A systematic review of the role of terrestrial vertebrates in ecological integrity assessment

Natural systems face human pressures, demanding urgently Ecological Integrity (EI) assessments. EI assessments identify the state of an ecosystem through biotic and abiotic indicators. Fauna is a key element in the functioning of ecosystems, and therefore, their inclusion in the indicator stock may enhance EI evaluations. We conducted a systematic literature review to evaluate the use of terrestrial vertebrate-derived information as indicators of EI. Fifty-eight publications used information on terrestrial vertebrates as EI. Birds (39) were the group most frequently used as an indicator, followed by mammals (16), amphibians (5), and reptiles (3). Species composition was the most frequently evaluated element of EI, and community metrics such as richness, diversity, indicator species, and abundance stand out as the most frequently used for evaluating the relation of the EI to a terrestrial vertebrate group. The Index of Biological Integrity (IBI) and indices derived from it were the most frequently used to identify the state of integrity of an ecosystem using vertebrates. Few studies have developed a conceptual model that explains the causal relationship between EI and metrics associated with terrestrial vertebrates. EI assessments are a valuable tool for identifying the state of a system. However, it is necessary to complement them with faunal indicators that include various taxonomic groups. The inclusion of more than one taxonomic group would allow for the identification of changes at different levels and generate biological hypotheses of relationships between measurable variables at the faunal level and their incorporation into IE analysis.