Net Primary Productivity, Vegetation Index Analysis, and Assessment of Protected Areas, Vulnerabilities, and Management Strategies: Review

This bibliographic analysis focused on various methods for estimating net primary productivity, vegetation indices and their various applications, as well as vulnerability assessment and management strategies for protected areas. To do this, a bibliography on the different topics collected using search engines Scopus, Science Direct, ResearchGate, and Google Scholar via the Publish or Perish portal was analyzed. Of the 1128 scientific papers on the selected topic after refining the database, 978 were journal articles, 59 were books, 52 were reports, 20 were conference proceedings, and 19 were theses. These documents detail numerous methods for estimating net primary productivity, a key parameter for assessing ecosystem performance. Methods using remote sensing data, especially vegetation indices, appear to be the easiest, least costly, and least labor-intensive today, ensuring reliable results. These innovative methods are best suited for assessing fragile ecosystems. This is the case for protected areas which have been facing the combined effects of anthropogenic actions and climate change in recent years. Considering the challenges posed by the management of Togolese protected areas, particularly since the socio-political disturbances of the 1990s, it is urgent to assess the health status of these specific ecosystems, focusing on their performance.