1,721,014 research outputs found
Extent, distribution and origin of non-native forest tree species in Europe
No full textThe management of non-native tree species in European forests has a long history, but the information on the current number and geographic distribution of these species in European forests is incomplete and scattered across various datasets. This study aims to perform an inventory of the most frequent non-native tree species growing in European forests and analyse their current extent, geographic distribution and geographic origin. Our results show that at least 150 non-native tree species are currently growing in European forests and provenance trials. The genera represented by largest number of species are Eucalyptus, Pinus, Acacia and Abies. Species growing at the largest areas are Robinia pseudoacacia (2.44 million ha), Eucalyptus globulus (1.46 million ha), Picea sitchensis (1.16 million ha) and Pseudotsuga menziesii (0.83 million ha). In total, non-native tree species in Europe are found in an area of approximately 8.54 million ha, or 4.0% of the European forest area, and the five most abundant species account for up to 77% of this area. The largest number of these 150 species were introduced from North America (71), followed by Asia (45) and Australia (20). North American species occupy by far the largest area
North American Douglas-fir (P. menziesii) in Europe: establishment and reproduction within new geographic space without consequences for its genetic diversity
No full textGenetic admixture and plasticity along with propagule pressure, large seed dispersal distances and fast adaptation support successful establishment and spread of introduced species outside their native range. Consequently, introductions may display climatic niche shifts in the introduced range. Douglas-fir, a controversial forest and ornamental conifer represented by two ecologically different and hybridising varieties, was transferred multiple times outside the native range in North America. Here, we compare climatic and genetic patterns of 38 native populations from North America with six old Pseudotsuga menziesii populations with natural regeneration in the introduced range in Central Europe. Following variety and geographic origin assessment of introduced populations, genotypic and climatic data were examined for signatures of inter-varietal gene flow, reduced genetic diversity, presence of fine-scale spatial genetic structure (SGS), dispersal patterns, and climate similarities between native and introduced range. In the introduced range, dominating coastal variety originated from a restricted area in the US, whereas the interior variety, with limited presence in the European sites, displayed wider geographic origin. Variety hybrids with contributing coastal, but not the interior parent were identified. Differences in genetic diversity between both ranges, but also among the parent and their respective offspring populations in Europe were not found. Old populations in general lacked any SGS, whereas natural regeneration revealed different patterns of SGS. Distances of propagule dispersal ranged between 2.5 and 92 m. The climate of the studied European introduced range was most similar to the climate of the coastal variety from the western Cascade range from which the majority of the analysed coastal European Douglas-fir, but not the European interior variety, was assigned to originate. The results we present here shed not only light on dynamics of invasive species in the introduced range in general, but also allow for refinement of climatic niche modeling when using lower than species level
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