Tree species mixing of oak (Quercus petraea (Matt.) Liebl./Quercus robur L.) and pine (Pinus sylvestris L.) has been shown to have positive effects on ecosystem service provision. From a management perspective, however, it is still uncertain which thinning regime provides the highest possible productivity of mixed oak–pine forests in the long term. Because of a lack of empirical studies dealing with thinning and species mixing effects on oak–pine forests, we simulated forest growth in order to test which thinning type and intensity may provide the highest productivity in the long-term. To achieve this, we simulated the growth of pure and mixed stands of oak and pine for 100 years in 23 triplets located on an ecological gradient across Europe. For this purpose, we applied four different growth simulators and compared their results: the distance-independent single-tree simulator PROGNAUS, the distance-dependent single-tree simulator SILVA, the gap model ForCEEPS, and the process-based simulator 3D-CMCC-FEM. We investigated the effects of species mixing and thinning from the upper (thinning from above) and lower tail (thinning from below) of the diameter distribution by reducing the stand basal area to 50 and 80% of the maximum basal area. We compared simulated results of the relative volume productivity of mixed versus pure stands and of thinned versus unthinned stands to empirical results previously obtained on the same set of triplets. Simulated relative volume productivity ranged between 61 and 156%, although extremes of 10% and of 300% could be observed. We found the relative volume productivity to be influenced by stand age, but not by stand density, except for PROGNAUS. Relative volume productivity did not increase with the site water supply of the triplet location. Highest long-term productivity for oak, pine and oak–pine stands can be expected in consequence of thinning from above, but the effect of thinning intensity differed between simulators. Thinning effects were positively affected by stand density, but not by stand age, except for thinning from above predicted by PROGNAUS. Predicted thinning effects showed good approximation of results from thinning experiments for oak, but not for pine stands. We hypothesize the results might be caused by the insufficient simulator representation of climate and its interaction with other site variables and stand structure. Further work is needed to reduce the revealed limitations of the existing growth models, as we currently see no alternative to such kind of studies and simulators.

事实证明，混合树种（橡树栎（Quercus petraea），松树栎（Quercus robur L.））和松树（Pinus sylvestris L.）对生态系统服务的提供具有积极作用。但是，从管理的角度来看，从长远来看，哪种疏伐方式仍可能提供最高的橡树林混交林生产力。由于缺乏关于稀疏和物种混合对橡树林的影响的经验研究，我们模拟了森林的生长，以测试哪种稀疏类型和强度可以长期提供最高的生产力。为了实现这一目标，我们模拟了欧洲和欧洲沿生态梯度分布的23个三胞胎中橡树和松树纯净和混合林分的生长100年。为此，我们应用了四个不同的增长模拟器并比较了它们的结果：距离无关的单树模拟器PROGNAUS，距离无关的单树模拟器SILVA，间隙模型ForCEEPS和基于过程的模拟器3D-CMCC-FEM。我们通过将林分基础面积减少到最大基础面积的50％和80％，研究了直径分布的上部（从上方变细）和下部尾部（从下方变细）进行物种混合和变稀的影响。我们将混合林与纯林，稀林与未林林的相对体积生产力的模拟结果与先前在同一组三胞胎上获得的经验结果进行了比较。尽管可以观察到10％和300％的极限值，但是模拟的相对体积生产率在61％和156％之间。我们发现相对体积生产力受林分年龄的影响，但不受林分密度的影响，除了PROGNAUS。相对体积生产率没有随着三重态位置的现场供水而增加。由于从上方变薄，因此可以预期橡树，松树和橡松树的最高长期生产力，但不同模拟器之间的变薄强度影响不同。稀疏效应受林分密度的积极影响，但不受林分年龄的影响，除了PROGNAUS预测的从上方稀疏。预测的间伐效果显示出橡木的间伐实验的结果非常近似，而松木则没有。我们假设结果可能是由于气候的模拟器表示不足以及其与其他站点变量和林分结构的相互作用所致。需要做进一步的工作来减少现有增长模型所揭示的局限性，