Previous studies on patterns in ungulate size variations have emphasized the effect of a particular environmental factor such as Bergmann's rule and the island rule. However, although multiple environmental factors may influence the body size, these studies focused on a single factor, and various measurements that may be influenced by different environmental factors (at least partly) were used as indices of body size. In this study, we used several skull and limb measurements to examine size variations among island populations of sika deer (Cervus nippon) in southern Japan considering the effects of multiple environmental factors. We found that all measurements differed markedly between populations. We focused on the skull and limb condylobasal length (CBL) and metacarpal length because they had the most important variations among the populations and the largest sample sizes. The common environmental factors influencing CBL and metacarpal length were island area and precipitation. Since these environmental factors reflect the availability of food resources, the causal factor of body size variation may be food resources. Interpopulation variation in metacarpal length was greater than that of CBL, indicating that metacarpal length may be affected by additional factors besides the common factors shared with CBL. Specific environmental factors influencing relative (CBL adjusted) metacarpal length were precipitation and slope. A common direct cause of those environmental factors was discussed in relation to topography. Analyses of phenotypic variation using multiple measurements with multiple environmental factors are useful to gain insight into underlying causes and can lead to identification of a measurement-specific variation with a specific driving force.

Transplant and common garden experiments have been used in studies on local adaptation, but are diicult to be conducted for large animals with long life span. A previous study on the southern Japanese islands demonstrated that relative limb lengths of sika deer (Cervus nippon) were short on islands with steep slopes. We hypothesized that this morphological variation was evidence for local adaptation, and tested this hypothesis by comparing phenotypic divergence with neutral genetic divergence among eight populations of the sika deer in the southern Japanese islands. Divergence patterns difered between the phenotypic and neutral genetic features. Genetic similarity was high among individuals on Kyushu (OI, KGS, and KGK). Individuals on Tanegashima (TN) and Yakushima (YK) also constituted a group, whereas individuals on Tsushima (TS), Wakamatsujima (WM), and Kuchinoerabujima (KE) formed a genetically distinct group. Phenotypic data indicated that individuals from TS, OI, KGS, and KGK exhibited similarity, whereas individuals on YK formed an isolated group that was separated from the other populations. The degree of phenotypic divergence was larger than that of neutral genetic divergence between TN and YK. These results suggest that divergent selection worked between two of the eight island populations (TN and YK). The morphological trait of captive-bred individuals from TN and YK, which had never experienced their original environments, retained their original morphological features. By combining the results of multiple analyses, we found that the diference in relative limb length between the two populations was consistent with local adaptation hypothesis, although conclusive results were not obtained for the other populations.

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We present the largest freely available EcoPlate dataset for Japan, comprising data collected from a network of 33 natural forest sites (77 plots) in regions of East Asia ranging from cool temperate to subtropical. EcoPlate is a 96-well microplate that contains three repeated sets of 31 response wells with different sole carbon substrates. The utilization of each carbon substrate by the microbial community is quantified by the color density of the well during incubation. EcoPlate can provide a multifunctional index of a soil microbial community. Soil properties (water content, carbon [C] and nitrogen[N] contents, the C/N ratio, and pH) that are essential for interpreting the EcoPlate results were also measured. The network is part of the Forest and Grassland Survey of the Monitoring Sites 1000 Project established by the Ministry of the Environment. Using a standardized protocol, soil was sampled between September and December 2020. A preliminary principal component analysis was performed on the temporal integration of color density using 31 substrates. For the temporal integration, we calculated the cumulative amount of color development by integrating the color density development curve.