This study aims to verify the concept of niches at multiple spatial scales in plant communities. To this end, we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three spatial scales. At the local scale, we calculated the Importance Value (IV) of species in five communities in the north of the Da Hinggan Mountains. At the intermediate scale, we examined five communities in their entirety, calculated the niche breadth of the species, and integrated niche overlap and interspecific association to analyze interspecific relationships. Further, the generalized additive model (GAM) was used to analyze the impact of topography and soil factors on niche characteristics. At the regional scale, we analyzed the geographical distribution of dominant species of R. dauricum plant communities in Northeast China and used principal component analysis (PCA) to analyze the impact of geographical and climate factors on species distribution. The results show that at the local scale, the IV of the species in each community varies widely. At the intermediate scale, species with a wide niche breadth tend to have a high value for IV. Larix gmelinii, Betula platyphylla, R. dauricum, Ledum palustre, and Vaccinium vitis-idaea had a relatively wide niche breadth and a high niche overlap, and the interspecific associations were almost all positive. Elevation and soil nutrients were the most dominant environmental factors. At the regional scale, species with a wide niche breadth tend to have a wide range of distribution, and temperature and precipitation were the most dominant environmental factors. This study suggests that the niche characteristics at three scales are both related and different. Niche characteristics at the local scale were various and labile, and niche characteristics at the intermediate and regional scales were relatively regular. These results show some degree of consistency with previous studies from an evolutionary perspective. The action mechanisms of these communities are related to differences in the dominant environmental factors. In addition, the integration of niche overlap and interspecific association determine interspecific relationships more accurately.

中文翻译：

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东北杜鹃植物群落生态位特征的多空间尺度分析

本研究旨在验证植物群落中多个空间尺度的生态位概念。为此，我们从三个空间尺度分析了东北杜鹃花植物群落的生态位特征。在局部尺度上，我们计算了大兴安岭北部五个群落物种的重要性值（IV）。在中等规模上，我们对五个群落进行了整体检查，计算了物种的生态位宽度，并整合了生态位重叠和种间关联以分析种间关系。此外，广义加性模型（GAM）用于分析地形和土壤因素对生态位特征的影响。在区域尺度上，我们分析了 R 优势种的地理分布。利用主成分分析法（PCA）分析了东北地区的大枣植物群落，分析了地理和气候因素对物种分布的影响。结果表明，在局部尺度上，每个群落中物种的IV差异很大。在中等规模上，生态位宽度较宽的物种往往具有较高的 IV 值。Larix gmelinii、Betula platyphylla、R. dauricum、Ledum palustre 和 Vaccinium v​​itis-idaea 具有相对较宽的生态位宽度和较高的生态位重叠，并且种间关联几乎都是正的。海拔和土壤养分是最主要的环境因素。在区域尺度上，生态位广度大的物种往往分布范围广，温度和降水是最主要的环境因子。本研究表明，三个尺度的生态位特征既相关又不同。局部尺度的生态位特征多样且不稳定，中间和区域尺度的生态位特征相对规律。从进化的角度来看，这些结果与之前的研究有一定程度的一致性。这些群落的作用机制与主导环境因素的差异有关。此外，生态位重叠和种间关联的整合更准确地确定种间关系。从进化的角度来看，这些结果与之前的研究有一定程度的一致性。这些群落的作用机制与主导环境因素的差异有关。此外，生态位重叠和种间关联的整合更准确地确定种间关系。从进化的角度来看，这些结果与之前的研究有一定程度的一致性。这些群落的作用机制与主导环境因素的差异有关。此外，生态位重叠和种间关联的整合更准确地确定种间关系。