Floral
Diversity
The park is known for its rich floral diversity.
It contains diverse ecosystems ranging from tall
alluvial floodplain grassland of early successional
stage to climax stage sal forest established on
uplands. A vegetation study conducted by Dinerstein
(1979) classified six major vegetation types.
Jnawali and Wegge (1993) later modified this into
seven major vegetation types. Sharma (1999) has
classified the vegetation of southwestern section
of the park into 15 different microhabitats. Major
vegetation types found in the park are summarized
below:
Sal Shorea robusta forest
makes above 70% of the forest cover in the park
and grows on well-drained uplands. S. robusta,
Terminalia sps., Buchanania latifolia, Carrya
arboria and Dilenia pentagyna are common species
found in this vegetation type.
Khair-sissoo forest is established
on relatively old floodplain and consist of
Dalbergia sissoo and Acacia catechu as dominating
tree species. Other tree species found in this
association include Ehretia laevis, Trewia nudiflora
and Mallotus philippinensis. Murraya koinigii,
Callicarpa macrophylla and Colebrookia opposotofolia
are important shrub species that form dense
under story cover.
Moist riverine forest extends
along watercourses. Syzigium cumini, Mallotus
philippinensis, Ficus glomerata, Trewia nudiflora,
and Dalbergia sissoo are among commonly found
tree species in this type of vegetation. The
groung is relatively open and contains humain
soil. Climbing plam Calamus tanusi and Karot
(Teliacora sps), both climbers are indicator
species of moist riverine forest.
Mixed hardwood forest grows
in well-drained areas. Adina Cordifolia, Casearia
tomentosa, lagerstroemia parviflora and Mitragyna
parviflora are among tree species found in this
type.
Wooded grasslands are similar
to Savanna type where ground vegetation is dominated
by grass species with sparsely distributed tree
species. Common grass species found in this
vegetationtype are Saccharum spontaneum, Imperata
cylindrica and Saccharum bengalensis, Desmostachia
bipinnata and Vetiveria zizanoides. Sparsely
distributed tree species include Bombax ceiba,
M. phillippensis, A. cordifolia, Largerstroemia
parviflora and Dalbergia sissoo.
Phantas are the open short grassland area on
previously cultivated fields. Imperata cylindrica,
Saccharum spontanum and Narenga perphrocoma
are the dominating grass species in phantas.
Baghaura and Lamkoili Phantas in the southwestern
section, and Guthi, Shivpur, Sanosiri, Thulosiri
and Chepang phantas are the typical example
of this type.
Tall alluvial floodplain grassland grows on
the riverbeds of Geruwa, Orai and Babai Rivers.
The dominating species of these grasslands include
Saccharum spontaneum, Saccharum bengalensis,
Phragmites karka and arundax.
