Marchi Maurizio, Cocozza Claudia
CNR-Institute of Biosciences and BioResources (IBBR), Via Madonna del Piano 10, I-50019 Sesto Fiorentino (Florence), Italy.
Department of Science and Technology in Agriculture, Food, Environment and Forestry, University of Florence, Via S. Bonaventura 13, I-50145 Florence, Italy.
Plants (Basel). 2021 Jan 23;10(2):215. doi: 10.3390/plants10020215.
The introduction of Douglas-fir [ (Mirb.) Franco] in Europe has been one of the most important and extensive silvicultural experiments since the 1850s. This success was mainly supported by the species' wide genome and phenotypic plasticity even if the genetic origin of seeds used for plantations is nowadays often unknown. This is especially true for all the stands planted before the IUFRO experimentation in the 1960s. In this paper, a methodology to estimate the Douglas-fir provenances currently growing in Italy is proposed. The raw data from the last Italian National Forest Inventory were combined with literature information to obtain the current spatial distribution of the species in the country representing its successful introduction. Afterwards, a random forest classification model was run using downscaled climatic data as predictors and the classification scheme adopted in previous research studies in the Pacific North West of America. The analysis highlighted good matching between the native and the introduction range in Italy. Coastal provenances from British Columbia and the dry coast of Washington were detected as the most likely seed sources, covering 63.4% and 33.8% of the current distribution of the species in the country, respectively. Interior provenances and those from the dry coast of Oregon were also represented but limited to very few cases. The extension of the model on future scenarios predicted a gradual shift in suitable provenances with the dry coast of Oregon in the mid-term (2050s) and afterwards California (2080s) being highlighted as possible new seed sources. However, only further analysis with genetic markers and molecular methods will be able to confirm the proposed scenarios. A validation of the genotypes currently available in Italy will be mandatory as well as their regeneration processes (i.e., adaptation), which may also diverge from those occurring in the native range due to a different environmental pressure. This new information will also add important knowledge, allowing a refinement of the proposed modeling framework for a better support for forest managers.
自19世纪50年代以来，花旗松[（米尔布.）佛朗哥]引入欧洲一直是最重要、规模最广泛的造林试验之一。即便如今人工林所用种子的遗传来源往往不明，但该树种广泛的基因组和表型可塑性为其成功引入提供了主要支撑。对于20世纪60年代国际林联试验之前种植的所有林分而言，情况尤其如此。本文提出了一种估算目前生长在意大利的花旗松种源的方法。将意大利上一次国家森林资源清查的原始数据与文献信息相结合，以获取该树种在该国的当前空间分布，这代表了其成功引入。之后，使用降尺度气候数据作为预测因子，并采用美国太平洋西北部先前研究中的分类方案，运行随机森林分类模型。分析结果突出显示了意大利本土范围与引入范围之间的良好匹配。来自不列颠哥伦比亚省的沿海种源以及华盛顿州干燥海岸的种源被检测为最有可能的种子来源，分别占该树种目前在该国分布范围的63.4%和33.8%。内陆种源以及来自俄勒冈州干燥海岸的种源也有出现，但数量极少。该模型在未来情景下的扩展预测，适宜种源将逐渐发生变化，中期（2050年代）俄勒冈州干燥海岸以及之后（2080年代）加利福尼亚州被突出显示为可能的新种子来源。然而，只有通过遗传标记和分子方法进行进一步分析，才能证实所提出的情景。对意大利目前可用的基因型及其更新过程（即适应性）进行验证也将是必不可少的，由于环境压力不同，这些过程可能也与本土范围内发生的过程有所不同。这些新信息还将增添重要知识，有助于完善所提出的建模框架，从而更好地为森林管理者提供支持。
