Twenty years of soil organic carbon research in Ecuador: a bibliometric and GIS-based assessment of trends and research gaps

Abstract

The study assesses the evolution of soil organic carbon (SOC) research in Ecuador between 2003 and 2023 using a bibliometric approach. The search was conducted in the Scopus, Web of Science, and SciELO databases, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework. This protocol enabled the systematic identification and evaluation of the literature, resulting in a final selection of 60 peer-reviewed documents focused on SOC in Ecuador. These documents were analysed using RStudio (Bibliometrix), VOSviewer, and QGIS to map research output, collaboration networks, and thematic evolution. The main findings highlight that research on SOC in Ecuador has increased since 2003, largely due to international collaboration, primarily with institutions in Germany, Spain, and the United States. Early studies primarily focused on land-use change (deforestation and agriculture), whereas recent research emphasises remote-sensing applications, carbon stabilisation mechanisms, and nature-based solutions. Most research focuses on high-altitude provinces and protected areas, such as Loja and Chimborazo. The results also indicate that in volcanic ash soils (Andosols), altitude and land-use intensity are the main drivers of variation in SOC stocks. Key gaps include a lack of studies in the Amazon basin and coastal lowlands, as well as the absence of long-term SOC monitoring, both of which limit the development of national SOC inventories. While research output has increased steadily over time, addressing the identified gaps is necessary to establish a comprehensive scientific basis for climate change adaptation and sustainable soil management across the country’s diverse ecosystems.