Sedmáková Denisa, Jaloviar Peter, Mišíková Oľga, Šumichrast Ladislav, Slováčková Barbora, Kucbel Stanislav, Vencurik Jaroslav, Bosela Michal, Sedmák Róbert
Department of Silviculture, Faculty of Forestry, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovak Republic.
Department of Wood Science, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovak Republic.
Plants (Basel). 2024 Dec 15;13(24):3502. doi: 10.3390/plants13243502.
Gap dynamics are driving many important processes in the development of temperate forest ecosystems. What remains largely unknown is how often the regeneration processes initialized by endogenous mortality of dominant and co-dominant canopy trees take place. We conducted a study in the high mountain forests of the Central Western Carpathians, naturally dominated by the Norway spruce. Based on the repeated forest inventories in two localities, we quantified the structure and amount of deadwood, as well as the associated mortality of standing dead canopy trees. We determined the basic specific gravity of wood and anatomical changes in the initial phase of wood decomposition. The approach for estimating the rate of gap formation and the number of canopy trees per unit area needed for intentional gap formation was formulated based on residence time analysis of three localities. The initial phase of gap formation (standing dead tree in the first decay class) had a narrow range of residence values, with a 90-95% probability that gap age was less than 10 or 13 years. Correspondingly, a relatively constant absolute number of 12 and 13 canopy spruce trees per hectare died standing in 10 years, with a mean diameter reaching 50-58 cm. Maximum diameters trees (70-80 cm) were represented by 1-4 stems per hectare. The values of the wood-specific gravity of standing trees were around 0.370-0.380 g.cm, and varied from 0.302 to 0.523 g.cm. Microscopically, our results point out that gap formation is a continuous long-lasting process, starting while canopy trees are living. We observed early signs of wood degradation and bacteria, possibly associated with bark beetles, that induce a strong effect when attacking living trees with vigorous defenses. New information about the initial phase of gap formation has provided a basis for the objective proposal of intervals and intensities of interventions, designed to promote a diversified structure and the long-term ecological stability of the mountain spruce stands in changing climate conditions.
林窗动态驱动着温带森林生态系统发育过程中的许多重要进程。但在很大程度上仍不清楚的是，由优势和共优势冠层树木的内源死亡引发的更新过程多久发生一次。我们在中西部喀尔巴阡山脉的高山森林中开展了一项研究，该地区自然以挪威云杉为主。基于两个地点的重复森林清查，我们量化了枯立木的结构和数量，以及现存死亡冠层树木的相关死亡率。我们测定了木材的基本比重以及木材分解初始阶段的解剖学变化。基于对三个地点的滞留时间分析，制定了估算林窗形成速率和有意形成林窗所需每单位面积冠层树木数量的方法。林窗形成的初始阶段（处于第一个腐烂等级的枯立木）滞留值范围较窄，林窗年龄小于10年或13年的概率为90 - 95%。相应地，每公顷相对恒定的绝对数量为12至13棵冠层云杉树在10年内死亡并保持直立状态，平均直径达到50 - 58厘米。最大直径的树木（70 - 80厘米）每公顷有1 - 4株。现存树木的木材比重值约为0.370 - 0.380克/立方厘米，范围在0.302至0.523克/立方厘米之间。在微观层面，我们的结果指出林窗形成是一个持续的长期过程，在冠层树木存活时就已开始。我们观察到了木材降解和细菌的早期迹象，这些可能与树皮甲虫有关，当攻击具有强大防御能力的活树时会产生强烈影响。关于林窗形成初始阶段的新信息为客观提出干预间隔和强度提供了依据，旨在促进山区云杉林分在不断变化的气候条件下形成多样化结构和长期生态稳定性。
