Knowledge of forest structure and floristics are necessary for the study of forest
dynamics, plant-animal interactions and nutrient cycling. An aspect that has generated
considerable attention for many years among ecologists as well as evolutionary and
conservation biologists has been the analysis of the patterns, causes and maintenance of
biological diversity in the tropics (Gentry, 1988; Huston, 1994). More recently, there has
been an awareness of and an increasing interest in understanding the variation in species
diversity within the tropics (Gentry, 1982, 1995). Tropical moist deciduous forests are the
most diverse from the floristic point of view.
Gandhamardan hill range is such a tropical moist deciduous system in Odisha, India.
Due to diversified topography with twenty-two perennial streams, the hill range having
most congenial environment for the luxuriant growth of plant resources. These resources
are under severe threat due to over-exploitation by the local people for collection of
firewood, fodder and medicinal plants and heavy incidence of grazing. Some sporadic
works on floristic and ethnobotanical studies were carried out earlier (Raju, 1960;
Panigrahi et al., 1964; Brahmam and Saxena, 1990a, b; Mishra et al., 1994, 2001; Misra
and Behera, 1998; Mishra and Das, 2003; Misra, 2004). But, this floristically rich hill
range with varied terrain conditions and environmental factors along with its
phytogeographical position was not explored well in the past.
The present study is, therefore, the first attempt to make an inventory and analysis of
the entire flora of Gandhamardan hill range based on copious field observations,
available literature and herbarium data, with a view to contribute to the overall
knowledge of Gandhamardan flora and to the management of this sacred hill range.
Materials and Methods
Gandhamardan hill range (between 20˚42′ and 21˚00′ N latitude and 82˚41′ and
83˚05′ E longitude) is stretches over 240 km2 area in Bargarh and Bolangir districts of Odisha, India. The hills are believed to be of ancient age and sacred because legend says, when Hanuman carried the mountain from Himalayas to Sri Lanka in search of Sanjivani, some part it fell down in Odisha. There are two temples (Nrusinghnath and Harishankar) of 11th century based in the foothills on the northern and southern parts of the plateau on the bank of two perennial streams. The hill ranges are composed of a cluster of hills with
altitude varying between 600 and 1005 m. Bender, Butel, Chalidilli, Chhatradandi
Gandhamardan, Potpani and Thuta are the prominent hills in this area. The range stands
as a natural barrier at the border of Bolangir and Bargarh districts of Odisha (Fig. 1). This
Fig. 1. Map of the Gandhamardan hill range (A), the study area, in Odisha (B), India (C).
area enjoys tropical monsoon climate. The mean annual rainfall ranges between 1250 and
1400 mm. The rainfall in the hill region and temperate climate facilitate tropical
deciduous forest with a good number of medicinal plant species. Normally the rain
depends on north-east monsoon. The maximum temperature goes up to 37˚C in summer
(April-May) whereas the minimum falls to 12˚C in winter (December-January). The
humidity is relatively high. The rock formation is archaic metamorphic called
‘Khondalite’ to high-level laterite (Pandey and Chatterjee, 1984).
The present study was carried out during 2004-2006. Data on taxon distribution
within the Gandhamardan hill range were collected mainly from two sources: field
observations and collection of specimens, and literature, while only in a few cases data
were assembled from the Herbarium of Regional Research Laboratory (RRL-B). The
majority of field observations were carried out from 2004 to 2006 during multiple field
trips throughout each growth season. Accordingly, information on habit, habitat,
flowering, fruiting period, etc. was recorded. Collection of plant specimens was carried
out in both dry and wet seasons to know more information on habitat. The specimens
collected were deposited in herbarium of RRL-B. The identification of specimens was
carried out by consulting relevant literature (Patro, 1993; Saxena and Brahmam, 1995;
Misra and Das, 1998, 2004) and regional floras (Gamble and Fischer, 1915-35; Haines,
1921-25; Mooney, 1950; Saxena and Brahmam, 1996). Life-form categories were
identified according to Raunkiaer’s system of classification (Raunkier, 1934).
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