Oak

Individual tree mortality models were developed for the six major forest species of Austria: Norway spruce (Picea abies), white ®r (Abies alba), European larch (Larix decidua), Scots pine (Pinus sylvestris), European beech (Fagus silvatica), and oak (Quercus spp.); a joint model for the remaining broadleaf species was also developed. Data came from 5-year remeasurements of the permanent plot network of the Austrian National Forest Inventory. Parameters of the logistic equation were estimated using maximum likelihood methods. For all species, we found the hyperbolic transformation of diameter (D À1) to be highly signi®cant in predicting the high mortality rates for small diameter trees and decreasing mortality rates for larger diameters. For spruce, a quadratic transformation in D was needed to accurately model the increase in mortality observed for large, low-vigor trees with diameter >70 cm, which resulted in a U-shaped distribution. Crown ratio was also consistently signi®cant, except for oak. We likewise found basal-area-in-larger-trees (BAL) to be a highly signi®cant predictor of mortality rate for all species except ®r and oak. Predicted mortality rate increases as the basal area in larger trees increases and as crown ratio decreases. The resulting logistic mortality model had the same general form for all species, with the signs of all parameters conforming to expectations. In general, chi-square statistics indicate that the most important variable is D À1 , the second most important is crown ratio, and the third most important predictor is BAL. The relative importance of crown ratio appears to be greater for shade tolerant species (®r, beech, spruce) than for shade intolerant species (larch, Scots pine, oak). Examination of graphs of observed vs. predicted mortality rates reveals that the species-speci®c mortality models are all well behaved, and match the observed mortality rates quite well. The D À1 transformation is¯exible, as can be seen by comparing the rather different mortality rates of larch and Scots pine. Predicted and observed mortality rates with respect to crown ratio are quite close to the observed mortality rates for all but the smallest crown ratios (CR<20%), a class with very few observations. Finally, the logistic mortality models passed a validation test on independent data not used in parameter estimation. The key ingredient for obtaining a good mortality model is a data set that is both large and representative of the population under study, and the Austrian National Forest Inventory data satisfy both requirements.

Vogiatzakis, I. N., Griffiths, G. H. & Bacchetta, G. 2005: Human impacts on Quercus suber habitats in Sardinia: Past and present. Bot. Chron. 18(1): 293-300. Quercus suber L. is a species confined to the centre and western Mediterranean basin. On the island of Sardinia its distribution is limited mainly by soils. Apart from its economic significance to local communities, cork oak habitats are recognised as having both cultural and biodiversity value at a European level. Although traditionally associated with human activities these habitats are today under increasing threat. Among the problems that affect cork oak habitats on the island are soil erosion and loss of organic matter due to ploughing and seeding for pasture. Stock numbers have increased while grazing cattle have been replaced by sheep and are proven to be particularly damaging especially to cork oak regeneration. Although the species is a passive pyrophyte, frequent fires render the trees susceptible to fungal and defoli...

Density Functional calculations have proven to be a powerful tool to study the ground state of many materials. For finite temperatures the situation is less ideal and one is often forced to rely on models with parameters either fitted to zero temperature first principles calculations or experimental results. This approach is especially unsatisfactory in inhomogeneous systems, nano particles, or other systems where the model parameters could vary significantly from one site to another. Here we describe a possible solution to this problem by combining classical Monte Carlo calculations-the Wang-Landau method[2] in this case-with a firs principles electronic structure calculation, specifically our locally selfconsistent multiple scattering code (LSMS)[3]. The combined code shows superb scaling behavior on massively parallel computers. The code sustained 1.836 Petaflop/s on 223,232 cores of the Cray XT5 jaguar system at Oak Ridge.

