Ecologically Fragile Lands
RED LISTED THREATENED TREE SPECIES IN KERALA:
Situated along the west coast of India and bordered by the Lakshadweep, the State of Kerala
enjoys a tropical Climate. It is estimated that about 27 per cent of the area of the State is under
forests. The tropical rain forests along the windward side of the Western Ghats are remarkable for
their species diversity and endemism. The Western Ghats, one of the megadiversity centres in the
world is also a biodiversity hotspot. The State of Kerala has an area of 38,864 km
, which is only
indigenous flowering plants recorded from Kerala, 812 are trees. There are 1387 Peninsular Indian
endemic species and 218 among them are restricted to Kerala. Among the 822 tree species, 327 are
Peninsular Indian endemics and 26 are so far known only from Kerala. According to the various
publications on threatened plants, 495 species recorded from Kerala belong to the Rare and
Threatened (RET) categories, including 151 tree species. The floristic studies carried out during
the last three decades resulted in relocating several RET species. However, the status of the
populations of these species has not yet been evaluated. Despite the recent floristic studies as
many as 23 tree species could not be relocated. As per the IUCN criteria on threatened species,
two species are Extinct in the wild (Ilex gardneriana and Syzygium gambleanum), 26 Critically
Endangered, 63 Endangered, 38 Vulnerable and 22 species are Low Risk/near Threatened.
The Western Ghats, running parallel to the west coast of Peninsular India have a
series of hill ranges covering a distance of 1600 km from Thapti Valley in Gujarat to
Kanyakumari in Tamil Nadu traversing through the states of Maharastra, Goa,
Karnataka and Kerala. Though the average height of the hill ranges is 1000 m, the
highest peaks south of Himalayas - the Anamudi (2695 m) and Dodabattai (2637m)-
are in the Western Ghats. The western side of the Western Ghats facing the Arabian
Sea receives maximum rainfall and the annual precipitation varies from 2000 mm to
7450 mm. The eastern side of the Western Ghats is in the rain shadow region,
therefore receives relatively less rainfall. The mean temperature is between 24°C and
20°C however, the temperature will be zero to subzero in the mountain peaks during
winter. The major soil types are laterite, red loam, medium black, alluvial, red
gravelly and hill soils.
Depending on the amount of rainfall, soil type and altitude, different vegetation
coast tropical evergreen forests, west coast semievergreen forests, southern moist
mixed deciduous forests, southern dry mixed deciduous forests and scrub jungles
(Champion and Seth, 1968). At higher elevations the vegetation becomes southern
montane wet temperate forests (sholas) and southern montane wet grasslands
Government of Kerala
FORESTS AND WILDLIFE DEPARTMENT
(grasslands). Certain edaphic types such as Myristica swamp forests, bamboo breaks,
reed breaks, etc. are restricted to some eco-physical regions.
The tropical rain forests, particularly the evergreen, semi-evergreen and shola
biodiversity. The Western Ghats, one of the megadiversity centres in the world is
also a biodiversity hotspot. The principal plant communities in the Western Ghats
are the Angiosperms. In the Western Ghats, the southern Western Ghats consisting
southern parts of Karnataka, Kerala and southern Tamil Nadu are the richest in
terms of diversity. Out of the 4000 species of flowering plants estimated, 3,900 occur
in the southern Western Ghats and 3,800 in Kerala (Nayar, 1997). The Western Ghat
is considered as one of the 18 centres in the world where mega diversity exists. The
distribution pattern of the major families in the Westem Ghats and Kerala is almost
the same. The State of Kerala with an area of 38,863 km
, is only 1.18 per cent of the
There are 4,465 taxa of flowering plants in Kerala belonging to 1,315 genera in 192
(Sasidharan, personal observation). Among the 4,465 species recorded, 4050 are
indigenous and the rest exotics. There are 812 species of trees in Kerala. The families
dominated by tree species are Euphorbiaceae, with 67 species under 31 genera,
followed by Leguminosae (65 species/35 genera), Lauraceae (55 species /l 0 genera),
Rubiaceae (47 species/26 genera), Annonaceae (32 species/11 genera), Ebenaceae (25
species/one genus), Anacardiaceae (24 species/11 genera) and Clusiaceae (21
The endemic species in the flora of a geographical region are noteworthy. Among
restricted to Kerala. Genera such as Poeciloneuron, Blepharistemma and Otonephelium
are endemic to the Western Ghats. Among the families with arborescent endemic
taxa, Lauraceae rank first with 44 endemics (out of the 55 species) followed by
Euphorbiaceae (25/67), Rubiaceae (22/47), Myrtaceae (21/41), Annonaceae (17/32),
Leguminosae (14/65), Anacardiaceae (13/24), Dipterocarpaceae (11/13), Ebenaceae
(10/25) and Clusiaceae (10/21).
