Data from: The impact of even-aged and uneven-aged forest management on regional biodiversity of multiple taxa in European beech forests

For managed temperate forests, conservationists and policymakers favour fine-grained uneven-aged management over more traditional coarse-grained even-aged management, based on the assumption that within-stand habitat heterogeneity enhances biodiversity. There is, however, little empirical evidence to support this assumption. We investigated for the first time how differently grained forest management systems affect the biodiversity of multiple above- and below-ground taxa across spatial scales.
We sampled 15 taxa of animals, plants, fungi and bacteria within the largest contiguous beech forest landscape of Germany and classified them into functional groups. Selected forest stands have been managed for more than a century at different spatial grains. The even-aged (coarse-grained management) and uneven-aged (fine-grained) forests are comparable in spatial arrangement, climate and soil conditions. These were compared to forests of a nearby national park that have been unmanaged for at least 20 years. We used diversity accumulation curves to compare γ-diversity for Hill-numbers 0D (species richness), 1D (Shannon diversity) and 2D (Simpson diversity) between the management systems. Beta diversity was quantified as multiple-site dissimilarity.
Gamma diversity was higher in even-aged than in uneven-aged forests for at least one of the three Hill-numbers for six taxa (up to 77%), while eight showed no difference. Only bacteria showed the opposite pattern. Higher γ-diversity in even-aged forests was also found for forest specialists and saproxylic beetles.
Between-stand β-diversity was higher in even-aged than in uneven-aged forests for one third (all species) and half (forest specialists) of all taxa, driven by environmental heterogeneity between age-classes, while α-diversity showed no directional response across taxa or for forest specialists.
Synthesis and applications. Comparing even-aged and uneven-aged forest management in Central European beech forests, our results show that a mosaic of different age-classes is more important for regional biodiversity than high within-stand heterogeneity. We suggest reconsidering the current trend of replacing even-aged management in temperate forests. Instead, the variability of stages and stand structures should be increased to promote landscape scale biodiversity.

针对经营型温带森林（managed temperate forests），保护学者与政策制定者更青睐精细化异龄林经营模式，而非传统的粗粒化同龄林经营模式，其核心假设为林内生境异质性可提升生物多样性。然而，目前支撑这一假设的实证证据寥寥无几。本研究首次探究了不同粒度的森林经营体系，如何在多个空间尺度上影响地上与地下类群的生物多样性。
研究团队在德国最大的连片山毛榉林景观中，对动物、植物、真菌与细菌共15个类群进行了采样，并将其划分为功能群。所选林分均已按不同空间粒度开展经营超一个世纪：同龄林（粗粒化经营）与异龄林（精细化经营）在空间布局、气候与土壤条件上均保持一致。此外，研究还将上述林分与附近一处至少20年未开展经营的国家公园森林进行对照。本研究采用多样性累积曲线，针对Hill数（Hill-numbers）0D（物种丰富度）、1D（香农多样性指数）与2D（辛普森多样性指数）三类指标，比较不同经营体系下的γ多样性（伽马多样性）；β多样性（贝塔多样性）则通过多站点相异性进行量化。
结果显示，在15个类群中，至少有6个类群的γ多样性在同龄林中高于异龄林（最高可达77%），其余8个类群则无显著差异；仅细菌类群呈现相反的变化趋势。森林专性类群与食朽甲虫（saproxylic beetles）的γ多样性同样在同龄林中更高。
林分间的β多样性方面，针对全部类群的三分之一、以及森林专性类群的一半，同龄林均高于异龄林，这一现象由林分年龄级之间的环境异质性所驱动；而α多样性（阿尔法多样性）则未在所有类群或森林专性类群中表现出明确的方向性响应。
研究结论与应用启示。通过对比中欧山毛榉林的同龄与异龄经营模式，本研究结果表明：相较于高林分内异质性，由不同年龄级构成的林分镶嵌体对区域生物多样性更为重要。我们建议重新审视当前温带森林中替换同龄林经营模式的趋势，转而通过提升林分发育阶段与结构的多样性，以促进景观尺度的生物多样性保护。