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Floristic Studies of Sasihithlu Estuary of Dakshina Kannada, Karnataka, India

Abhishek Bharadwaj R , Devi Prasad A.G
Applied Ecology and Environmental Sciences. 2021, 9(4), 458-464. DOI: 10.12691/aees-9-4-5
Received March 04, 2021; Revised April 07, 2021; Accepted April 16, 2021

Abstract

Estuaries constitute the unique wetland ecosystems possessing the floristic richness. They are an abode of diverse and unique flora. The present study is aimed to document the floristic diversity of Sasihithlu estuary which is a pre-requisite to understand the vegetation structure. Random quadrat method was employed for floral documentation. The species were identified using standard taxonomic methods. The results of the study have shown the occurrence of 88 species of 81 genera belonging to 46 families. Among these, 11 true mangroves and nine mangrove associates were documented. The occurrence of one endangered species and one vulnerable species has been catalogued.

1. Introduction

Vegetation studies form an essential component of evaluation of the quality of ecosystems. Vegetation studies help in the enhancement of sustainability and ecological restoration. Studies of floral taxonomy and composition provide valuable information about ecology and the ecosystem. It is also important to assess the ecological health and well-being of ecosystems and is a foundation for biodiversity conservation and natural resource management 1. The floral composition of an area serves as the most conspicuous ecological feature 2. Estuaries are complex, dynamic and highly productive ecosystems. These unique ecosystems form the transition zone between freshwater and marine environments. Estuaries host a greater biodiversity compared to sea and river ecosystems 3. The unique conditions of estuaries harbour mangroves 4. Mangroves are a vital segment of estuarine ecosystem. They store and cycle nutrients, filter pollutants from land run-offs 5, 6. They are of prodigious ecological and socio-economic significance 7 and provide various socio-economic services to mankind 8, 9, 10, 11. They help in the stabilization of shoreline by trapping sediments and controlling erosion 12. Mangroves and associated wetlands shelter a wealth of genetic and species diversity 13. Mangroves are classified into two types based on their habitat use; true mangroves which specifically grow in intertidal regions and mangrove associates which occur in littoral or terrestrial habitats. India has rich mangrove density and diversity which accounts for about three percent of the world's mangroves 14, 15, 16. Withal, India has lost 40% of the mangrove area in the last century and National Remote Sensing Agency has registered a decline of 7000 ha of mangrove between 1975 to 1981 17. Estuaries are under great strain caused by natural and anthropogenic reasons 7 which has led to a rapid loss in floristic diversity and changing vegetation patterns. Understanding the species composition of mangroves is elemental for assessing the quality of estuarine ecosystems and helps in their management 18, 19. Scientific information regarding the floristics of Sasihithlu is lacking. Considering the vast array of ecosystem services of estuaries, the present commentary has been undertaken to document the floral diversity which can be used as a baseline data for formulating management and conservation strategies.

2. Study Area

Sasihithlu estuary is a confluence point of rivers Nandini and Shambhavi which originates in Western Ghats (Figure 1). It is a cardinal area from environmental, ecological and biological points of view. It is located 25 Km north of Mangaluru city (13.02°N & 74.47°E) with an average elevation of 3 m above mean sea level. The climate and weather pattern of the area is prototypical to that of a coastal region. The temperature varies between 26°C and 42°C with an annual precipitation of about 3,500 mm. The mouth of the estuary is dominated by sand whereas the mid and the upper reaches of the estuary is dominated by silt and clay sediments. The estuary is hugely influenced by tidal inundations exhibiting semidiurnal tides and hence the water is brackish throughout the year. Five sampling sites were selected in Delta Point (mouth of the estuary), Hejmady and Chitrapu (parts of Shambhavi river) and Kollachikambla (part of Nandini river) (Table 1) with a minimum distance of 500 m from each other to ensure Quasi independence 20.

