Sambar.
Locally, when equal areas
are compared, there are more species of birds per unit area in the central parts
of the Western Ghats, especially in the Uttara Kannada district. This is
primarily due to mixing of migrants and generalist species of birds with the
resident specialists and endemics. Wet evergreen forests and montane sholas,
despite providing habitat to a number of specialists and endemic birds with
greater conservation value, are comparatively less diverse in bird species than
secondary/disturbed evergreen and moist deciduous forests.
Human interference of
forests has led to the disappearance of birds locally in the Western Ghats.
However, when large landscapes are considered, species richness of the avifauna
has remained stable during the past 100 years. Whereas the floristic composition
of woody plants determine the nature of bird species that might inhabit a forest
in the Western Ghats, bird species diversity may be inversely related to woody
plant species diversity, locally. Monocultures in the Western Ghats may support
an assemblage of birds as diverse as (or even more diverse than) evergreen
forests. However, birds that inhabit the monocultures are often generalist
habitat users drawn from a wide range of neighbouring habitats. Teak plantations
may provide habitat to a number of species of birds in the Western Ghats.
However, hole-nesting birds were found to avoid nesting on teak trees in
One hundred and twenty
species of mammals are known from the Western Ghats. Fourteen species are
endemic (Table 8). The mammalian fauna of the Western Ghats is dominated by
insectivores (11 species), bats (41 species) and rodents (27 species including
the porcupine). Few studies have however paid attention to the community
structure and organisation of these small mammals in the Western Ghats although
there have been attempts to review our understanding of the status and ecology
of smaller cats and lesser carnivores.
Table 8: Endemic
mammals of the Western Ghats
Evergreen forests are
particularly suited to frugivorous arboreal primates and squirrels while the
deciduous forests offer the best habitat for the larger grazing herbivores like
the gaur and deer. Drought resistant ungulates, particularly antelopes are
specially adapted to the open dry scrub. Elsewhere in the Western Ghats of
Karnataka, the distribution and biomass of large herbivores have been studied.
From this it emerged that the large herbivores biomass was highest in moist
deciduous forests and adjacent teak plantations whereas it was the lowest in the
dry deciduous forests.
Studies on other
communities of mammals have been sporadic and more illustrative in nature. As
mentioned before these studies have frequently addressed the smaller cats and
lesser carnivores. Estimates of home ranges of civets and mongooses in the
Western Ghats have suggested that the Indian Grey Mongoose (Herpestes
edwardsii) and the Small Indian Civet (Viverricula indica) have
monthly home ranges of 20.69-102 ha and 3.4-4.9 ha respectively. In another
study of small carnivores in the Nilgiris it was found that civets were the most
abundant (especially in evergreen forests) followed by mongooses, cats and
marten. Canopy opening and the consequent weed infestation in evergreen forests
adversely affects the civets.
At the scale of individual
species, it has been found that endemic species of arboreal mammals including
the spiny dormouse (Platacanthomys lasiurus) and the Nilgiri langur (Trachypithecus
johnii) do not prefer evergreen forests that are either selectively
logged or fragmented. The spiny dormouse is affected by habitat fragmentation.
The food plants of the Nilgiri langur have been selectively lost in disturbed
The endemic primate
Macaca silenus (Lion-tailed macaque or LTM) is amongst the few carefully
studied mammals in the Western Ghats. In 1985, the population of this primate in
the state of Karnataka was estimated as 3000. More recent estimates have placed
the numbers in Karnataka around 1000-2000. A smaller population is known from
Tamilnadu. Including the nearly 2000 individuals in Kerala, the population of
LTM has been most recently placed at 4000. LTM is an inhabitant of evergreen
rainforests, below 700 m ASL, with a home range of 1.25 sq km. Shape of the
patches of these forests has a significant effect on the population of LTM. An
opening of 0.5 sq km of canopy may block the path of a moving troop of LTM.
The Nilgiri Tahr (Hemitragus
hylocrius) exists in the higher elevations between Nilgiris and Ashambu
Hills in the Western Ghats. Over this 400 km range, around 2000 animals are
estimated to occur: 150 in the Nilgiris, 570-690 in Anaimalais, 890 in
Eravikulam, 280-310 in Palani Hills and a handful over the rest of the range.
Asian Elephant (Elephas
maximus) is another species of mammal that has attracted both scientific and
popular interest. Recent estimates place the population of elephants in the
states of Karnataka, Tamilnadu and Kerala at 12,500. A majority of this
population is within protected areas in the Western Ghats. Unlike the LTM, the
elephant is more of a habitat generalist utilising a wide range of natural and
man-made habitats in and around the Western Ghats.
