Li Dandan, Zhang Feng, Luo Guangyu, Zhang Ting, Lv Jinqiao, Wang Wenchao, Yang Jun, You Dejun, Xu Nanlong, Guo Shuiliang, Yu Jing
College of Life Sciences Shanghai Normal University Shanghai China.
Ecol Evol. 2023 Feb 24;13(2):e9844. doi: 10.1002/ece3.9844. eCollection 2023 Feb.
To explore the taxon-dependent contribution of dispersal limitation versus environmental filters to bryophyte assemblages. We investigated bryophytes and six environmental variables on 168 islands in the Thousand Island Lake,China. We compared the observed beta diversity with the expected values based on six null models (EE, EF, FE, FF, PE, and PF), detected the partial correlation of beta diversity with geographical distances. We quantified the contributions of spatial versus environmental variables and island isolation per se to species composition (SC) using variance partitioning. We modeled the species-area relationships (SARs) for bryophytes and the other eight biotas. To explore the taxon-dependent effects of spatial versus environmental filters on bryophytes, 16 taxa including five categories (total bryophytes, total mosses, liverworts, acrocarpous, and pleurocarpous mosses) and 11 species-richest families were included in the analyses. The observed beta diversity values were significantly different from the predicted values for all 16 taxa. For all five categories, the observed partial correlations between beta diversity and geographical distance after controlling environmental effects were not only positive, but also significantly different from the predicted values based on the null models. Spatial eigenvectors are more important in shaping SC than environmental variables for all 16 taxa except Brachytheciaceae and Anomodontaceae. Spatial eigenvectors contributed more to SC variation in liverworts than in mosses and in pleurocarpous mosses than in acrocarpous mosses. The effects of island isolation on SC were significant for all five categories, highly varied at the family level. The z values of the SARs for the five bryophyte categories were all larger than those of the other eight biotas. In subtropical fragmented forests, dispersal limitation exerted significant, taxon-dependent effects on bryophyte assemblages. It was dispersal limitation rather than environmental filtering that predominantly regulated the SC patterns of bryophytes.
为探究扩散限制与环境过滤对苔藓植物群落的分类群依赖性贡献。我们在中国千岛湖的168个岛屿上调查了苔藓植物和六个环境变量。我们将观察到的β多样性与基于六个零模型（EE、EF、FE、FF、PE和PF）的预期值进行比较，检测β多样性与地理距离的偏相关性。我们使用方差分解量化了空间变量与环境变量以及岛屿隔离本身对物种组成（SC）的贡献。我们模拟了苔藓植物和其他八个生物群落的物种 - 面积关系（SARs）。为探究空间与环境过滤对苔藓植物的分类群依赖性影响，分析中纳入了包括五类（总苔藓植物、总藓类、苔类、顶蒴藓类和侧蒴藓类）的16个分类群以及11个物种最丰富的科。所有16个分类群的观察到的β多样性值均显著不同于预测值。对于所有五类，在控制环境影响后，β多样性与地理距离之间观察到的偏相关性不仅为正，而且也显著不同于基于零模型的预测值。除了短月藓科和异齿藓科外，对于所有16个分类群，空间特征向量在塑造SC方面比环境变量更重要。空间特征向量对苔类SC变异的贡献大于藓类，对侧蒴藓类SC变异的贡献大于顶蒴藓类。岛屿隔离对SC的影响在所有五类中均显著，在科级水平上差异很大。五个苔藓植物类别的SARs的z值均大于其他八个生物群落的z值。在亚热带破碎森林中，扩散限制对苔藓植物群落产生了显著的、分类群依赖性的影响。主要调节苔藓植物SC模式的是扩散限制而非环境过滤。
