Analyses of dendrochronological data from 15 recently established tablished stands of pedunculate oak (Quercus robur L.) revealed that functions describing potential tree growth in the absence of neighbours varied more between stands than functions describing competitive effects of conspecific neighbours. This suggests that competition functions can more easily be transferred among stands than potential growth functions. The variability inherent in the natural establishment of tree stands raises the question whether one can find general models for potential growth and competition that hold across stands. We investigated variation in potential growth and competition among recently established stands of Q. robur and tested whether this variation depends on stand structure. We also tested whether competition is symmetric or asymmetric and whether it is density-dependent or size-dependent. Lastly, we examined whether between-year growth variation is synchronous among stands. Potential growth, competition and between-year growth variation were quantified with statistical neighbourhood models. Model parameters were estimated separately for each stand using exhaustive mapping and dendrochronology data. Competition was best described with an asymmetric size-dependent model. Functions describing potential growth varied more among forest stands than competition functions. Parameters determining these functions could not be explained by stand structure. Moreover, annual growth rates showed only moderate synchrony across stands. The substantial between-stand variability in potential growth needs to be considered when assessing the functioning, ecosystem services and management of recently established Q. robur stands. In contrast, the relative constancy of competition functions should facilitate their extrapolation across stands.

中文翻译：

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树木潜在生长的差异大于自发建立的有花序橡树林分之间的竞争（Quercus robur）

对 15 个最近建立的有花梗橡树 (Quercus robur L.) 表列的树木年代学数据的分析表明，在没有邻居的情况下，描述潜在树木生长的函数在不同林分之间的差异比描述同种邻居的竞争影响的函数更大。这表明竞争功能比潜在增长功能更容易在林分之间转移。林分自然建立所固有的可变性提出了一个问题，是否可以找到跨林分的潜在增长和竞争的通用模型。我们调查了最近建立的 Q. robur 林分之间潜在增长和竞争的变化，并测试了这种变化是否取决于林分结构。我们还测试了竞争是对称的还是不对称的，以及它是依赖于密度还是依赖于大小。最后，我们检查了林分之间的年间增长变化是否同步。潜在增长、竞争和年间增长变化通过统计邻域模型进行量化。使用详尽的绘图和树木年代学数据分别估计每个林分的模型参数。用不对称的大小相关模型最好地描述了竞争。与竞争功能相比，林分之间描述潜在增长的功能差异更大。决定这些功能的参数无法用支架结构来解释。此外，各展位的年增长率仅表现出适度的同步性。在评估最近建立的 Q. robur 林分的功能、生态系统服务和管理时，需要考虑林分之间潜在增长的巨大可变性。相比之下，竞争函数的相对恒定性应该有助于它们跨看台的推断。