In order to evaluate the content of betulin and betulinic acids in Birch barks originating from Western Carpathians, Transylvania (Romania) forests, in relation with the location of birch trees, it was recorded the geographic and vegetation conditions at the specific locations of each type of sample. Two groups of birch tree bark (totally 10 samples) were collected, from two regions, pasture surfaces where birch trees appeared spontaneously (samples 1 to 5) and another group from forests of combined trees, including mainly pine trees (samples 6 to 10). The identification and quantitation of betulin and betulinic acid were made by High Performance Liquid Chromatography with UV detection. In the first region it has been found mean concentrations of 126.85 ± 12.56 mg/g betulin bark while acid betulinic had average values of 12.78 ± 1.26 mg/g bark. In the second region we found mean concentrations of 89.84 ± 8.43 mg/g betulin of bark while acid betulinic had average values of 10.60 ± 0.97 mg/g bark. Statistically, significant differences were noticed between the two regions, the first region being richer in these molecules. Generally, the percentage of betulinic acid was around 11.23% against betulin, higher in the second region, even the absolute concentrations were lower for both molecules. These data are useful indicators of the potential offered by birch bark sources found in Transylvania region, to obtain extracts enriched in betulin and betulinic acid.

The organic carbon stock (SOC) (t/ha) was calculated in different approaches in order to enhance the differences among methods and their utility regarding specific studies. Using data obtained in Romania (2000-2012) from 4,500 profiles and 9,523 soil horizons, the organic carbon stock was calculated for the main forest soils (18 types) using three different methods: 1) on pedogenetical horizons, by soil bulk density and depth class/horizon thickness; 2) by soil type and standard depths; 3) using regression equations between the quantity of organic C and harvesting depths. Even though the same data were used, the differences between the values of C stock obtained from the three methods were relatively high. The first method led to an overvaluation of the C stock. The differences between methods 1 and 2 were high (and reached 33% for andosol), while the differences between methods 2 and 3 were smaller (a maximum of 23% for rendzic leptosol). The differences between methods 2 and 3 were significantly lower especially for andosol, arenosol and vertisol. A thorough analysis of all three methods concluded that the best method to evaluate the organic C stock was to distribute the obtained values on the following standard depths: 0 - 10 cm; 10 - 20 cm; 20 - 40 cm; > 40 cm. For each soil type, a correlation between the quantity of organic C and the sample harvesting depth was also established. These correlations were significant for all types of soil; however, lower correlation coefficients were registered for rendzic leptosol, haplic podzol and fluvisol.

Black locust (Robinia pseudoacacia) is recognised as a forest species of interest due to its multiple uses. The management of forest genetic resources and their efficient conservation suffer from variations in traits and start with seed germination. The aim of the current study was to investigate the germination of seeds obtained from plus trees selected in eight Romanian provenances, as well as to investigate the influence of the origin upon plants’ growth and development. Two experiments were undertaken to test seed germination: one treatment involved water-soaked seeds and heat/cold treatment, while the other treatment was based on sulphuric acid, at different concentrations (50, 70, 90%). The results were correlated with the morphological analysis of the seeds. Satu-Mare had the lowest germination rate within both treatments. Sulphuric acid did not improve seed germination as much as the heat treatment. The highest germination rate occurred for the water and temperature treatment on seeds from Bihor provenance (68.2%). The most distant provenance was Bihor, in inverse correlation with Bistrița Năsăud and grouped separately within the hierarchical dendrogram of cluster analysis based on the analysed parameters of the provenances investigated. The results demonstrated that the genotypes and environmental heterogeneity of the seed origin within the provenances may finally result in different performances.

Black locust (Robinia pseudoacacia L.) was among the first North-American tree species imported in Europe. In Romania, black locust has established itself as a forest tree appreciated for multiple uses. The objective of the hereby study was to identify a quality planting material at black locust using seeds from trees with superior traits from five stands geographically close, located in North-western of Romania. An empirical selection was done, thus trees with the most favourable traits were selected as plus trees. Among the averages of the main traits (tree height, diameter at breast height, basal area, self pruning trunk length, crown diameter) of the plus trees from the five stands, there were registered significant differences, and two stands stood out with a high biomass growth. Even if the stands had different ages (between 20-35 year), the age did not influence significantly the growth traits of the trees. The seeds of the plus trees (open-pollinated) from all the stands had large size (mean seed weight of 0.057 g/seed). The seedling emergence rate was high, especially in the solarium condition (between 52.7-73.7% compared with 33.0-41.3% in the field). Coefficient of genetic correlation and heritability calculated for the seedlings belongings to half-sib families highlighted that black locust breeding can be extremely effective by a proper selection.

Hippophae salicifolia is an Euro-Asian species used in many industries, from medicine to cosmetics, nutrition, or soil sciences (enriching degraded fields, diminishing soil erosion, preventing and treating diseases). The purpose of this study was to analyse the culture of this species in Europe together with the chemical content of its fruits. In order to achieve this, Hippophae salicifolia seeds were sown in greenhouses, seedlings were planted in fields, while the fruits were harvested and analysed both fresh, as well as after preservation for 1 year and 5 months. The properties of H. salicifolia fruits were also compared with the fruits of Hippophae rhamnoides, both fresh and preserved for 7 months. The analysis have shown that fresh fruits contain an average quantity of 31; 811 and 231 mg/100 total carotenoid, polyphenol, and ascorbic acid, respectively. The vitamin C content was much higher than that observed for H. rhamonides. If kept in adequate conditions, H. salicifolia fruits lose only a small amount of vitamin C and exhibit a vitamin C content (224 mg/100g) superior to the fresh fruit of H. rhamonides (100-150 mg/100 g). By comparing the chemical characteristics of H. salicifolia and H. rhamnoides fruits preserved over a long period of time, a higher concentration of vitamin C was observed in H. salicifolia, while the differences between the other chemical characteristics were insignificant. The obtained results strongly suggest that H. salicifolia can be successfully cultured in Europe, while its exceptional fruit qualities can be capitalised on by a variety of industries.