Aqueous extracts of 30 plants were investigated for their antioxidant properties using DPPH and ABTS radical scavenging capacity assay, oxygen radical absorbance capacity (ORAC) assay, superoxide ...dismutase (SOD) assay, and ferric reducing antioxidant potential (FRAP) assay. Total phenolic content was also determined by the Folin−Ciocalteu method. Antioxidant properties and total phenolic content differed significantly among selected plants. It was found that oak (Quercus robur), pine (Pinus maritima), and cinnamon (Cinnamomum zeylanicum) aqueous extracts possessed the highest antioxidant capacities in most of the methods used, and thus could be potential rich sources of natural antioxidants. These extracts presented the highest phenolic content (300−400 mg GAE/g). Mate (Ilex paraguariensis) and clove (Eugenia caryophyllus clovis) aqueous extracts also showed strong antioxidant properties and a high phenolic content (about 200 mg GAE/g). A significant relationship between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants.
The Sentinel-2 program provides the opportunity to monitor terrestrial ecosystems with a high temporal and spectral resolution. In this study, a multi-temporal Sentinel-2 data set was used to ...classify common tree species over a mature forest in central Sweden. The tree species to be classified were Norway spruce (Picea abies), Scots pine (Pinus silvestris), Hybrid larch (Larix × marschlinsii), Birch (Betula sp.) and Pedunculate oak (Quercus robur). Four Sentinel-2 images from spring (7 April and 27 May), summer (9 July) and fall (19 October) of 2017 were used along with the Random Forest (RF) classifier. A variable selection approach was implemented to find fewer and uncorrelated bands resulting in the best model for tree species identification. The final model resulting in the highest overall accuracy (88.2%) came from using all bands from the four image dates. The single image that gave the most accurate classification result (80.5%) was the late spring image (27 May); the 27 May image was always included in subsequent image combinations that gave the highest overall accuracy. The five tree species were classified with a user’s accuracy ranging from 70.9% to 95.6%. Thirteen of the 40 bands were selected in a variable selection procedure and resulted in a model with only slightly lower accuracy (86.3%) than that using all bands. Among the highest ranked bands were the red edge bands 2 and 3 as well as the narrow NIR (near-infrared) band 8a, all from the 27 May image, and SWIR (short-wave infrared) bands from all four image dates. This study shows that the red-edge bands and SWIR bands from Sentinel-2 are of importance, and confirms that spring and/or fall images capturing phenological differences between the species are most useful to tree species classification.
The Quercus robur 'Fastigiata' is an important ornamental plant, in which the complete chloroplast genome (accession no. MN562095) was identified and sequenced. The genome size is 161,172 bp, with a ...large single-copy (LSC, 90,505 bp) region, a small single-copy (SSC, 18,997 bp) region, and two inverted repeat regions (IRs, 25,835 bp each). A total of 134 genes are successfully annotated, including 89 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic relationships inferred that Q. robur 'Fastigiata' is closely related to Quercus mongolica, Quercus wutaishanica, and Quercus dentata.
•Oil yield in the oak acorns of Q. rubra reached 20.1–24.0% vs 3.1–6.3% in Q. robur.•Q. rubra and Q. robur acorn oils are rich in oleic and linoleic acids.•The β and γ-tocopherol are predominated ...forms in Q. rubra and Q. robur, respectively.•β-Sitosterol constituted over 60% of total phytosterols in acorn oil of both species.•PCA analysis may help to distinguish the acorn oils recovered from different species.
The acorns (fruits) of the oak species Quercus rubra L. and Quercus robur L., grown over the world mainly in forests and parks, are usually not collected or utilised, therefore represent a potentially cheap/free source of plant material with potential applications in the processing industry. In the present study, oil recovery and composition from acorns collected from Q. rubra (n=6) and Q. robur (n=7) individuals was evaluated. Oil yields from Q. robur and Q. rubra acorns ranged from 3.1 to 6.3% and 20.1–24.0%, respectively. In the oils of both species C18:1 (28.4–65.7%), C18:2 (24.1–48.0%) and C16:0 (7.5–17.9%) were the main fatty acids with some differences in proportions between species. On average, β-sitosterol constituted 64.3% and 68.1% of total sterol concentration, which amounted to 244.9 and 271.4mg/100g oil in Q. robur and Q. rubra, respectively. Q. rubra acorn oil was rich in β-tocopherol (93%), while Q. robur in γ-tocopherol (96%). A nearly six-fold higher level of total tocopherol content was recorded for Q. robur relative to Q. rubra. Principal component analysis of chemical composition data confirmed their ability to distinguish between Q. robur and Q. rubra samples. The unique and high concentration of lipophilic compounds in both species, and the availability (cheap/free) of acorns, make oak fruits an interesting source of plant material for industrial applications.
