Large carnivore extirpation linked to loss of overstory aspen in Yellowstone

摘要: Abstract The striping of bark on the lower portion aspen trees (Populus tremuloides) by Rocky Mountain elk (Cervus canadensis), or “barking”, increases entry points for disease organisms such as wood-decaying fungi, thereby increasing tree mortality from heart rot. We hypothesized that this has occurred in Yellowstone's northern range stands part a trophic cascade and contributed to premature widespread loss overstory trees. To evaluate these potential effects, we randomly selected along 60-km traverse across park's range. For ≥15 cm diameter at breast height (DBH) within stands, which were accessible elk, measured barking (as indicated deeply furrowed/blackened bark) proportion increment core lengths with Sampled had an average 2.2 m 93.8% them In contrast, only 13.3% grown environment protected Heart rot comprised 45.2% 2.5% elk-accessible respectively. Results support multi-level cascade, predator-to-prey-to-plants-to-fungi, whereby incomplete large carnivore guild, over period seven decades, allowed occur. This, turn, may have increased prevalence accelerated