Are Wolf-Mediated Trophic Cascades Boosting Biodiversity in the Great Lakes Region?

摘要: In recent years, conservation biologists broadened their efforts beyond genes, species, and ecosystems to include the of species interactions such as mutualisms predation (Kearns et al. 1998 ; Soule 2003, 2005) . Ecologists generally agree that predators generate top-down effects in food webs, but consensus ends there. Considerable disagreement remains over strength effects, relative importance versus bottom-up how these differs among systems, seasons across scales (Polis 1999 Polis 2000 Shurin 2002 Schmitz 2004) The question is further complicated because many top were significantly reduced abundance or eliminated from temperate zone decades centuries before ecologists formally conceptualized trophic cascades (cf. Jackson 1997 2001) Still, view recovery gray wolf ( Canis lupus ) Great Lakes region more than a success story. This carries with it hope expectation generated by wolves will aid maintenance regional biodiversity (McShea 2005 Ray High densities white-tailed deer Odocoileus virginianus throughout much upper pose challenge efforts. Densities are so great harvests have set state records within last 10 years (e.g., Michigan 1998, Wisconsin 2000, Minnesota 2003). come at an ecological cost: browsing contributed loss plant diversity few (Rooney , and, turn, losses might be generating additional indirect on insects, birds, other Waller 2003 McShea Several studies western North America suggest strong vegetation lateral assemblages scavengers (Ripple 2001 Wilmers Hebblewhite Are having similar effect states? While tempting simply extrapolate findings apply them