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•We compare 13 Tree Carbon estimation methods for 5 major Tree species in Europe.•We apply the methods on a consistent dataset to avoid biases due to input data.•Variation is large ...both for whole Europe as well as for European forest regions.•Possible reasons are Sample material, Biomass definition or Input variables.•These are important findings for reliable carbon stocks in Europe and worldwide.
National and international carbon reporting systems require information on carbon stocks of forests. For this purpose, terrestrial assessment systems such as forest inventory data in combination with carbon estimation methods are often used. In this study we analyze and compare terrestrial carbon estimation methods from 12 European countries. The country-specific methods are applied to five European tree species (Fagus sylvatica L., Quercus robur L., Betula pendula Roth, Picea abies (L.) Karst. and Pinus sylvestris L.), using a standardized theoretically-generated tree dataset. We avoid any bias due to data collection and/or sample design by using this approach. We are then able to demonstrate the conceptual differences in the resulting carbon estimates with regard to the applied country-specific method. In our study we analyze (i) allometric biomass functions, (ii) biomass expansion factors in combination with volume functions and (iii) a combination of both. The results of the analysis show discrepancies in the resulting estimates for total tree carbon and for single tree compartments across the countries analyzed of up to 140tcarbon/ha. After grouping the country-specific approaches by European Forest regions, the deviation within the results in each region is smaller but still remains. This indicates that part of the observed differences can be attributed to varying growing conditions and tree properties throughout Europe. However, the large remaining error is caused by differences in the conceptual approach, different tree allometry, the sample material used for developing the biomass estimation models and the definition of the tree compartments. These issues are currently not addressed and require consideration for reliable and consistent carbon estimates throughout Europe.
•We carried out vegetation studies in the ancient oak forest Hasbruch in Germany.•We analysed drivers of changes in vascular plant species richness.•We analysed the effect of management and ...vegetation type on these changes.•The main drivers for changes in species richness were light and water availability.•Effects of the drivers strongly depended on the vegetation type.
We carried out vegetation studies in the ancient Hasbruch forest, which provided the unique conditions of unmanaged (UM) and managed (M) stands in two vegetation types Stellario-Carpinetum loniceretosum (POOR) and stachyetosum (RICH) stands in one closed forest allowing us to study (1) the changes in species composition and richness over 20 years considering the entire forest as well as (2) group-specific changes.
Hasbruch forest in the lowlands of Lower Saxony, Germany.
In 2016 we resurveyed the vascular plant species composition of 79 semi-permanent plots analysed in 1996. General and group-specific trends as well as drivers of changes were analysed using DCA, PCA, LM, t-test, U test, ANOVA.
Tree and shrub layer coverage increased significantly in the entire forest. Herb layer species richness decreased significantly only in group RICH_UM. While the pH-value increased significantly in group POOR, it decreased significantly in group B. EIV F increased significantly in group POOR_M and decreased significantly in group RICH_UM. EIV L increased significantly in both of the managed groups, while it decreased significantly in group RICH_UM. An increase was found for EIV N in group POOR_M, whereas a decrease was found in group RICH_M. Strongly increasing species were Ilex aquifolium, Rubus fruticosus agg. and Hedera helix; strongly decreasing species Geum urbanum and Primula elatior. The change in species richness was positively affected by ΔpH and negatively affected by ΔT1cov in the entire forest.
The main drivers for changes in species richness and composition in the Hasbruch forest were light and water availability. The effects of the drivers strongly depended on the vegetation type. Changes in species composition were more pronounced in nutrient-rich forests than on nutrient-poor sites. In nutrient-rich forests, decreased groundwater influence led to decreased soil pH which especially affected typical woodland plants in a negative way. Management positively affected light-demanding species as well as some N-demanding species. Thus, unmanaged, nutrient-rich stands displayed the highest losses in species diversity. In the nutrient-poor stands, changes in species composition were not significantly related to changes in soil and management. However, increasing pH as well as increased Ellenberg L, F, and N values suggest a tendency towards eutrophication. This is possibly a consequence of N deposition and recovery from soil acidification.
•Aboveground biomass, carbon and nutrients were quantified in pedunculate oak.•Six harvesting methods were simulated in an average oak stand at rotation age.•Harvesting oak can remove a specific ...nutrient further than other fast-growing species.•Differences in nutrient extraction depend on the species, nutrient and harvesting method considered.
In northern Spain, the use of biomass to produce bioenergy has led to increased exploitation of both natural pedunculate oak (Quercus robur L.) stands and fast-growing plantations of natural or exotic species. In this study, we developed a model for estimating aboveground biomass, carbon and nutrient contents in different pedunculate oak components at individual-tree and at stand level. Six harvesting methods were simulated in an average stand, ranging from whole-tree to stem wood extraction (stem without bark) and including the conventional harvesting method used in the region (extraction of stem plus branches of diameter >7cm). The biomass and macronutrients extracted were compared with those removed during harvesting of fast-growing tree species (Eucalyptus globulus Labill., Pinus radiata D. Don and Pinus pinaster Ait.) on the same temporal basis (mean annual values). Harvesting pedunculate oak stands generally extracted lower amounts of nutrients than harvesting fast-growing species, although the differences depended on the species, macronutrients and harvesting regime considered.
