对朗乡林区土壤的评价和合理利用的建议

对朗乡林区所拥有的各类土壤进行评价并提出合理利用的建议。     

Emissions of CO2, CH4 and N2O from Southern European peatlands

Peatlands play an important role in emissions of the greenhouse gases CO₂, CH₄ and N₂O, which are produced during mineralization of the peat organic matter. To examine the influence of soil type (fen, bog soil) and environmental factors (temperature, groundwater level), emission of CO₂, CH₄ and N₂O and soil temperature and groundwater level were measured weekly or biweekly in loco over a one-year period at four sites located in Ljubljana Marsh, Slovenia using the static chamber technique. The study involved two fen and two bog soils differing in organic carbon and nitrogen content, pH, bulk density, water holding capacity and groundwater level. The lowest CO₂ fluxes occurred during the winter, fluxes of N₂O were highest during summer and early spring (February, March) and fluxes of CH₄ were highest during autumn. The temporal variation in CO₂ fluxes could be explained by seasonal temperature variations, whereas CH₄ and N₂O fluxes could be correlated to groundwater level and soil carbon content. The experimental sites were net sources of measured greenhouse gases except for the drained bog site, which was a net sink of CH₄. The mean fluxes of CO₂ ranged between 139 mg m⁻² h⁻¹ in the undrained bog and 206 mg m⁻² h⁻¹ in the drained fen; mean fluxes of CH₄ were between −0.04 mg m⁻² h⁻¹ in the drained bog and 0.05 mg m⁻² h⁻¹ in the drained fen; and mean fluxes of N₂O were between 0.43 mg m⁻² h⁻¹ in the drained fen and 1.03 mg m⁻² h⁻¹ in the drained bog. These results indicate that the examined peatlands emit similar amounts of CO₂ and CH₄ to peatlands in Central and Northern Europe and significantly higher amounts of N₂O.     

Quality of Highbush Blueberry (Vaccinium corymbosum L.) and Bilberry (Vaccinium myrtillus L.) Jam

ABSTRACT

Jam from wild bilberries and from the blueberry culti vars ‘Bluecrop’ and ‘Berkeley’ were analyzed by means of sensory profiling and by instrumental measurement of anthocyanins, color, pH and soluble solids. The study shows that bilberry jam has more “bluish black color,” compared to a more “reddish-blue color” and “glossy” surface of the jam from cultivated blueberries. Bilberry jam was less “smooth” and higher in “viscosity” and “berry density” as well as less distinct in “flavor of flowers and fruits,” while the “blueberry flavor and odor” were more distinct in the bilberry jam than that made of highbush blueberries. Analysis of color by means of sensory hue and instrumental a Hunter lab corresponded well, as did saturation measured by the sensory method and chroma instrumentally measured.     

笃斯越桔叶片中矿质营养年周期变化规律的研究

作者采用叶分析技术对中国东北地区笃斯越桔矿质营养元素年周期变化规律进行了研究。发现笃斯越桔叶片中各矿质营养元素的年周期变化规律具有一定模式,大多数营养元素在7月中旬至8月中旬处于含量变化相对稳定时期。此期为笃斯越枯叶分析的最适采样期。相关分析表明,土壤中营养元素的年周期变化规律与叶片中营养元素的年周期变化规律之间很少存在显著相关关系。     

Airborne small-footprint discrete-return LiDAR data in the assessment of boreal mire surface patterns, vegetation, and habitats

Boreal mires encompass high diversity in species and habitats, many of which are endangered. In Finland, extensive use of peatlands has resulted in habitat fragmentation. A need for accurate and cost-efficient vegetation mapping and monitoring of habitat changes exists in mire conservation, restoration and peatland forestry. LiDAR is an emerging and excellent tool for probing the geometry of vegetation and terrain. Modern systems measure the backscattered signal accurately and also provide radiometric information. Experiments were carried out in a complex minerotrophic–ombrotrophic eccentric raised bog in southern Finland (61°47′N, 24.18′E). First, we tested discrete-return LiDAR for the modeling of mire surface patterns and the detection of hummocks and hollows, as well as the effect of mire plants on the Z accuracy of the surface echoes. Secondly, the response of different mire vegetation samples in LiDAR intensity was examined. Thirdly, we tested area-based geometric and radiometric features in supervised classification of mire habitats to discover the meaningful variables. The vertical accuracy of LiDAR in mire surface modeling was high: 0.05–0.10 m. A binary hummock-hollow model that was estimated from a LiDAR-based elevation model matched flawlessly in aerial images and had moderate explanatory power in habitat classification trials. The intensity of LiDAR in open-mire vegetation was mainly influenced by the surface moisture, and separation of vegetation classes spanning from ombrotrophic to mesotrophic vegetation proved to be difficult. Area-based features that characterize the height distribution of LiDAR points in the canopy were the strongest explanatory variables in the classification of 21 diverse mire site types. Actual qualifying differences in the ground flora were unattainable in the LiDAR data, which resulted in inferior accuracy in the characterization of ecohydrological conditions and nutrient level of open mires and sparsely forested wet sites. Mire habitat classification accuracy with LiDAR surpassed earlier results with optical data. The results suggested that LiDAR constitutes an efficient aid for monitoring applications. We propose the co-use of images and LiDAR for enhanced mapping of open mires and tree species. In situ calibration and validation procedures are required until invariant geometric and radiometric features are discovered.     

