Showing papers by "Forest Research Institute published in 2003"

Tropospheric O3 moderates responses of temperate hardwood forests to elevated CO2: a synthesis of molecular to ecosystem results from the Aspen FACE project

Abstract: Summary 1. The impacts of elevated atmospheric CO 2 and/or O 3 have been examined over 4 years using an open-air exposure system in an aggrading northern temperate forest containing two different functional groups (the indeterminate, pioneer, O 3 -sensitive species Trembling Aspen, Populus tremuloides and Paper Birch, Betula papyrifera , and the determinate, late successional, O 3 -tolerant species Sugar Maple, Acer saccharum ). 2. The responses to these interacting greenhouse gases have been remarkably consistent in pure Aspen stands and in mixed Aspen/Birch and Aspen/Maple stands, from leaf to ecosystem level, for O 3 -tolerant as well as O 3 -sensitive genotypes and across various trophic levels. These two gases act in opposing ways, and even at low concentrations (1·5 × ambient, with ambient averaging 34‐36 nL L − 1 during the summer daylight hours), O 3 offsets or moderates the responses induced by elevated CO 2 . 3. After 3 years of exposure to 560 µ mol mol − 1 CO 2 , the above-ground volume of Aspen stands was 40% above those grown at ambient CO 2 , and there was no indication of a diminishing growth trend. In contrast, O 3 at 1·5 × ambient completely offset the growth enhancement by CO 2 , both for O 3 -sensitive and O 3 -tolerant clones. Implications of this finding for carbon sequestration, plantations to reduce excess CO 2 , and global models of forest productivity and climate change are presented.

Characterization of anatomical features and silica distribution in rice husk using microscopic and micro-analytical techniques

Abstract: Rice husk is a by-product of rice milling process, and a great resource as a raw biomass material for manufacturing value-added composite products. One of the potential applications is to use rice husk as filler for manufacturing lignocellulosic fiber–thermoplastic composites. This study was conducted to examine the silica distribution in rice husk in preparation to use it as reinforcing filler for thermoplastic polymers. Microscopic techniques, such as light microscopy, scanning electron microscopy and field-emission SEM (FE-SEM) were used to observe the surface and internal structure of rice husk. Microscopic examination showed that two main components of husk, lemma and palea consisted of outer epidermis, layers of fibers, vascular bundles, parenchyma cells, and inner epidermis, in sequence from the outer to the inner surface. Histochemical staining showed that epidermal and fiber cell walls were lignified, and the walls of parenchyma and lower epidermal cells were not lignified. The outer epidermal walls were extremely thick, highly convoluted and lignified. The outer surface of both lemma and palea were conspicuously ridged. The energy dispersive X-ray micro-analysis attached to the FE-SEM provided information on the distribution of silica in the husk. Most of the silica was present in the outer epidermal cells, being particularly concentrated in the dome-shaped protrusions. These observations provided valuable background information on the organization of husk tissues and the distribution of silica, which will help optimize processes related to the use of rice husk for making lignocellulosic fiber–thermoplastic composites in our future work.

Root turnover and root necromass accumulation of Norway spruce (Picea abies) are affected by soil acidity

Abstract: Fine root distribution and turnover were investigated in ca. 40-year-old pure Norway spruce (Picea abies Karst.) stands in Germany, growing on four sites that differed in soil acidity (Ebergotzen < Barbis < Fichtelgebirge = Harz). The density of fine root biomass and necromass in different soil horizons differed among the sites. At one of the most acidic sites (Harz), fine root density in the humus layer was more than twice that at the least acidic site (Ebergotzen). At the two most acidic sites, Fichtelgebirge and Harz, the ratio of biomass to necromass was significantly lower than at Ebergotzen and Barbis, particularly in the subsoil layer. In each stand, clear vertical gradients in fine root length density and root tip density were observed. Most of the roots and the root tips were in the humus layer and in the first mineral soil horizon (0-10 cm). There was a significantly different decrease in specific root length (cm gDM (-1)) and specific root tip density (root tips gDM (-1)) in the more acidified stands Fichtelgebirge and Harz compared with Ebergotzen and Barbis. Fine root production estimated by ingrowth cores and a net method was approximately twice as high in the more acidic stands Fichtelgebirge and Harz compared with Ebergotzen and Barbis. Rates of living fine root biomass turnover were higher at the Fichtelgebirge and Harz sites than at the Ebergotzen site. Rates of necromass turnover were similar at all sites. The results suggest that the accumulation of necromass was not due to a slower disappearance at the more acid sites, but to earlier root death. Roots contributed 46% to root + needle litter and 32% to root + total aboveground litter at the Harz site in 1997.

