Belowground biodiversity

A worm in soil

Role of Belowground Biodiversity in Ecosystem Services

Nutrient cycling

Belowground organisms, including bacteria, fungi, protozoa, and invertebrates, are integral to nutrient cycling processes. They decompose organic matter, facilitating the release of nutrients essential for plant growth. For instance, mycorrhizal fungi form symbiotic relationships with plant roots, enhancing nutrient uptake—particularly phosphorus—while contributing to soil organic matter formation.

Soil structure and stability

Soil fauna, such as earthworms and arthropods, contribute to the physical structure and stability of soils. Their burrowing activities promote aeration and water infiltration, improving soil drainage and root penetration. Additionally, soil organisms participate in the formation of soil aggregates, which protect organic matter and enhance soil fertility.

Carbon sequestration

Belowground biodiversity plays a significant role in carbon sequestration. The decomposition of organic materials by microbial communities leads to the stabilization of soil organic carbon, mitigating climate change by reducing atmospheric CO2 levels. The diverse microbial processes involved in carbon cycling are crucial for maintaining soil health and productivity.

Disease regulation

A diverse soil microbiome can suppress plant pathogens through various mechanisms, including competition for resources and the production of antimicrobial compounds. This biocontrol function is essential for promoting plant health and reducing the reliance on chemical pesticides.

Threats to belowground biodiversity

The key threats to belowground soil biodiversity are:

Land use change

Intensive agricultural practices, urbanization, and deforestation significantly alter soil ecosystems, leading to habitat degradation and loss of biodiversity. The application of chemical fertilizers and pesticides can disrupt microbial communities and reduce overall soil health.

Climate change

Climate change poses a direct threat to belowground biodiversity through alterations in temperature and moisture regimes. These changes can impact the distribution and activity of soil organisms, potentially leading to declines in biodiversity and ecosystem functioning. Furthermore, increased frequency of extreme weather events can exacerbate soil erosion and degradation.

Soil contamination

Pollution from heavy metals, plastics, and agrochemicals adversely affects soil organisms. Contaminants can reduce microbial diversity and alter community composition, impairing ecosystem services and soil health.

Invasive species

The introduction of non-native species can disrupt local soil ecosystems. Invasive organisms may outcompete native species for resources, leading to a decline in biodiversity and alterations in ecosystem functioning.

Conclusions

Establishing the importance of belowground biodiversity in delivering ecosystem services is critical for promoting sustainable land management and conservation strategies. Protecting soil biota from various threats is essential for maintaining soil health, resilience, and the myriad of services that support human and ecological well-being.

Life and soils

STARS PhD student, Paul George discusses life in soil. He explains how living organisms play crucial roles in maintaining soil health across the planet; providing plants and animals with the water, nutrients and habitat they need to survive. Greater understanding of these organisms and their interactions has the potential to promote sustainable and healthy agricultural systems.

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