Munemitsu Akasaka, a lecturer at the Department of Nature Maintenance, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, analyzed the effectiveness of nature reserves using 1572 species of endangered plants in Japan, and plants with narrower distribution areas are included in the reserve. It was clarified that local extinction is likely to occur because it is difficult, and the distribution area is likely to be narrowed.
Nature reserves have been set up in more than 20 locations around the world and have been confirmed to be effective in curbing the decline in habitats and populations of living organisms.However, landscapes and industries have been prioritized over the distribution of living things.Therefore, many problems have been reported overseas that they are not necessarily placed in a place suitable for the conservation of living things.Furthermore, it has been reported in Europe and the United States that species with a narrow distribution that should be prioritized tend to be unprotected due to uneven placement of protected areas or chance.
In this study, if the protected area is arranged without considering the distribution of organisms, species with a narrow distribution are less likely to be included in the protected area, so they are likely to become extinct locally and the distribution area is likely to be narrowed. We paid attention to the possibility of a "vicious cycle to extinction" that makes it difficult to be included in the protected area to be set up in Japan and further increases the risk of extinction.
The research team first statistically analyzed 1572 species of endangered plants using national distribution data collected during the two periods 1994-95 and 2010-11.As a result, the proportion of the protected area and the distribution area overlapping was lower in the plants with a narrow distribution area than in the plants distributed over a wide area.Also, the distribution of at least 2 species did not overlap the protected area at all.
Next, when the probability of local extinction for about 15 years was investigated, the susceptibility to local extinction (4.9%) of plants growing in the protected area was suppressed to at least 8.7/2 compared to the outside (3%). Was there.This proved the effectiveness of the protected area for the first time in the world.
Furthermore, as a result of simulation analysis to see if a "vicious cycle to extinction" could occur by repeating the establishment of new protected areas without considering the distribution of organisms, the risk of extinction of species with a wide distribution is reduced due to the effect of the new protected areas. It has been confirmed that narrow species fall into a "vicious circle to extinction."
Based on the research results, it is required to strategically allocate protected areas when establishing or expanding them in the future.In particular, many plants with a narrow distribution are at high risk of extinction, so it is necessary to take priority conservation measures.
