Global Underground Network of Arbuscular Mycorrhizal Fungi Mapped for the First Time

The global underground network of arbuscular mycorrhizal (AM) fungi has been mapped for the first time, highlighting its critical role in ecosystems and climate change mitigation. This discovery is vital for UPSC aspirants, particularly for GS Paper 3, which covers environmental and ecological issues. Last Updated: 17-06-2026

Key Facts About Arbuscular Mycorrhizal (AM) Fungi

• Classification: AM fungi belong to the phylum Glomeromycota.
• Symbiotic Associations: They form symbiotic associations with the roots of 70–90% of land plant species, making them one of the most widespread terrestrial symbioses.
• Evolutionary Significance: AM fungi are considered "living fossils" and "ancient asexuals," having existed since the earliest land plants, with no known sexual stage.
• Structure & Nutrient Network: AM fungi consist of fine, branching hyphae that act as two-way conduits, transporting nutrients and carbon between plants and soil.
• Ecosystem Role: AM fungi are key biotic components of soil. Their absence or depletion reduces ecosystem efficiency, nutrient cycling, and overall soil health.
• Biodiversity Hotspots: Around 40% of global AM fungal networks are concentrated in grasslands such as South Sudan, the Tibetan Plateau, and India’s Banni grasslands.
• Carbon Storage & Climate Role: AM networks store roughly 300 million tonnes of carbon and sequester about 4 billion tonnes of CO₂-equivalent annually, supporting climate mitigation.
• Ecological Function: AM fungi act as natural biofertilizers, enhancing water and nutrient uptake, improving plant growth, and providing pathogen protection in exchange for photosynthetic carbon.
• Threats & Policy Relevance: Cropland ecosystems typically have 50% lower fungal density than wild ecosystems, highlighting the need to integrate AM fungi into climate and ecosystem management policies.

Global Ecological and Climate Significance

The mapping of AM fungi networks is crucial for understanding their macro-level significance in global ecology and climate strategies. These fungi play a pivotal role in nutrient cycling and carbon storage, aligning with India's strategic goals for sustainable development and climate change mitigation. The vast networks, spanning approximately 110 quadrillion kilometers, underscore the potential for enhancing global carbon sequestration efforts, contributing to international climate commitments.

UPSC Relevance

GS Paper Mapping: This topic is relevant for GS Paper 3 (Environment and Ecology) and GS Paper 1 (Geography).

Prelims Angle: Questions could focus on the classification, symbiotic relationships, and ecological roles of AM fungi.

Mains Angle: Potential essay themes include the role of AM fungi in climate change mitigation and sustainable agriculture.

Essay Paper / Optional Subjects: Relevant for Environmental Science and Geography optional subjects.

FAQ Section

What is Arbuscular Mycorrhizal (AM) Fungi? AM fungi are a group of fungi that form symbiotic relationships with the roots of most land plants, aiding in nutrient and water absorption.

Why is AM Fungi important? They are crucial for ecosystem efficiency, nutrient cycling, and carbon storage, playing a significant role in climate change mitigation.

What are the key features of AM Fungi? Key features include their classification under Glomeromycota, their role as natural biofertilizers, and their vast global network that supports plant growth and soil health.