Glycosyltransferase gene family 1, also known as uridine diphosphate glycosyltransferase (UGT), is the largest glycosyltransferase family in plants, playing a vital role in their growth and ...development. In this study, 244
UGT
genes with conserved PSPG motifs were identified in the genome of
Quercus robur
L. The collinearity analysis results showed that tandem repeat was the main way of
UGT
genes expansion in
Q. robur
, with 21 groups of 55 tandem repeat genes.
UGT
genes were divided into 15 subgroups A–P; group K was lost, and the gene structure and conserved domain of the same subgroup were basically the same. Cis-element analysis showed that upstream 2,000 bp promoter sequence of
UGT
genes contained light response elements, plant hormone response elements, and stress-related cis-elements, which indicated that
UGT
genes of
Q. robur
might be regulated by various metabolic pathways. In particular, some
UGT
s in group L of
Q. robur
contained a conserved promoter structure. The expression pattern analysis results demonstrated that
UGT
genes of groups B, D, E, and I were differentially expressed under
Tortrix viridana
L. stress. The expression of
UGT
s in group E decreased under stress, the expression of group L increased, and that of genes in groups D and B were different. The functions of
UGT
genes in E and L groups are relatively conservative, and their functions may also conserve among species. The study results have a particular reference value for further research on the function of
Q. robur UGT
genes.
Trees concentrate rainfall to near-stem soils via stemflow. When canopy structures are organized appropriately, stemflow can even induce preferential flow through soils, transporting nutrients to ...biogeochemically active areas. Bark structure significantly affects stemflow, yet bark-stemflow studies are primarily qualitative. We used a LaserBark to compute bark microrelief (MR), ridge-to-furrow amplitude (R) and slope (S) metrics per American Society of Mechanical Engineering standards (ASME-B46.1-2009) for two morphologically contrasting species (Fagus sylvatica L. (European beech), Quercus robur L. (pendunculate oak)) under storm conditions with strong bark water storage capacity (BWSC) influence in central Germany. Smaller R and S for F. sylvatica significantly lowered BWSC, which strongly and inversely correlated to maximum funnelling ratios and permitted stemflow generation at lower rain magnitudes. Larger R and S values in Q. robur reduced funnelling, diminishing stemflow drainage for larger storms. Quercus robur funnelling and stemflow was more reliant on intermediate rain intensities and intermittency to maintain bark channel-dependent drainage pathways. Shelter provided by Q. robur's ridged bark also appears to protect entrained water, lengthening mean intrastorm dry periods necessary to affect stemflow. Storm conditions where BWSC plays a major role in stemflow accounted for much of 2013's rainfall at the nearest meteorological station (Wulferstedt).
Editor M.C. Acreman; Associate editor not assigned
Masting—temporally variable seed production with high spatial synchrony—is a pervasive strategy in wind‐pollinated trees that is hypothesized to be vulnerable to climate change due to its correlation ...with variability in abiotic conditions. Recent work suggests that aging may also have strong effects on seed production patterns of trees, but this potential confounding factor has not been considered in previous times series analysis of climate change effects. Using a 54 year dataset for seven dominant species in 17 forests across Poland, we used the proportion of seed‐producing trees (PST) to contrast the predictions of the climate change and aging hypotheses in Abies alba, Fagus sylvatica, Larix decidua, Picea abies, Pinus sylvestris, Quercus petraea, and Quercus robur. Our results show that in all species, PST increased over time and that this change correlated most strongly with stand age, while the standardized precipitation–evapotranspiration index, a measure of drought, contributed to temporal trends in PST of F. sylvatica and Q. robur. Temporal variability of PST also increased over time in all species except P. sylvestris, while trends in temporal autocorrelation and among‐stand synchrony reflect species‐specific masting strategies. Our results suggest a pivotal role of plant ontogeny in driving not only the extent but also variability and synchrony of reproduction in temperate forest trees. In a time of increasing forest regrowth in Europe, we therefore call for increased attention to demographic effects such as aging on plant reproductive behavior, particularly in studies examining global change effects using long‐term time series data.
Using 54 years of data for seven common temperate forest trees in Poland, we investigated how climate change and aging may affect temporal trends in mast‐seeding, measured by the change in extent, variability, autocorrelation, and synchrony of the proportion of seed‐producing trees (PST) over time. Contrary to expectations, changing climatic conditions only had a minor effect on temporal trends, while stand age was the dominant driver. Such demographic effects have previously been ignored but may play a major role in driving temporal changes of tree reproduction over time.
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