Species richness and carbon stock of Sharngakavu sacred grove, Chengannur Kerala

Abstract

Global warming and biodiversity loss are the major environmental issues faced by the planet today. The “sacred groves” are repositories of woody vegetation that successfully and efficiently conserve these “trees outside the forests”. Documentation of the species present in such C sinks will help to document the native species that are conserved here. Estimation of carbon locked up in these vegetated areas will help to further understand the potential of these sacred natural sites in mitigating climate change. With this background, a study titled “Species richness and carbon stock of Sharngakavu sacred grove, Chengannur, Kerala” was attempted on Sharngakavu sacred grove, Aalapuzha during 2018- 2019. The objectives of the study were to document the floristic wealth of the grove, enumerate the carbon stock of the grove and to understand the people’s perception on the role of conservation of this sacred grove in combating climate change. The grove was delineated into core zone and buffer zone for detailed vegetation analysis and estimation of carbon stock. Fifty three plant species were recorded from the core zone of the grove, while from the buffer zone, 37 species could be identified. Actinodaphne malabarica and Xanthophyllum arnottianum which is endemic to Western Ghats were observed in the core region. Other species identified, included some major evergreen and semi- evergreen species such as, Aphanamixis polystachya, Ardisia pauciflora, Carallia brachiata, Cinnamomum malabatrum, Cinnamomum verum, Lagerstroemia microcarpa, Morinda citrifolia, Pongamia pinnata and Strebles asper. Some deciduous tree species such as Alangium salvifolium, Grewia tillifolia and Boswellia serrata were also found. The Shannon Weiner index value of the core was about 1.9, which suggests the grove inhabits a fairly good number of species. The core zone was dominated by Xanthophyllum arnottianum while the buffer was dominated by Caryota urens. The carbon stock of the soil was found to be decreasing with depth. The carbon stock of the standing vegetation was found to be the highest in the core which could be attributed to the species richness. The total carbon stock was also found to be the highest in the core zone (456.71 Mg ha-1), while 344.36 Mg ha-1was recorded total C of the buffer zone, even though in terms of area, this constituted

the major portion of the grove. Perception studies revealed that majority of the respondents are strongly interested in the conservation of the grove. They also considered deforestation and exploitation of nature as the major causes of climate change. It was also clear that the people’s perception on the causes and impacts of climate change was highly influenced by their age, gender, education and occupation. Among the local residents, people’s interest to conserve the grove was influenced by their age, while among non-resident devotees, education levels was observed to influence their attitude. Traditional beliefs certainly had an influence on the existence of the grove. Even though the grove has been conserved as a part of cultural belief, its role in biodiversity conservation was well understood by the people. Strengthening the people’s knowledge on the importance of value of the grove in both biodiversity conservation and climate change mitigation will help to conserve this Important Plant Area (IPA).