A Nutritional Comparison Study of Three Oaks Species Grown in Gara Mountains

The preferred livelihood assets for meat and nutritious milk in thousands villages of Kurdistan rejoin/Iraq are sheep and goats. They generally rely on free roaming in rangeland during the growing seasons. In order to maintain their livestock during the scarcity of forages at winter seasons, the leaves and twigs of (Quercus aegilops, Q. infectoria and Q. libani) are harvested and dried as (dry leaf faggots) at autumn season to use as major substitute of feed. This study was conducted to evaluate the nutritional values of those three oaks species’ leaves at the same time of collecting period. Gara Mountains were chosen due to the wide presence of all three species. Leaves samples were collected at late September 2015 at elevation about 1250 MASL. The results have shown differences in chemical composition. Q. libani recorded higher content of dry matter (DM), ash and crude protein (CP), and lower content of crud fiber (CF). Higher content of ether extract (EE) was recorded in both Q. aegilops and Q. libani. The higher content of nitrogen free extract (NFE) and potassium (K) were recorded in Q. infectoria. While Q. aegilops recorded higher (CF) content. All Quercus species can be used as alternative feed substitute for small ruminant especially with some additives (such as salt, vitamin, and water), but more nutritive value was Q. libani then Q. infectoria followed by Q. aegilops. Therefore, the priority should be for Q. libani in foremost followed by Q. infectoria when dry leaves faggot were made.

Variations in Acorn Traits in Two Oak Species: Quercus mongolica Fisch. ex Ledeb. and Quercus variabilis Blume

Quercus mongolica Fisch. ex Ledeb. and Q. variabilis Blume are two main oak species in China, producing large amounts of acorns every year. However, the trait variations in acorns, as a promising energy crop material, are not fully understood, hence we compared the traits of acorns from the different populations with the altered geographic distribution in this study. Thirteen acorn traits, including phenotype, proximate compositions and functional compounds, were analyzed in both Quercus L. species collected from 44 populations across China. The results showed that, except large differences found among accessions in acorn sizes, the starch varied from 140.96–297.09 mg/g in Q. mongolica and 130.99–306.28 mg/g in Q. variabilis, indicating its substantial differences among populations. The total polyphenols, total flavonoids and soluble tannins varied from 41.76–158.92, 23.43–91.94, and 15.11–17.81 mg/g, respectively, in Q. mongolica, 89.36–188.37, 50.59–116.07, 15.24–17.33 mg/g, respectively, in Q. variabilis, demonstrating their large variations in the levels of polyphenols among populations. Moreover, the acorns of Q. mongolica in North China and Q. variabilis in Southwest China had higher levels of starch and polyphenols. As the geographical location approached in the distribution of two Quercus species, the difference in acorn sizes gradually increased, while that in polyphenols were opposite. Principal component analysis and cluster analysis further revealed that the acorn sizes became larger and polyphenols became less with the increasing latitudes in both species. In North China, the acorns of Q. mongolica had small sizes and high polyphenols, which was contrary to those in Q. variabilis. These findings indicated that acorn traits were closely associated with the geographical distribution. Thus, our results will provide references for the selection breeding of acorn with the high starch, high or low polyphenols in the different regions.

Climatic Rather than Edaphic Variables Determine Leaf C, N, P Stoichiometry of Deciduous Quercus Species

Purpose Leaf elemental stoichiometry is indicative of plant nutrient limitation, community composition, ecosystem function. Understanding the variations of leaf carbon (C), nitrogen (N), and phosphorus (P) stoichiometry at genus-level across large geographic regions and identifying their driving factors are important to predict species’ distribution range shifts affected by climate change.MethodsHere, we determined the patterns of leaf concentrations ([ ]) and ratios ( / ) of C, N, P of five deciduous oaks species (Quercus) across China covering ~ 20 latitude (~21–41˚ N) and longitude (~99–119˚ E) degrees, and detected their relationships with climatic, edaphic variables. ResultsLeaf [C], [N] and N/P, C/P significantly increased, while leaf [P] and C/N decreased with the increasing latitude. Leaf stoichiometry except for leaf [C] had no significant trends along the longitude. Climatic variables, i.e. mean annual temperature, mean annual precipitation, the maximum temperature of the warmest month, temperature seasonality, aridity index, and the potential evapo-transpiration were the determinants of the geographic patterns of leaf C, N, P stoichiometry. The mean annual precipitation and the maximum temperature of the warmest month indirectly regulated leaf C/N, C/P and N/P via altering leaf [P]. Edaphic variables had non-significant effects on leaf C, N, and P stoichiometry at the broad geographic range.ConclusionsClimatic variables have more important effects than edaphic properties on leaf C, N, P stoichiometry of the studied deciduous Quercus species, which imply the ongoing climate change will alter nutrient strategies and potentially shift the distribution range of this eurytopic species.