A dehesa is a multipurpose agroforestry system with scattered oaks. This study focuses on the influence of trees on soil chemical fertility and on the consequences of dehesa land use for soil fertility and nutritional status of trees. To achieve that we have studied the content of several nutrients in soils and tree leaves in four Spanish dehesas, considering three types of land use: scattered holm oak with an understorey of either native grasses (G), shrubs (E) or crop (C: either fertilized or unfertilized). We randomly selected six oaks per farm and land use for soil and tree leaf sampling. Soil samples were taken at five distances from each tree trunk (2, 5, 10, 15, and 20 m) at a depth of 0–30 cm. SOM, CEC, total and mineral-N, available-P, and exchangeable Ca, Mg and K were analysed. Foliar samples were collected from every tree in two consecutive years (2002 and 2003) at leaf maturity. The total content of N, P, K, Ca, and Mg was determined. Soils of C plots showed significantly higher contents for most of the nutrients studied than G ones. Cropping also affected trees positively, with higher foliar contents of N and K in C plots than in G ones. Foliar content did not decrease for any nutrient, and tree-crop interaction is interpreted as a mechanism of complementarity in terms of nutrient use. Shrub encroachment led to a higher content of organic-N and exchangeable cations in soils, but to a decrease in mineral N and available-P. The tree foliar contents of N, Mg, and Ca were lower in E plots than in G plots, probably as a consequence of the tree-shrub competition for those nutrients. By contrast, P content of tree leaves increased significantly in E plots compared to G plots.

This study concerned an experimental truffle bed of downy oaks infected by the ectomycorrhizal fungus Tuber melanosporum and planted in 1983. The presence of T. melanosporum creates rounded areas with little herbaceous cover, termed AbrulisB, where carpophores are found. Thê investigation was aimed at relating the occurrence and carpophore production of T. melanosporum to soil properties, i.e., organic matter, structure, aeration and fertility, expressed in terms of total organic C, aggregate size classes, DTPA-extractable Fe and Mn, and host plant height. Data were Ž . processed by multivariate geostatistical techniques. A linear model of coregionalization LMC Ž . Ž . Ž . including i a nugget effect, ii a short-range spherical structure with a range of 7 m and iii a long-range spherical structure with a range of 32 m, was fitted to the experimental direct and Ž . cross-variograms of the investigated properties. Factorial kriging analysis FKA was used to separate the sources of variation of the data according to the spatial scale at which they operate, and to summarize and map them in terms of spatial factors. An indicator approach was adopted to estimate and map the conditional probability of presence and fructification of T. melanosporum. The visual comparison between the spatial pattern of the long-range structure of the first regionalized factor with the probability map of finding brulis plus carpophore production revealed ) Corresponding author. A. Castrignano . 0016-7061r00r$ -see front matter q 2000 Elsevier Science B.V. All rights reserved.

1. 5054 adult beetles of 144 species were collected in a total of 696 1-m 2 collecting trays by knockdown insecticide fogging of 36 different oak trees in closed canopy woodland at Richmond Park, U.K., with three of the trees sampled on each of 12 dates, at 2-to 3-week intervals, between April and October 1984.

O ur ohjective is to descrihe a multi-layer model of C.r canopy processes that effectively simulates houri)' C02 :uul latent ener gy (U~) lluxcs in a mixed deciduous Quercus-Acer (oak-maple) st'.111d in c~ntral l\ l~1ssac~1u selts, US/\. The key hy pothesis J!OVe rnmg the b1oloA1cal component of the model is Urnt stomata! conductance (g,.) is var ied s o that d ail y carbon uptake per unit of foliar nit r oj:!en is maximized wit hin the limitations of ca1101>Y water avr1ilability. T he h ydraulic system is modelled as :m a nalo~ue to simple electr ical circuits in parallel. includinJ! a separate soil hydraulic resistance. plant resistance and plant capacitance for each c:m op y layer. Stomata! openin(! is initially controlled to conserve plant water stores and delay the o nset or water stress. Stomata! clos ure at :i threshold minimum l~1f water potential prevents xyle m cavitation and contr ols the maximum r:itc of wate r llux through the h ydraulic system. We show a strong correlat ion between predicted hourly C0 2 exchange rate (r2 = 0•86) and LE (r 2 = 0•87) with independent whole-forest measurements made by the eddy correlation method during the s ummer of 1992. Our theoretical derivation s hows that observed relationships between C0 2 assimilation a nd LE nux can he explained on the basis of s tomata! behaviour 01>timizing c:irhon gain, and provides mt exi>licit link hetwecn canopy structure, soil pro1>erties. atmos pheric conditions and stomatal conductance.

