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The great majority of studies on foundation species focused on a single dominant plant in a community, while more than one such species can often coexist and compete for space and limited resources. Morphologically different coexisting foundation species can create diverse niches occupied by different subsets of beneficiary species. To test this hypothesis, we sampled alpine plant communities at exposed fellfields in alpine zone, in the Taisetsu Mountains (Hokkaido, northern Japan), with coexisting putative foundation species Pinus pumila (evergreen shrub) and Diapensia lapponica (evergreen cushion‐forming shrub), and analyzed their spatial relationships with other plants. Preliminary vegetation survey indicated that fruticose lichens and Loiseleuria procumbens (evergreen mat‐forming shrub) might also act as a foundation species; thus, we included them in our analyses. The coexisting foundation species had both general as well as specific effects on plant community structure. Namely, almost all the members of the community aggregated spatially with lichens, while the other foundation species were spatially segregated from each other. These foundation plants associated with different members of the community, thus showing species‐specific effects on the community structure. Blooming species showed even stronger patterns of species‐specific spatial associations, suggesting that foundation species had beneficial effects on their associated species. We conclude that the focus on coexisting foundation species can reveal important details of community structure which would be hidden if we treated all species as equal members of the community. Studying the effects of coexisting foundation species could greatly advance our understanding of how species diversity functions in plant communities. [ABSTRACT FROM AUTHOR]

Coldwater‐adapted freshwater fishes, especially their populations along warm‐range margins, are most vulnerable to the climate oscillations associated with global warming. Stocking is a major strategy for avoiding the extinction of these species. However, while stocking can reverse the decline of isolated populations, it may also result in a loss of genetic diversity in the native local population due to the introgressive replacement of hatchery genes. To plan an adequate strategy for conserving locally adapted populations, the genetic impacts of stocking on native lineages should be evaluated from small river branches to wide‐ranging drainage areas. We investigated the population genetic structure of white‐spotted charr (Salvelinus leucomaenis) within its southern range (Lake Biwa basin, Japan). By applying genome‐wide SNP analysis to the population's genetic structure, we assessed the extent of genetic introgression resulting from stocking. White‐spotted charr in the Lake Biwa watershed constitutes a distinctive genetic group, within which apparent genetic differentiation was observed. The hatchery‐reared fish line commonly used for supplementation stocking in the catchment was discernable from the native population, enabling us to analyze genetic introgression across the entire drainage area. Admixed individuals resulting from hatchery introgression were observed in most of the stocked sites that showed relatively high heterozygosity and nucleotide diversity. However, their genetic differentiation was much lower than that of native populations. The supplementation history as well as the road availability contributed substantially to the introgression of hatchery genes. Populations with the native genetic structure remained in the upstream regions of the tested rivers. However, their heterozygosity and nucleotide diversity were low when compared with that of the populations with hatchery supplementation. Our results shed light on the genetic impacts of stocking on isolated native populations and suggest that conventional supplementation methods cannot preserve a unique biodiversity in the distribution margin. [ABSTRACT FROM AUTHOR]