Bilberry extract protect restraint stress-induced liver damage through attenuating mitochondrial dysfunction

The aim of the present study is to investigate the protective effect of bilberry extract on liver damage in restraint stressed mice. A remarkable increase in alanine aminotransferase (ALT) and reactive oxygen species (ROS) levels was observed in stressed mice. Treatment with bilberry extract restored ALT and ROS to normal levels, and enhanced mitochondrial complex II activity that was lowered in restraint stressed mice. The mitochondrial electron transfer chain (ETC)-related gene expression was measured by RT-PCR, and a significant up-regulation of complex II mRNA was observed for SDHA, B, C and D mRNA in bilberry extract-treated group compared with that in stressed group. Bilberry extract administration also profoundly elevated the Na⁺-K⁺-ATPase activity and mitochondria membrane potential (?Ψ_m), which was reduced in the stressed group. Bilberry extract exhibited protective effect by scavenging free radicals and attenuating mitochondrial dysfunction in the liver of restraint stressed mice. It may be used as a promising therapeutic agent in preventing and delaying the life-related disease.     

Hydrologic controls on water chemistry, vegetation and ecological patterns in two mires in the South-Eastern Alps (Italy)

We examined how hydrology influenced water chemistry, vegetation, nutrient status, aboveground net primary production (ANPP) and litter decomposition rates in two mires on the South-Eastern Alps of Italy. One of the mires had a modest hydraulic gradient and prevalently acted as a recharge system, although there were short phases of vertical flow reversal during dry periods. This mire was, therefore, prevalently fed by rainwater and was covered by bog-like vegetation, mainly hummocks and scrubs with a ground layer rich in Sphagnum mosses. The other mire presented a steeper hydraulic gradient, with the surface being fed by mineral water either by surface runoff or by vertical, upwards directed ground water flow. Compared to the bog-dominated mire, the pore water was less acidic and richer in telluric cations. This mire was covered by fen-like vegetation, prevalently fen meadows. Nitrogen (N) content in the vegetation was very similar in the two mire sites, while phosphorus (P) content was lower in the fen-dominated site. Contrary to our expectations, ANPP did not differ significantly between the two mire sites while litter decomposition rates were significantly lower in the fen-dominated mire, presumably because of P limitation of decomposers. This suggests that the development of ombrogenous mires in this region need not be due to increased accumulation of peat during succession from mineralwater-fed to rainwater-fed conditions.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Effects of Extraction Conditions on the Content of Anthocyanins and Bioelements in Berry Fruit Extracts

Abstract

Two methods for extracting anthocyanins and bioelements [calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe)] from black chokeberry, black currant, strawberry, and bilberry fruits were compared in this study. Correlations between the content of anthocyanins and bioelements in fruit extracts were determined using method A [extraction with hydrochloric acid (HCl)] and method B [extraction with water (H₂O)]. Relationships between the content of anthocyanins and particular nutrients, as well as between Mg and Ca and between Zn and Fe, in fruit extracts obtained by method A and by method B were also established.

The mean content of anthocyanins and bioelements (Ca, Mg, Zn, Fe) was the highest in black chokeberry fruits, regardless of the extraction method used. Bilberry fruits had the lowest nutrient content, despite a high anthocyanin content. The mean content of anthocyanins and bioelements was higher in fruit extracts obtained by method A than method B. The coefficients used to recalculate method A into method B were anthocyanins, 5.1; Ca, 1.1; Mg, 1.2; and Zn, 2.2. The statistical analysis showed that the effect of a given extraction method on the content of anthocyanins and bioelements (except for Ca) in fruit extracts depended on fruit species. The correlations between the content of anthocyanins, Ca, Mg and Zn in fruit extracts obtained by method A were found to be positive and highly significant, in comparison with method B. There was no correlation between the content of anthocyanins and particular nutrients in fruit extracts obtained by method A and by method B. The Mg content of fruit extracts was highly significantly higher than the Ca content, irrespective of the extraction method applied.