The Tiger (Panthera
tigris) is comparatively better studied amongst other large mammals. In the
Western Ghats, the Tiger is presently restricted to states of Karnataka, Kerala
and Tamilnadu. The exact population of this large and elusive cat is much less
predictable than that of the Elephant, Nilgiri Tahr or LTM. Study of the
natural food habits of larger carnivores in Nagarhole has suggested that the
Tiger selectively preys on animals weighing more than 176 kg. Non-selective
predation by the Tiger on other animals is more likely the result of prey
Human ecology and its impact on the
biodiversity of the Western Ghats
The Western Ghats first
came under human influences during the palaeolithic or old stoneage some 12,000
years ago (see Table 9). Stone tools used by palaeolithic people have been
excavated in the river valleys of Palakkad, Mallapuram and Dakshina Kannada
districts in the Western Ghats. Elsewhere, palaeolithic artifacts have been
found in and around Mysore, Chickmagalur and Shimoga districts of western
Table 9: Chronology of
human ecological events in the Western Ghats
(12,000-5000 ybp) have been discovered around the river Mandovi in Goa. Charcoal
beds dating back to 5000 ybp in Tenmalai (southern Western Ghats) suggest that
humans burnt forests around this time. During the new stoneage (5000-3000 ybp)
there were domesticated cattle, sheep and goats in and around the Western Ghats.
Whereas rainfed crops including millets and horse gram were cultivated, in
Maharashtra the Jorwe people cultivated wet rice. Shifting cultivation was
apparently the form of agriculture that predominated the Western Ghats till
recently. Crops such as Eleucine coracana, Cajanus cajan, Ricinus communis,
Panicum sumatrense, etc were mainly cultivated in this traditional system of
Human influences have had
varied impacts on the biodiversity of the Western Ghats. History of species
extinctions in the Western Ghats was certainly coincident with the climatic and
human histories. Extended arid periods and human interference starting 12,000
years before present, led to slow but extensive transformation of habitats in
and around the Western Ghats. Unique landscape elements such as the Myristica
swamps gave way to cultivation of rice. Along with the swamps, trees such as
Myristica fatua var magnifica, Gymnacranthera carnatica,
Semecarpus auriculata and the palm Pinanga dicksonii,
The use of fire to clear
forests for cultivation has had a major influence on the forests of the Western
Ghats. The spread of bamboo and deciduous trees in the region would have been
aided by this human practice. Widespread occurrence of fire tolerant trees such
as Acacia catechu, Careya arborea, Dalbergia latifolia, Dillenia pentagyna,
Schleichera oleosa, Tectona grandis, Terminalia spp and Xylia xylocarpa
Hill agroecosystems in the
Western Ghats are today dominated by estates - chiefly of tea, coffee, rubber
and monocultures of various tree species, including the oil palm, that was
introduced lately. Available estimates indicate that above an altitude of 1500 m
in the Western Ghats, there are 750 sq km of tea plantations. A total of not
less that 1500 sq km are under coffee and 825 sq km under cardamom. It has also
been highlighted that the Nilgiri district with a total area of 2549 sq km has
around 1000 sq km under various forms of cultivation.
first appeared in Uttara Kannada district between 1868 and 1869. Till then the
forest plantations were of native species. Teak was first raised as monocultures
in 1840. The first teak plantation in Kerala was established in Nilambur in
1844. Over the years, eucalypts, cinchona, wattle, rubber, clove, etc, have
displaced extensive patches of natural forests throughout the Western Ghats.
The impact of monocultures
on the biodiversity of the Western Ghats has been little understood. In the
Uttara Kannada district, monocultures were found to support as diverse a
community of birds as natural forests. The bird assemblage may however include
a greater number of generalist species than the natural forests. As mentioned
above, teak when raised as a monoculture fails to attract hole-nesting birds.
Apart from the
introduction of commercially important plants, there have been invasions by a
number of aggressive alien plant species. The British Colonists spread over most
of the Western Ghats in the late seventeen hundreds and early eighteen hundreds.
The Nilgiris were colonised only in 1813 almost 2000 years after the Todas did.
Much of the exotic flora, especially those of temperate origin, came in after
this. A large number of ornamental plants of temperate origin have since run
wild in the higher elevations of the Western Ghats. For instance, in Palani
Hills alone there are 600 such species especially, around Kodaikanal. Similarly,
400-500 introduced species of plants have been reported from the Nilgiris.
Important amongst these
are Lantana camara (var aculeata), Eupatorium odoratum, Mikania
cordata, Parthenium hysterophorus, etc. Wattle (Acacia sp) once
introduced for the extraction of tannin in the higher hills is today a major
threat to the sholas and grasslands at these altitudes. The impact of these
exotic plants has been reason for a lot of debate. Contrary to general
predictions, the presence of Lantana camara has not been detrimental to
woody plant species diversity in the BR Hills.
In selectively logged
evergreen forests, the woody plant species diversity has declined. This has been
accompanied by the selective loss of certain plant species of greater economic
value and an overall reduction in forest biomass. Other organisms have responded
to human disturbance rather differently. Selective logging (consequently lower
tree and canopy density) has locally increased the diversity of butterflies,
lizards and birds in the Western Ghats. To balance the impacts of human
interests with the long-term conservation of biodiversity in the Western Ghats
is the greatest future challenge.
This summary is extracted
from the National Biodiversity Strategy and Action Plan – Western Ghats
Ecoregion, submitted to the Ministry of Environment and Forests, Government of
India, in 2001. About 150 published and unpublished sources were consulted in