1. Alagona PS, Sandlos J, Wiersma YF (2012) Past imperfect: using historical ecology and baseline data for conservation and restoration projects in North America. Environ Philos 9:49–70
2. Andersen T, Carstensen J, Hernández-García E, Duarte CM (2009) Ecological thresholds and regime shifts: approaches to identification. Trends Ecol Evol 24:49–57
3. Aplet G, Keeton WS (1999) Application of historical range of variability concepts to biodiversity conservation. In: Baydack RK, Campa H, Haufler JB (eds) Practical approaches to the conservation of biological diversity. Island Press, New York, pp 71–86
4. Aplet G, Thomson J, Wilbert M (2000) Indicators of wildness: using attributes of the land to assess the context of wilderness. In: Wilderness science in a time of change. USDA Forest Service Rocky Mountain Research Station RMRS-P-15-VOL-2, Missoula, pp 89–98
5. Arno SF, Scott JH, Hartwell MG (1995) Age-class structure of old growth ponderosa pine/Douglas-fir stands and its relationship to fire history. Research paper INT-RP-481, Intermountain Research Station, Forest Service, USDA