Status of Tree Diversity in Digha, West Bengal, India with Special Reference to their Phytochemical Constituents

Background: Digha is a coastal area in the district of Purba Medinipur, West Bengal, India. The vegetation in this area is unstable, like many other coastal zones. Trees play an important role in this region to prevent soil erosion and act as a windbreak. Also, the local people here depend on trees for their livelihood. Objectives: The current study aims to enumerate the tree species growing along the Digha seashore with special reference to their IUCN status and phytochemical constituents. Materials and Methods: The study area was rigorously surveyed over a period of about 4 years to record the trees of the area. Standard literature and websites were followed to summarize IUCN status and chemical constituents of the documented trees. Results: A total of 65 tree species belonging to 59 genera, and under 28 families have been documented with Fabaceae contributing the most (14 species). Tectona grandis was the only endangered tree species among the plants recorded. Conclusion: Conservation strategies must be adopted by the Forest Department and other government organizations to protect the relevant tree species as well as this fragile biozone.


INTRODUCTION
Digha is a seaside area, [1] situated near the northern tip of the Bay of Bengal.It is a part of the Purba Medinipur district of West Bengal, India.It lies between the latitude of 21º32 ' N to 22º40 ' N and longitude of 88º05 ' E to 89º00 ' E.Even before India's independence, Digha gained recognition as a tourist destination, and its popularity has grown over time. [2]Large number of tourists visit Digha mostly between January and December, also on other holidays. [3]Digha have unique vegetation because of its climate, soil, water and sand dunes.There is a great deal of floral diversity in the freshwater-and saltwater-logging areas, both temporary and permanent.Due to fragile nature, [4] trees in this area play a vital role in preventing soil erosion.Initiatives have long been in place to create a shelterbelt of Casuarina equisetifolia to prevent wind erosion of the surrounding terrain.Although some work has been done on the vegetation of this region, no work has been done so far on the diversity of tree species.The current survey gives a comprehensive account of the diversity of trees in Digha and nearby areas with emphasis on their IUCN status, and phytochemical profiles.

MATERIALS AND METHODS
Digha, in Purba Medinipur district of West Bengal, India, was the area for this study (Figure 1).Survey of trees in Digha was carried out from February 2019 to October 2023 in three seasons: winter, pre-monsoon, and post-monsoon, in order to make a list of trees, and to assess their current IUCN status.[7] Correct nomenclature of the species/genera/families is given (www.powo.science.kew.org; downloaded in December 2023).Voucher specimens were preserved in the herbarium of Ramnagar College.IUCN status of the relevant trees was assessed following the website of IUCN (https://www.iucnredlist.org;downloaded in December 2023).Chemical profiles of each tree species were documented by thorough survey of literature (see references).

RESULTS
A total of 65 tree species belonging to 59 genera fewer than 28 families have been documented in this study.Highest number of trees was found under the family Fabaceae (14 species (22%), see Figure 2).List of the tree species along with their IUCN status, and phytochemical profiles is recorded in Table 1.

Family
Scientific name; Voucher specimen

DISCUSSION
The study addresses 65 tree species growing in Digha.Terminalia arjuna, Alstonia scholaris, Azadirachta indica are commonly known medicinal trees in that area.Phytochemical study revealed the presence of arjunolic acid in Terminalia arjuna.Arjunolic acid is a novel phytocompound with multiple medicinal properties like antioxidant, antimicrobial, hepatoprotective, cardioprotective activity. [91,92][98] Indole alkaloids of Alstonia scholaris exhibit multiple pharmacological properties. [99,100]Casuarina equisetifolia is one of the dominant trees in this area to prevent soil erosion, also acts as a windbreak.
In addition, various species of mangroves such as Sonneratia alba, Sonneratia apetala, Rhizophora mucronata, Ceriops decandra are found in this coastal belt, which stabilize the habitat.Timber yielding plants like Tectona grandis is placed on the endangered category by IUCN.These ecologically, economically, and medicinally important trees require immediate conservation, both in situ and ex situ.

CONCLUSION
The study reveals 65 tree species in Digha, which are natural and/or planted.There are a few vulnerable and endangered tree species, that require due attention of the Forest department and other organizations for conservation.Further cultivation of trees in Digha and nearby areas is strongly recommended.

SUMMARY
According to the current study, there are about 65 natural/ planted trees found in Digha coastal region.The documented trees contain diverse chemical compounds which can be a major source of alternative system of medicine.They also play important roles to prevent soil erosion and function as wind break.Conservation strategies should be applied to protect these trees in fragile coastal region.

Figure 1 :
Figure 1: A. Map of India showing West Bengal, B. Map of West Bengal showing Purba Medinipur district, C. Study area showing Digha and its adjoining areas (Source: Google Earth).