High herbivore density associated with vegetation diversity in interglacial ecosystems

Area of Science:

• Ecology and conservation science
• Paleoecology
• Quaternary science

Background:

• The role of large herbivores in shaping prehistoric European ecosystems remains debated.
• The wood-pasture hypothesis suggests herbivores maintained diverse habitats, contrasting with a closed-forest model.
• Understanding herbivore-vegetation dynamics before Late Quaternary megafauna extinctions is crucial.

Purpose of the Study:

• To investigate the impact of large herbivores on vegetation structure in Great Britain before modern human influence.
• To test the wood-pasture hypothesis by analyzing faunal and floral evidence from different interglacial and post-glacial periods.

Main Methods:

• Synthetic analysis of beetle fossils from Great Britain.
• Comparison of dung-associated beetle representation between the Last Interglacial and early Holocene.
• Interpretation of beetle assemblages to infer vegetation structure (closed forest vs. semi-open mosaic).

Main Results:

• Beetles associated with herbivore dung were more abundant during the Last Interglacial (132,000–110,000 years B.P.) than the early Holocene (10,000–5,000 years B.P.).
• Beetle assemblages indicate a greater mix of semi-open vegetation and forest during the Last Interglacial compared to closed/partially closed forest in the early Holocene.
• Large herbivores appear to have been more abundant and associated with higher vegetation structural diversity before Pleistocene megafauna extinctions.

Conclusions:

• Abundant and diverse large herbivores were key to maintaining structurally diverse temperate forest ecosystems.
• The decline of megafauna and the rise of human activity led to less herbivore abundance and more prevalent closed woodland.
• Findings support the ecological importance of past herbivore-vegetation interactions and advocate for rewilding-based conservation.