First attempts towards the restoration of gorgonian populations on the Mediterranean continental shelf     

Maria Montseny  Cristina Linares  Núria Viladrich  Alejandro Olariaga  Marc Carreras  Narcís Palomeras  Nuno Gracias  Klemen Isteni   Rafael Garcia  Stefano Ambroso  Andreu Santín  Jordi Griny  Josep‐Maria Gili  Andrea Gori 《水产资源保护:海洋与淡水生态系统》2019,29(8):1278-1284

Using LC-MSMS to assess glutathione levels in South African white grape juices and wines made with different levels of oxygen     

du Toit WJ  Lisjak K  Stander M  Prevoo D 《Journal of agricultural and food chemistry》2007,55(8):2765-2769

The effect of oxygen on the levels of glutathione, an important antioxidant, in must and wine was studied using a novel LC-MSMS method for the analysis of reduced and oxidized glutathione. This study found that the storage of grape juice at high SO2 and ascorbic acid levels at -20 degrees C did not lead to a decrease in reduced glutathione levels. The effect of varying the oxygen levels in South African white grape juices, which included a reductive treatment (less than 0.3 mg/L dissolved O2 added), a control treatment (between 1.0 and 1.5 mg/L dissolved O2 added), and an oxidative treatment (3.5-4 mg/ L dissolved O2 added, without SO2) on reduced glutathione levels in the juice and resulting wine was also investigated. A custom build press was used to press whole bunches of two different Sauvignon Blanc and Colombard grapes. Alcoholic fermentation and oxygen additions to the must led to lower reduced glutathione levels in the wine. Reduced glutathione levels were only significantly higher in the wine made from reductive juice that had the highest initial reduced glutathione levels in the grapes.  相似文献   

Can the structure of dormant cambium and the widths of phloem and xylem increments be used as indicators for tree vitality?     

Jožica Gričar  Špela Jagodic  Bogoslav Šefc  Jelena Trajković  Klemen Eler 《European Journal of Forest Research》2014,133(3):551-562

We investigated the structure and width of the dormant cambium and of the increments of phloem and xylem of Quercus robur to estimate their potential as indicators for tree vitality. The samples were taken from three woodlands, two in Slovenia [Krakovo forest (KRA) and Murska Suma (MUS)] and one in Croatia [Kobiljak (KOB)], with reported tree decline. The number of dormant cells seems to reflect the initial capacity of the cambium to accomplish cell division. With the exception of two trees at KRA, cell production was always higher on the xylem side than on the phloem side. The annual phloem increments were narrower, less variable among trees and with clear lower and upper limits. With increased cambial cell productivity, the share of the xylem in the total annual radial increment increased following a curvilinear function. In trees with an annual radial increment >3.5 mm, the xylem size represented more than 90 % of the total radial growth. The anatomical variables analyzed show that the most limiting environmental conditions seem to prevail at KRA, whereas the conditions at MUS seem to be most favorable in terms of radial growth. Analysis of the width and structure of xylem and phloem increments, the number of dormant cambial cells and their inter-relationships can provide additional information on the vitality of oaks.  相似文献   

Cambial activity, wood formation and sapling survival of Pinus halepensis exposed to different irrigation regimes     

Martin de Luis  Klemen Novak  José RaventósJo?ica Gri?ar  Peter PrislanKatarina ?ufar 《Forest Ecology and Management》2011,262(8):1630-1638

Wood formation and the anatomical characteristics of tree-rings play a decisive role in plant performance and survival due to the importance of water transport. Saplings may be especially vulnerable to water stress; however, the level of water stress that they can endure still remains largely unexamined. Thus, the general objective of our research is to determine the plasticity of wood formation in Pinus halepensis saplings. We evaluated cambial activity, xylem growth ring formation and its anatomical characteristics in different experimental irrigation conditions and tested for its influence on the success rate of sapling establishment. Our results demonstrate a high phenological plasticity in wood formation with juvenile P. halepensis saplings in relation to water availability. Dry conditions during spring and summer strongly limit their cambial activity, which is suggested to be linked to sapling survival during summer. Width and anatomical characteristics of tree-rings differ in saplings exposed to different irrigation conditions. Our results suggest that increasing water stress during spring and summer periods, as predicted by future climate change scenarios, may seriously affect the success of both natural regeneration and reforestation of P. halepensis, and this could severely modify potential distribution of the species.  相似文献   

Sources of soil CO2 in calcareous grassland with woody plant encroachment     

Gregor Plestenjak  Klemen Eler  Dominik Vodnik  Mitja Ferlan  Matja? ?ater  Tja?a Kandu?  Primo? Simon?i?  Nives Ogrinc 《Journal of Soils and Sediments》2012,12(9):1327-1338

Purpose

The objective of this study is to estimate the contribution of various sources that influence soil CO₂ concentrations in calcareous grassland.

