关于内蒙古大兴安岭林区实施森林抚育补贴项目的探讨

文章通过对内蒙古大兴安岭林区实施森林抚育补贴项目的背景、必要性的分析,论述了森林抚育是促进林区生态、经济和社会协调发展的有力措施。     

Nutrient accumulation and role of atmospheric deposition in coniferous stands

Three stand types on drained wetlands, all 31 years old, were studied. The stands were: (1) Scots pine, unfertilized; (2) Scots pine, fertilized; and (3) Norway spruce, fertilized. Amounts of nutrients (N, K, Ca, Mg, P, S, B, Fe, Mn, Zn, Cu) in above-ground biomass for all three stand types could be simulated precisely by a curvilinear regression model, with stand volume on bark as regressor. Net H⁺ production of the fertilized pine was estimated to be 661 mol H⁺ ha⁻¹ year⁻¹ from establishment to 31 years of age. The corresponding value for spruce was 1232 mol H⁺ ha⁻¹ year⁻¹. Atmospheric inputs to the pine and spruce sites were 695 and 516 mol H⁺ ha⁻¹ year⁻¹, respectively. Atmospheric input of N was 2.3 and 1.3 times the accumulation in the biomass of unfertilized and fertilized pine, whereas the value for spruce was 0.7. The corresponding ratios for S were 43, 19, and 11.     

Anthocyanins, phenolics, and antioxidant capacity in diverse small fruits: vaccinium, rubus, and ribes.

Fruits from 107 genotypes of Vaccinium L., Rubus L., and Ribes L., were analyzed for total anthocyanins (ACY), total phenolics (TPH), and antioxidant capacities as determined by oxygen radical absorbing capacity (ORAC) and ferric reducing antioxidant power (FRAP). Fruit size was highly correlated (r = 0.84) with ACY within Vaccinium corymbosum L., but was not correlated to ACY across eight other Vaccinium species, or within 27 blackberry hybrids. Certain Vaccinium and Ribes fruits with pigmented flesh were lower in ACY, TPH, ORAC, and FRAP compared to those values in berries with nonpigmented flesh. ORAC values ranged from 19 to 131 micromol Trolox equivalents/g in Vaccinium, from 13 to 146 in Rubus, and from 17 to 116 in Ribes. Though ACY may indicate TPH, the range observed in ACY/TPH ratios precludes prediction of ACY from TPH and vice versa for a single genotype. In general, TPH was more highly correlated to antioxidant capacity than ACY was. This study demonstrates the wide diversity of phytochemical levels and antioxidant capacities within and across three genera of small fruit.     

Comparison of anthocyanin pigment and other phenolic compounds of Vaccinium membranaceum and Vaccinium ovatum native to the Pacific Northwest of North America

Two huckleberry species, Vaccinium membranaceum and Vaccinium ovatum, native to Pacific Northwestern North America, were evaluated for their total, and individual, anthocyanin and polyphenolic compositions. Vaccinium ovatum had greater total anthocyanin (ACY), total phenolics (TP), oxygen radical absorbing capacity (ORAC), and ferric reducing antioxidant potential (FRAP) than did V. membranaceum. The pH and degrees Brix were also higher in V. ovatum. Berry extracts from each species were separated into three different fractions--anthocyanin, polyphenolic, and sugar/acid-by solid-phase extraction. The anthocyanin fractions of each species had the highest amount of ACY, TP, and antioxidant activity. Each species contained 15 anthocyanins (galactoside, glucoside, and arabinoside of delphinidin, cyanidin, petunidin, peonidin, and malvidin) but in different proportions. Their anthocyanin profiles were similar by high-performance liquid chromatography with photodiode array detection (LC-DAD) and high-performance liquid chromatography with photodiode array and mass spectrometry detections (LC-DAD-MS). Each species had a different polyphenolic profile. The polyphenolics of both species were mainly composed of cinnamic acid derivatives and flavonol glycosides. The major polyphenolic compound in V. membranaceum was neochlorogenic acid, and in V. ovatum, chlorogenic acid.     

Leaching of soil organic carbon and nitrogen in sandy soils after cultivating grass-clover swards

Several studies have focused on the formation and losses of dissolved organic matter in forest systems, whereas a limited number have dealt with this aspect in agricultural soils. The purpose of this study was to estimate the leaching of dissolved organic carbon (DOC) and nitrogen (DON), with focus on the period after cultivating grass-clover swards. Grass-clovers were ploughed in the spring prior to sowing cereals followed by either catch crops or bare soil. The concentrations of DOC and DON decreased with soil depth and ranged at 90-cm soil depth between 7 and 21 mg C L⁻¹ and between 1 and 3 mg N L⁻¹, respectively, in a sandy loam soil, and between 16 and 63 mg C L⁻¹ and between 1 and 10 mg N L⁻¹, respectively, in a coarse sandy soil. The resulting DOC/DON ratios were in the range between 2 and 42, with higher values in the coarse sandy soil than in the sandy loam soil. The total percolation was 218 mm in the sandy loam soil and 596–645 mm in the coarse sandy soil, which resulted in an annual leaching of 22–40 kg DOC ha⁻¹ year⁻¹ and 3–4 kg DON ha⁻¹ year⁻¹ in the sandy loam soil, and 174–310 kg DOC ha⁻¹ year⁻¹ and 10–31 kg DON ha⁻¹ year⁻¹ in the coarse sandy soil. It was shown that higher amounts of DOC were lost by leaching under the catch crops than from bare soil, that losses of DON were higher from bare soil than from soils with catch crops and that DON contributed significantly to the total N loss. Thus, DON needs to be taken into account in N-balance calculations.     

