Researchers from Pune have discovered a low-level basalt plateau, an isolated flat-topped steep hill, in the Western Ghats in Maharashtra. The researchers have also recorded 76 plant species belonging to 24 families and registered a floristic inventory which they claim to be important from the conservation point of view, considering the rampant urbanisation.
The discovery was from Manjare village and the details of the same were published in National Academy Science Letters in December 2022.
Aboli Kulkarni, the lead author of the study, told Down To Earth:
Three types of rock outcrops are known in the biodiveristy hotspot of Western Ghats — lateritic outcrops at high (HLF) and low altitude (LLF), and basalt outcrops at high altitudes (BM). But now a low altitude basalt outcrop has been found in Murbad district, about 100 kilometres from Mumbai.
Rock outcrops are landscape habitats with more areas of rock surface exposure than surrounding areas. “It emerges when the surface soil and other materials wear off, exposing the parent rock surface. The outcrop is identified if the area has more than 50 per cent of such rocks,” Kulkarni explained.
Besides the outcrops, the team also recorded 76 plant species belonging to 24 families, mainly from Poaceae, Leguminosae and Cyperaceae ranges.
Aparna Watve, another researcher and author of the paper, had previously predicted that such outcrops could exist in the Western Ghats, but they were not recorded, said Kulkarni.
“It is the first time that such plants were found during a research on floral biodiversity,” she said. The researcher said the discovery holds significance as flora growing on these rocks experience multiple environmental stresses.
“As they grow among rocks, the flora faces a harsher environment compared to other species growing elsewhere,” Kulkarni said
These plants have limited soil, restricting their nutrient availability. And the lack of soil also reduces water retention capacity, which puts additional water stress on the plants, she added.
Moreover, the plants also face challenges during peak summers. In summer, the rock surfaces have higher temperatures than soil or other surfaces, making it difficult for these species to survive.
“But despite multiple stresses, these plants are found thriving which shows that these plants have adapted to their surroundings and indicates that a certain level of endemism also exists,” she said.
Speaking from the conservation point of view, Mandar Datar, a scientist at Agharkar Research Institute, Pune, said, “The outcrop was found during a field exploration and interactions with locals revealed the landscape. They referred it similar to Kas plateau.”
Kas plateau, a UNESCO world natural heritage site in Maharashtra, is a lateritic plateau that hosts many endemic wild flowering plants.
Considering the rapid urbanisation on Mumbai’s outskirts, identifying such biodiversity landscapes is important. “Steps can be taken towards protecting such unique habitats only with the knowledge of their ecological and biodiversity values,” Datar said.
He added that the finding would lead to documentation and awareness of the unique landscape. “We have explored and documented an area of 0.21 square kilometres and there are many patches in the surrounding areas which will require further detailed study,” he said.
Another uniqueness of the site is that it features plant species from all the three other outcrops mentioned above, which is not seen in other locations.
The site could also be used to study further the interactions between different species and how they interact with the environment, Datar said.