The Silence Forest assessment

Silence Forest is one of the forested areas of Auroville that houses many species of the Tropical Dry Evergreen Forest (TDEF), the original flora of the coastal part of Tamil Nadu, of which now only a few patches remain. Like many of Auroville’s forests, intermittent TDEF forestation started in the 1970s, along with indigenous tree planting and extraction of fallen trees for timber. But about a decade ago Silence was converted into an experiment in natural regenerative forestry.

Stewarding Silence Forest

Dave, who holds a M.Sc. in ecological forestry from the University of Wageningen in The Netherlands, has been working in Silence since 2015 and became its steward in 2017. Together with Elumalai, who has been involved with forestry activities for over three decades, he ensures the forest’s continued vitality. “Taking care of Silence Forest hasn’t been a profit-making venture,” he says. “I have invested lakhs to bring the forest to what it is today, a thriving and valuable ecosystem.”

Dave also gives talks about his work, such as to students of Yuvabe, an Auroville unit that does impact assessments for various units and services of Auroville. Agreement was reached that Yuvabe would support volunteer students from Pondicherry University to do a research project in order to obtain an independent professional assessment of Silence Forest, and understand its environmental impact. The study took several months; when Dave was not there, he provided inputs remotely.

The assessment agrees with Dave’s appraisal. The team focused on a 2.5-acre area of Silence Forest, where it recorded 62 tree species, 23 species of birds, 18 species of butterfly, 14 fungi species, 7 mammal species, and 5 different types of frogs. “They didn’t count the number of mosquitoes,” says Dave drily. “During the monsoon this forest is knee-deep in water; a few months later, the ground is still soggy in places. It’s an ideal mosquito breeding ground.” Visitors are warned. ‘Beware of mosquitos,’ reads the notice board at the entrance gate.

Dave takes me on a tour through the forest. It’s beautiful, with many small shrubs interspersed with tall and very tall trees. “During 24 hours in spring, the forest floor is white,” says Dave. “That’s the time that the Mutti (Coffea_ wightiana_) blossoms. This is a beautiful shrub with a jasmine-like fragrance. We showed a sample to a representative of Kew Gardens in England who verified it. It is a species of coffee which they had not seen in the wild. We harvested the seeds and Marc roasted them. They produce an excellent coffee, similar to so-called “Arab coffee”, with a distinctive taste of cardamon.”

The tall trees are identified as African Mahogany (Khaya senegalensis) and Vengai (Pterocarpus marsupium) – both home to many mammal species – as well as the Kassod tree (Senna siamea). The abundant presence of the Kassod tree makes the soil nitrogen-rich, which improves overall soil health and increases the growth rate of the forest. The forest has also an abundance of Tamarind trees (Tamarindus indica), one of the homing trees of flying foxes, also known as fruit bats.

Dave points at a tree canopy where a large number of bats are roosting. “They are unique to this forest, you won’t find them anywhere else within the Auroville city area,” he says. “I estimate that there may have been up to 800 fruit Auroville bats roosting here. Individuals travel upwards of 93 miles (150 km) in search of food. There is a large colony at Kaluperumbakkum, a village near Mattur. That village considers this animal as very auspicious and protects them; even the use of firecrackers during festivals is not allowed.” Asked why they have chosen Silence Forest as their roosting colony, Dave says he doesn’t know. “Elumalai tells me it’s because the energy in Silence is very special. I can tell you that these bats may have planted more trees than all the foresters of Auroville together. The seeds from ingested fruits are dispersed through their waste.” He mentions that in March this year a student from the Department of Ecology of the University of Pondicherry will come to Silence Forest to research the ecological and social significance of the Indian fruit bat for his M.Sc. thesis.

Like in many places in India, the bats in Silence Forest are threatened by habitat destruction caused by urbanisation or the building of roads. “Silence, unfortunately, is situated at the edge of the city area and the outer ring road is envisaged to cut straight through its middle,” says Dave. “Bulldozers have already started clearing some undergrowth, and as a result, one part of the fruit bats’ colony has disappeared.”

Carbon sequestration and groundwater recharge

Emphasizing that effective strategies for ensuring the long-term sustainability of a forest can only be developed by understanding and monitoring carbon storage, the researchers also studied the levels of carbon sequestration - the process of removing carbon dioxide from the atmosphere and storing it in carbon sinks such as forests, which store carbon in their biomass, and forest soils, which store carbon as organic matter.

Based on data collected from five plots of 20x20 meters each, the researchers found that six tree species in particular play a crucial role in the capturing and storage of carbon. They are the indigenous species Tamarindus indica, Azadirachta indica [Spiritual atmosphere], Albizia lebbeck [Integral wisdom] and the exotic species Senna siamea, Acacia auriculiformis [Work tree] and Khaya senegalensis. [The names in square brackets are those given by The Mother, eds.] These trees not only play a vital role in storing carbon but also serve as pioneering species in the forest’s growth, in whose shade many indigenous species can germinate.

Groundwater recharge is equally essential. The researchers found that the trees play a crucial role in slowing down the runoff, in boosting soil infiltration and expanding the water storage. Forests act like sponges, absorbing rain and letting it percolate underground, and so replenishing aquifers. The team observed negligible runoff, with water loss during rainfall primarily attributed to evapo-transpiration.

Conclusions

In its final assessment, the team states that the existence of a Silence Forest positively influences groundwater retention and enhances water quality by serving as a natural filtration system, and that the forest plays a vital role in mitigating climate change by sequestering carbon dioxide. It recommends further study of the forest’s biome by extending the survey to the entire 11.2 acres of the forest and including the study of additional species of insects and of herbaceous and woody plants.

The report mentions that the forest can serve as an example of integrating green and public spaces into urban planning. For this to happen, planners will have to cooperate with forest managers to minimise disturbances in the forest and help foster the occurrence of more flora and fauna. In particular, the effects of the Outer Ring Road crossing Silence Forest will need to be evaluated. 

For more information on the assessment contact Yuvabe at info@yuvabe.com

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Silence Forest’s overarching mission extends beyond the boundaries of its lush canopy. It serves as a sanctuary for biodiversity conservation, an important sink for carbon, and a wellspring of cultural and socio-economic enrichment within the Auroville community. Furthermore, in its role as a recreational space, it offers respite and leisure to the township’s residents, and also for visitors such as those staying at the neighbouring Afsanah and Vérité guesthouses, making it an indispensable asset to the community and a vital cornerstone of Auroville's commitment to sustainable living and unity. This report was written to inform people in and outside of Auroville about the ecological processes that shape this forest and how to manage it sustainably to enhance its ecological benefits. The assessment has not gone into the social, economic, and spiritual characteristics of the forest.

From the assessment