Levanič Tom, Štraus Hana
Department of Forest Yield and Silviculture, Slovenian Forestry Institute, Večna Pot 2, SI-1000 Ljubljana, Slovenia.
Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, SI-6000 Koper, Slovenia.
Plants (Basel). 2022 Jun 14;11(12):1571. doi: 10.3390/plants11121571.
Douglas-fir ( (Mirb.) Franco) is a non-native tree species in Slovenia with the potential to partially replace Norway spruce in our native forests. Compared to spruce, it has several advantages in terms of volume growth, wood quality and tolerance to drought. This is important given the changing climate in which spruce is confronted with serious problems caused by increasing temperatures and drought stress. At three sites (one on non-carbonate bedrock and deep soils, and two on limestone with soil layers of varying depths), 20 Douglas-fir and 20 spruce per site were sampled in order to compare their radial growth response to climate and drought events. The radial growth of Douglas-fir exceeds that of spruce by about 20% on comparable sites. It is more responsive to climate than spruce. Above-average temperatures in February and March have a significant positive effect on the radial growth of Douglas-fir. In recent decades, above-average summer precipitation has also had a positive influence on the radial growth of Douglas-fir. Compared to spruce, Douglas-fir is less sensitive to extreme drought events. Our results indicate that Douglas-fir may be a good substitute for spruce in semi-natural managed forest stands in Slovenia. The planting of Douglas-fir should be allowed in Slovenian forests, but the proportion of it in forest stands should be kept lower than is the case with spruce today.
花旗松（(Mirb.) Franco）是斯洛文尼亚的外来树种，有潜力在我们的原生森林中部分替代挪威云杉。与云杉相比，它在材积生长、木材质量和耐旱性方面有几个优势。鉴于气候变化，云杉面临着气温升高和干旱胁迫带来的严重问题，这一点很重要。在三个地点（一个位于非碳酸盐基岩和深厚土壤上，另外两个位于不同深度土层的石灰岩上），每个地点采集了20株花旗松和20株云杉样本，以比较它们对气候和干旱事件的径向生长响应。在可比地点，花旗松的径向生长比云杉高出约20%。它对气候的响应比云杉更敏感。2月和3月的平均气温以上对花旗松的径向生长有显著的积极影响。近几十年来，夏季降水高于平均水平也对花旗松的径向生长有积极影响。与云杉相比，花旗松对极端干旱事件不太敏感。我们的结果表明，在斯洛文尼亚半天然经营的林分中，花旗松可能是云杉的良好替代品。斯洛文尼亚森林应允许种植花旗松，但其林分中的比例应低于目前云杉的比例。
