New Article: Soil organic carbon stock as an indicator for monitoring land and soil degradation in relation to United Nations' Sustainable Development Goals
Seventeen Sustainable Development Goals (SDGs) adopted in September 2015 aim to end hunger and poverty, to protect the Planet, and to ensure peace and prosperity for all. The soil organic carbon (SOC) stock is a major planetary resource supporting many critically important ecosystem services (ESs) and underpins realization of some of the SDGs at the national level. Thus, decrease in the SOC stock is among the significant universal indicators for land and soil degradation and compromises efforts to achieve the SDGs especially those with reference to food, health, water, climate, and land management.
However, there is currently no well‐established relationship (i.e., quantitative evidence) between the SOC stock and the level of ESs attributable to it. Further, basic soil data and monitoring systems including those of SOC stock and its changes are not available for many regions and nations.
This uncertainty affects the suitability of using the SOC stock as absolute indicator to monitor changes in land and soil degradation and, particularly, in relation to the SDG monitoring framework. Thus, although the SOC stock is arguably an important indicator for land and soil degradation among others, more research and data on a national level are needed to establish the relationship between the SOC stock and the targets to monitor progress towards achieving the SDGs with reference to food, health, water, climate, and land management.
To the best of authors' knowledge, this is the first review on the suitability of the SOC stock as an indicator for monitoring land and soil degradation with regard to the SDG framework.
Nevertheless, the SOC stock plays a conceptual role as indicator for land and soil degradation by fostering the input of information, ideas, and perspectives into realms where decisions on land and soil degradation and on SDGs are made . This may be achieved through (a) public dialogue, (b) background information, and (c) cocreation of knowledge. The indicator SOC stock may also play a political role with regard to land and soil degradation when policy makers influence agenda setting and problem definition, highlighting overlooked issues, or (de)stabilize and (de)legitimize predominant frameworks of knowledge and actors.
The SOC stock may particularly indicate hotspots of land and soil degradation.
The following recommendations are made:
- The central role of the SOC stock for soil health should be used to identify land and soil degradation hotspots among other indicator soil properties.
- Research is needed to enhance the knowledge on the importance of SOC stock changes for land and soil degradation and for achieving the SDGs with reference to food, health, water, climate, and land management.
- Soil degradation should be assessed by a composite soil degradation index including data on SOC stock changes among other soil properties.
- Land degradation should be assessed by a composite land degradation index including data on SOC stock changes among other data for soil properties, land use cover, and land productivity.
- The SOC stock in the subsoil and those of urban areas should be determined and its importance for soil‐based ESs assessed.
- To increase the acceptance of the indicator SOC stock, the knowledge base on processes affecting SOC stocks and their relation to land and soil degradation must be strengthened, and routine, harmonized, and comparable approaches for systematic SOC stock data collections must be established.