3. Materials and Methods

Five study sites with varying floral composition were selected along the estuary. Periodic field surveys were carried out using random or scattered quadrat method covering an area of approximately 0.9 ha. 10m x 10m quadrats were laid in the study sites and within each quadrat, all individual flora were identified and documented using authentic information, data, field keys and standard taxonomic methods 21, 22, 23, 24, 25, 26, 27. Canon EOS 70D and 600D DSLR cameras with 18 - 135 mm lens was used to photograph the flora. Garmin Etrex 30X GPS machine was used to take the waypoints (latitude and longitude) and altitude of the area.

4. Results and Discussion

Sasihithlu estuary is a mosaic of natural and cultivated flora. In the present study, 88 floral species belonging to 81 genera and 46 families were documented from the five selected sites of the study area. This included 11 true mangrove species belonging to six families (Table 2). Out of this, 18.18% were shrubs and the rest were trees. Nine species of mangrove associates belonging to nine families (Table 3) were also recorded. 44.44% of the documented mangrove associates were herbs, 22.22% were climbers and creepers, 11.11% were shrubs and 22.22% of them were trees. Fabaceae was found to be the dominant family with seven species. Of the documented flora, 29.76% were trees, 19.04% were shrubs, 42.85% were herbs and 8.33% were climbers or creepers (Figure 2). The floral growth of the estuary can be differentiated based on the zones. These mangrove zones are governed by tidal activity, fresh water inflow, soil texture and quality, salinity and nutrient content 28, 29, 30. Highly saline euhaline zones were colonised by Avicennia officinalis, Rhizophora apiculata and Rhizophora mucronata. This can be attributed to their high tolerance to fluctuating and hostile conditions. Polyhaline zones with medium salinity were dominated by Bruguiera cylindrica (Figure 3), Bruguiera gymnorhiza, and Lumnitzera racemosa. Sonneratia alba (Figure 4), a species threatened in India 31 and Aegiceras corniculatum were documented in Site 4 from the banks of riverine system. Population of this threatened mangrove species in the study area was very less. Acanthus ilicifolius, Excoecaria agallocha and Kandelia candel were documented from the low saline mesohaline zones. The oligohaline zones with high freshwater influx and low salinity was occupied by Acrostichum aureum, Derris trifoliata (Figure 5), Pandanus odoratissimus and other mangrove associates. Sesuvium portulacstrum, Spinifex littoreus and Ipomoea pes-carpae were noted growing on the sand banks among the mangroves. Canavalia rosea dominated the sand banks adjacent to river Shambhavi. Lantana camara was documented from the degraded mangrove patches and human frequented areas. Scaevola taccada was restricted to the sandy stretches of beach and was completely absent from riverine and estuarine systems. Occurrence of species like Biophytum reinwardtii, Impatiens minor, Impatiens oppositifolia (Figure 6), Cyanotis cristata, Cleome rutidosperma and Talinum cuneifolium was seasonal. They were recorded predominately during monsoon and post-monsoon season. Curculigo orchioides (Figure 7), an endangered species and Santalum album, a vulnerable species was documented from the terrestrial habitats in study site 3 next to river Nandini. The study has also revealed some threats to the mangroves and the estuary. Mangroves in the area are exploited for timber, fuel wood, manure and occasionally for fodder. Over fishing and extraction of shells, conversion of mangroves and wetlands into aquaculture ponds for fish and shrimp farming, dredging, solid waste deposition by rivers and sea, water pollution, riverine and coastal erosion and increased human interference caused by tourism are the major threats to the area.

5. Conclusions

Presence of 88 floral species along with the threatened species in the quantified area indicates that Sasihithlu estuary is qualitatively diverse providing conducive conditions for floral growth. The gathered data provides an insight about the floral composition of the area. Majority of the documented floral species are of great ecological and conservational importance. The study also revealed the threats to mangroves and the estuarine ecosystem. Environmental pollution, habitat loss and destruction along with various other intense anthropogenic activities have severe negative consequences on the ecosystem and biodiversity. Providing protection and incorporating better management practices can help in ecosystem management and biodiversity conservation. The baseline data from this study can be used as an effective tool for regular monitoring of habitats, mangrove regeneration initiatives and restoration programs. It can also be used for sustainable management and to formulate conservation strategies.