Nuclear ribosomal DNA sequences encoding the 5.8S RNA and the Xanking internal transcribed spacers (ITS1 and ITS2) were used to test the phylogenetic relationships within 12 Italian Quercus taxa (Fagaceae). Hypotheses of sequence orthology are tested by detailed inspection of some basic features of oak ITS sequences (i.e., general patterns of conserved domains, thermodynamic stability and predicted conformation of the secondary structure of transcripts) that also allowed more accurate sequence alignment. Analysis of ITS variation supported three monophyletic groups, corresponding to subg. Cerris, Schlerophyllodrys (D Ilex group sensu Nixon) and Quercus, as proposed by Schwarz [Feddes Rep., Sonderbeih. D, 1-200]. A derivation of the "Cerris group" from the "Ilex group" is suggested, with Q. cerris sister to the rest of the "Cerris group." Quercus pubescens was found to be sister to the rest of the "Quercus group." The status of hybrispecies of Q. crenata (Q. cerris £ Q. suber) and Q. morisii (Q. ilex £ Q. suber) was evaluated and discussed. Finally, the phylogenetic position of the Italian species in a broader context of the genus is presented. The utility of the ITS marker to assess the molecular systematics of oaks is therefore conWrmed. The importance of Italy as a region with a high degree of diversity at the population and genetic level is discussed.

The pinyon/juniper woodlands of the Great Basin were a vital source of structural wood and energy products for the mining industry from the 1860's to the 1930's. Pinyon and juniper were cut extensively for fuel wood and for the prod uction of charcoal, the only available fuel or energy source for the smelters of central Nevada. Firewood and fence post for ranches wexe also important uses of pinyon and juniper. Deforestation by cutting, promiscuous burning continued unabated until the 1920's and 1930's, when fossil fuels, substitute types of structural wood, and fire control combined to decrease disturbance in this vegetation type.

Repeated oak decline and mortality events have occurred in the Ozark region for decades and probably longer. We sampled an age sequence of 1,259 black and scarlet oaks (Quercus velutina Lam. and Quercus coccinea Muench.) to better describe the process of oak decline and mortality in the red oak group (subgenera Erythrobalanus). Trend in basal area increment (BAI) over the most recent 40 years was used to establish three vigor classes for trees with decreasing, stable, or increasing growth (Declining, Stable, or Healthy). We compared crown condition measures with absolute BAI and boundary line BAI, a measure of radial growth adjusted for tree size. A pulse of mortality was found to occur just subsequent to the most recent drought, although decline often started decades previously. Time series of individual tree BAI suggests that half of all oak decline events were incited by one or two drought-related step-changes in growth and variance. Predisposing factors to decline generally showed significant but weak relationships with crown conditions. Surviving oaks growing in high-mortality stands had poorer crown conditions and grew more slowly than trees in low-mortality stands. When recently dead trees were accounted for, the same high-mortality stands had significantly greater predecline basal area and stocking than low-mortality stands. Thus, a less competitive growth environment may afford some buffer to drought stress before oak decline but does not appear to help afflicted stands improve their growth and vigor. FOR. SCI. 54(1):8 -20.

Chondrosarcomas are malignant cartilage-forming tumors that represent the second most common malignant solid tumor of bone. These biologically poorly understood neoplasms vary considerably in clinical presentation and biologic behavior. Chemotherapy and radiation therapy are generally ineffective. Here we describe the establishment and characterization of a new human chondrosarcoma cell line named ch-2879, and we compare the cell line with its tumor of origin. The cell line was established from a recurrent grade 3 chondrosarcoma of the chest wall and characterized by growth kinetics and morphologic studies. Immunocytochemistry and RT-PCR were performed to examine the expression of cartilage-specific phenotypes. Genetic characterization was performed using cytogenetics, fluorescence in situ hybridization, flow cytometry, and molecular techniques for analysis of the genes implicated in cell cycle control, amplification of MDM2, CDK4, and Cyclin D1, and mutations in the p53 gene. ch-2879 cells were subcultured for more than 80 passages. They expressed vimentin, HNK-1, HBA-71, Ki-67, cyclin D1, Fli-1, S-100, p21, p27, and p53 and were negative for cytokeratin, EMA, p14, p16, MDM2, Rb, and c-erb-b2 antigens. Cytogenetically the recurrent tumor showed a hyperhaploid karyotype with clonal numerical and structural abnormalities. The sole structural abnormality was a chromosome derivative of a t(1;21) translocation. The cell line at passage 3 showed two populations: the hyperhaploid and an exactly duplicated, hypotriploid population. After the 18th passage, only the hypotriploid population was present. The cells expressed collagen 2. Molecular comparison of the primary and recurrent tumor evidenced an in vivo molecular change consisting of a deletion of 9p21 genes in the recurrence, probably caused by a selection process. Because of its gene expression profile, including expression of genes implicated in chondrogenesis in uncoated plastic dishes, this cell line may prove useful for cellular and molecular studies as well as studies of chondrosarcoma characterization and treatment. (Lab Invest 2003, 83:877-887).

