Abstract
A botanical survey was conducted during the periods of 2015-2017 to study some threatened
plant species' present status in their in-situ habitats in Karnaphuli range of Kaptai reserve
forest, a protected area of Rangamati district, Bangladesh. A total of 34 plants were listed
under various threat categories recorded from the Kaptai reserve forest and its adjacent
areas based on 'Red Data Book of Vascular Plants of Bangladesh' (Vol- I & II) and
'Encyclopedia of Flora and Fauna of Bangladesh' (Vol- 5 to 12). A combination of transect
with quadrats methods was used for sampling. The quadrates of 20m × 20m, 5m x 5m anp
1m x 1m sized were fixed for trees, shrubs and herbs, respectively, to get density,
abundance, relative density, relative frequency and basal area etc. The density and
frequency represented the species composition, whereas the importance value index
indicated the dominancy of one species over another, and Shannon and Simpson's indices
revealed the species diversity and concentration dominance of plant species, respectively.
During the study, a total of 318 species comprising 116 trees, 79 shrubs, 113 herbs and 10
climbers belonging to 91 families and 245 genera were observed. Out of the 318 recorded
plant species in the Karnaphuli range, 21 species were found threatened; of them, 4 as
Endangered (EN) (1 shrub and 3 herbs) and 17 as Vulnerable (VU) (11 trees, 3 shrubs and 3
herbs). Besides these threatened species, 22 were found as Near Threatened (NT), 6 species
as Data Deficient (DD), 220 species as Least Concern (LC) and the rest 49 as Not Evaluated
(NE). Top three dominant families were Rubiaceae, Zingiberaceae and Fabaceae, while
Moraceae, Rubiaceae and Zingiberaceae was the dominant family for tree, shrubs and herbs,
respectively. Out of 34 targeted species 17 species viz. Aglaonema hookerianum, Bhesa robusta,
Crepidium biauritum, Cucumis hystrix, Diospyros ramiflora, Harpullia arborea, Hedyotis thomsonii,
Homalomena aromatic, Horsfieldia kingii, Mangifera sylvatica, Marsdenia tenacissima, Mycetia
longifolia, Nervilia aragoana, Pilea melastomoides, Scaphium scaphigerum, Symplocos macrophylla
and Xerospermum laevigatum were recorded. The recorded species comprises trees, shrubs,
and herbs of which 13 are vulnerable (8 tree, 2 shrubs and 3 herbs) and 4 endangered (1
shrub and 2 herbs and 1 climber). All the phytosociological parameters of the targeted
species showed lower value which indicates that these plants are limited in number except
Aglaonema hookerianum. The species showed a contagious distribution pattern. Shannon
Wiener diversity index was 3.53, 3.98 and 4.53 for trees, shrubs and herbs, respectively.
Horsfieldia kingii, Scaphium scaphigerum and Symplocos macrophylla were found to have only
one individual who needed immediate conservation attention. Particular attention should be
taken to maintain these small scale individuals' habitat for further studies on population
demography and ecological requirements of these threatened species. Over exploration of
natural resources and anthropogenic activities adversely affect the existing ecosystem,
leading to the rarity of numerous species in the near future. There is a critical need for
developing pragmatic conservation strategies for the conservation of these threatened
plants.