Effect of acid rain on pine needles as food for capercaillie in winter

The effects of long-range air pollution on the chemical composition of needles of Scots pinePinus sylvestris and consequences for capercaillieTetrao urogallus feeding on the needles were studied. Samples of pine needles from localities receiving different amounts of acid rain were taken in early March. Concentrations of N and P were highest in needles from the most acidified areas, and N concentration was 35% higher in the most heavily polluted area than in the least polluted. Secondary chemicals decreased significantly with increasing acidification. Concentrations of Cd in pine needles were closely correlated with the acid deposition levels, with highest concentrations in the most polluted area. Al concentration also increased with increasing acidification. These results provide evidence that acid rain increases the nutritive value of pine needles through a fertilizing effect. Enhanced levels of certain metals are considered too low to be directly toxic to capercaillie. However, behavioural anomalies cannot be excluded.     

Seed-shedding in heather (Calluna vulgaris (L.) Hull

Abstract

Background: Accumulating evidence, mainly from small-scale experiments, suggests that species diversity helps stabilise ecological communities; however, this relationship needs testing at larger scales in a wider range of natural communities.

Aims: In experimentally burnt ericaceous shrub stands, we aimed to determine whether more diverse stands had more stable vegetation cover.

Methods: Using two prescribed fire management experiments – one on heathland and one in forest – at scales of 100–700 m², we compared pre-disturbance vegetation characteristics (measures of diversity, traits and composition) with resistance (degree of perturbation on disturbance), resilience (here defined as post-disturbance recovery rate) and stability (the inverse of temporal variability).

Results: Responses to disturbance were usually best explained by a measure of dominance: Simpson's index. High dominance was associated with high resilience, but low resistance and low stability. Within the forest, the shrub community had lower dominance and higher stability than it did on heathland. Dominance and diversity were strongly linked as opposite poles of a principal axis of vegetation variation; therefore, more diverse vegetation was more stable.

Conclusions: Ericaceous shrub cover is known to support important ecosystem services, such as soil protection, carbon sequestration, flood prevention and livestock grazing. Our results suggest that high shrub diversity would support stable provision of these services. Land managers who prioritise this aim in British heathlands and pinewoods should consider a wider range of management approaches than those of typical current practice.     

Kin groups in closely spaced capercaillie leks

We quantified the genetic structure among 58 capercaillie (Tetrao urogallus) from three closely spaced leks in boreal Russia using ten microsatellite loci. We did not find significant structuring with respect to lek membership in an overall analysis. However, all but one individual could be strongly assigned to one of two genetic clusters, which we interpret as reflecting different local lineages or extended family groups. There was evidence for structuring among some clusters within leks, and one smaller lek consisted of nine out of ten males from one cluster, which could reflect kin biasing of lek membership. One cluster was apparently outperforming the other, since nine out of ten juveniles sampled belonged to it.     

Extracts of bilberry (Vaccinium myrtillus L.) fruits improve liver steatosis and injury in mice by preventing lipid accumulation and cell death

ABSTRACT

Bilberry has been reported to have anti-oxidant and anti-inflammatory properties. We studied the effect of bilberry (Vaccinium myrtillus L.) fruits extracts (BEs) on the pathogenesis caused by lipid accumulation in fatty liver and non-alcoholic steatohepatitis (NASH). 5 μg/ml of BEs was enough to suppress lipid accumulation in the fatty liver model of the mouse hepatic AML12 cells. BEs increased cell viability and anti-oxidant capacity, presumably by activating (phosphorylating) Akt/STAT3 and inducing MnSOD/catalase. BEs also significantly reduced Rubicon and induced p62/SQSTM1, possibly contributing to reduce cellular lipids (lipophagy). When the mice were fed supplemented with BEs (5% or 10%, w/w), hepatic steatosis, injury, and hypercholesterolemia/hyperglycemia were significantly improved. Furthermore, histological and cytokine studies indicated that BEs possibly suppress hepatic inflammation (hepatitis) and fibrosis. Therefore, BEs improved liver steatosis and injury, and potentially suppress fibrosis by suppressing inflammatory response, which therefore may prevent the progression of fatty liver to NASH.     