A floristic analysis of the lowland dipterocarp forests of Borneo

Abstract: Aim To (1) identify floristic regions in the lowland (below 500 m a.s.l.) tropical dipterocarp rain forest of Borneo based on tree genera, (2) determine the characteristic taxa of these regions, (3) study tree diversity patterns within Borneo, and (4) relate the floristic and diversity patterns to abiotic factors such as mean annual rainfall and geographical distance between plots. Location Lowland tropical dipterocarp rain forest of Borneo. Methods We used tree (diameter at breast height ‡ 9.8 cm) inventory data from 28 lowland dipterocarp rain forest locations throughout Borneo. From each location six samples of 640 individuals were drawn randomly. With these data we calculated a Sorensen and Steinhaus similarity matrix for the locations. These matrices were then used in an UPGMA clustering algorithm to determine the floristic relations between the locations (dendrogram). Principal coordinate analysis was used to ordinate the locations. Characteristic taxa for the identified floristic clusters were determined with the use of the INDVAL method of Dufrene & Legendre (1997). Finally, Mantel analysis was applied to determine the influence of mean annual rainfall and geographical distance between plots on floristic composition.

Out of Anatolia: longitudinal gradients in genetic diversity support an eastern origin for a circum-Mediterranean oak gallwasp Andricus quercustozae

Abstract: Many studies have addressed the latitudinal gradients in intraspecific genetic diversity of European taxa generated during postglacial range expansion from southern refugia. Although Asia Minor is known to be a centre of diversity for many taxa, relatively few studies have considered its potential role as a Pleistocene refugium or a potential source for more ancient westward range expansion into Europe. Here we address these issues for an oak gallwasp, Andricus quercustozae (Hymenoptera: Cynipidae), whose distribution extends from Morocco along the northern coast of the Mediterranean through Turkey to Iran. We use sequence data for a fragment of the mitochondrial gene cytochrome b and allele frequency data for 12 polymorphic allozyme loci to answer the following questions: (1). which regions represent current centres of genetic diversity for A. quercustozae? Do eastern populations represent one refuge or several discrete glacial refugia? (2). Can we infer the timescale and sequence of the colonization processes linking current centres of diversity? Our results suggest that A. quercustozae was present in five distinct refugia (Iberia, Italy, the Balkans, southwestern Turkey and northeastern Turkey) with recent genetic exchange between Italy and Hungary. Genetic diversity is greatest in the Turkish refugia, suggesting that European populations are either (a). derived from Asia Minor, or (b). subject to more frequent population bottlenecks. Although Iberian populations show the lowest diversity for putatively selectively neutral markers, they have colonized a new oak host and represent a genetically and biologically discrete entity within the species.

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree-ring width

Abstract: Two reconstructions of spring (May–June) precipitation have been developed for southwestern Turkey. The first reconstruction (1776–1998) was developed from principal components of nine chronologies of Cedrus libani, Juniperus excelsa, Pinus brutia ,a ndPinus nigra. The second reconstruction (1339–1998) was derived from principal components of three J. excelsa chronologies. Calibration and verification statistics of both reconstructions indicate reasonably accurate reconstruction of spring precipitation for southwestern Turkey, and show clear evidence of multi-year to decadal variations in spring precipitation. The longest period of reconstructed spring drought, defined as consecutive years with less than 80% of normal May–June precipitation, was 4 years (1476–79). Only one drought event of this duration has occurred during the last six centuries. Monte Carlo analysis indicates a less than 33% probability that southwestern Turkey has experienced spring drought longer than 5 years in the past 660 years. Apart from the 1476–79 extended dry period, spring droughts of 3 years in length have only occurred from 1700 to the present. The longest reconstructed wet period, defined as consecutive years with more than 120% of normal May–June precipitation, was 4 years (1532–35). The absence of extended spring drought during the 16th and 17th centuries and the occurrence of extended wet spring periods during these centuries suggest a possible regime shift in climate. Preliminary analysis of links between large-scale climatic variation and these climate reconstructions shows that there is a relationship between extremes in spring precipitation and anomalous atmospheric circulation in the region. Copyright  2003 Royal Meteorological Society.

