Introduced Predators Transform Subarctic Islands from Grassland to Tundra -- Croll et al. 307 (5717): 1959 -- Science:
Top predators often have powerful direct effects on prey populations, but whether these direct effects propagate to the base of terrestrial food webs is debated. There are few examples of trophic cascades strong enough to alter the abundance and composition of entire plant communities.
This is neat stuff, especially in light of item 411
. These fragile ecosystems came together through a complex interaction of species, each adapting to the community and adapting the community along the way. Changing the community has huge consequences.