Mapping Land Productivity Dynamics: Detecting critical trajectories of global land transformations
All life on Earth depends on the conversion and fixation of solar energy in the form of organic carbon compounds. On land, this process is driven by the photosynthesis of plants that form the terrestrial vegetation cover and the resulting output is typically referred to as land productivity, which can be quantified in terms of Net Primary Production (NPP). All other organisms (e.g., humans, other species of animal, bacteria, fungi) depend directly and indirectly on this primary production for their health and well‑being. Globally, humans appropriate a constantly increasing proportion of this NPP, affecting the structure and functioning of ecosystems, and which in many cases exceeds their natural variability and dynamics.
Hence, land productivity is an essential variable for detecting and monitoring active land transformations typically associated with land degradation processes. It can be expressed as an equivalent of terrestrial NPP per unit of area and time, and reflects the overall capacity of land to support biodiversity and provide ecosystem services. Changes in land productivity are the result of environmental conditions and/or land use and management that impacts the quantity and quality of terrestrial ecosystem services. A persistent decline in land productivity points to the long ‑term alteration in the health and productive capacity of the land, the basis for economic growth and sustainable livelihoods. Against this background, trends in land productivity has been adopted by the United Nations Convention to Combat Desertification (UNCCD) as one of three biophysical progress indicators for mandatory reporting and is proposed as a sub‑ indicator for the global indicator to monitor progress towards achieving Sustainable Development Goal (SDG) target 15.3 on land degradation neutrality (LDN).
Mapping Land Productivity Dynamics: Detecting critical trajectories of global land transformations (Global Land Outlook; Annex two)