Expert-based measures of human impact to vegetation

Background Human impact has had a profound influence on modern vegetation. Expert-based vegetation indicator systems have been developed to measure and characterize human impacts on vegetation. Floristic Quality Assessment (FQA) is a widely used, primarily North American system for assessing degradation and natural quality through species-based values called coefficients of conservatism. The hemeroby and naturalness indicator value (NIV) systems were independently developed for users to assess human impacts in Europe. Despite the similarities among these indicator systems, there is no mutual recognition among them, and they have developed and operate in relative isolation from one another. Approach We review the FQA, hemeroby, and NIV systems to provide a basic summary of the three systems and to evaluate them, highlighting their nearly identical core mechanics and conceptual commonalities. We also compare and contrast the three systems to less integrative ecological indicator systems that can be used to indirectly measure human impact, notably the Ellenberg system. Findings We describe how FQA and naturalness indicator values, in particular, could be considered twin systems. Despite these core similarities, users of these systems do not cite each other, potentially overlooking benefits from applying methods and concepts from separate systems. The FQA, hemeroby, and NIV systems have unique weaknesses, strengths, and primary applications compared to other ecological indicator systems. Conclusions We conclude by discussing the future role and utility of the three specialized human impact indicator systems for scientists and practitioners. Human impact indicator values may be valuable for use in basic research, but arguably their most important applications are in the practice of conservation, such as monitoring restored ecosystems.

Automated summary

Human impact has had a profound influence on modern vegetation. Different expert-based vegetation indicator systems such as FQA, hemeroby, and NIV have been developed to assess human impacts. Despite their similarities, these systems are not mutually recognized and operate in isolation from each other. Users may benefit from integrating methods and concepts from different indicator systems in assessing human impact.