Background: Pollen from trees of the order Fagales are important allergen sources in most parts of the world. Clinical, immunochemical, and molecular biology studies indicate that they contain cross-reactive allergens. The major birch pollen allergen, Bet v 1, and birch profilin, Bet v 2, a highly crossreactive allergen, have been cloned and expressed in Escherichia coli. Objective: The purpose of this study was to demonstrate the presence of allergens in Fagales pollens that share IgE epitopes with recombinant Bet v 1 and Bet v 2 and to determine the percentage of birch, alder, hornbeam, hazel, and oak pollen-specific IgE that can be preabsorbed with rBet v 1 and rBet v 2 from 102 sera of different populations of subjects allergic to Fagales tree pollen. Methods: The presence of rBet v 1-and rBet v 2-homologous allergens in tree pollen extracts was investigated by IgE immunoblot inhibition experiments, and the percentage of tree (birch, alder, hornbeam, hazel, and oak) pollen-specific IgE that was bound by a mixture of rBet v 1 and rBet v 2 was determined by RAST-based quantitative IgE inhibition experiments. The clinical significance of IgE antibody cross-reactivity was studied by skin prick testing with rBet v 1, rBet v 2, and Fagales pollen extracts. Results: Natural birch, alder, hornbeam, hazel, and oak pollen contain allergens that share IgE epitopes with rBet v 1 and rBet v 2. A combination of rBet v 1 and rBet v 2 accounted for 82% of tree pollen-specific IgE on average. Most of the tree pollen-specific IgE was directed against rBet v 1. Conclusion: rBet v 1 and rBet v 2 contain most of the Fagales pollen-specific IgE epitopes and may therefore substitute natural tree pollen extracts not only for diagnosis but also for patient-tailored immunotherapy of tree pollen allergy. (J Allergy Clin Immunol 1998;102:579-91.)

When a community or ecosystem is lost, some of its properties may remain, leaving behind an ecological memory. The soil properties, spores, seeds, stem fragments, mycorrhizae, species, populations and other remnants of the previous inhabitants contribute to shaping the replacement community and building a new ecosystem. The loss of ecological memory for the natural stability domain of a site reduces ecosystem resilience and enables alien invasive species to become established more easily. These invasives may eventually create a new ecosystem with its own ecological memory and resilience. These new ecosystems are described here as novel ecosystems and are placed in the context of adaptive cycles. Ecological restoration of urban ecosystems requires removing the ecological legacy of invasive alien species. To be successful, invasive species control must address both internal within patch memory of invasives and external between patch memory. The restoration of Garry oak ecosystems (Quercus garryana), by students of the Restoration of Natural Systems Program at the University of Victoria, British Columbia, and a number of other examples are presented here that highlight why ecological memory is especially important in urban ecosystems.

