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Povzetek: The southern Baltic region spans a significant part of the European continent with its forests under significant pressure due to climate changes. The implications of these changes are crucial for both native and non-native tree species. Under future climate scenarios, most native conifer populations might lose their climatic optima in the region. In contrast, for non-native Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), climatic conditions are expected to become optimal in the Baltic Sea region. Therefore, understanding the acclimatisation trajectory of Douglas-fir over the last century is essential to assess its potential to supplement retreating species and reduce pressure on local habitats. To study the region-wide acclimatisation in the secondary distribution, we established a network of 27 Douglas-fir tree-ring chronologies along the south Baltic Sea. We determined the spatio-temporal stability of the climate signal in tree rings and the potential coastal effect on the plasticity of the growth response. We found a region-wide trend of climate-growth relationships, with a dominant effect of the early-growth season temperatures being more pronounced for mature than young stands. Sites with higher mean annual temperatures exhibit a stronger positive temperature–growth correlation, demonstrating the sensitivity of Douglas-fir to climate warming. Douglas-fir could serve as a more heat-tolerant alternative to the declining European species of the Pinaceae family and contribute to the preservation of functionally comparable coniferous forest communities. However, forest practitioners should be aware that Douglas-fir may alter habitat conditions affecting microclimate and influencing species diversity.
Ključne besede: climate warming, climate–growth relationships, dendroecology, Europe, tree growth
Objavljeno v DiRROS: 09.07.2025; Ogledov: 492; Prenosov: 388
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Povzetek: Climate change is modifying precipitation distribution and increasing drought events frequency, leading to decline in many stands. Pinus nigra was introduced to Poland in the 19th century as a measure to mitigate negative effects of soil pollution. This species is also known to be well adapted to drought conditions. However, its response to drought on different soil conditions remains unclear. The aim is to investigate the growth relation of P. nigra to drought and its resilience under the same climatic conditions but different soil types (fertile and poor soils) in central Poland. Two mature stands of P. nigra were selected, one on fertile soil and one on poor soil. Tree-ring data were collected and analysed to assess growth pat­terns and climate sensitivity. Resilience indices were calculated for seven common drought years, i.e. 1940, 1954, 1963, 1976, 2003, 2006 and 2015, to compare the impact of soil conditions on drought response. The study found similar climate-growth correlations for both soil types, with March temperatures and summer precipitation positively affecting growth, highlighting the significant influence of local climatic conditions on growth. However, resilience to drought varied between poor and fertile soil, with opposite trends ob­served in the drought year 1976 (characterized by dry June, wet July and dry August) and in the drought years 1963 and 2006 (characterized by wet June and dry July and August). With a higher resilience for the trees on poor soil in 1976 and a higher resilience on fertile soil in 1963 and 2006. Moreover, differences were not consistently observed: only 3 of the 7 years were significantly different. The study indicates that soil conditions partially influence the resilience of P. nigra to drought, but the relationship seems drought episode-dependent. Relationships between soil fertility and climate-growth dependencies are complex, and to draw more robust conclusions, further studies are needed, incorporating additional soil types.
Ključne besede: resilience, drought, water capacity, fertility, Poland
Objavljeno v DiRROS: 21.03.2025; Ogledov: 699; Prenosov: 444
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Povzetek: Non-native forest tree species have been introduced in Europe since the 16th century, but only in the second half of the 20th century the significance of the seed source origin for their economic use was recognized, resulting in the establishment of numerous provenance trials at a national, regional, European and International level, as those led by IUFRO. Breeding programs have also been launched in the continent for the most economically important species. Aim of this work is the formulation of provenance recommendations for planting of five non-native tree species in Europe (Douglas fir, grand fir, Sitka spruce, lodgepole pine and black locust), based on the information obtained from twenty countries, in the frame of the EU FP-1403 NNEXT Cost Action. The survey revealed that official and non-official national recommendations, based on provenance research results, have been elaborated and followed at a different level and extend for the above five species, but only for Douglas fir recommendations exist in almost all the participating to the survey countries. The compilation of provenance recommendations across Europe for each species is presented in the current work. Besides the recommended introduced seed sources, European seed sources are also preferred for planting, due to ease of access and high availability of forest reproductive material. European breeding programs yielding genetic material of high productivity and quality constitute currently the seed source of choice for several species and countries. Consolidation of trial data obtained across countries will allow the joint analysis that is urgently needed to draw solid conclusions, and will facilitate the development of ‘Universal-Response-Functions’ for the species of interest, rendering possible the identification of the genetic material suitable for global change. New provenance trial series that will test seed sources from the entire climatic range of the species, established in sites falling within and outside the environmental envelopes of their natural ranges, are urgently needed to pinpoint and understand the species-specific climate constraints, as well as to correlate functional traits to the seed origin and the environmental conditions of the test sites, so that the selection of suitable forest reproductive material of non-native tree species in the face of climate change can be feasible.
Ključne besede: provenance recommendations, provenance testing, breeding programs, adaptation, exotic tree species, Douglas fir, Sitka spruce, grand fir, lodgepole pine, black locust
Objavljeno v DiRROS: 09.02.2022; Ogledov: 1906; Prenosov: 1642
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