Each soil is characterized by a set of physical and chemical properties unique to the soil type and the prevailing conditions, which enable specific soil processes to take place. These processes are referred to as soil functions.
Soil functions provide the basis for the provision of Soil Ecosystem Services (SES); a range of benefits that soils deliver to humans. For example, flood mitigation is an ecosystem service facilitated by soil functions like water infiltration and the subsequent reduction of surface flow as well as by vegetation growth, which can attenuate runoff through transpiration and by slowing down water flows through interception.
Although soil functions and Soil Ecosystem Services are not necessarily the same, they refer to similar phenomena and are often used as interchangeable terms. For example, the Food and Agriculture Organization of the UN (FAO, 2015) identified 11 soil functions, which they equated with Soil Ecosystem Services:
Soil Ecosystem Services
Soil ecosystem services are ecosystem services provided specifically by soils. Interestingly, soils are capable of delivering most ecosystem services, which goes to show their fundamental role in processes that are vital for both nature and human beings. Ecosystem services are often categorized into four groups, namely supporting, provisioning, regulating and cultural (Metro Vancouver, 2023).
Different soils offer soil ecosystem services to varying extents based on their health status and numerous physical, chemical and biological properties. In an ideal scenario, these services benefit soil biota, humans and the surrounding environment alike.
The relevance of certain benefits is strongly determined by location and landscape. For instance, the prevalence of high relief slopes in mountainous regions, which tend to intensify flood velocity and erosion rates, creates a strong demand for ecosystem services like flood regulation and erosion control. For a more detailed, yet concise, Alpine-region-specific overview of soil ecosystem services, their mechanisms and the threats they face, take a look at our pocket book Soil Ecosystem Services in Brief.
It is essential to note that soils can only fulfill their role as fundamental ecosystem service providers if they are in a healthy state themselves. The need for sustainable soil management is rooted in this very logic, whereby humans recognize that depleted and degraded soils are no longer be able to deliver the benefits that are crucial for the functioning of both the environment and our co-dependent society.
Within the Alpine region, sustainable soil management and protection guidelines are provided by the Alpine Convention. Their Soil Conservation Protocol is grounded in sustainable development principles and serves as the framework for safeguarding the multifaceted functions of Alpine soils.
Soil biodiversity
Soil biodiversity refers to the myriads of living organisms, which, although not visible to the naked eye, are abundant in healthy soils. They include micro-organisms (e.g., bacteria, fungi, protozoa, nematodes), meso-fauna (e.g., acari and springtails) as well as macro-fauna like earthworms and termites.
The interactions between these organisms, plant roots and their environment constitutes the biological activity that contributes to the provision of soil ecosystem services. They are principal agents responsible for cycling nutrients, regulating soil organic matter content, sequestering carbon, determining greenhouse gas emissions, modifying the physical and chemical structure of soil as well as controlling the amount and efficiency of nutrient uptake by vegetation and enhancing plant health. For instance, micro-organisms are restless decomposers of organic materials and pollutants while earthworms’ create underground tunnel systems that can increase soils’ water infiltration capacity.
You can read more about earthworms and their essential contributions to mountainous forest landscapes in our Earthworms booklet. We are also happy to share our earthworm identification sheet, so that more eager audiences can gain further insights into the various earthworm species living in mountain soils.