The rare and threatened plants of southern India have been documented by Joseph
Nayar and Sastry (1987, 1988, 1990). Nayar (1997) listed 1,272 Western Ghats taxa
endemic to Kerala, 483 among them were placed under threatened categories. Based
on published literature, there are 497 species recorded from Kerala that belong to the
Red Listed categories, including 151 tree species (Table 1). As per the IUCN (1994)
criteria the Red Listed tree species are assigned to the following categories: Extinct (2
Government of Kerala
FORESTS AND WILDLIFE DEPARTMENT
species), Low Risk/near threatened (22 species) Critically Endangered (26 species),
Vulnerable (38 species) and
No. of tree sps.
No. of Red
Eravikulam National Park
Peechi- Vazhani Wildlife
Silent Valley National Park
Neyyar Wildlife Sanctuary
Periyar Tiger Reserve
Shenduruny Wildlife Sanctuary
Note: The figures in parentheses indicate the percentage of trees out of the total.
Buchanania barberi Gamble
var. wlfnaedica Ellis & Chandra.
Nothopegia heyneana (Hook. f.) Gamble
Tabernaemontana heyneana Wall.
Humboldtia unijuga Bedd.
Dipterocarpus bourdillonii Brandis
Rhododendron arboreum J. E. Smith ssp.
nilagiricum (Zenk.) Tagg.
Drypetes confertiflora (Hook.f.) Pax &
Orypetes malabarica (Bedd.) Airy Shaw
var. johnstonei (Hook. f.) Chakrab.&
var. tomentosum (Dalz.) Chakrab. &
Actinodaphne campanulata Hook.f.
var. obtusa Gamble
Benth. ex Hook. f.
Mohanan & Henry
Cinnamomum filipedicellatum Kosterm.
var. magnifica (Bedd.) Sinclair
Rathkr. & Nair
Bennet & Raizada
Hook. f. ex Bedd.
Canthium neilgherrense Wight
Sivadasan & Mohanan
Ochreinauclea missionis (Wall. ex G. Don)
EX=Extinct; CR=Critically Endangered; EN=Endangered; LR/nt=Low Risk/near
(63 species). Among the families, Myrtaceae has 20 Red Listed tree species followed
Euphorbiaceae and Anacardiaceae (10 species), Annonaceae and Rubiaceae (8
species), Symplocaceae and Meliaceae (7 species), Flacourtiaceae (6 species),
C1usiaceae (5 species) and Sapotaceae (4 species). Recent floristic studies have
reported the rediscovery of many threatened taxa including a few that were
presumed to be extinct (Ramachandran, 1982; Mohanan, 1996; Mohanan et al., 1997,
1999 & 2000; Sasidharan, 1998). However, the effort to relocate species such as
Actinodaphne lawsonii, Atuna indica, Buchanania barberi, Cinnamomum perrottetii,
Casearia rubescens var. gamblei, Cleistanthus malabaricus, Diospyros barberi, Diospyros
sulcata, Drypetes travancorica, Eugenia argentea, Hopea jacobii, Hopea utilis, Humboldtia
laurifolia, Litsea mysorensis, Litsea nigrescens, Madhuca diplostemon, Memecylon
sisparense, Polyalthia rufescens, Psychotria beddomei, Rapanea thwaitesii, Syzygium
courtallensis, Syzygium gambleanum and Syzygium stocksii were not successful so far.
An analysis of the habitats of Red Listed species reveals that shola forests support 23
species, one species in the dry deciduous forests and the rest in the evergreen/semi-
evergreen forests. The only Red Listed tree species recorded from dry deciduous
forests is Albizia lathamii (Sajeev and Sasidharan, 1998).
The State of Kerala has a relatively higher percentage of protected areas. About 24
Wildlife Sanctuaries and 2 National Parks. The flora of most of the protected areas
have been studied recently resulting in the discovery of several new as well as
threatened species (Manilal, 1988; Mohanan, 1995; Sasidharan, 1997, 1998,
1999,2002). The Red Listed tree species recorded in the Protected Areas are provided
in Table 2.
Though, several Red Listed trees were rediscovered recently, quite a few of them are
low (Sasidharan, 1998b). This calls for
immediate measures to enhance their
means for conservation of RET tree species. Detailed studies are needed to
understand the genetical variation in the disjunct small population of these tree
species. The Red Listed trees are also to be raised in ex situ centres like arboreta and
AhmeduLlah, M. and Nayar, M.P. 1987. Endemic Plants of the Indian Region. Botanical
Survey of India, Calcutta.
Champion, H.G. and Seth, S.K. 1968. A Revised Survey of
Govt. of India Press, Delhi.
Henry, AN., Vivekanandan, K. & Nair, N.C. 1979. Rare and Threatened Flowering
Plants of South India. J. Bombay Nat. Hist. Soc. 75: 684-697.
IUCN, 1994. IUCN Red List Categories. IUCN, Gland, Switzerland.
Jain, S.K. and Sastry, A.R.K. 1984. The Indian Plant Red Data Book. Botanical Survey of
Joseph, J. 1977. Floristic studies in India-with special reference to Southern Circle of
Botanical Survey of India. Bull. Bot. Surv. India 19: 109-111.
