Relocations of protected area is a candidate options as climate change adaptation for natural ecosystems. However, potential risk of species range loss due to climate change have been estimated, especially narrow geographical range species. These species may be difficult to hold in a protected area because of their narrowness for climate ranges. We predicted potential habitats of four Japanese zonal tree species under the current climate and three RCPs (2.6, 4.5, 8.5) with twenty general circulation models. The presence/absence records of each species, extracted from vegetation database, were used as response variables. Climatic variables were used as explanatory variables. Based on these results, we assessed (1) the vulnerability of four target species under future climate conditions, and (2) the capacity of protected areas relocations for conserve the species.
Vulnerability index (the rate of change of potential habitat area with respect to current potential habitat area) of all the species were predicted to consistently increase, especially for sub-alpine (Abies veitchii) and alpine (Pinus pumila) species on the higher RCPs. Adaptive capacity, which was defined as the area of sustainable potential habitats located outside the current protected areas, was predicted to be different depend on the RCPs and the species. Adaptation capacity of the warm-temperate species (Quercus acuta) were sufficiently maintained all of the RCPs (55,249 - 58,670㎢), while the sub-alpine (-590 - -3,044 ㎢) and alpine (-5,745 - -13,830㎢) species were predicted to be the no adaptive capacity even in the RCP 2.6. Adaptive capacity of the cool-temperate species (Fagus crenata) were maintained under the RCP 2.6 (16,698 ㎢) and 4.5 (10,318 ㎢), while were predicted to be below zero (i.e. no adaptive capacity) under the RCP 8.5 (-10,657㎢).
Our findings indicate that although relocation of the protected area would be feasible in preserving sustainable habitats for warm and cool temperate species under RCP 2.6 and 4.5, it would be insufficient to conserve all of the species under three RCPs. Changing the potential habitats of cool to alpine species under the RCP 8.5 may exceed the capacity of protected area relocations, and thus indicated that RCP 4.5 as stabilization target should be required to ensure the survival of these species.