Role of complement activation in atherosclerosis.

Abstract: Purpose of reviewAtherosclerosis is characterized by a strong inflammatory component. One factor contributing to inflammation in the arterial intima is the complement system. Here we summarize recent progress in the field of complement research on atherogenesis.Recent findingsThe complement system i

Mast Cell Chymase Induces Smooth Muscle Cell Apoptosis by a Mechanism Involving Fibronectin Degradation and Disruption of Focal Adhesions

Abstract: Objective— Chymase released from activated mast cells has been shown to induce apoptosis of vascular smooth muscle cells (SMCs) in vitro. The proteolytic activity of chymase is essential for the proapoptotic effect, but the mechanism of chymase-induced apoptosis has remained unknown. Methods and Results— Here we show by means of FACS analysis, immunohistochemistry, and Western blotting that mast cell–derived chymase induces SMC apoptosis by a mechanism involving degradation of an extracellular matrix component, fibronectin (FN), with subsequent disruption of focal adhesions. The FN degradation products induced SMC apoptosis of similar magnitude and with similar changes in outside-in signaling, as did chymase. Sodium orthovanadate, an inhibitor of tyrosine phosphatases, inhibited the chymase-induced SMC apoptosis. Focal adhesion kinase (FAK), one of the key mediators of integrin–extracellular matrix interactions and cell survival, was rapidly degraded in the presence of chymase or FN degradation products. Loss of phosphorylated FAK (p-FAK) resulted in a rapid dephosphorylation of the p-FAK–dependent downstream mediator Akt. Conclusions— The results suggest that chymase-secreting mast cells can mediate apoptosis of neighboring SMCs through a mechanism involving degradation of pericellular FN and disruption of the p-FAK–dependent cell-survival signaling cascade.

Large-scale climatic variability and radial increment variation of Picea abies (L.) Karst. in central and northern Europe

Abstract: High-frequency variation of Norway spruce radial increment [Picea abies (L) Karst] and its dependence on various climatic variables was compared in stands across latitudinal and altitudinal transects in southwestern and eastern Germany, Norway, and Finland The tested variables included local temperature and precipitation, northern hemisphere temperature anomalies, and the climatic teleconnection patterns (North Atlantic Oscillation, East Atlantic, East Atlantic Jet, East Atlantic/West Russia, and Scandinavian patterns) Climatic impact on radial increment increased towards minimum and maximum values of the long-term temperature and precipitation regimes, ie trees growing under average conditions respond less strongly to climatic variation Increment variation was clearly correlated with temperature Warm Mays promoted radial increments in all regions If the long-term average temperature sum at a stand was below 1,200–1,300 degree days, above average summer temperature increased radial increment In regions with more temperate climate, water availability was also a growth-limiting factor However, in those cases where absolute precipitation sum was clearly related to radial increment variation, its effect was dependent on temperature-induced water stress The estimated dates of initiation and cessation of growing season and growing season length were not clearly related to annual radial increment Significant correlations were found between radial increment and climatic teleconnection indices, especially with the winter, May and August North Atlantic Oscillation indices, but it is not easy to find a physiological interpretation for these findings

Postglacial population growth of Cunninghamia konishii (Cupressaceae) inferred from phylogeographical and mismatch analysis of chloroplast DNA variation.

