カルスト地質が森林の多様性に与える影響を解明(Calcium Rich Karst Bedrock Reshapes Latitudinal Pattern of Forest Species Diversity)

2025-10-30 中国科学院(CAS)

中国科学院亜熱帯農業研究所の陳宏松教授らの研究チームは、カルシウムを多く含む石灰岩質の岩盤が森林における緯度多様性勾配(LDG)を反転させることを発見した。中国南部の60地点を調査し、岩盤の化学組成・土壌特性・気候条件を統合解析した結果、カルスト林では非カルスト林と異なり、緯度が高いほど樹種多様性が増す「逆LDG」現象が確認された。これは、カルシウムやマグネシウムに富む岩盤が土壌形成と栄養分供給を制限し、生態系構造を変化させるためと考えられる。解析では、岩盤SiO₂含有量や土壌深度が多様性と強く相関し、地質多様性が生物多様性分布を支配することが示された。研究は、地質要因を考慮した森林保全と生態系修復戦略の重要性を強調している。

カルスト地質が森林の多様性に与える影響を解明(Calcium Rich Karst Bedrock Reshapes Latitudinal Pattern of Forest Species Diversity)
Locations of the transect and relationships between species diversity and latitude within karst and non-karst forests, respectively (Image by HUANG Li)

<関連情報>

カルスト森林と非カルスト森林における緯度方向の多様性勾配の対照:岩盤駆動による調節の証拠 Contrasting Latitudinal Diversity Gradients in Karst and Non-Karst Forests: Evidence for Bedrock-Driven Modulation

Li Huang, Yunpeng Nie, Ivan Prieto, Zidong Luo, Wenna Liu, Wei Zhang, Hongsong Chen
Diversity and Distributions  Published: 06 October 2025
DOI:https://doi.org/10.1111/ddi.70098

ABSTRACT

Aim

Plant diversity is essential for ecosystem stability and the delivery of ecosystem services. While climate, through energy and water (i.e., productivity), is the primary driver of the latitudinal diversity gradient (LDG), edaphic conditions modulate resource storage and heterogeneity. The role of bedrock-driven edaphic gradients in shaping LDG patterns remains poorly understood. Here, we tested how edaphic conditions interact with climate to shape species diversity and LDG patterns, underscoring the role of geodiversity in conservation.

Location

Subtropical forests spanning ~10° latitude in Southwestern China.

Methods

We conducted a large-scale vegetation survey across 60 forest plots on parallel limestone (karst) and clastic (non-karst) bedrocks recording over 17,000 individuals belonging to 654 woody species. We analysed diversity patterns in relation to latitude, climate, soil physicochemical properties and bedrock composition using structural equation modelling and linear mixed models.

Results

Despite similar climatic variation, karst forests exhibited higher topsoil Ca and Mg concentrations (SoilPC1) than non-karst forests. Together with shallower soils and lower SiO2 contents at low latitudes, elevated SoilPC1 was associated with lower species richness, consistent with the ~20% lower richness in karst forests. We found a positive effect of climate on richness (0.22), while SoilPC1 exerted a stronger negative effect (−0.34). Non-karst forests followed the traditional LDG pattern, with diversity increasing towards lower latitudes whereas it declined towards lower latitudes within karst forests, reversing the LDG trend. This divergence was associated with increasing SoilPC1 and declining soil depth and SiO2 contents towards low-latitude karst regions.

Main Conclusions

Our findings provide evidence that bedrock-driven differences in edaphic conditions between karst and non-karst systems fundamentally regulate plant diversity reshaping LDG patterns. This advances the floristic geo-lithology hypothesis and calls for integrating geodiversity into conservation frameworks. Given the ecological sensitivity and global extent of karst ecosystems, understanding bedrock–climate interactions is critical for conservation planning.

1304森林環境
ad
ad
Follow
ad
タイトルとURLをコピーしました