Long-term biological legacies of herbivore density in a landscape-scale experiment: forest understoreys reflect past deer density treatments for at least 20 years

摘要: Summary 1. Ungulate browsers, when at high densities, are major drivers of vegetation change in forests world-wide. Their effects operate via a variety generalizable mechanisms related to plant palatability and relative growth rate with respect browsing pressure. 2. Though such impacts obviously long-lasting they determine composition tree regeneration, we document unique long-term (30 year) experiment that biological legacies initial deer density persist the understorey herbaceous least 20 years after densities were equalized. 3. We sampled former clear-cut areas where white-tailed (Odocoileus virginianus) was manipulated (3.9–31.2 km 2 ) for 10 (1979–1990), stands experienced ambient (ca. 10–12 next (1990–2010) whether treatments still influenced 30-year-old, closed-canopy forests. 4. Stands initially (1979–1990) exposed higher had ca. five times fern cover three seedling forb 2010, as well significantly lower angiosperm species density, compared densities. 5. These results appear driven by avoidance ferns, allowing them expand sequester sites decades. 6. Synthesis. Our long-term, experimental show unequivocally elevated cause significant, profound legacy on persisting years. Of relevance regionally globally have created depauperate understoreys, expect reduction alone does not guarantee recovery; may need be managed removing recalcitrant layers (e.g. ferns).