Quantitative Analysis of Floristic Composition, Biological Spectrum and Leaf Spectrum of a Sacred Grove in Jhargram District, West Bengal, India

Sacred Groves are tracts of virgin forests, left untouched and protected by local people, because of culture and religious beliefs. These tracts are remnants of the once-dominant flora, reservoirs of the rich biodiversity, and the last refuge for preserving the rich indigenous culture and traditions. For these reasons, the biological and leaf spectra, as well as the conservation status of the current sacred grove vegetation, Maa Mongalmoyee Than (MMT) in Jhargram district of West Bengal, India, have been studied. Data were collected during different seasons. The floristic list is taxonomically arranged based on clade, order, and family. In addition, photographs of some common, locally uncommon, endemic and valuable plant species within the sacred grove were taken. The herbarium sheets were then described by matching properly annotated materials available at the Herbarium Section of Vidyasagar University as well as the Botanical Survey of India. The results of floristic studies showed 217 MMT's angiosperm species, belonging to 196 genera, distributed under 59 families of 27 orders. Furthermore, Poales (13.82%) and Fabaceae (12.44%) are the dominant order and family, respectively, in terms of species population. Meanwhile, the biological spectrum showed the grove enjoys a "thero-chamaephyte" phytoclimate form, as well as a comparatively undisturbed status, being a sacred grove. Also, the preservation of germplasm within the grove is based on traditional belief in the social system.


INTRODUCTION
According to Khan et al. (2008), a classic example of culturally responsive communitybased natural small-scale resource management, are sacred groves. These are small patches of forests devoted to deities and ancestral spirits, with socio-cultural, spiritual and political significance for the indigenous communities caring for them. All around the world, sacred groves have also provided a rich bio-diverse ecosystem, preserved culture, created awareness for bio-diversity conservation, and fostered mutual respect between people and nature within these communities, over the centuries (Verschuuren et al., 2012). Meanwhile, international organizations, including the UNESCO, the IUCN and the WWF are attracting increasing interest in the role of these natural sacred sites. The IUCN treats sacred groves as natural religious places, in addition to areas recognized as sacred by indigenous and traditional communities, or as places of worship and remembrance by religions or faiths. Natural sacred sites are highly diverse in biology and culture, and are the oldest protected areas in the world.
A study by Hughes & Chandran (1998) stated immemorial sacred groves have been preserved and revered by numerous people, in the name of indigenous God or Goddess, within Africa, Asia, Autro-Pacific region, North and South America, as well as Europe, throughout history, while Kent (2013) reported the existence of forest areas where supernatural entities were claimed to live and immoral practices, including tree felling, wood poaching, plant or leaf collection, hunting, domestic animal grazing, were forbidden.
India has the highest number of sacred groves in the entire world, estimated at over 100000 (Khan et al., 2008), as a result of high ethno-cultural diversity. These groves occur in many regions, with a variety of cultural practices (Rath & Ormsby, 2020). Indigenous communities across India have protected forest patches as indigenous sacred groves, for generations (Bhagwat & Rutte, 2006). However, these forests, along with the sacred groves are currently disappearing due to cultural change, industrialization, agricultural land encroachment, and exotic weed invasions. Berkes (2017) reported sacred forests as islands of biodiversity protecting a large number of plant and animal species, including some rare, endangered and endemic taxa, although called by different names in different states of India, and controlled by local people for various reasons. Generally, sacred groves are repositories and nurseries of many local tribal and other folk medicines, and these are the original sources gradually entering modern medicine, after careful screening (Sen, 2018). This article therefore, provides an insight on how human beliefs, norms, social practices, and ethics, help conserve plants in a tribal area of Jhargram district in West Bengal, through sacred groves.

