found: Dynamics of the tundra-taiga interface, c2002:pp. 3-4 (tundra-taiga treeline; latitudinal treeline; "One of the major problems in the current studies of the latitudinal 'treeline' and related phenomena such as 'timberline', etc. is the concept of 'line' ... these boundaries are not lines, but zones.")
found: Bunn, A.G. Temporal and spatial patterns at alpine treeline in the Sierra Nevada USA, k2004:p. 1 (alpine treeline, the boundary between forest and tundra on high mountains)
found: Ecological processes in the timberline ecotonic web site, Jan. 19, 2005(Timberline; Alpine timberline)
