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QuestionHow does plant species richness respond to simulated area loss based on the realistic geometry of area loss in subalpine moorland ecosystems?LocationHakkoda mountain range, Aomori, Japan.MethodsWe constructed species distribution models based on relationships between species distributions and environmental conditions in subalpine moorland ecosystems. We then simulated moorland area loss based on the realistic geometry of area loss from the past (1967) to the present (2019) to predict future changes in plant diversity. Here, we defined the realistic geometry of area loss as the plausible spatial pattern of future habitat loss. Finally, we analyzed how the rate of species loss in response to the realistic area loss can be explained by a range of factors including spatial patterns in species distributions, total number of species present, and environmental variables for the focal moorland.ResultsWithin each moorland site, areas prone or those less prone to be lost were distributed non-randomly at a local scale. In general, the patterns of species loss caused by the realistic area loss differed from those caused by random area loss. At most sites, realistic area loss caused a relatively small decline in species richness up to a certain threshold of area loss, and accelerating decline thereafter. None of the factors can explain the rate of decrease in species richness caused by the realistic area loss. At the species level, however, species with lower occurrence rates at a given site can be lost earlier than those with higher occurrence rates by the realistic area loss.ConclusionsPatterns of habitat loss and species distributions are not spatially random, and the classical approach based on the species–area relationship assuming random area loss can thus either under- or overestimate the risk of species loss.

This paper describes the reinforcing effect of the newly proposed reinforcing method using SFRC paving with ordinary Portland cement and low shrinkage type mixture material for orthotropic steel decks of highway bridges, which have been suffering from fatigue cracking due to heavy traffic loading. To examine the fatigue performance of paving material and steel deck slab, a running wheel fatigue test was conducted using a scale model of the typical orthotropic steel deck without and with SFRC paving. The test results showed that the proposed SFRC paving material was verified to have all the required performance of the specifications for highway bridges in Japan, and the proposed stiffening method effectively improves the fatigue endurance of steel decks. 本研究では，鋼床版に発生する疲労き裂を抑制するためのSFRC舗装材の提案および接着剤塗布型SFRC舗装におけるひずみ・たわみの低減効果について検証した．その結果，普通セメントに低収縮型早強性混和材を配合したSFRCは36時間で本材料の要求性能である圧縮強度30 N/mm2を確保するとともに，接着剤塗布後の界面の付着強度も2.59 N/mm2であり，鋼床版の舗装材として有効な材料である結果が得られた．また，鋼床版の舗装材として，普通セメントに低収縮型早強性混和材を配合したSFRC材を用いた接着剤塗布型SFRC舗装は，輪荷重走行疲労試験を行った結果，デッキプレートおよびUリブのひずみ・たわみの増加が大幅に抑制された．よって，鋼床版にSFRC舗装することで耐疲労性が向上する結果となった．

1Fellow of JSCE, Part-time Lecturer, Dept. of Civil Eng., Nihon University ( Izumicho1-2-1, Narashino, Chiba 275-8575, Japan) E-mail: Yutaka-kawai@mue.biglobe.ne.jp 2Member of JSCE, Project Assistant Professor, Dept. of Civil Eng., University of Tokyo (Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan) E-mail: dion@bridge.t.u-tokyo.ac.jp 3Fellow of JSCE, Project Professor, Dept. of Civil Eng., University of Tokyo ( Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan) E-mail: fujino@sogo.t.u-tokyo.ac.jp