Consumption of fruit, vegetables, sweets and soft drinks are associated with psychological dimensions of eating behaviour in parents and their 12-year-old children

OBJECTIVE: We investigated associations between consumption of fruits, vegetables, sweets and soft drinks and the psychological dimensions of eating in parents and their children. The role of the parent's characteristics for their children's food intake was also explored. DESIGN: Food intake patterns were assessed by self-reported consumption of the respective foods. Eating behaviour was measured by the Dutch Eating Behaviour Questionnaire and self-esteem by Harter self-perception scale. The participants were 1441 families (mother, father and their 12-year-old child), and additionally 354 mothers and thirty fathers. RESULTS: Among parents, reported intake of fruit and vegetables were associated with restrained eating, higher self-esteem, and higher education and age. Intake of sweets was related to more external and less restrained eating, and for mothers also emotional eating. Parent's intake of soft drink was foremost related to a younger age, and also weakly associated with psychological characteristics. The food intake of parents was more important for the children's food intake than any other characteristics. However, children's intake of sweets showed clear-cut positive associations with external eating. CONCLUSIONS: Psychological dimensions of eating behaviour are associated with patterns of food intake, in particular for consumption of sweets, and are most prominent in the parents. The children's food intake mirrored their parents' intake. Being sensitive to external food cues may increase unhealthy food consumption in our society, whereas more restrained eating may indicate proneness or intention to healthier food choices among parents. Emotional eating may imply a proneness to consume sweets for comfort, in particular among mothers.     

Performance of an elite,hybrid family of a northern × southern highbush cross (‘Draper’ × ‘Jewel’)

A family of the cross of the northern highbush blueberry ‘Draper’?×?the southern highbush ‘Jewel’ (D?×?J) was propagated and phenotyped for plant size, yield, rate of flower, bud, and fruit development, leafing ability, winter hardiness, and fruit quality for 2 years in the field in Florida (FL), Georgia (GA), Michigan (MI), and Oregon (OR). In addition, a controlled greenhouse study was conducted on these progenies to estimate their chilling requirements. Significant levels of genotypic variability were observed for all the traits and the majority showed significant location and genotype?×?environmental interactions. Most of these traits were normally distributed across genotypes. There were many more flower buds per cane in GA than FL and OR, and many more vegetative buds broke in OR than in the southeastern states. Most of the various yield and growth traits were significantly correlated, except for flower buds per cane with plant height and width, and strength of leafing with plant width and flower buds/cane. Plants in OR developed much more slowly than those in FL and GA. There was a significant G?×?E effect on days to early green tip, floral bud break, and full bloom. Significant correlations were observed between all the developmental rates except between floral bud break and the days to full flowering and first blue fruit. Most individuals were severely damaged by winter cold in MI, although a few showed good tolerance. Significant location effects were observed for pH, titratable acidity (TA), soluble solids (SS), and SS/TA. Fruit in FL were a little softer and had higher SS/TA ratios than those in GA. There were significant interactions between genotype and environment for all the fruit quality traits except for fruit scar, firmness, anthocyanin content (ACY), and % juice. Fruit scar had a significant positive relationship with firmness and a significant negative relationship with flavor. Fruit color was significantly associated positively with soluble solids and ACY. Firmer fruit had significantly lower levels of ACYs. Fruit pH showed significant positive correlations with TA, TA/SS, and % juice, and significant negative relationship with SS and ACY. TA was significantly associated negatively with TA/SS and positively with ACY and % juice. TA/SS and ACY were positively correlated significantly with % juice. Two or three individuals were identified at each location that had high yields, were very early or late ripening and had excellent overall fruit quality. There were significant levels of genotypic, environmental (chilling hours) and G?×?E interaction among vegetative and floral buds for numbers of buds per shoot, percentage that developed and their developmental rate. The chilling requirement of highbush blueberry appears to be regulated polygenically as the D?×?J family segregated normally. On average, genotypes did more poorly at 250 and 350 chilling hours than the other chilling treatments.     

Pilot evaluation of a novel test strip for the assessment of dissolved thiol levels,as an indicator of canine gingival health and periodontal status

This study evaluated a novel test strip designed to assess thiol levels as they relate to gingival/periodontal health in dogs. The simple to use strip (similar in form to a pH test strip) provides a colorimetric signal which estimates the level of thiols dissolved in oral fluid. Among several oral sites tested (left and right lingual vestibules, lower buccal vestibule, and upper buccal gingival margin), fluid from the maxillary gingival margin gave results with the best dynamic range, and its thiol levels correlated well with several oral health parameters (Pearson coefficients between 0.55 and 0.84; P < 0.001), especially those relating directly to the gingiva. The strip, which can be used on animals which are awake, may be useful as a quick, objective assessment of periodontal health, potentially enhancing compliance for thorough examinations, and promoting earlier and better-sustained treatment programs.