Abstract: Phylogeographical and mismatch analysis of chloroplast DNA (cpDNA) variation were used to infer the temporal dynamics of distributional and demographic history of Taiwan fir (Cunninghamia konishii). We examined 64 and 52 trees from 17 populations of C. konishii and 14 provenances of C. lanceolata, respectively, by sequencing three intergenic spacers and one intron using cpDNA universal primers. Of the aligned 1888 base pairs (bp) sequence, 30 varied among 28 haplotypes, which consisted of three transitions, 14 transversions and 13 indels. One ancestral haplotype was found in 86 individuals across the surveyed range of both species, C. konishii and C. lanceolata, which was distributed in all populations and provenances. The 28 haplotypes also included 15 C. konishii specific and 12 C. lanceolata-specific haplotypes. Ancestral haplotype was found fixed in five populations of C. konishii and five provenances of C. lanceolata. Other haplotypes occurred mainly as singletons. The levels of population differentiation studied are relatively low in both Cunninghamia species. The nucleotide diversity (theta) of chloroplast DNA sequences within C. konishii was slightly higher than that of C. lanceolata. Excess in singletons as well as star-like phylogeny of haplotypes suggested no clearcut migration patterns of C. konishii after glacial maximum. One probable demographic history of C. konishii is the postglacial population growth of C. konishii after a glacial bottleneck event. This inference is supported by the combined results of fossil pollen record, low nucleotide diversity, significant Tajima's d-value, phylogeographical analysis and unimodal mismatch distribution. Similarities and discrepancies between our results and those of Lu et al. (2001) are discussed.

Activation and proliferation signals in primary human T lymphocytes inhibited by ergosterol peroxide isolated from Cordyceps cicadae

Abstract: Effects of ergosterol peroxide (C28H44O3; Cpd 6A) from Cordyceps cicadae on phytohemagglutinin (PHA)-stimulated cell proliferation were studied in primary human T cells. The results showed that Cpd 6A suppressed T-cell proliferation for about 24 h after stimulation with PHA. Cell cycle analysis indicated that Cpd 6A arrested the cell cycle progression of activated T cells from the G1 transition to the S phase. To localize the point in the cell cycle where arrest occurred, a set of key regulatory events leading to the G1/S boundary, including the expression of cyclins D2, E, A1, and B1, interleukin (IL)-2, IL-4, interferon-gamma (IFN-gamma), and activating protein-1 (AP-1), was examined. Cpd 6A suppressed, in activated T lymphocytes, the production and mRNA expression of cyclin E, IL-2, IL-4, IL-10, and IFN-gamma in a dose-dependent manner. Expression of AP-1 proteins, consisting of c-Fos and c-Jun, in activated T lymphocytes was decreased by Cpd 6A. The kinetic study indicated that the inhibitory effects of Cpd 6A on IL-2 mRNA expressed in T cells might be related to blocking c-Fos protein synthesis. T-cell proliferation after Cpd 6A treatment was partially restored by addition of IL-2, IL-4, and IFN-gamma. These suppressant effects of Cpd 6A on T-cell proliferation, activated by PHA, appeared to be mediated, at least in part, through the inhibition of early gene transcripts, especially those of cyclin E, IFN-gamma, IL-2, and IL-4, and by arresting cell cycle progression in the cells.

Association Between Complement Factor H and Proteoglycans in Early Human Coronary Atherosclerotic Lesions. Implications for Local Regulation of Complement Activation

Abstract: Objective— Complement activation has been suggested to play a role in atherogenesis. To study the regulation of complement activation in human coronary atherosclerotic lesions, we examined the spatial relationships between the major complement inhibitor, factor H, and the complement activation products C3d and C5b-9. Methods and Results— In early lesions (American Heart Association types II and III), factor H was immunohistochemically found in the superficial proteoglycan-rich layer in association with numerous macrophages and C3d, whereas C5b-9 was found deeper in the intima, where factor H was virtually absent. In vitro experiments involving surface plasmon resonance and affinity chromatography analyses demonstrated that isolated human arterial proteoglycans bind factor H, and functional complement assays showed that glycosaminoglycans inhibit the complement activation induced by modified low density lipoprotein or by a foreign surface. Conclusions— The present observations raise the possibility that proteoglycans, because of their ability to bind the major complement inhibitor factor H, may inhibit complement activation in the superficial layer of the arterial intima. In contrast, deeper in the intima, where factor H and proteoglycans are absent, complement may be activated and proceed to C5b-9. Thus, the superficial and the deep layers of the human coronary artery appear to differ in their ability to regulate complement activation.

Obesity is associated with impaired platelet-inhibitory effect of acetylsalicylic acid in nondiabetic subjects.

Abstract: Obesity is associated with impaired platelet-inhibitory effect of acetylsalicylic acid in nondiabetic subjects

Composition and antimicrobial activity of the essential oil of Hypericum rumeliacum subsp. apollinis (Boiss. & Heldr.)

