Evolution and paradigm shift in forest health research: A review on global trends and knowledge gaps

Abstract

AbstractForests provide key ecosystem services to human society, and the ability to provide these services depends on their overall health. Forest health is an attractive and interesting concept in forestry research, which environmental, social and political interests have shaped. Assessing forest health is crucial, but finding a single definition of the concept is complex. It is determined by the aim of the forest study, different areas of knowledge, scales of work, technology, methodologies, historical moment or source of funding, among others. With almost a century of scientific evidence, the aim is to identify and contextualise temporal changes in the relevance of this key concept. Trends are analysed through the construction of three main descriptors (state variables, drivers and methods) and the main conceptual subdomains (themes). This review reveals the significant geographical bias in the research, which the Global North predominantly conducts. We observe the evolution of forest health research driven by diverse needs and interests, ranging from air pollution to the multifaceted impacts of climate change. Methodologies applied in this field have also evolved from traditional crown condition inventories to the use of advanced tools such as remote sensing or ecophysiology, improving the characterisation of forest health patterns at both global and individual scales. Forest health research has evolved towards more holistic and multidisciplinary approaches, reflected in the broadening and integration of methodologies and technologies, influenced by historical context, which influence what is being researched today and future scenarios. We identified key knowledge gaps in the scientific literature, in particular the concepts of ecosystem services, Essential Biodiversity Variables (EBVs) and the concept of ‘One Health’. These findings highlight the need for future research to incorporate these critical but often overlooked areas, potentially reshaping future directions and scenarios for forest health research.