Diversity of Urban Trees of Karwar, Karnataka

 Urban trees serve many useful functions such as climate change mitigation by carbon sequestration, air quality improvement by air pollution abatement,  biodiversity conservation and  source of ecosystem goods to urban inhabitants. They also have aesthetic, socio-religious and recreational value in urban contexts. In spite of the importance, they have not received much  scientific attention. we ( Shivananda Bhat, Jayakara Bhandary & Syed Fasihuddin, Department of Botany, Govt. College, Karwar)  have  investigated the diversity and density of tree species growing both within the built environment as well as road-side avenues in the seaside town of Karwar  which  is  the administrative headquarters of Uttara Kannada district of Karnataka.    The total area of the town  is 27.15 km² and  population (2001 census) is 62,973. 

                The tree flora of Karwar comprises of about 106 species in which about 70% are indigenous species. The other 30% involves exotic and introducedd species.  The top five dominant species are Mangifera indica  (Wild mango, 20.016% of total tree population), Polyalthia longifolia (False Ashoka, 12.544%), Peltophorum pterocarpum ( Yellow flame tree,  6.763%), Samania saman (Rain tree, 5.072%) and Artocarpus heterophyllus (Jackfruit, 5.045%). The tree diversity represents a good assemblage of  different utility categories such as wild and cultivated fruit yielding trees, shade and ornamental trees, sacred and religious trees, etc. Besides the high proportion of older  trees of wild mango and jackfruit,  presence of other wild fruit yielding trees like  Artocarpus incisus and Spondias pinnata, large sized sacred trees such as Ficus religiosa  and  F. benghalensis, rare medicinal species such as Garcinia indica,  Saraca asoca, Terminalia bellirica, etc., are some of the notable features of the urban tree flora of Karwar.

Old gigantic trees cooling the heart of Karwar town

Tree shades - a hub of activities

Avenue trees of Karwar

A 300 year old sacred Syzygium cumini tree

Wild mango trees - dominant tree of Karwar

              This is, in fact, the summary abstract of this project presented at Lake 2011 Conference held at Indian Institute of Sciences, Bangalore, from 22nd to 24th December 2011. 

The Real 'Ashoka' Tree

Saraca asoca - The real Ashoka

Ashoka tree is  reputed for its medicinal values in Ayurveda. Preparations such as ‘ashokarishta’ prepared mainly from the bark of this tree is considered as the panacea for urino-genital disorders.  Besides medicinal importance, this tree also has religious and cultural significance. This tree provided shade and shelter to Sita while she was in the captivity of Ravana. This tree which is very attractive while in bloom owing to its crimson-red bunch of flowers  is also considered as the symbol of chasity and worshipped by women in many parts of India.

            Botanically, Ashoka is called Saraca asoca  and it belongs to the family Fabaceae.  Due to overexploitation, its natural population has dwindled and it has entered into the list of rare and threatened plants of India.  Its one among the 100 red listed medicinal plants of South India.

Polyalthia longifolia - duplicate Ashoka

            The common avenue tree Polyalthia longifolia   (Family Annonaceae) is also known as ‘ashoka tree’. But for the common name, there is no similarity in appearance or properties between this and Saraca asoca. Ironically, many believe that this is the real Ashoka of Ayurveda! There are also reports indicating that the bark of this easily available ‘nakli (duplicate) ashoka’ is used  in ashoka preparations, either as a substitute or as an adulterant,  to  the rare and difficult to find real Ashoka.