Manilal, K.S. 1988. Flora of Silent Valley: Tropical Rain Forests of India.
Calicut University, Calicut.
Mohanan, N. 1995. Flora of Agasthymala. Ph.D. Thesis, University of Calicut,
Mohanan, N. 1996. Rediscovery of Syzygium bourdillonii (Gamble) Rathakr. & N.C.
Nair (Myrtaceae), an endemic and little known species of Western Ghats. J. Econ.
Bot. 20(3): 729-731.
Species of Western Ghats. J. Econ. Tax. Bot. 24(1): 78-80.
Mohanan, N., Shaju, T. and Kiranraj, M. S. 1999. Rediscovery of Poeciloneuron
paucifiorum Bedd.: An endemic and little known species of W. G., presumed to be
For. 7(1): 87-89.
(Bourd.) (Clusiaceae): A little known endemic species of Western Ghats. lndian J.
Forestry 20(4): 383-385.
Nayar, M. P. 1997. Biodiversity challenges in Kerala and Science of conservation
Biology. In: P. Pushpangadan & K. S. S. Nair (eds.) Biodiversity of Tropical Forests:
the Kerala Scenario. STEC, Trivandrum, Kerala.
Nayar, M.P. and Sastry, A.R.K. 1987. Red Data Book 011 Indian Plants, Vol. I. Botanical
Nayar, M.P. and Sastry, A.R.K. 1988. Red Data Book on Indian Plants, Vol. II. Botanical
Nayar, M.P. and Sastry, A.R.K. 1990. Red Data Book on Indian Plants, Vol. III.
Botanical Survey of India, Calcutta.
Ramachandran, V.S., Nair, N.C. and Nair, V.J. 1982. Rediscovery of Meteoromyrtus
Bombay Nat. Hist. Soc. 79: 46-462.
Sajeev, K.K. and N. Sasidharan, 1998 (1999). Albizia lathamii Hole - a critically
endangered species from Chinnar Wildlife Sanctuary. J. Econ. Tax. Bot. 22: 629-
Sasidharan, N. 1997. Forest Trees of Kerala - A Checklist. KFRI Handbook No. 2. Kerala
Sasidharan, N. 1997. Studies on the Flora of Shenduruny Wildlife Sanctuary with
Sasidharan, N. 1998a. Studies on the Flora of Periyar Tiger Reserve. KFRI Research
Report No. ISO, Kerala Forest Research Institute, Peechi.
Sasidharan, N. 1998b. Rediscovery of four threatened and possibly extinct endemic
tree Legumes from Kerala. Indian J. For. (Addl. Ser.) 10: 605-613.
Sasidharan, N. 1999. Study on the Flora of Chinnar Wildlife Sanctuary. KFRI
Research Report No. 167. KFRI, Peechi.
Sasidharan, N. 2002. F/oristic Studies in Parambikulam Wildlife Sanctuary. KFRI
Research Report No. 246. KFRI, Peechi.
explored for the RET species?
being explored, but reports
are not available. Northern Kerala needs to be
and 12 districts have been already completed. Wayanad and Ernakulam have not
been completed. Aralam is another important area where there is scope for further
there are specimens from Karnataka.
(District) should be changed. As they occur in the forest areas, they should be
studied on the natural geographical area basis. GIS data should be also generated. It
should not be a taxonomist's job alone. KFD should initiate programmes to conserve
them, otherwise they can become extinct. Trees require more attention.
N.S.: 1 agree with Or Nayar. As custodians, KFD should take the initiative.
Handbooks, CDs, and videos can also be brought out, so that untrained people can
also understand and identify the species.
Dr.V.M. Chandrashekara: We have established nearly 60 permanent plots for the
study of biodiversity, distributed throughout Kerala. And we have located the rare
tree, Actinodaphne lawsonii, in two of plots in the Nilambur area.
reproductive biological studies other than just exploration and identification?
located in sacred groves.
ecologically valuable RET species economically also valuable? Are you going to
involve forest officials in conserving the RET species?
N.S.: Yes, the RET species are to be assessed based on the recently revised IUCN
(1994) criteria. Their website gives the details. Just as the RET species are ecologically
important, many of them are economically important too. In fact, some of them are
keystone species. Perhaps Dr M.P. Nayar can further highlight this aspect. We
would be very happy to involve the forest officials for conservation of the RET
e.g. for pollinators. The relationship is actually mutual. Take the case-of Cullenia
exarillata - the lion tailed macaques are dependant on it for food. Conservation
biology is related to the web of life. Any break in the food chain or web will create
loss of species. Keystone species are important. So a holistic ecosystem study
approach is required. The recently revised IUCN criteria provide more guidelines
for defining the different RET categories.
Dr J.K. Sharma: RET species should be studied in close association with other
species as they have strong ecological niches. Dr Nair has indeed made some good
comments on this. Since a holistic approach is required, institutions should come
together to tackle the problems jointly.