Acknowledgements

I wish to express my sincere thanks to Dr. Shwetha and Dr. B G Tanuja for their guidance, encouragement and motivation during the course of the study. I am grateful to Dr. Usha M and Mr. Arjun M S for their valuable suggestions and constant support. Thanks to Mr. Dileep Saliyan and Mr. Chandra Kumar for providing all the required data and facilities during the fieldwork.

Conflict of Interests

There is no conflict of interest with respect to this research article.

References

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In article      View Article
 
[2]  Sharma, P.; Rana, J. C.; Usha, D.; Randhawa, S. S. and Rajesh, K. 2014. Floristic Diversity and Distribution Pattern of Plant Communities along Altitudinal Gradient in Sangla Valley, Northwest Himalaya. The Scientific World Journal 2014. 264878. 11 pages.
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[3]  Kaladharan, P.; Zacharia, P.U. and Vijayakumaran, K. 2011. Coastal and marine floral biodiversity along the Karnataka coast. Journal of the Marine Biological Association of India 53(1): 121-129.
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[4]  Abhishek Bharadwaj, R. and Devi Prasad, A.G. 2020. Studies of Avifaunal Diversity in Sasihithlu Estuary of Dakshina Kannada, Karnataka, India. Applied Ecology and Environmental Sciences 9(1): 1-7.
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[5]  Rao, T. A.; Aggarwal, K. R. and Mukherjee, A. K. 1963. Ecological studies on the soil and vegetation of Krusadi group of islands in the Gulf of Mannar. Bulletin of the Botanical Survey of India 5, 141-148.
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[7]  Madhusudhana Rao, K.; Krishna, P. V. and Hemanth Kumar, V. 2015. Mangrove floral diversity and necessity for conservation of Interu mangrove swamp of River Krishna estuarine region Andhra Pradesh, India. International Journal of Advanced Research 3(6): 829-839.
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[8]  Banerjee, L. K.; Sastry, A. R. K. and Nayar, M. P. 1989. Mangroves in India, identification manual. Government of India. Botanical Survey of India.
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[10]  Upadhyay, V. P.; Ranjan, R. and Singh, J. S. 2002. Human mangrove conflicts: The way out. Current Science 83: 1328-1336.
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[11]  Zhang, Y.; Wang, W.; Wu, Q.; Fang, B. and Lin, P. 2006. The growth of Kandelia candel seedlings in mangrove habitats of the Zhang jiang estuary in Fujian, China. Acta Ecologica Sinica 26: 1648-1656.
In article      View Article
 
[12]  Elizabeth McLeod and Rodney, V. S. 2006. Managing Mangroves for Resilience to Climate Change. The World Conservation Union (IUCN), Gland, Switzerland.
In article      
 
[13]  Roychoudhury, N.; Meshram, P. B. and Rajesh, K. M. 2017. Floral diversity in mangrove forests of Bhitarkanika, Odisha. Van Sangyan 4(10). Oct.2017.
In article      
 
[14]  Giri, C.; Ochieng, E.; Tieszen, L. L.; Zhu, Z.; Singh, A.; Loveland, T.; Masek, J. and Duke, N. 2011. Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography 20(1): 154-159.
In article      View Article
 
[15]  Arun, T. R. and Shaji, C. S. 2013. Diversity and Distribution of Mangroves in Kumbalam Island of Kerala, India. IOSR Journal of Environmental Science, Toxicology And Food Technology 4(4): 18-26.
In article      View Article
 
[16]  Madhusudhana Rao, K. and Krishna, P. V. 2014. Checklist of Fishes from Interu Mangrove Swamp of River Krishna Estuarine Region Andhra Pradesh, India. International Journal of Advanced Research 2(8): 301-306.
In article      
 