Use of sodium hydroxide DNA extraction methods for nested PCR detection of Bretziella fagacearum in the sapwood of oak species in Minnesota

Oak wilt caused by Bretziella fagacearum is an important disease of Quercus species, but its diagnosis may be confused with damage resulting from other diseases, insects, or abiotic factors. Laboratory diagnosis is important in such situations and when disease control action is desired. Polymerase chain reaction (PCR) tests can provide accurate lab diagnosis within two days. Two variations of a simple DNA extraction protocol using sodium hydroxide (NaOH) were compared to that of the proprietary protocol of a commercially available kit (CK) for nested PCR to detect the pathogen in oak sapwood. High frequencies of pathogen detection (98 to 100% of 48 branch segments assayed) were found for northern pin oak using the two NaOH-based and the CK methods. Detection rates were similar but lower for bur oak (ranged from 58 to 79%) and white oak (ranged from 54 to 71%) regardless of DNA extraction method. Using our alternative DNA extraction protocols may reduce total time and cost of B. fagacearum detection in PCR-based diagnosis and other downstream applications.

Conservation of forest genetic resources through the example of native Quercus species from the “Košutnjak” park forest in Serbia

Given the importance of urban park forests and protected natural areas in the urban environment, the implementation of the concept of genetic conservation is one of the main ways to save and improve this category of natural resources. Forests such as Košutnjak can be considered a refuge for flora and fauna and by establishing conservation programs for certain species, the entire ecosystem would be better protected. The purpose of this paper is to elaborate a systematic approach to in situ conservation of forest genetic resources in urban areas through the example of four native oak species: pedunculate oak, sessile oak, Hungarian oak and downy oak in the protected natural area “Košutnjak” in the capital of Serbia – Belgrade, to develop replicable conservation guidelines for urban park forests. The methodological framework for the development of guidelines for genetic conservation, presented in this paper, is a replicable model whose basic principles can be applied in other cases of urban park forests.

Climatic rather than edaphic variables determine leaf C, N, P stoichiometry of deciduous Quercus species

Purpose Leaf stoichiometry of carbon (C), nitrogen (N) and phosphorus (P) is indicative of plant nutrient limitation, community composition, ecosystem function. Understanding leaf stoichiometry patterns of C, N, P of eurytopic species at genus-level across large-scale geographic regions and identifying their driven factors are of great importance to assess and to predict species’ distribution range shifts affected by climate change. Methods Here, we determined the patterns of leaf C, N, P stoichiometry of five deciduous oaks species (Quercus) across China covering ~ 20 latitude (~ 21–41˚ N) and longitude (~ 99–119˚ E) degrees, and detected their relationships with climatic, edaphic variables. Results We found that the concentrations ([ ]) of leaf C, N and the ratios ( / ) of N: P, C: P significantly increased, while leaf [P] and C/N decreased with the increasing latitude. However, leaf stoichiometry had no significant trends along the longitudinal gradient with an exception of leaf [C] which decreased with increasing longitude. The climatic variables, i.e. mean annual temperature precipitation (MAP), the max temperature of the warmest month (Tmax), temperature seasonality (TS), aridity index (AI) were the determinants on the geographic patterns of leaf C, N, P stoichiometry. The studied deciduous Quercus species growing in warm and wet environments tended to increase leaf [C], [N], C/P, and N/P, but to decrease leaf [P] and C/N, which maybe their nutritional strategies to improve adaptability. Conclusion The adaptative mechanisms of leaf stoichiometry should be further studied to assess the fate of deciduous Quercus species affected by climate change.