Ecologists studied amphibians in the Western Ghats to examine their response to agroforestry practices. While some endemic frogs face harm, others adapt to modified habitats. Highlighted is Microhyla nilphamariensis, a nocturnal frog found in South Asia. Frogs, crucial bioindicators, face threats from habitat loss, climate change, and disease, necessitating conservation efforts.
Key Findings of the Study
- Impact of Agricultural Expansion: Paddy fields and orchard expansion threaten frog population with paddy fields showing the lowest frog diversity and mango and cashew orchards housing the fewest frogs overall.
- Decline of Rare Frog Species: Rare species, such as the CEPF Burrowing Frog (Minervarya cepfi) and the Goan Fejervarya (Minervarya gomantaki), were scarce in altered agricultural habitats.
- Global and Local Amphibian Decline: About 40.7% (8,011 species) of amphibians worldwide are classified as threatened due to habitat destruction, pollution, climate change and diseases like chytridiomycosis. The Western Ghats, a biodiversity hotspot with 252 amphibian species (226 frogs), is facing habitat loss and declining frog populations.
Reasons for Decline
- Loss of Microhabitats: Important microhabitats like rock pools, which protect frog eggs and tadpoles during dry spells, are being threatened by agricultural practices.
- Wetland Destruction: Agricultural and urban expansion is destroying wetlands crucial for frog reproduction.
- Agricultural Runoff: Agricultural runoff with pesticides and fertilizers harms water quality, endangering sensitive frog populations.
- Climate Change: Frogs’ sensitivity to even minor environmental changes makes them vulnerable to climate change and human disturbances.
| Frogs hold cultural importance in Indian communities, symbolizing rain and fertility. E.g., In Assam, Bhekuli Biya (frog marriage) is practised as a means of invoking rain. In southern India, frog marriage is known as Mandooka Parinaya for invocation for rain. In Uttar Pradesh, frog marriage is practised in places like Sonebhadra, Gorakhpur, and Varanasi. Nadukani-Moolamattom-Kulamavu tribes of Kerala harvest the pig-nose purple frog for food during the monsoon season. |
How Agricultural Expansion Threatens Biodiversity
- Deforestation: Conversion of forests into farmland is the leading cause of habitat decline.The area of primary forest worldwide has decreased by over 80 million hectares since 1990 resulting in habitat destruction, fragmentation, and eventual extinction.
- Habitat Destruction: Between 1962 and 2017, approximately 340 million hectares of new cropland and 470 million hectares of natural ecosystems were converted into pastures globally leading to the destruction of critical ecosystems.
- Monoculture: Large-scale agricultural practices like cattle ranching, soy, and palm oil cultivation replaces previously diverse ecosystems with monocultures and domesticated animals like cows, goats, sheep, and pigs.
- Overuse of Chemicals: Industrial agricultural practices, especially the overuse of pesticides, fertilizers, and chemicals pollute groundwater and water systems, affecting both aquatic and terrestrial species.
- Reduced Carbon Storage: Cropland stores significantly less carbon compared to the original forests or vegetation.Land-use changes could release 17 gigatons of CO2 in the long-term, worsening the climate crisis and threatening biodiversity by disrupting ecosystems.
- Extinction Risks: Around 13,382 species of the 25,000 identified as threatened by the IUCN are endangered primarily due to agricultural land clearing and degradation. In addition, some 3,019 species are affected by hunting and fishing, and 3,020 by pollution from the food system.
- Isolation of species: Agricultural expansion fragments habitats, isolating ecosystems and increasing species’ extinction risk due to inbreeding, resource scarcity, and limited mobility.