[17]  Government of India. 1987. Mangroves in India - Status report. New Delhi, Ministry of Environment and Forests. 52-55.
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[18]  Dislich, R. and Pivello, V. R. 2002. Tree structure and species composition changes in an urban tropical forest fragment, Sao Paulo, Brazil during a five-year interval. Boletim de Botanica da Universidade Sao Paulo 20: 1-12.
In article      View Article
 
[19]  Sreelekshmi. S.; Chakkalakkal, M. P.; Rani, V.; Philomina, J.; Chalil, V. A. et al. 2018. Diversity, stand structure, and zonation pattern of mangroves in southwest coast of India. Journal of Asia-Pacific Biodiversity 11(4): 573-582.
In article      View Article
 
[20]  Ralph, C. J.; Sauer, J. R. and Droege, S. 1995. Monitoring Bird Populations by Point Counts. Gen Tech Rep PSW-GTR-149 Albany, CA. US Department of Agriculture, Forest Service, Pacific Southwest Research Station. 187 pages.
In article      View Article
 
[21]  BSI. 1998. Mangroves, Associates and Salt Marshes of the Godavari and Krishna Delta. A. R. K. Sastry.; L. K. Banerjee and D. Ghosh(eds), ENVIS, Botanical Survey of India.
In article      
 
[22]  Gamble. J. S. 1957. Flora of the Presidency of Madras. Botanical Survey of India, Calcutta.
In article      
 
[23]  Matthew, K. M. 1983. The Flora of the Tamil Nadu Carnatic. The Rapinat Herbarium, Tiruchirapalli.
In article      
 
[24]  Gamble, J. S. 1921-1935. Flora of the Presidency of Madras. Volume I - III. Botanical Survey of India, Calcutta.
In article      
 
[25]  Pascal, J.P. and Ramesh, B.R. 1987. A Field Key to the Trees and Lianas of the Evergreen Forests of the Western Ghats (India). French Institute, Pondicherry.
In article      
 
[26]  Pascal, J.P. 1988. Wet Evergreen Forests of the Western Ghats of India - Ecology, Structure, Floristic Composition and Succession. French Institute, Pondicherry, India.
In article      
 
[27]  Ghosh, A.; Mukherjee, S.; Sen, N.; Dasgupta, M. and Naskar, M. 2003. Floral diversity of mangroves and mangrove associated species in the Indian Sundarbans with special reference to distribution and abundance. Journal of the Indian Society of Coastal Agricultural Research 21(1): 53-58.
In article      
 
[28]  Clarke, L. D. and Hannon, N. J. 1967, 1969. The mangrove swamp and salt marsh communities of the Sydney district. II Tholocoenotic complex with particular references to physiography. Journal of Ecology 57, 213-234.
In article      View Article
 
[29]  Macnae, W. 1968. A general account of the flora and fauna of the mangrove swamps and forests in the Indo-west Pacific region. Advanced Marine Biology 6: 73-270.
In article      View Article
 
[30]  Twilley, R. R. and Chen, R. 1998. A water budget and hydrology model of a basin mangrove forest in Rookery Bay, Florida. Australian Journal of Freshwater and Marine Research 49: 309-323.
In article      View Article
 
[31]  ENVIS Center on Floral Diversity. 2014. Botanical Survey of India. http://bsienvis.nic.in/Database/Indian Mangroves_3941.aspx.
In article      
 

Published with license by Science and Education Publishing, Copyright © 2021 Abhishek Bharadwaj R and Devi Prasad A.G

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Cite this article:

