Land-use changes hit endemic biodiversity on Western Ghats plateaus

Habitats of endemic and threatened animals are adversely impacted by disruptive land-use patterns on the plateaus of a Western Ghats section, a new study has found.

The study examined the animals’ response to the removal of large rocks from plateaus for paddy cultivation and construction, and habitat changes caused by land conversion to create orchards.

Researchers upturned more than 7,000 rocks in the Western Ghats region of Ratnagiri district in Maharashtra, and compared the number of various animal groups in three environments – loose rocks in natural plateaus, farmlands that were earlier under traditional paddy cultivation, and mango/cashew orchards expanding on these plateaus.

The focal animals included the white-striped viper gecko (Hemidactylus albofasciatus) that are only found on the plateaus and listed as “threatened” in the International Union for Conservation of Nature (IUCN)’s Red List, Seshachari’s caecilian (Gegeneophis seshachari), a legless amphibian that mostly lives under soil, the saw-scaled viper (Echis carinatus) which is one of India’s big-four venomous snakes, spiders, and scorpions.

The study showed “a drastic impact” on snakes and geckos in the orchards and paddy.

The researchers surveyed 7,179 surface rocks across the three environments and detected 5,738 animals – 2,405 in plateaus, 1,421 in orchards and 1,912 in paddy – across 38 animal groups. The findings were published in the international peer-reviewed journal Global Ecology and Conservation.

Sensitive to change

Loose rocks double up as shelter for the animals through extreme, varying climates.

Jithin Vijayan, lead author and researcher at Nature Conservation Foundation (NCF), said since many of these animals were sensitive to minor habitat changes, even “removing a rock” could impact biodiversity.

Manali Rane, researcher at Bombay Environmental Action Group, Aparna Watve, coordinator of the IUCN SSC Western Ghats Plant Specialist Group, Varad Giri, head scientist at the Reliance Foundation, Junagadh, and Rohit Naniwadekar, scientist at NCF, are co-authors of the study, conducted between June and September, 2022.

“Orchards created by destroying these plateaus pose a serious problem. While we cannot stop the construction, it is important to be sensitive to the microhabitats and ensure that the large rocks are not removed,” Jithin told DH.

A “significant portion” of the diversity under the loose rocks on these ancient plateaus is unique to the region, the researchers said. Watve noted that while the Konkan region has endemic biodiversity in human-modified landscapes, the situation can worsen with “aggressive land-use changes”.

In contrast with the larger theme of the findings, it was noted that Seshachari’s caecilian gained advantage from soil and rocks added for paddy cultivation, when they were abandoned.

The plateaus – most of them privately owned or under the state revenue department – are often classified as wastelands. They are also home to around 70 endemic plant species, three of them found to be threatened globally.

“The findings can help in protecting the plateaus as Biodiversity Heritage Sites, through conservation efforts involving the local communities,” Jithin said.