Analysis of wood charcoal that was conducted as a part of an interdisciplinary project at Pyeonggeo-dong, a multi-period agricultural complex located in Jinju, South Korea, reveals oak (Quercus sp.) to be the most commonly encountered wood over the period of 4000-1500 cal. B.P. The charcoal data indicate that Quercus was one of the most abundant woody plants in the surrounding vegetation, although its dominance in the charcoal assemblage may partly represent preferential human selection in the past. The data suggest that Quercus-dominant forest declined with the growth of a secondary forest of Platycarya strobilacea around the site from about A.D. 300. This change postdates by more than a thousand years the earliest evidence of largescale agriculture, which is visible in the form of carbonized crops and large tracts of prehistoric agricultural fields. A relatively large number of pit dwellings for the Three-Kingdoms period (ca. A.D. 300-500) at Pyeonggeo-dong suggests that this late sign of human impact on vegetation is related to the extension of agricultural fields to previously uncultivated hilly areas and/or increased needs for fuel and timber caused by high population density of the site.

In order to study the possible interactions between air poll~.ion and climate coaditions in Mediterranean evergream broadleaf species, since 1987 we have been monitoring the annual and infra-annual variations in crown density of Quercus ilex L. (holm oak) in a p~t sample plot. The behaviour of crown deazsity has been compared with litterfall pattern and aging processes in leaves. The results of this ~udy confirm the important impact of climate on crown condition in Meditea-raneeaa broadleaves, so that even the role of nonacute pollution ~ be disguised. Xeromorph adaptaticlas in hohn oak leaves are also a medaanism providing a greater protection against polha, ants.

Alcohol abuse and maxillofacial trauma, particularly that due to interpersonal violence, have a well-established relationship in the literature. We present a retrospective audit comparing the role of alcohol in maxillofacial trauma between Selly Oak Hospital in Birmingham, United Kingdom and Westmead Hospital in Sydney, Australia, and the association between alcohol involvement and patient demographics, including age, sex, marital status, and employment status. Also presented are the differences between the two centers in terms of mechanisms and types of injuries and the locations where these injuries were sustained. Alcohol was involved in 34.78 and 30.77% of patients at Westmead and Birmingham, respectively. A multiple logistic regression analysis revealed a reduced likelihood of alcohol involvement in episodes of maxillofacial trauma where patients were unemployed (P 5 .04), and where injuries were sustained secondary to mechanisms other than assault (P ! .001) and in locations other than pubs and nightclubs (P 5 .024). There appeared to be no statistically significant contribution to the likelihood of alcohol involvement by treating center, marital status, patient sex, or age. Alcohol continues to be a strong driving factor in cases of maxillofacial trauma, particularly those due to alleged assault, with a typical patient demographic of the gainfully employed frequenting drinking establishments being most at risk for alcohol-related trauma, most commonly sustaining their injuries secondary to assault. Identifying patient groups most at risk is a key step in developing public health strategies aimed at prevention, and our findings would appear to suggest this group of patients as being the most worthwhile to target with measures aimed at reducing alcohol-fueled maxillofacial trauma. Ó

In this study, a distance-independent mixed model was developed for predicting the diameter growth of individual trees in Mediterranean oak (Quercus pyrenaica Willd.) coppices located in northwest Spain. The data used to build the model came from 41 permanent plots belonging to the Spanish National Forest Inventory with the dependent variable being 10-year diameter increment over bark for trees larger than 7.5 cm at breast height. The basic field data required for predictions had been divided into four main groups: size of the tree, stand variables, competition indices and biogeoclimatic variables. The most significant independent variables were the individual-tree diameter, the basal area of trees larger than the subject tree, dominant height, site index and biogeoclimatic stratum. The model was defined as a mixed linear model with random plot effect, achieving an efficiency of 44.38%. The accuracy of the model was tested against the modelling data and against independent data from the same stands. Mixed model calibration of diameter increment was carried out with the independent data using a different sample of complementary observations of the dependent variable. The calibrated model was an improvement on the trivial model, which assumes constancy in diameter increment for a short projection period, especially the pattern of residuals with respect to predicted diameter and the independent variables. #

Advanced Tokamak (AT) research in DIII-D focuses on developing a scientific basis for steady-state, high performance operation. For optimal performance, these experiments routinely operate with β above the n=1 no-wall limit, enabled by active feedback control. The ideal wall β limit is optimized by modifying the plasma shape, current and pressure profile. Present DIII-D AT experiments operate with f BS ≈50%-60%, with a longterm goal of ~90%. Additional current is provided by neutral beam and electron cyclotron current drive, the latter being localized well away from the magnetic axis (ρ≈0.4-0.5). Guided by integrated modeling, recent experiments have produced discharges with β≈3%, β Ν ≈3, f BS ≈55% and noninductive fraction f NI ≈90%. Additional control is anticipated using fast wave current drive to control the central current density.