Abstract: The composition and the antimicrobial activity of the aerial parts of Hypericum rumeliacum are reported. Analysis was carried out by GC/MS. The major constituents were α-pinene (43.80%), β-pinene (9.82%), dehydro-aromadendrene (6.81%) and α-copaene (5.41%). The essential oil showed a moderate in vitro activity against the six Gram negative and positive bacteria and a stronger one against the three-tested pathogenic activity. Copyright © 2003 John Wiley & Sons, Ltd.

Mast cell‐mediated apoptosis of endothelial cells in vitro: A paracrine mechanism involving TNF‐α‐mediated down‐regulation of bcl‐2 expression

Abstract: Degranulated mast cells are present in the subendothelial space of eroded (de-endothelialized) coronary atheromas Upon degranulation, mast cells secrete into the surrounding tissue an array of preformed and newly synthesized mediators, including proapoptotic molecules, such as chymase and TNF-alpha In a co-culture system involving rat serosal mast cells and rat cardiac (microvascular) endothelial cells, we could show, by means of competitive RT-PCR, immunoblotting, immunocytochemistry, annexin staining, flow cytometry, and DNA-laddering, that stimulation of mast cells with ensuing degranulation rapidly (within 30 min) down-regulated the expression of both bcl-2 mRNA and protein, with subsequent induction of apoptosis in the endothelial cells The major effect of bcl-2 down-regulation resided in the exocytosed granule remnants, a minor effect also being present in the granule remnant-free supernatant No significant changes were observed in the expression levels of the pro-apoptotic protein, bax The mast cell-mediated apoptotic effect was partially (70%) dependent on the presence of TNF-alpha and involved the translocation of cytochrome C from mitochondria into cytoplasm These results are the first to show that one of the cell types present in the atherosclerotic plaques, namely the mast cell, by releasing both granule-remnant-bound and soluble TNF-alpha, may contribute to the erosion of atherosclerotic plaques by inducing apoptosis in adjacent endothelial cells Published 2003 Wiley-Liss, Inc

Sawmill Trial of At-Line Prediction of Recovered Lumber Stiffness by NIR Spectroscopy of Pinus Radiata Cants:

Abstract: Pinus radiata D. Don cants (100 or 200 mm thick × 4.8 m) from a commercial sawmill operation were assessed in the green state using near infrared (NIR) spectroscopy. Near infrared spectra were acquired along the centre line of one cant face and at 50 mm offsets to one side of the centre line. The cants were ripped to produce either 50 × 100 or 50 × 200 mm rough sawn boards, which were then kiln-dried and gauged to final dimensions. The long-span modulus of elasticity (L MoE) on each board was determined using a four-point bending test and the corresponding NIR spectra of each board (the 50 mm edge from the cant) were regressed against the long-span MoE value using partial least squares modeling. The results are explained in terms of the potential for NIR to predict the potential upgrade to higher value products for timber recovered from the corewood zone of logs.

Molecular identification and phylogeny of Armillaria isolates from South America and Indo-Malaysia.

Abstract: Armillaria root rot is a serious disease, chiefly of woody plants, caused by many species of Armillaria that occur in temperate, tropical and sub- tropical regions of the world. Very little is known about Armillaria in South America and Southeast Asia, although Armillaria root rot is well known in these areas. In this study, we consider previously un- identified isolates collected from trees with symptoms of Armillaria root rot in Chile, Indonesia and Malay- sia. In addition, isolates from basidiocarps resembling A. novae-zelandiae and A. limonea, originating from Chile and Argentina, respectively, were included in this study because their true identity has been uncer- tain. All isolates in this study were compared, based on their similarity in ITS sequences with previously sequenced Armillaria species, and their phylogenetic relationship with species from the Southern Hemi- sphere was considered. ITS sequence data for Armil- laria also were compared with those available at GenBank. Parsimony and distance analyses were con- ducted to determine the phylogenetic relationships between the unknown isolates and the species that showed high ITS sequence similarity. In addition, IGS-1 sequence data were obtained for some of the species to validate the trees obtained from the ITS data set. Results of this study showed that the ITS sequences of the isolates obtained from basidiocarps