Normal Style
Abhishek Bharadwaj R, Devi Prasad A.G. Floristic Studies of Sasihithlu Estuary of Dakshina Kannada, Karnataka, India. Applied Ecology and Environmental Sciences. Vol. 9, No. 4, 2021, pp 458-464. http://pubs.sciepub.com/aees/9/4/5
MLA Style
R, Abhishek Bharadwaj, and Devi Prasad A.G. "Floristic Studies of Sasihithlu Estuary of Dakshina Kannada, Karnataka, India." Applied Ecology and Environmental Sciences 9.4 (2021): 458-464.
APA Style
R, A. B. , & A.G, D. P. (2021). Floristic Studies of Sasihithlu Estuary of Dakshina Kannada, Karnataka, India. Applied Ecology and Environmental Sciences, 9(4), 458-464.
Chicago Style
R, Abhishek Bharadwaj, and Devi Prasad A.G. "Floristic Studies of Sasihithlu Estuary of Dakshina Kannada, Karnataka, India." Applied Ecology and Environmental Sciences 9, no. 4 (2021): 458-464.
Share
[1]  Adams, J.B.; Veldkornet, D. and Tabot, P. 2016. Ecology and biodiversity of estuaries. South African Journal of Botany.
In article      View Article
 
[2]  Sharma, P.; Rana, J. C.; Usha, D.; Randhawa, S. S. and Rajesh, K. 2014. Floristic Diversity and Distribution Pattern of Plant Communities along Altitudinal Gradient in Sangla Valley, Northwest Himalaya. The Scientific World Journal 2014. 264878. 11 pages.
In article      View Article  PubMed
 
[3]  Kaladharan, P.; Zacharia, P.U. and Vijayakumaran, K. 2011. Coastal and marine floral biodiversity along the Karnataka coast. Journal of the Marine Biological Association of India 53(1): 121-129.
In article      
 
[4]  Abhishek Bharadwaj, R. and Devi Prasad, A.G. 2020. Studies of Avifaunal Diversity in Sasihithlu Estuary of Dakshina Kannada, Karnataka, India. Applied Ecology and Environmental Sciences 9(1): 1-7.
In article      
 
[5]  Rao, T. A.; Aggarwal, K. R. and Mukherjee, A. K. 1963. Ecological studies on the soil and vegetation of Krusadi group of islands in the Gulf of Mannar. Bulletin of the Botanical Survey of India 5, 141-148.
In article      
 
[6]  Rao, T. A. and Sastry, A. R. K. 1973. Studies on the flora and vegetation of coastal Andhra Pradesh, India. Bulletin of the Botanical Survey of India 15, 92-107.
In article      
 
[7]  Madhusudhana Rao, K.; Krishna, P. V. and Hemanth Kumar, V. 2015. Mangrove floral diversity and necessity for conservation of Interu mangrove swamp of River Krishna estuarine region Andhra Pradesh, India. International Journal of Advanced Research 3(6): 829-839.
In article      
 
[8]  Banerjee, L. K.; Sastry, A. R. K. and Nayar, M. P. 1989. Mangroves in India, identification manual. Government of India. Botanical Survey of India.
In article      
 
[9]  Deshmukh, S. V. 1991. Mangrove of India: Status report In:(Deshmukh, S. V. and Mahalingam, R., Eds). A Global Network of Mangrove Genetic Resource Centres Project Formulation Workshop. Madras, India. 15-25.
In article      
 
[10]  Upadhyay, V. P.; Ranjan, R. and Singh, J. S. 2002. Human mangrove conflicts: The way out. Current Science 83: 1328-1336.
In article      
 
[11]  Zhang, Y.; Wang, W.; Wu, Q.; Fang, B. and Lin, P. 2006. The growth of Kandelia candel seedlings in mangrove habitats of the Zhang jiang estuary in Fujian, China. Acta Ecologica Sinica 26: 1648-1656.
In article      View Article
 
[12]  Elizabeth McLeod and Rodney, V. S. 2006. Managing Mangroves for Resilience to Climate Change. The World Conservation Union (IUCN), Gland, Switzerland.
In article      
 
[13]  Roychoudhury, N.; Meshram, P. B. and Rajesh, K. M. 2017. Floral diversity in mangrove forests of Bhitarkanika, Odisha. Van Sangyan 4(10). Oct.2017.
In article      
 
[14]  Giri, C.; Ochieng, E.; Tieszen, L. L.; Zhu, Z.; Singh, A.; Loveland, T.; Masek, J. and Duke, N. 2011. Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography 20(1): 154-159.
In article      View Article
 