MATERIALS AND METHODS
The sacred grove studied (latitude 22º35΄51. 39΄΄N -22º35΄50.27΄΄ N and longitude 86º51΄57.82΄΄E-86º 51΄57.39΄΄E; average altitude 103 masl) consists of mixed deciduous, semi-deciduous and evergreen flora species, the present sacred grove, is popularly known as MMT (named the adjacent village as well as the presiding deity, Mongalmoyee). According to Fig. 1, the grove neighbours Malabati village, under Binpur II block, in Jhargram district, along the Jharkhand state's border, and is bordered on the north by Purulia and Bankura districts, on the east by the district of West Midnapore. In addition, the grove has widespread borders with the state of Orissa on the south, and with Jharkhand state, on the south. The region is also extremely humid and tropical. Temperatures are as high as 46°C, during the hot, dry days of May and June, and as low as 8°C in the chilly nights of December and January.  Jhargram covers an area of 3037.64 km 2 and has a population of 1,136,548. Furthermore, 96.52% of this population was rural, and only 3.48% were urban, while 20.11% and 29.37% belonged to the scheduled castes and tribes, respectively (WBPSPM, 2011). This 2-acre grove represents an isolated forest patch in near-climax stage and is surrounded by crop fields and forest land. The devotees collect money and other utensils from around the region and neighboring areas, to celebrate worship. Meanwhile, livestock, including goats and chickens, are sacrificed on 4 Magh (18/19 th of January) to satisfy the goddess, and this is a deep-rooted custom. Also, an iconic idol of Goddess Mongolmoyee was worshipped within the sacred grove and by the local tribal people, while maintenance and managerial activities are carried out by the local communities.
Field survey and data collection. The study area was thoroughly investigated during different seasons, between 2012 and 2018. This presented a prospect of the flora composition and field interpretation during the entire flowering and fruiting of the maximum species quantity. Subsequently, phytosociological data were collected by laying 20 × 20 m quadrates for tree species, 5 × 5 m for shrubs as well lianas, and 1 × 1 m for herbs and grasses. A brief floristic survey was carried out through a "spot identification" basis, and the specimens were then processed, preserved, poisoned and mounted on sheets of herbarium (Jain & Rao, 2016). In addition, photographs of some common, locally uncommon, endemic and valuable plant species within the sacred grove were taken. The herbarium sheets were then described by matching properly annotated materials available at the Herbarium Section of Vidyasagar University as well as the Botanical Survey of India. Numerous related catalogues (Anderson, 1862), regional flora (Hooker, 1875;Prain, 1903;Haines, 1926), monographs (Mitra, 1958), revision works (Datta & Majumdar, 1966) and other articles (Paria, 2005;Paria, 2010), were also consulted for identification purposes, while the scientific names were checked using the World Checklist of Vascular Plant (WCVP, 2020) website and confirmed after being deemed acceptable.
Analysis of vegetation. The floristic list is taxonomically arranged based on clade, order, and family, according to Angiosperm Phylogeny Group IV classification (Chase et al., 2016). Table 1 shows inferred habit, lifespan, flowering and fruiting time, Raunkiaer's life-form of each species with sub-type, leaf size, IUCN status and distribution within the grove. The resulting biological spectrum was then compared to the standard Raunkiaer spectrum, to determine the grove's phytoclimate (Raunkiaer, 1934;Muller-Dombois & Ellenberg, 1974). Also, leaf size information was used to assess the plant physiological systems and identify plant associations, while the Raunkiaer (1934) diagram was used to quickly estimate the leaves in the field. Subsequently, a list of invasive alien species was prepared, as described by Reddy (2008).
According to Sharma & Raina (2017), the highest percentage of therophytes within the area, is related to the subtropic character and often associated with various factors, including soil and climatic conditions, combined with grazing, lopping, felling, deforestation, introduction of annual weeds, and other anthropogenic activities. Thus, the present study indicates the flora are mostly subtropical, and with a higher percentage of therophytes as well as chamaephytes, compared to normal biological spectrum. Therophytes were also discovered to be strongly preferred in disturbed areas, and to be prevalent in regions having biotic pressure or unfavorable habitat conditions (Al-Yemeni & Sher, 2010). This is in accordance with the findings of this study. Nazir & Malik (2006) reported nanophanerophyte and therophytes as the biological spectra of Sarsawa hill Kotli. In addition, hot, dry and waterlogged conditions combined with overgrazing resulted in harsh conditions within the grove. This also agrees with the reports by Sher & Khan (2007), as well as Amjad et al. (2017), and Abbas et al. (2020) stating therophytes and nanophanerophytes are characteristic of subtropical ecosystems. Structurally and floristically, sub-tropical dry forests are less complex than wet forests, comprising about half or less wet forest tree species (Hasnat & Hossain, 2020). The forests serve as a refuge for valuable and endangered plants and animals. Hence, further study is required to quantify the data and suggest plans to conserve the sacred groves.  Table 1 and Table 4, as well as Fig. 4, also show the phylum megaphyll is equally distributed into Araceae, Cannabaceae and Fabaceae families. A leaf spectrum describes the plant adaptation and association in a community, with small-sized leaves present at the base and large leaves at the top, and is also correlated with climatic warming and water availability in the soil (Weber et al., 2012;Sakschewski et al., 2015;Badshah et al., 2016). The presence of middle-sized leaves indicates a sub-tropical climate. Furthermore, the meso and notophyllous elements dominant in the sacred grove, show moisture availability or wet condition. As a result of the therophytes and chamaephytes present, the proportion of leaf size groups was observed to change seasonally. However, in all seasons, the phanerophytes and some chamaephytes retained almost the same status.
IUCN categorization. About 161 of these 217 plants have currently not been evaluated. Furthermore, there are 55 Least Concerned (LC) and 1 Vulnerable (VU) species. Table 1 shows the IUCN categorization. Based on this grouping, climber Cayratia pedata is the vulnerable species (Saha et al., 2015). The results of threatened species assessment show most of the flora are perennial trees, while the phytosociological study with ecological data on IUCN red listed plants, indicates the plants are currently present and regenerate in the sacred groves, but disappear in nearby forests. This study therefore highlights the status and distribution of these species within the study area, the ecological characteristics required for their survival, and the threats to some of the species, identified by the IUCN criteria. Numerous factors led to the rise in numbers of vulnerable species. Overgrazing has been a significant cause of seedling destruction. However, anthropogenic activities, including the development of the plant and land-use amendment, are the foremost vital cause of this deterioration.

CONCLUSION
This study shows the possibility of using the Raunkiaer strategy to evaluate the major differences between the populations of angiosperm plants, associations in the forested landscape or biome, the percentage of flora species resulting from the established ecological parameters and environmental gradients. In addition, life-form analysis clearly shows the sacred grove's biological spectrum is "thero-chamaephytic" phytoclimate. Meanwhile, there is a need to further juxtapose the adjacent natural strands pattern along the environmental gradients, to reveal more than the mere forest covers in the ecosystem data. This indicates biotic variables are significant in shaping landscape vegetation, by guiding succession, and demonstrates the effect of anthropogenic diseases favoring therophyte growth, within the sacred grove. Therefore, any more damage to the sacred grove is able to facilitate potential changes within its present phytoclimate.