保全活動が絶滅危惧種保護に最も効果を発揮する地域を特定(Where nature conservation can make the greatest difference)

2026-06-22 リンショーピング大学

スウェーデンのリンショーピング大学の研究チームは、絶滅危惧種の保全効果を最大化するため、森林の老齢オーク林と半自然草地を対象に、生息地面積と種の存続可能性との関係を解析した。研究では、一般公開されている生物観測データベース「Artportalen」をはじめ、数百万件の生物分布データとオーク林・草地の地理空間データを統合し、各種が長期的に存続するために必要な生息地量の閾値を定量化した。その結果、生息地の量が一定の閾値を下回ると絶滅リスクが急増することが明らかとなり、特に老齢オークに依存する絶滅危惧菌類オレンジカワラタケ(Aurantiporus croceus)の生息条件を満たせば、他のオーク依存種の保全にも有効であることが示された。また、現在は種が生息していても生息地の分断や縮小により将来的な絶滅が予測される地域を特定できることから、限られた保全資源を重点的に投入すべき場所を科学的に選定できる。研究成果は、生物多様性保全の実効性を高める保全計画や生態系管理の基盤となることが期待される。

<関連情報>

生息地の閾値に基づいて、スウェーデンの半自然草地と老齢オーク(Quercus robur )の機能的景観を特定する Identifying functional landscapes in Sweden for semi-natural grasslands and old-growth oaks (Quercus robur) based on habitat thresholds

Karl-Olof Bergman,Leif Andersson,Markus Franzén,Victor Johansson & Lars Westerberg
Landscape Ecology  Published:22 May 2026
DOI:https://doi.org/10.1007/s10980-026-02373-4

保全活動が絶滅危惧種保護に最も効果を発揮する地域を特定(Where nature conservation can make the greatest difference)

Abstract

Context

The loss of biodiversity due to habitat destruction has been identified as a critical global issue. There is an urgent need for landscape-based guidelines for critical levels of habitat amount in conservation work.

Objectives

The aims were to identify habitat amount thresholds for species associated with old oaks and semi-natural grasslands, and to map functional areas and areas with habitat mismatch to guide conservation and restoration planning.

Methods

We used spatial data on the distribution of old oaks (Quercus robur) and semi-natural grasslands in southern Sweden, combined with an extensive dataset of occurrence records for species associated with these habitats. Presence and absence of 102 species in grid cells in relation to habitat amount were analysed using binomial GLMs weighted by survey effort.

Results

A total of 86 species showed a significant positive relationship between occurrence and habitat amount and these relationships were used to identify habitat thresholds. Species-specific threshold values within each habitat type ranged from low to high, showing considerable variation in habitat requirements. The mapping of functional areas showed clear patterns in the study area with large differences between regions. However, there were also large regions showing a habitat mismatch, i.e., occurrence of species in areas with habitat amounts below the estimated thresholds suggesting potential extinction debts. Our analysis shows that by prioritising habitat restoration sites it is possible to make them fully functional in the future, offering tools for cost-effective nature conservation.

Conclusions

The approach here, using extensive, partly citizen science data and relatively simple models to provide conservation practitioners and planners with decision support maps, can be a useful tool to tackle biodiversity loss. However, threshold values should be interpreted as minimum targets, and complementary consideration of habitat connectivity and climate change is recommended.

1903自然環境保全
ad
ad
Follow
ad
タイトルとURLをコピーしました