Species composition and community structure of forest stands in ...

172 FOREST STRUCTURE IN KUMAON HIMALAYA
Results
Tree species classification
Nineteen broad communities have been
recognised in Kumaon. Overall, 63 tree, 56 shrub,
90 herb and 21 grass species were recorded in the
23 forest stands. A total of five homogenous groups
of tree species, in relation to the environmental
variables, was identified through TWINSPAN
analysis (Fig. 2). The left arm of the first dichotomy
contained 25 species, which was further divided into
two groups. First negative group consisted of four
species which were characteristic of site 8 (for site
code see Fig 1). Second positive group also consisted
of two homogenous groups. The first group
contained Quercus semecarpifolia as a dominant
species at sites 12, 13 and 17. The second group
consisted of Abies pindrow and Taxus baccata as
dominant species and represented mixed coniferous
habitat. Further subdivisions did not provide any
additional ecological information. The right arm of
the first dichotomy had 38 tree species, which were
further divided into two groups. First negative
group contained 21 species. These tree species were
mainly encountered at sites 2, 4, 5, 7, 18, 19 and 23.
At site 2, Q. leucotricophora, Pinus wallichiana and
Cedrus deodara were the dominant tree species
while at site 23 the dominant species was Q.
lanuginosa (Table 2).
Tree species ordination
DCA ordination successfully handled the
variation in tree species communities from low to
high altitude. All the sites and tree species showed
meaningful distribution on axis 1 and axis 2 of
DCA (Fig. 3 a). The first axis (eigen value = 0.389)
represents an altitude gradient (low to high). Sites
14, 15, 16, 20, 21, and 22 occupied extreme end of
the first axis and represented TWINSPAN group 3
(A. pindrow, T. baccata, Betula utilis, Tsuga
Table 2. Communities and their characteristic tree species with their codes (in parentheses used in
DECORANA computer program) in Kumaon based on TWINSPAN classification. Comm. = Community.
Groups Comm. Forest stand Tree species
1 1 BWS Acer caesium (20), Aesculus indica (23), Swida sp.(42),
Betula alnoides (44)
2 2 Daphiadura Gasi, Quercus semecarpifolia (4), Toona serrata (14),
Dodecademia grandiflora (37),
Dhakuri Symplocos sp. (50)
3 3, 4, 5, 6 Pindari, Sobala, Duku
Wachham, Sunderdunga,
Munsiary
4 7, 8, 9, 10, 11, 12, 13 Vinaiyak, Maheshkhan,
Gager, Jilling, Majtham,
Gandhura, Mechh
5 14, 15, 16, 17, 18, 19 Mukteshwer, Kilbery,
Pandavkholi, Sitlakhet,
Jageshwer, Kunjakharak
Abies pindrow (15), Jugulans regia (34), Prunus cerasoides
(63), Betula utilis (28) Rhododendron barbatum (7), Taxus
baccata (16), Tsuga demosa (35), Pyrus vestita (52),
Zanthoxylum armatum (58), Ficus palmata (46), Morus
serrata (47), Symplocos chinensis (51), Prunus cornuta (60),
Debregeasia hypoleuca (59), Acer cappadocicum (53),
Fraxinus sp. (48), Dendroephthoe falcate (43)
Cedrus deodara (17), Cupressus torulosa (25), Cassia fistula
(62), Quercus lanuginose (5), Engelhardia spicata (36),
Ficus auriculata (41), Daphnephyllum himalense (38),
Quercus glauca (3), Pinus roxburghii (19), Myrica esculenta
(24), Maytenus rufa (54), Benthamidia capitata (39),
Phoenix humilis (61), Castanopsis tribuloides (40), Quercus
leucotricophora (1), Pyrus pashia (13), Pinus wallichiana
(18), Euonymus tingens (10), Swida oblonga (27),
Macaranga pustulata (33), Picea smithiana (45)
Litsea umbrosa (30), Populus ciliate (49), Persea duthiei (9),
Rhododendron arboreum (6), Alnus nepalensis (21),
Viburnum mullaha (22), Ilex dipyrena (26), Stranvissia
nausea (57), Meliosma dillenaeafolia (29), Rhamnus
triqueter (56), Quercus floribunda (2), Fraxinus micrantha
(32), Symplocos theifolia (12), Lindera pulcherrima (31),
Lyonia ovalifolia (8), Euonymus pendulus (11), Viburnum
coriacieum (55)