The spring-fed wetlands around Ise Bay contain components of the Tokai hilly land elements, namely, Berberis sieboldii, Drosera tokaiensis, Eriocaulon nudicuspe, Veratrum stamineum var. micranthum and 11 other species endemic to the Tokai hills. In order to develop sustainable environmental management plans and conservation initiatives for this area, we analyzed the characteristics of pH, electric conductivity (EC), and NO2- and NO2- concentrations in interstitial water of each habitat at every month from 2003 to 2007. Seven areas with exceptionally high densities of the Tokai hilly land element were selected for analysis; six in Ena, Gifu Prefecture, and one in Kasugai City, Aichi Prefecture, Japan. Interstitial water pH and EC (μS/cm) samples from areas dominated by specific species were as follows. In Ena City, in areas where V. stamineum var. micranthum was dominant, pH was 6.3 (5.4-7.4) [median (minimum-maximum)] and EC = 24 (8-75); E. nudicuspe, pH 6.1 (5.5-7.1), EC = 30 (11-58); B. sieboldii, pH 6.5 (5.7-7.1), EC = 34 (9-60). D. tokaiensis in Ena, pH 6.0 (5.3-7.0), EC = 57 (23-98) and in Kasugai, pH 5.5 (4.5-6.9), EC = 138 (105-188). Interstitial water samples in these areas ranged from acidic to neutral, and, except for areas inhabited by D. tokaiensis, EC values were 60 μS/cm. Interstitial water NO3- concentrations in different areas inhabited by species endemic to the Tokai hills were 1.1 (0-4.4) μM in areas of B. sieboldii, 0.5 (0-2.8) μM in areas of E. nudicuspe, and 2.9 (0-8.9) μM in areas of V. stamineum var. micranthum; these concentrations are considered typical of oligotrophic conditions. D. tokaiensis exhibited an ability to adapt to both oligotrophic and eutrophic conditions. For example, NO3- concentrations in areas where D. tokaiensis was dominant were 26.2 (0-148) μM in Ena and 13.1 (0-74) μM in Kasugai. The median NO2- concentrations in all areas ranged from 0.8 to 1.2 μM. The NO3- concentration in areas dominated by D. rotundifolia in Ena, which is not a Tokai hilly land element, was 0.8 (0-3.3) μM. In this study, we demonstrated that acidic and oligotrophic conditions are not always limiting factors for the Tokai hilly land element in wetlands.
To study the relationship between plant communities and nest site selection of Tancho (Grus japonensis) in the Kushiro Mire, eastern Hokkaido, vegetation at the area covered by a nest, and about 100 ha circle around nest (buffer circle) was analyzed by using a vegetation map and the locations of the nests located by aerial surveys during the 2000-2009 period. Nests were found on 26 types of vegetation. The largest number of nests were in the alder (Alnus) community (27.8% N=916), and then in the tall reed (Phragmites- Calamagrostis) community (23.3%). Finally total 84.5% of nests were found on the alder dominated and the reed dominated communities. However, nesting vegetation types recorded in common with the core and the peripheral regions of the Kushiro Mire were few except alder and reed communities, and nests were much more found in terrestrial forest communities in the peripheral regions rather than those in the core region. Though vegetation types in a buffer circle around each nest varied at each site, the average composition of vegetation types in buffer circles of all nests was quite similar to that of core region of the Kushiro Mire. As vegetation types at nesting spots of new breeding pairs did not basically differ from those of successive breeding pairs, it is suggested that types of vegetation was not an absolute factor for nest site selection of the cranes. The results of this analysis seemed useful to apply for the conservation of potential habitats which are not yet protected in Hokkaido, although there were some discrepancies between the vegetation maps and actual nesting habitats shown by aerial photographs.
To examine the phylogeography of the water scorpion, Nepa hoffmanni, a semi-endemic species of the Circum Ise-Bay area (CIBA) in Japan, we sequenced part of the mitochondrial DNA 16S rRNA and examined the genetic diversity along with the relationship between the polymorphisms and the surface geological features of the habitats. We confirmed that intraspecific variation of 16S rRNA was present in the CIBA with two different haplotype groups: 1) the South West-Mikawa group, which diverged first and was distributed only in the Ryoke metamorphic bedrock formed by uplifting due to activation of tectonic tilting of the Nobi Plain (early to mid Pliocene, 5.3-3 Ma), 2) the CIBA-Chita group, which is distributed across the entire CIBA, was composed of haplotypes that were genetically closely related and underwent simultaneous radiation later than did the other groups. It was supposed that geographical variation in the genetic structure of N. hoffmanni in the CIBA resulted from the activation of tectonic tilting of the Nobi Plain after the early Pliocene (5.3 Ma).