Yuichi Yamaura

Each year, migratory birds move thousands of kilometres across international borders to track optimal environmental conditions. How tightly annual-cycle events are linked and how much flexibility exists in migration schedules will determine how vulnerable migratory birds are to environmental change. Using a global tracking database, we reconstructed full annual-cycle schedules of 2,324 individuals from 83 species. We found strong temporal links during autumn and spring migrations: departure from the breeding grounds predicted arrival at the non-breeding grounds and vice versa. During both migration periods, late-departing individuals shortened migration duration, but still arrived later than early-departing individuals. By contrast, arrival at and departure from the non-breeding grounds were not correlated, suggesting a temporal reset that buffered earlier delays. Despite resetting during the non-breeding period, migratory schedules remain globally interconnected, such that disruptions in one season can propagate to subsequent stages of the annual cycle, with consequences for migratory species and the ecosystem functions they support.

Retention forestry, which involves retaining part of the forest structure at the time of harvesting, can mitigate the harvesting impacts on forest species and develop future forest structures. Rete...

Biodiversity cannot be conserved by nature reserves alone. There are a range of reasons such as the limited area of nature reserves and their lack of representativeness, which were highlighted more...

Reversing biodiversity declines will require redesigning agricultural landscapes and their management. Farmland abandonment and intensification are emerging as major drivers of biodiversity changes, and their consequences vary widely from negative to positive among continents. Despite decades of research on agricultural biodiversity, no generalizable framework has been established to predict these variations globally, hindering the development of effective conservation strategies. Here, we combine broad-scale, multiseason avian field surveys across Japan with a global meta-analysis spanning four continents. In field surveys, we compared avian species richness among 2-ha plots in abandoned farmland (≤ 50 y since abandonment), traditional farmland, and intensive farmland, controlling for the surrounding land-use cover. We showed that the dominant functional group robustly explains the direction and strength of community-level responses to abandonment and intensification. When mature-habitat species comprise over 50% of communities, abandonment enhances species richness by over 240%, reaching levels comparable to natural wetlands. Abandoned farmlands hold the potential to offset past biodiversity declines and thus merit considerations for inclusion within the conservation area networks. Conversely, when disturbed-habitat species comprise more than 48% of communities, abandonment and intensification reduce species richness, underscoring the importance of biodiversity-friendly farming. This study provides a basis to understand how to address varied spatial variations in biodiversity responses to management and land-cover changes—a long-standing hurdle in conservation science. Complex bird diversity responses can be predicted globally by simply identifying the dominant functional group, thereby helping develop the most effective conservation strategies. Transferability beyond birds and across taxa should be evaluated empirically.

これまでの森林景観を対象とした評価研究は，評価者を実験室あるいは屋外の任意の視点場へ誘導し，写真等（実験室）や現実風景（屋外）を刺激として実験・調査が行われることが一般的であった。一方，そうした手法の限界として，特定の場面や対象についての評価情報は把握できるが，広域の情報収集が困難とされていた。しかし，GIS技術や森林資源情報のオープンデータを活用して，自治体の有する情報を活用し，評価者による地域の森林内の囲繞景観（一定の範囲を有する空間領域中での視覚的な環境状況）の評価を広域において予測可能とする手法があれば，評価手法に由来した様々な課題を解決するとともに，広域的な景観管理計画や風致施業および地域の施業計画に貢献することになるだろう。そこで，本研究では，評価者実験によって得られた既往モデルを基礎として，それを改良することで，地域の民有林の森林資源情報から，針葉樹人工林および広葉樹二次林の任意の視点場における囲繞景観の評価ポテンシャルをより正確かつ広域的に予測・視覚化する改良モデルを開発した。さらに既往モデルや新たに行なった心理調査で得た評価結果等と比較検討し，改良モデルの精度について確認した。

Promoting nature-positive forestry requires sustainable timber production that aligns with ecosystem service (ES) conservation. However, Japan’s recently implemented top-down timber production policy may undermine sustainability in local forest landscapes. We assessed the spatial sustainability of plantation forestry by comparing actual logged areas (2000–2019) with allowable logging areas. Logged areas were identified using satellite imagery analysis, while allowable logging areas were estimated by excluding forests at high risk of landslides or with unclear ownership and dividing the remaining area by the standard logged age. While total logged area remained below the experience-based sustainable threshold, logging in profitable forests exceeded allowable levels in recent years. Forests with higher profitability experienced concentrated logging after 2015, indicating the strong influence of the national policy. This spatial imbalance threatens long-term sustainability by depleting productive forest patches while ignoring underutilized unprofitable forests. Our findings demonstrate the risks of uniform, production-oriented policies and highlight the need for adaptive, locally responsive forest governance. By integrating ecological and social constraints into spatial analysis, this study proposes a new sustainability measurement in line with nature-based solutions. Future forest policy must incorporate local knowledge and participatory decision-making to sustain forest ESs and timber supply under changing social and environmental conditions.

Understanding the current status of biodiversity is crucial to preventing its loss in a changing world. We examined changes in the geographical range size and abundance of 165 bird species breeding in Japan during the past 40 years, as well as temperature niche changes in the past 20 years. Higher temperatures were recorded within the ranges of non-native species than in those of native species, and we detected range-size expansion and increased abundance among non-native species. Although open-land species exhibited range reductions from the 1970s to the 1990s, many recovered and the ranges of only a few species declined after this period. Nevertheless, the abundance of open-land species did decline, despite range-size recovery; similar inconsistencies were detected for waterbirds and raptors. Analysis of long-term temperatures suggested that species left warmest areas within their distributions while maximum temperatures experienced by species during the survey years did not change systematically. Birds in warm regions may be facing a crisis, with attrition of native bird communities and expansion of non-native species. It is necessary to establish efficient measures to prevent further expansions of non-native species and conservation measures of native species within managed areas in warm regions with few intact habitats.

Many long‐distance migratory birds are experiencing global declines, creating an urgent need for conservation actions. Engaging public commitment to their conservation is therefore crucial. However, this task is challenging as the social interest diminishes as the geographic distance to conservation issues increases. One potential solution is to reduce people's psychological distance by providing visual information that illustrates how avian migratory routes connect countries and how conservation organizations implement conservation measures in distant countries. In this study, we conducted a discrete choice experiment with the Japanese public ( n = 1081) to estimate their willingness to pay (WTP) for conservation measures aimed at improving and protecting the wintering habitats of migratory birds in Southeast Asia (i.e., establishing wetland/forest nature reserves and implementing environmentally friendly farming/forestry). We tested the impact on WTP of showing respondents avian migratory routes and photographs of activities undertaken by conservation organizations in Southeast Asia. Contrary to predictions, showing the evidence‐based migratory routes connecting Japan and Southeast Asia had limited effects on the WTP of the Japanese public for conservation measures in Southeast Asia. Surprisingly, showing photographs of activities undertaken by conservation organizations in Southeast Asia had slightly negative impacts on WTP. Instead, WTP was strongly linked to subjective connection with nature (nature relatedness), with those exhibiting a stronger nature relatedness showing higher WTP. People showed higher WTP to establish nature reserves in Southeast Asia than to implement environmentally friendly farming/forestry in Southeast Asia, and there were weak negative interactions between implementing nature‐reserve establishment and environmentally friendly farming/forestry simultaneously. These findings suggest that providing visual information alone may not be effective to foster social support for conservation measures in distant countries. Rather, approaches that cultivate the connection with nature—such as environmental education, residential camps, and local nature experiences—are needed, ideally beginning from a young age.