Amphibians at Risk from Climate Change Heat Stress

Recent research marks the alarming impact of climate change on amphibians. A study published in *Nature* reveals that 104 of 5,203 amphibian species are already facing overheating in shaded terrestrial environments. This represents 2% of the species studied. Scientists warn that a 4°C rise in global temperatures could threaten 7.5% of these species. Amphibians are particularly vulnerable to climate change, with over 40% classified as threatened.

About Amphibian Vulnerability

Amphibians are ectothermic animals. They depend on external sources to regulate their body temperature. This makes them sensitive to temperature changes in their habitats. The study estimated thermal limits for 60% of the examined species. It assessed their daily operative body temperatures and tolerance to extreme heat events in various microhabitats.

Effects of Global Warming

The research indicates that a 2°C increase in global temperatures could serve as a tipping point for amphibians. Beyond this threshold, the adverse effects amplify . Under a 4°C warming scenario, species may overheat for as many as 207.18 days annually. This could account for 22.8% of the warmest days.

Microhabitats and Their Importance

Microhabitats play important role in helping amphibians regulate their body temperature. Shaded areas, vegetation, and water bodies provide necessary cooling. However, deforestation, urbanisation, and droughts threaten these microhabitats. The loss of shaded areas can lead to increased body temperatures and desiccation stress for amphibians.

Implications for Ecosystems

Local extinctions of amphibian species could disrupt regional ecosystems. The decline in these species may erode genetic diversity and impact food chains. The study suggests that most amphibians will not experience overheating events across their entire range. Instead, local extirpations may occur, leading to broader ecological consequences.

Future Projections and Concerns

The study puts stress on the need for conservation efforts. As climate change progresses, amphibians face increasing risks. Prolonged exposure to high temperatures can affect their activity, reproductive success, and overall survival. The urgency of the situation calls for immediate action to protect these vulnerable species and their habitats.

Questions for UPSC:

1. Discuss the impact of climate change on biodiversity and ecosystem stability.
2. Critically examine the role of microhabitats in the survival of ectothermic species.
3. What is the significance of amphibians in ecological health? Explain with examples.
4. Comment on the potential consequences of local extinctions on genetic diversity and food webs.

Answer Hints:

1. Discuss the impact of climate change on biodiversity and ecosystem stability.

1. Climate change leads to habitat loss and alteration, affecting species survival.
2. Shifts in temperature and precipitation patterns disrupt breeding and migration cycles.
3. Increased extinction rates diminish biodiversity, weakening ecosystem resilience.
4. Changes in species interactions can lead to imbalances in food webs.
5. Loss of biodiversity threatens ecosystem services essential for human survival, like clean water and pollination.

2. Critically examine the role of microhabitats in the survival of ectothermic species.

1. Microhabitats provide critical thermal refuges that help regulate body temperatures.
2. Shaded areas and water bodies are essential for preventing overheating in ectotherms.
3. Loss of microhabitats due to urbanization and climate change increases vulnerability.
4. Access to diverse microhabitats enhances species resilience to environmental stressors.
5. Microhabitats support biodiversity by providing varied ecological niches for different species.

3. What is the significance of amphibians in ecological health? Explain with examples.

1. Amphibians serve as bioindicators, reflecting environmental health and ecosystem changes.
2. They play a key role in food webs, acting as both predators and prey.
3. Amphibians contribute to nutrient cycling and pest control within ecosystems.
4. Examples include frogs controlling insect populations and salamanders enriching soil quality.
5. The decline of amphibians can indicate broader ecological issues affecting other species and habitats.

4. Comment on the potential consequences of local extinctions on genetic diversity and food webs.

1. Local extinctions reduce genetic diversity, limiting adaptability to environmental changes.
2. Loss of species can disrupt food webs, leading to overpopulation of certain species.
3. Extirpated species may be key predators or prey, destabilizing ecosystem dynamics.
4. Genetic erosion can impair future species resilience, affecting long-term survival.
5. Local extinctions may lead to cascading effects, altering habitat structures and ecosystem functions.