In the absence of primeval floodplain forests, near-natural remnants are key references for close-to-nature forestry and nature conservation. Old-growth forest characteristics (OGCs) were quantified in 16 managed (rotation or selection) and abandoned semi-natural floodplain forests by taking snapshot inventories of structural features. Principal component analysis revealed a short gradient from closed-canopy managed stands dominated by large trees (mainly oaks) and hornbeams, with less deadwood, to abandoned older stands with more gaps, very large trees and different kinds of deadwood. All the studied forests are mainly in the early and late biostatic phases of forest development, with innovation and degradation phases almost completely absent. Results showed that selection forests had significantly more very large trees compared to rotation stands. The difference in structure between abandoned selection stands and abandoned rotation stands was more pronounced than in their counterparts that are still managed. Based on diameter distribution and the amount of very large trees and deadwood, abandoned selection stands were closest to the structure of natural forests. Selection forests may recover certain OGCs more rapidly than rotation forests. We concluded that after 100–150 years of homogenising rotation forestry, OGCs are slow to develop in just 25 years of non-intervention. Based on our results, we recommend: (i) an increase in the rotation cycle with selective logging in order to restore and maintain OGCs in managed rotation forests and (ii) total abandonment in certain well-preserved, near-natural forests with natural flooding regimes. However, the failure of oak to regenerate naturally remains a challenge.

中文翻译：

---

潘诺尼亚生态区硬木漫滩森林中管理方法的遗产和对旧生长属性的放弃

在没有原始洪泛区森林的情况下，近自然的残余物是近自然林业和自然保护的关键参考。通过对结构特征进行快照清单，在 16 个管理（轮换或选择）和废弃的半天然洪泛平原森林中量化了原始森林特征 (OGC)。主成分分析显示，从以大树（主要是橡树）和角树为主、枯木较少的封闭式树冠管理林分到具有更多间隙、非常大的树木和不同种类枯木的废弃旧林分之间的梯度很短。所有研究的森林主要处于森林发展的早期和晚期生物静止阶段，几乎完全没有创新和退化阶段。结果表明，与轮作林相比，选择林具有明显更多的非常大的树木。废弃选择看台和废弃轮换看台之间的结构差异比仍在管理的对应看台更为明显。根据直径分布和非常大的树木和枯木的数量，废弃的选择林最接近天然林的结构。选择林可能比轮作林更快地恢复某些 OGC。我们得出的结论是，经过 100-150 年的轮作林业均质化，OGC 在仅 25 年的非干预中发展缓慢。根据我们的结果，我们建议：(i) 通过选择性伐木增加轮作周期，以恢复和维护管理轮作森林中的 OGC，以及 (ii) 在某些保存完好的森林中完全放弃，具有自然洪水制度的近天然森林。然而，橡木不能自然再生仍然是一个挑战。