Neutralidade da Degradação da Terra: de onde vem, para onde vai?; análise dos indicadores biofísicos e metodologias de avaliação da Degradação de Terras e da Desertificação (LDD)

Abstract

Land degradation and desertification (LDD) affect extensive dryland areas across the planet, compromising biodiversity, ecosystem services, and the most vulnerable populations. Given the complexity of these phenomena, the scientific community has sought indicators, methods, and techniques capable of diagnosing, assessing, and globally monitoring LDD, with remote sensing standing out as a key approach. In this context, this work brings together two scientific articles that examine the global panorama of LDD research, identifying patterns of biophysical indicators and methodologies, and discussing the implementation of the LDN target, with emphasis on evaluating and monitoring these processes, particularly in the semiarid region of Northeastern Brazil. The first article analyzed biophysical indicators and methodologies applied to LDD between 1997 and 2019 through a quali-quantitative investigation and a bibliometric analysis of Scopus-indexed publications. The results indicated that: (i) China concentrates both the highest number of publications and the most prolific author; (ii) NDVI is the main indicator used to assess LDD; (iii) remote sensing is the most relevant tool for diagnosing the spatiotemporal dynamics of land degradation; and (iv) the MEDALUS methodology, validated primarily for Mediterranean landscapes, is the most widely applied. The bibliometric analysis showed that a single indicator or method is insufficient to assess the complexity of land degradation and desertification processes across different spatial and temporal scales. The second article discussed the implementation of the Land Degradation Neutrality (LDN) target, identifying conceptual gaps, methodological challenges, and uncertainties in the biophysical indicators used. Through an integrative literature review combined with a bibliometric analysis of Scopus-indexed studies and grey literature, it was observed that the UN, through the UNCCD, has intensified its concern regarding the expansion of land degradation, culminating in the inclusion of LDN in the 2030 Agenda (2015). The findings also revealed that the conceptual framework and indicators associated with LDD and LDN present challenges that require further scientific refinement to effectively achieve the goal of a land degradation– neutral world. In summary, the results of both articles reinforce the need for integrated approaches, robust methodologies, and more consistent indicators to understand, monitor, and address LDD at global and regional scales. By discussing both the state of the art in LDD research and the challenges of LDN implementation, this work contributes to advancing scientific debate and offering insights that support public policies, especially in vulnerable regions such as the Brazilian semiarid.