Land in Balance, a science-policy brief prepared by the UNCCD Science-Policy Interface
Scientific Conceptual Framework for Land Degradation Neutrality, a report of the UNCCD Science-Policy Interface
Land degradation neutrality (LDN) aims to achieve no net loss of land-based natural capital, compared with the baseline. Monitoring achievement of neutrality is based on quantifying the baseline and then assessing the balance between the area of “gains” (significant positive changes/improvements) and area of “losses” (significant negative changes/degradation) relative to the baseline, within each land type, at the end of LDN implementation.
The LDN indicators and metrics
The scientific conceptual framework for LDN specifies what to measure (the indicators) and how it is assessed (the metrics) as part of the LDN monitoring process. Following a selection process undertaken by the UNCCD, three global indicators (land cover, land productivity, and carbon stocks) were selected, which provide good coverage and together can assess the quantity and quality of land-based natural capital and most of the associated ecosystem services.
The indicators are reasonable proxies for change in land-based natural capital. They are quantified via associated metrics, which are universally applicable and interpretable, and should ideally be quantifiable with available data sets. The indicators and their associated metrics (in parentheses) are already used for UNCCD reporting and for the sustainable development goals (SDGs):
- Land cover (land cover change);
- Land productivity (net primary productivity, NPP);
- Carbon stocks (soil organic carbon, SOC).
The associated metrics are quantified for each land type at the baseline setting period (prior to LDN implementation). To monitor achievement of LDN the metrics are quantified again, using the same methods used at baseline, during at least two intermediate monitoring points and at the end of LDN implementation.
Countries pursuing LDN are encouraged to use additional indicators/metrics for ecosystem services and social and economic outcomes that address their national or sub-national priorities, and to include these as part of LDN monitoring. Complementary indicators could come from the SDG indicators and could include indicators on human wellbeing, such as the maintenance of land rights, or on biodiversity, such as the Red List Index.
Determining LDN status: the “one-out, all-out” principle
The “one-out, all-out” principle is used to evaluate the indicators and metrics and determine LDN status. According to the one-out, all-out principle, degradation occurs when (compared with baseline):
- SOC decreases significantly; or
- NPP decreases significantly; or
- negative land cover change occurs.
The LDN indicators and associated metrics are complementary components of land-based natural capital and are not intended to be aggregated into a single value. As such, they are quantified and evaluated separately. As gains in one of these measures cannot compensate for losses in another, if one of the indicators/metrics shows a negative change, LDN is not achieved, even if the others are substantially positive. Each individual land unit is determined this way, and the results are aggregated to the level of the land type, to determine LDN status per land type.
A simplified example, provided in the figure below, illustrates how LDN is monitored using the metrics to identify areas of change, and the one-out, all-out principle to identify gains and losses. The baseline values for each land unit (A1-A5) are quantified at the baseline ("t0") and again at the end of LDN implementation ("t1"). The areas of gains and losses are tabulated for each land unit, which are then summed to determine the LDN status for that land type (grassland).
Verification and interpretation
Neutrality is achieved when the area of losses equals the area of gains, within each land type, and across land types, at national scale. The results of the monitoring of LDN indicators should be verified against national and local data sets and expert opinion, to confirm the accuracy of the monitoring data and the consequent assessment of LDN status. This should be done using a participatory process involving stakeholders (e.g. experts, local communities, etc.). Interpreting and verifying the results is also a component of the LDN learning process, in which the results help to evaluate the effectiveness of past interventions in maintaining ecosystem services, and to plan future land management.
- Principles related to monitoring (Module E)
1. Make use of three land-based indicators and associated metrics: land cover (assessed as land cover change), land productivity (assessed as NPP) and carbon stocks (assessed as SOC), as minimum set of globally agreed indicators/metrics, which were adopted by the UNCCD for reporting and as a means to understanding the status of degradation (UNCCD, 2013b).
2. The integration of results of the three global indicators should be based on a “one-out, all-out” approach where if any of the three indicators/metrics shows significant negative change, it is considered a loss (and conversely, if at least one indicator/metric shows a significant positive change and none shows a significant negative change it is considered a gain).
3. Make use of additional national and sub-national indicators, both quantitative and qualitative data and information, to aid interpretation and to fill gaps for the ecosystem services not fully covered by the minimum global set.
4. Apply in-situ validation and local knowledge obtained through local multi-stakeholder platforms to interpret monitoring data according to local context and objectives, within agreed guidelines
5. Monitoring should be viewed as a vehicle for learning. Monitoring provides: opportunities for capacity building; the basis for testing hypotheses that underpin the counterbalancing decisions and the interventions implemented, the LDN concept, and this conceptual framework; and knowledge to inform adaptive management.