Viability and Management of an Endangered Capercaillie (Tetrao urogallus) Metapopulation in the Jura Mountains, Western Switzerland

The populations of Capercaillie (Tetrao urogallus), the largest European grouse, have seriously declined during the last century over most of their distribution in western and central Europe. In the Jura mountains, the relict population is now isolated and critically endangered (about 500 breeding adults). We developed a simulation software (TetrasPool) that accounts for age and spatial structure as well as stochastic processes, to perform a viability analysis and explore management scenarios for this population, capitalizing on a 24 years-long series of field data. Simulations predict a marked decline and a significant extinction risk over the next century, largely due to environmental and demographic stochasticity (average values of life-history parameters would otherwise allow stability). Variances among scenarios mainly stem from uncertainties about the shape and intensity of density dependence. Uncertainty analyses suggest to focus conservation efforts on enhancing, not only adult survival (as often advocated for long-lived species), but also recruitment. The juvenile stage matters when local populations undergo extinctions, because it ensures connectivity and recolonization. Besides limiting human perturbations, a silvicultural strategy aimed at opening forest structure should improve the quality and surface of available patches, independent of their size and localization. Such measures are to be taken urgently, if the population is to be saved.     

Habitat and diet of young grouse broods: resource partitioning between Capercaillie (Tetrao urogallus) and Black Grouse (Tetrao tetrix) in boreal forests

We compared habitat use and diets of young Capercaillie and Black Grouse broods in a boreal forest in southeast Norway. We used pointing dogs to search for broods (N = 83) in mature “natural” forest types and examined the crop content of 66 chicks 1–9 weeks old. We also measured the abundance of insects in the habitats where broods were found. Although overlapping substantially in both habitat and diets, there were notable differences: Capercaillie broods were more frequently recorded in bilberry-dominated forest types, whereas Black Grouse preferentially used pine bog forest, a more open habitat with little bilberry. Capercaillie chicks ate proportionally more insects, particularly lepidopteran larvae, and insects dominated their diet for a longer period of time (until age 28–29 days) than in Black Grouse (14–15 days). After reaching their peaks, the quantity of insects in the crops declined rapidly especially in Capercaillie, and in one of 2 years this occurred at a time when insects, including larvae, were still abundant in the habitats. Among plant foods, both species ate large amounts of Bilberry (Vaccinium myrtillus) and Bog Whortleberry (V. uliginosum). The main difference between species was a large proportion of both over-wintered and new, not yet ripe, berries of Cranberry (Oxycoccus quadripetalus) in Black Grouse, and a higher proportion of the forb Melampyrum sylvaticum in Capercaillie. The difference in diets reflected their differential use of habitats; the Vaccinium-preferred habitats of Capercaillie were richer in insects, particularly larvae, than the pine bog habitat preferred by Black Grouse. Because insects, especially larvae, comprised a larger proportion of the diet of Capercaillie chicks and chicks of this species need more food to sustain their rapid growth, Capercaillie is likely to be more sensitive to variation in insect food than Black Grouse. Also, by reducing the abundance of bilberry, the main host plant of larvae chick food, clearcutting forestry has negative effects on the brood habitat quality of both species.     

Geographical pattern in photosynthetic light response of Pinus sylvestris in Europe

1. The geographical aspects in photosynthetic light response and stomatal conductance in the shoots of Pinus sylvestris were studied together with structural properties of shoots and needles. Seven stands within the natural distribution area of P. sylvestris in Europe were chosen. CO₂ exchange, irradiance and stomatal conductance ( g_s ) for water vapour were measured and the maximum photosynthetic rate ( P_m ) was determined from the CO₂ exchange measurements.
2. There was a clear pattern in the average values of P_m along the latitudinal gradient. Highest values of P_m were found in the middle parts of the distribution area and they decreased towards both ends of the transect. The highest value was almost twice as high as the lowest one.
3. The between-site variation explained 70% of the total variation in the maximum photosynthetic rate. P_m was not clearly correlated with any single climatic variable or nitrogen concentration in the needles.
4. P_m was closely coupled with stomatal conductance ( r ²=0·74). The differences in P_m and g_s between the sites is likely to reflect adaptation and acclimation to different climates.     

