Land degradation neutrality: A review of progress and perspectives

Abstract

In October 2015, the 12th Conference of the Parties (COP12) of the United Nations Convention to Combat Desertification (UNCCD) proposed a definition for land degradation neutrality (LDN). In the same year, the United Nations made LDN one of the targets of Sustainable Development Goal 15 (Life on Land, 15.3 By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world). LDN has critical to global environmental change and sustainable development research. The available LDN reviews mainly focus on the concept of LDN and do not sufficiently elaborate on the progress of LDN research. The objectives of our work aim (1) to summarise the overview of articles on LDN (number of articles, countries of publication, and research hotspots); (2) to outline LDN assessment indicators; (3) to clarify the analysis methods of LDN driver factors; (4) to understand the research progress of predicting LDN; and (5) to assess the relation between LDN and land degradation, land restoration, and SDGs. To achieve our objectives, we searched articles focused on “land degradation neutrality” between 2013 and 2021 on the Web of Science. In total, we found 183 articles. By reviewing these papers, We found that (1) the number of articles on “land degradation neutrality” increased from 2013 to 2021; the articles on LDN mainly originate from Australia, Germany, the UK, Russia, Switzerland, and the USA; the research hotspots are focused on land degradation, desertification, sustainable land management, conservation, climate change, and land cover; (2) most of the research methods adopt the three indicators stipulated by the UNCCD (productivity, land cover, and soil organic carbon), and sole studies have improved the indicators; (3) there are few studies on the drivers and future projections of LDN, which have broad research prospects; and (4) LDN is a dynamic balance between land degradation and restoration, and there are trade-offs and synergies between LDN and other SDGs. The review revealed the need to (1) identify the LDN indicators in different regions and develop a method to qualitatively and quantitatively monitor LDN changes; (2) quantify LDN drivers and clarify the factors that affect LDN; and (3) clarify future LDN trends and promote SDG 15.3 implementation.