| 要旨トップ | ESJ73 シンポジウム 一覧 | | 日本生態学会第73回全国大会 (2026年3月、京都) 講演要旨 ESJ73 Abstract

シンポジウム S29 3月15日 9:00-12:00 Room S: 国際Annex

#### The Old-Growth Values of Semi-Natural Ecosystems: Insights from Human-Managed Grasslands of Japan and Beyond【E】

Hiroko KUROKAWA（Kyoto Univ.）, Shogo IKARI（Univ. of the Ryukyus）, Atushi USHIMARU（Kobe Univ.）

Grasslands are often regarded as transient, early successional ecosystems with lower ecological value than forests. This perception has been particularly strong for grasslands maintained by human activities, which are often dismissed as merely "secondary" or "degraded" nature. By contrast, recent studies recognize the existence of old-growth grasslands that have persisted for many centuries, or even millennia, under natural and anthropogenic disturbance regimes, even in regions climatically suitable for forests. Old-growth grasslands can harbor high levels of biodiversity comparable to those of primary forests and offer important ecosystem services to society. In our previous symposia, “Hidden Environmental Values of Old-Growth Grasslands" (held over the past two years), studies conducted mainly in Nagano Prefecture, Japan, demonstrated that the diversity of plants, herbivores, pollinators, and symbiotic microorganisms is higher in old-growth grasslands than in recently established grasslands or forests. Moreover, these long-established grasslands appear to provide superior ecosystem services, including aesthetic appeal, carbon storage, disaster prevention, and genetic resources.
Building on these findings and discussions, the present symposium aims to reassess the biodiversity and environmental values of ecosystems maintained by long-term anthropogenic disturbances, challenging the perspective that human-managed ecosystems are inherently secondary and thus of lower conservation value. Our discussion will extend beyond grasslands to encompass a broader range of disturbed or managed landscapes that have developed stable ecological structures and functions through long-term persistence.
To deepen this discussion, we will invite Dr. Joseph W. Veldman, who has played a leading role in extending the concept of “old-growth" to savannas and grasslands in recognition that many of Earth's grassy ecosystems are ancient. His research has highlighted the long-overlooked conservation value of grasslands and demonstrated that they can be as ecologically complex and irreplaceable as old-growth forests. By integrating Dr. Veldman's insights with the results of our ongoing grassland project, as well as with studies from other semi-natural ecosystems, we will identify approaches to maintain long-standing human-ecosystem relationships and reposition semi-natural ecosystems as mature and valuable components of the biosphere—not as degraded or secondary nature—that represent both ecological history and cultural heritage. Through discussions among speakers and participants, we aim to foster a broader understanding of the ecological significance of ecosystems maintained by long-term human stewardship.

[S29-1]
Toward an Old-Growth Concept for Japanese Semi-Natural Grasslands: Why It Matters *Atushi USHIMARU（Kobe Univ.）, Yuki A. YAIDA（Kobe Univ.）, Gaku S. HIRAYAMA（Kobe Univ.）, Airi A. ASADA（Kobe Univ.）, Taiki INOUE（MSC, Univ. Tsukuba）, Mahoro TOMITAKA（MSC, Univ. Tsukuba）, Shogo IKARI（Univ. of the Ryukyus）, Hiroko KUROKAWA（Kyoto Univ.）, Kenta TANAKA（MSC, Univ. Tsukuba）

[S29-2]
Why the natural versus anthropogenic dichotomy is unhelpful for old-growth grassland conservation *Joseph W. VELDMAN（Texas A&M University）

[S29-3]
Conservation biogeography of Japanese seminatural grasslands: understanding their uniqueness across space and time *Shogo IKARI（Univ. of the Ryukyus）, Yasuhiro KUBOTA（Univ. of the Ryukyus）, Kenta TANAKA（MSC, Univ. Tsukuba）

[S29-4]
Hidden Environmental Values: Biodiversity and Ecosystem Services in Old-Growth Grasslands *Hiroko KUROKAWA（Kyoto Univ.）, Mahoro TOMITAKA（MSC, Univ. Tsukuba）, Mayuka HIGO（Teikyo Univ. of Science）, Mikihito NOGUCHI（Kyoto Univ.）, Airi A. ASADA（Kobe Univ.）, Taiki INOUE（Sunlit Seedlings Ltd., MSC, Univ. Tsukuba）, Akihisa SUZUKI（MSC, Univ. Tsukuba）, Yuina DOI（MSC, Univ. Tsukuba）, Issui TAKIZAWA（MSC, Univ. Tsukuba, IT-Tera Co., Ltd.）, Yuto TERASHIMA（MSC, Univ. Tsukuba）, Sachiko ICHINO（MSC, Univ. Tsukuba）, Mizuki IRIE（MSC, Univ. Tsukuba）, Hiroki ASADA（Kumamoto Univ.）, Shun NONAKA（Yokohama National Univ.）, Mingqiang HUANG（Kyoto Univ.）, Kei SHIMAZAKI（MSC, Univ. Tsukuba, Ina Food Industry Co., Ltd.）, Gaku S. HIRAYAMA（Kobe Univ.）, Haruko SAITO（Tokyo Univ. of Agriculture）, Taku KATO（Tokyo Univ. of Agriculture）, Ayumi ONUMA（Keio University）, Hirokazu TOJU（Kyoto Univ.）, Takehiro SASAKI（Yokohama National Univ.）, Kenichi NONAKA（Teikyo Univ. of Science）, Atushi USHIMARU（Kobe Univ.）, Kenta TANAKA（MSC, Univ. Tsukuba）

[S29-5]
Hard come, easy go: abandoned rural settlements as showcases of degraded seminatural landscapes in Japan *Keita FUKASAWA, Fumiko ISHIHAMA（NIES）

[S29-6]
Connecting "Old-Growth Grasslands (Sogen)" to the Future: Actions and a Roadmap from the Japan Sogen Network *Katsunobu SHIRAKAWA（Co-Creation Assets Lab.）, Masahito INOUE（The Nature Museum of Mt. Sanbe）, Yoshitaka TAKAHASHI（Japan Sogen Network）

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