Materials and methods

The research was performed at the Podgorski Kras plain (45?°33?? N, 13?°55?? E, 400?C430?m.a.s.l.) in the sub-Mediterranean region of Slovenia (SW Slovenia), where many meadows and pastures have been abandoned. In parallel to the measurement of soil respiration R _s, soil gas was sampled for stable isotope analysis. Samples were taken biweekly at two sites, Grassland and Invaded, from July 2008 until November 2010. In addition, daily variations in concentration and stable isotope composition of soil CO₂ were determined in May 2009. The partitioning of soil CO₂ concentrations was performed using stable isotope mass balance calculation.

Results and discussion

The concentration and isotope composition of soil CO₂ exhibited similar seasonal variations at both sites. Lower ??¹³C_CO2 values, ranging from ?28.2 to ?15.2 ??, which occurred during warm periods and higher values, up to ?12.1 ??, were typical of cold winter periods, from December to March. Organic sources were estimated to constitute between 78 and 99?% of total soil CO₂ during warmer periods from May until October. This contribution was lower during the winter, ranging from 46 to 77?%. In winter, the atmospheric component to soil CO₂ dominated, constituting up to 60?%. On average, the inorganic contribution was estimated to comprise 12?% of the soil CO₂ at all sampling locations. The contribution of this source to soil CO₂ concentration, at up to 41?%, was highest in Grassland during the growing season. The inorganic source of soil CO₂ was also an important component during daily variations. The highest contribution was observed during the day, in parallel to the highest respiration rates.

Conclusions

The inorganic pool is shown to be an important part of soil CO₂ in calcareous areas and should be considered as equal to organic CO₂ as a source in soil CO₂ partitioning.  相似文献   

Long-term changes of structure and tree species composition in Dinaric uneven-aged forests: are red deer an important factor?     

Matija Klopcic  Klemen Jerina  Andrej Boncina 《European Journal of Forest Research》2010,129(3):277-288

Uneven-aged silver fir-European beech forest stands were studied to (1) analyse the dynamics of diameter structure and tree species composition in the past two centuries and (2) determine the impact of red deer on the regeneration and recruitment of silver fir. The study used current data on forest stands, archival data from old forest management plans for the period 1789–2004, and red deer harvesting records for the period 1907–2006. During the observation period, the silver fir population aged and silver fir and European beech alternated in dominance. The study revealed a strong impact of red deer on the composition and recruitment of tree regeneration, especially on silver fir regeneration. The drastic changes in red deer density (from extermination up to 5.8 animals km⁻²) and past forest management practices were apparently the main factors driving the population dynamics of silver fir (regeneration, recruitment, and diameter structure) in the study area during the past two centuries.  相似文献   

Estimating habitat suitability and potential population size for brown bears in the Eastern Alps   总被引：1，自引：0，他引：1  

Denise Güthlin  Felix Knauer  Thomas Kneib  Helmut Küchenhoff  Petra Kaczensky  Georg Rauer  Marko Jonozovi?  Andrea Mustoni  Klemen Jerina 《Biological conservation》2011,(5):1733-1741

According to the Habitats Directive of the European Union, a favorable conservation status for the brown bear (Ursus arctos) should be targeted at the population level in large contiguous habitats such as the Alps, the largest mountain range in Europe. However, in most of the Alps brown bears are extinct and habitat suitability in these areas is often questionable. For this paper, radio-tracking data from four projects with 42 individual bears was compiled to assess habitat suitability. Discrete-choice models with random bear effects were fitted and compared to results obtained from compositional analysis and logistic regression. Sound definition of the available area in the discrete-choice model turned out to be essential. Brown bears showed a preference for forested and steep habitats and an avoidance of roads.Results from the three approaches were used to predict habitat suitability across the entire range of the Eastern Alps. Minimum potential population size was projected based on observed densities in Trentino and Central Austria, and ranged from 1228 to 1625 individuals, with 518–686 mature bears. This would satisfy a favorable conservation status. The developed methodology also has wide applicability to quantification of habitat suitability and potential population size in other cases where species are at risk.  相似文献