同所性オークが気候適応において異なる進化戦略を示すことを解明(Sympatric Oaks Show Divergent and Convergent Strategies for Climate Adaptation)

2026-07-15 中国科学院(CAS)

中国科学院(CAS)華南植物園の研究チームは、中国に共存する2種のオーク(Quercus acutissima、Q. variabilis)が、気候変動に対して異なる適応戦略と共通する適応戦略を併せ持つことを明らかにし、その成果をPlant, Cell & Environmentに発表した。研究では、中国の温帯から亜熱帯にかけて分布する両種について、15種類の植物機能形質、形質ネットワーク、および生態学的戦略を比較した。その結果、15形質のうち9形質で種間差が認められ、Q. acutissimaは形態形質の変動が小さい一方で生理形質の可塑性が高く、Q. variabilisは逆の傾向を示した。また、形質間ネットワークは適温域では両種とも類似した変化を示したが、低温・高温環境や降水量の違いでは異なる応答を示した。両種はいずれも競争戦略とストレス耐性戦略を採用していたが、分布域の周縁ではQ. variabilisの方が競争力に優れ、Q. acutissimaはストレス耐性が高かった。これらの結果は、近縁種が形質の可塑性と統合性を調整することで気候勾配に適応し、生態的地位(ニッチ)の分化と森林群集の形成を促進していることを示している。

同所性オークが気候適応において異なる進化戦略を示すことを解明(Sympatric Oaks Show Divergent and Convergent Strategies for Climate Adaptation)

Plant trait networks of Quercus acutissima and Q. variabilis, and variation in edge density and modularity of plant trait network along climate gradients. (Image by LAI Yuan)

<関連情報>

同所的に生育するオークは、気候勾配に沿って適応戦略において局所的な分岐と収束を示す Sympatric Oaks Exhibit Local Divergence and Convergence in Adaptive Strategies Along Climate Gradients

Yuan Lai, Yutong Lin, Songbo Tang, Jordi Sardans, Josep Peñuelas, Canyue Sun, Jianfeng Liu, Yuanwen Kuang

Plant, Cell & Environment  Published: 09 July 2026

DOI:https://doi.org/10.1111/pce.70742

ABSTRACT

The coexistence mechanisms of wide-ranging species across climate gradients are crucial for predicting their geographic range shift and community assembly. Two coexisting oaks (Quercus acutissima and Quercus variabilis) were sampled from broad-leaved forests across China. Fifteen plant functional traits related to morphology, physiology and stoichiometry were determined to assess the interspecific and intraspecific variability, trait integration and ecological strategies. Nine among the 15 studied functional traits differed significantly between the two oaks. Given all the studied traits, the two oaks exhibited similar intraspecific variability (29.0 vs. 27.9), but diverged trait-level variability, with Q. acutissima showing 13.1% lower morphological but 11.4% higher physiological variability than Q. variabilis. The connectivity and complexity within trait correlation networks of the two oaks covaried across favourable temperature ranges (ca. 15°C–20°C), but diverged below 15°C and above 20°C and along precipitation gradients. Both the oaks were clustered around competitive and stress-tolerant ecological strategies within their sampling ranges; however, Q. variabilis were more competitive but less stress-tolerant than Q. acutissima when growing at their distribution edges. Our results imply local divergent and convergent adaptation of the sympatric oaks via altering trait-level plasticity and trait integration along climate gradients, potentially leading to greater niche differentiation and complex community assembly.

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