Complex long-term biodiversity change among invertebrates, bryophytes and lichens

Area of Science:

• Ecology
• Biodiversity Science
• Conservation Biology

Background:

• Large-scale biodiversity assessments often rely on a limited number of well-studied taxonomic groups, such as vertebrates.
• Trends in these indicator groups may not accurately represent changes in overall biodiversity, particularly for invertebrates and other less-studied taxa.
• Understanding biodiversity dynamics across a wider range of species is crucial for effective conservation strategies.

Purpose of the Study:

• To analyze trends in the UK distributions of over 5,000 species of invertebrates, bryophytes, and lichens.
• To compare these trends with those of well-studied taxa like vertebrates and butterflies.
• To assess the overall complexity of biodiversity change in the United Kingdom.

Main Methods:

• Analysis of changes in species occupancy over the last 45 years for over 5,000 species.
• Categorization of species into major groups: terrestrial non-insect invertebrates, terrestrial insects, bryophytes and lichens, and freshwater species.
• Comparison of occupancy trends across different taxonomic groups and habitats.

Main Results:

• Significant variation in the magnitude, direction, and timing of biodiversity changes over 45 years.
• Only terrestrial non-insect invertebrates mirrored the declining trends seen in vertebrates and butterflies.
• Terrestrial insects, bryophytes, and lichens showed increased average occupancy; freshwater species recovered after initial declines.
• Despite stable or increasing average occupancy in many groups, substantial shifts in species commonness and rarity indicate significant community turnover and numerous species declines.

Conclusions:

• Biodiversity change in the UK is more complex than previously understood, with divergent trends across taxonomic groups.
• Well-studied taxa do not fully represent the biodiversity trends of neglected groups like invertebrates, bryophytes, and lichens.
• Conservation efforts must consider the varied responses of diverse species assemblages to accurately gauge and address biodiversity change.