Four cytosolic-type CuZn-superoxide dismutases in germinating seeds of Pinus sylvestris

A differential analysis of CuZn-superoxide dismutase (SOD. EC 1.15.1.1) isozymes after native-polyacry lamide gel elecrrophoresis (PAGE) and isoelectric focusing (IEF) indicated that germinating seeds of Scots pine (Pinus sylvestris L.) 3 days after the start of imbibition (3 DAI) contain five CuZn-SOD isozymes. Two isozymes co-migrated on native–PAGE but were separated after IEF. CuZn-SODs of Scots pine were purified from germinating seeds (3 DAI) by anion-exchange chromatography, hydrophobic interaction chromatography and chromatofocusing. The final separation of CuZn-SOD isozymes was accomplished by native-PAGE. CuZn-SOD isozymes were electroblotted and their NH₂-terminal amino acid sequence was determined. Comparisons of the amino acid sequences with sequences of CuZn-SOD isozymes from other plant sources indicated that one CuZn-SOD isozyme was of the chloroplastic type whereas the other four isozymes belonged to the cytosolic-type CuZn-SODs, The NH₂-terminal amino acid sequence of the chloroplastic CuZn-SOD and of one cytosolic-type CuZn-SOD were identical to those of two previously isolated, sequenced and localized CuZn-SOD isozymes from Scots pine needles. Two cytosolic-type CuZn-SOD isozymes showed a homology at 20 out of 21 NH₂-terminal amino acids. Mitochondria and glyoxysomes were isolated by differential and Percoll density-gradient centrifugation from germinating seeds (3 DAI). The cell fractionation experiments did not suggest that a major part of the CuZn-SOD activity in germinating seeds was derived from glyoxysomes or mitochondria.     

Porphyrin metabolism in chill-stressed seedlings of Scots pine (Pinus sylvestris)

Scots pine ( Pinus sylvestris L.) is generally resistant to chilling temperatures. Porphyrin metabolism under low temperature stress was studied in etiolated seedlings of Scots pine. Low temperatures affect porphyrin accumulation in at least 3 different temperature sensitive sites: 1) the light activated accumulation of 5-aminolevulinic acid, a porphyrin precursor, 2) the metabolism of 5-aminolevulinic acid to form porphyrins and 3) a preferential accumulation of chlorophyll a over chlorophyll b . The temperature sensitivity of pine is compared to maize ( Zea mays L.), a chilling sensitive plant.     

樟子松人工林一级枝条基径和枝长模型的研究

以东北林业大学帽儿山实验林场樟子松人工林为研究对象,采用枝解析的方法,于2002年、2003年测定了53株林木（年龄17~38 a,直径8.61~21.5 cm,树高7.48~18.24 m）的树冠变量,建立了基于总着枝深度（DINC）和树冠内一级枝条基径（BD）、枝长（BL）的预估模型。对于大小相同树木的一级枝条, 这些树冠变量随着DINC的增加而增大,而林木的胸径（DBH）、树高（HT）变量又很好地反映了不同大小树木的基径和枝长的变化。采用独立检验样本对构建的树冠内一级枝条基径和枝长模型进行了拟合统计量和精度检验,结果表明：模型预测效果良好,精度均达到95%以上。构建的一级枝条基径和枝长模型为进一步合理地描述樟子松人工林树冠的形状及其变化以及三维可视化经营提供依据。     

The pectic polysaccharide rhamnogalacturonan II is present as a dimer in pectic populations of bilberries and black currants in muro and in juice

Rhamnogalacturonan II (RG II) can play an important role during processing of berries due to its enzyme resistance and its possible role as a pectic cross-linker. This article describes the presence of RG II in cell walls, in juice and in press cake of bilberries and black currants. RG II was identified and quantified via its diagnostic sugar residues. RG II, which was released from homogalacturonan, was probably present in its dimeric form in muro. Juice contained the free RG II dimer, while from press cake dimeric RG II was released by enzymatic degradation of homogalacturonan. A higher amount of RG II was present in juice than in press cake. During juice processing a cross-linker RG II might improve gel formation, which hinders the processability of berries. In addition, enzymes used during juice processing release dimeric RG II from pectin molecules and accumulate RG II in the juice.     

Cell wall polysaccharides in black currants and bilberries—characterisation in berries, juice, and press cake

Cell wall polysaccharides from black currants and bilberries were characterised in three approaches. First, compositions of skin, pulp, and seeds show the distribution of polysaccharides over these tissues. A sequential extraction of cell wall material with different aqueous extractants informs about the extractability of the different polysaccharides, viz. pectins, hemicellulose, and cellulose. Finally, by isolation of cell wall polysaccharides from juice and press cakes obtained by the conventional juice manufacturing. The polysaccharide distribution was followed during juice processing. The main difference between bilberries and black currants is the dominant sugar residue in seeds: mannose for black currants and xylose for bilberries. Most of the hemicellulolytic sugars and cellulose can be found back in the press cake. The sugar composition of the press cake is similar to the composition of the residue after sequential extraction. Black currants contain more pectic sugars than bilberries. Consequently, a commercial enzyme used during processing releases more pectic material into the juice.