Secondary metabolites refer to small molecules that are non-essential for the growth and reproduction of plants, but have a wide range of effects on the plant itself and other living organisms. On the other hand, the plants’ secondary metabolites and other bioactive compounds can be attributed to the changing conditions as a response to various types of environmental stresses which affect their production. Wild fruit fields could be affected by not meeting winter chilling requirements, which is specific for every fruit species. Extreme environmental conditions due to climate change or variability are a threat to wild-growing species, crop production, productivity, and livelihood. Wild fruits are underutilized plants that are well adapted to the local climatic conditions.
Nowadays, the greatest threat to silver fir is undoubtedly the browsing pressure by ungulates which can jeopardize its regeneration and must therefore be properly regulated to increase the proportion of silver fir in Swiss mixed forests. In addition, dendroecological studies have shown a higher resistance and resilience of silver fir to drought compared to Norway spruce, suggesting that silver fir could be promoted by foresters. This literature survey shows that this species could actually grow under warmer conditions provided that precipitation remains sufficient, which seems to be the case for most regions of Switzerland according to climatic model predictions for the end of the century.
On the other hand, paleoecological studies reveal that this species was widely distributed under much warmer and probably drier climate, suggesting a high potential to face future climate warming. On the one hand, species distribution models predict a strong decline of its climatic niche in the future. While it is clear that some tree species will increasingly suffer from climate warming, the fate of silver fir (Abies alba Mill.) remains very uncertain because contradictory results have been published about the suitability of this species to cope with climate warming. What future for silver fir in Switzerland under ongoing climate change?įoresters in many countries are currently seeking for the most suitable forest species or provenances for facing the future climate, which will be much warmer than today with more extreme summer droughts. The quick canopy closure of young regeneration results in an appropriate dune fixation and wind erosion control. This intervention is from below, heavy (intensity over 25% by number of trees or basal area) and of negative selection type, removing mostly low Kraft’s class, dead or dying, and defective trees.Ĭonclusions: This R&D project has shown the high potential of black locust to establish naturally by root suckers after a low coppice cut and stump removal, as well as the fast initial growth of regenerated black locust. ha-1 (2) The initial growth of black locust regeneration is quick and the young regeneration can close the canopy in 1-2 years, resulting in an appropriate dune fixation and wind erosion control (3) The young pure or mixed black locust-dominated stands are left untended until the first cleaning-respacing (mean diameter 5-6 cm), when the stand shows high stocking/density and a wide variation in tree size.
Results: The main outputs of the project are as follows: (1) Black locust was established naturally by root suckers and the stocking of newly established stands can be as high as 50,000 suckers A thorough statistical analysis using the data on initial, extracted and residual trees/stands was also performed. Biometrical measurements and analyses as well as biomass estimations were performed. Materials and Methods: Three sub-compartments were selected in IV Valea lui Mihai Working Circle, Săcueni Forest District: two pure natural regenerations by root suckers of black locust at different ages (sub-compartments 3B and 52A%) and a mixed black locust - black cherry stand (sub-compartment 23D). In this respect, a Research and Development (R&D) project has been carried out in Carei-Valea lui Mihai Plain (north-west of Romania) since 2016. Background and Purpose: The aim of this study is to highlight the importance of black locust (Robinia pseudoacacia L.), a North American-originating tree species of major importance in Romania, in extreme site conditions such as sand dunes.
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