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The contribution of sapling banks to the coexistence of species with different shade tolerance under the "wave regeneration" regime has not been researched extensively. This study first assessed spatial and temporal variations in the relative dominance of two Abies species, Abies veitchii and Abies mariesii, with different shade tolerance in a wave‐regenerated forest. Second, we present the age structure and its spatial variation in young Abies stands (sapling stage) to exhibit the prevalence and variability of regeneration from sapling banks (defined as trees established 10 years before canopy opening). The relative dominance of A. mariesii, the more shade‐tolerant species, compared to that of A. veitchii, did not change over a period of 10 years, irrespective of stand developmental stages, indicating the importance of initial dominance in determining the local species composition. The tree ages at the sapling stage were significantly higher for A. mariesii than for A. veitchii. Approximately, 30% of all trees were likely to arise from a sapling bank, and 86% of them were A. mariesii. Age structure significantly varied between 5 × 5 m quadrats; some quadrats were dominated by A. mariesii originating from sapling banks, while others were dominated by A. veitchii that were established at the time of canopy opening. These results indicate that regeneration from sapling banks contributes to the dominance of A. mariesii and that the spatial variation in the abundance of trees originating from sapling banks is essential for the coexistence of A. mariesii with A. veitchii. [ABSTRACT FROM AUTHOR]

We studied the spatio-temporal patterns in two fungal pathogens, Sporisorium kusanoi , along with Naemacyclus culmigenus , of the Japanese pampas grass ( Miscanthus sinensis ) in grassland communities on the Sugadaira plateau, Japan. Their disease symptoms emerged early in June, increased rapidly during the month and peaked early in July. We checked their presence at 11 sites (the regional-scale census) and recorded their presence in 6000 1 × 1-m subplots within a 60 × 100-m area at the specific site (the local-scale census). Sporisorium kusanoi and N. culmigenus were observed at eight and one sites in the regional-scale census, and in 987 and 2708 subplots in the local-scale census, respectively. The respective spatial distributions of S. kusanoi and N. culmigenus aggregated at the spatial scales of 13 m and 33 m. However, the spatial positions of the two fungi were slightly repulsive each other. Our results found that S. kusanoi was widely distributed within the region, whereas N. culmigenus was restricted within the specific site but had a higher frequency compared to S. kusanoi . The contrasting spatial patterns of the two pathogens may reflect differences in their dispersal processes. [ABSTRACT FROM AUTHOR]

Future climate conditions will alter the frequency and intensity of typhoons. Thus, post-windthrow management, which can enhance tree recovery in wind-disturbed forests with dense understory species, is essential for sustainable forest management to adapt to climate change. This study explores management options that can recover the above-ground biomass (AGB) and tree species composition after windthrow damage even under climate change. A case study area was established in the Oshima–Hiyama National Forest in southern Hokkaido, northern Japan, which were damaged by typhoons in late August 2016. We incorporated the understory species Sasa kurilensis as understory vegetation into the LANDIS-II Net Ecosystem Carbon and Nitrogen Succession extension v6.3 model to simulate the outcome of tree establishment under climate change. AGB recovery up to the year 2100 at 1,753 damaged grid cells was simulated for the Intergovernmental Panel on Climate Change representative concentration pathway (RCP) 2.6 and 8.5 scenarios. Different post-windthrow management cases were designed by varying the treatment of fallen trees and the types of trees planted. The results demonstrated that salvage logging and planting successfully recovered the AGB by 2050 at the landscape scale regardless of the climate change scenario, whereas leaving fallen trees in the damaged site or salvage logging only did not facilitate the recovery of AGB. Leaving fallen trees in damaged grid cells as ecological legacies recovered the AGB only in damaged grid cells with a sufficient number of advanced seedlings of adequate types of species irrespective of the climate change scenario. The decreasing water equivalent of snowpack in the RCP scenarios caused Sasa kurilensis mortality and promoted the recovery of AGB of trees. The dominant species recovered in natural forests, which experienced either salvage logging or leaving trees in the damaged site, varied among climate change scenarios. The warmer climate condition facilitated the recovery of Fagus crenata by 2100. These results can help designing a robust forest recovery even in uncertain future climate. [ABSTRACT FROM AUTHOR]