[15]  Arun, T. R. and Shaji, C. S. 2013. Diversity and Distribution of Mangroves in Kumbalam Island of Kerala, India. IOSR Journal of Environmental Science, Toxicology And Food Technology 4(4): 18-26.
In article      View Article
 
[16]  Madhusudhana Rao, K. and Krishna, P. V. 2014. Checklist of Fishes from Interu Mangrove Swamp of River Krishna Estuarine Region Andhra Pradesh, India. International Journal of Advanced Research 2(8): 301-306.
In article      
 
[17]  Government of India. 1987. Mangroves in India - Status report. New Delhi, Ministry of Environment and Forests. 52-55.
In article      
 
[18]  Dislich, R. and Pivello, V. R. 2002. Tree structure and species composition changes in an urban tropical forest fragment, Sao Paulo, Brazil during a five-year interval. Boletim de Botanica da Universidade Sao Paulo 20: 1-12.
In article      View Article
 
[19]  Sreelekshmi. S.; Chakkalakkal, M. P.; Rani, V.; Philomina, J.; Chalil, V. A. et al. 2018. Diversity, stand structure, and zonation pattern of mangroves in southwest coast of India. Journal of Asia-Pacific Biodiversity 11(4): 573-582.
In article      View Article
 
[20]  Ralph, C. J.; Sauer, J. R. and Droege, S. 1995. Monitoring Bird Populations by Point Counts. Gen Tech Rep PSW-GTR-149 Albany, CA. US Department of Agriculture, Forest Service, Pacific Southwest Research Station. 187 pages.
In article      View Article
 
[21]  BSI. 1998. Mangroves, Associates and Salt Marshes of the Godavari and Krishna Delta. A. R. K. Sastry.; L. K. Banerjee and D. Ghosh(eds), ENVIS, Botanical Survey of India.
In article      
 
[22]  Gamble. J. S. 1957. Flora of the Presidency of Madras. Botanical Survey of India, Calcutta.
In article      
 
[23]  Matthew, K. M. 1983. The Flora of the Tamil Nadu Carnatic. The Rapinat Herbarium, Tiruchirapalli.
In article      
 
[24]  Gamble, J. S. 1921-1935. Flora of the Presidency of Madras. Volume I - III. Botanical Survey of India, Calcutta.
In article      
 
[25]  Pascal, J.P. and Ramesh, B.R. 1987. A Field Key to the Trees and Lianas of the Evergreen Forests of the Western Ghats (India). French Institute, Pondicherry.
In article      
 
[26]  Pascal, J.P. 1988. Wet Evergreen Forests of the Western Ghats of India - Ecology, Structure, Floristic Composition and Succession. French Institute, Pondicherry, India.
In article      
 
[27]  Ghosh, A.; Mukherjee, S.; Sen, N.; Dasgupta, M. and Naskar, M. 2003. Floral diversity of mangroves and mangrove associated species in the Indian Sundarbans with special reference to distribution and abundance. Journal of the Indian Society of Coastal Agricultural Research 21(1): 53-58.
In article      
 
[28]  Clarke, L. D. and Hannon, N. J. 1967, 1969. The mangrove swamp and salt marsh communities of the Sydney district. II Tholocoenotic complex with particular references to physiography. Journal of Ecology 57, 213-234.
In article      View Article
 
[29]  Macnae, W. 1968. A general account of the flora and fauna of the mangrove swamps and forests in the Indo-west Pacific region. Advanced Marine Biology 6: 73-270.
In article      View Article
 
[30]  Twilley, R. R. and Chen, R. 1998. A water budget and hydrology model of a basin mangrove forest in Rookery Bay, Florida. Australian Journal of Freshwater and Marine Research 49: 309-323.
In article      View Article
 
[31]  ENVIS Center on Floral Diversity. 2014. Botanical Survey of India. http://bsienvis.nic.in/Database/Indian Mangroves_3941.aspx.
In article