Atmospheric transport models are used in studies of atmospheric chemistry as well as aerobiology. Atmospheric transport models in general needs accurate emissions inventories, which includes biogenic emissions such as Volatile Organic Compounds (VOCs) and pollen. Trees are important VOC and pollen sources and a needed requirement is specie distribution which takes into account important species such as Betula and Alnus. We present here a detailed tree species inventory covering Europe, parts of Africa and parts of Asia.

The Black Stork Ciconia nigra, following an expansion on European scale, started breeding in Italy in 1994 with one pair in the Piedmont Region and one in the Calabria Region. Since then, the breeding pairs established in Italy have progressively increased up to 18 in 2016, and they are currently in Piedmont, Lazio, Campania, Molise, Apulia, Basilicata and Calabria. However, the number of breeding pairs could be higher than 20, as indicated by records and observations of adults and juveniles, during the breeding period in potentially suitable nesting areas. Despite the low population density in Italy, the trend in the breeding population in Northwest and in Southern Central regions seems to show a slight and high increase respectively. Productivity, breeding success and fledging rate have been considered and analysed. A difference between the two macro areas has been found in the choice of nesting sites, which is on trees for Northwest couples, and cliffs for Southern Central couple...

Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700-900 8C whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830 8C and a steam/biomass ratio of 0.6-0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained.

&mdash; Morphological variability of oaks in Lorraine (northeastern France), was studied. Eight hundred oaks were sampled in 80 stands covering a broad range of ecological variability; 10 leaves, fruits and current-year shoots were collected per tree. Thirty-four morphological variables were measured and analyzed by factorial correspondance analysis. It is concluded that Q robur and Q petraea are clearly separated with a few morphologically intermediate individuals (3.5%). Q petraea is more variable than Q robur. Q pubescens and Q robur are totally isolated from each other, while Q petraea and Q pubescens form a continuum. Many variables discriminate between these 3 species; some of them have been little known prior to now (pilosity, presence of intercalary ribs). These results are compared with those from other parts of Europe. taxonomy / morphometrics / hybridization / introgression / Quercus robur / Quercus petraea / Quercus pubescens Résumé &mdash; Variabilité morphologique des chênes dans le Nord-Est de la France; résultats préliminaires. Nous avons étudié la différenciation morphologique des chênes pédonculé, sessile et pubescent dans le Nord-Est de la France. L'échantillonnage a porté sur 80 populations provenant de stations représentant toute la gamme de variation des milieux de chênaies en Lorraine. Sur 10 arbres par population, 10 feuilles, infruiescences et rameaux de l'année ont été prélevés. Trentequatre variables morphologiques ont été mesurées et analysées par analyse factorielle des correspondances. On observe une très nette séparation des chênes sessile et pédonculé, avec seulement 3,5% d'individus morphologiquement intermédiaires, ainsi qu'un isolement total du chêne pubescent et du chêne pédonculé. Par contre, les chênes sessile et pubescent forment un continuum. Le chêne pédonculé est moins variable que le chêne sessile. De nombreuses variables discriminent ces 3 espèces, dont certaines peu connues jusqu'alors (pilosité, présence de nervures intercalaires). Ces résultats sont comparés à ceux obtenus par ailleurs en Europe. taxonomie / morphométrie / hybridation / introgression / Quercus robur / Quercus petraea / Quercus pubescens

Size distributions of particulate hopanes, steranes, and polycyclic aromatic hydrocarbons (PAHs) were measured in the exhaust from four heavy-duty diesel vehicles (HDDVs) operated under idle, creep, transient, and two highspeed driving modes. Particulate matter was collected using a chassis dynamometer and a dilution sampling system equipped with cascade impactors and filter samplers. Samples were extracted using organic solvents and analyzed using gas chromatography-mass spectrometry. Size distributions of hopanes and steranes were functions of engine load conditions and vehicle technology. Hopanes and steranes peaked in size ranges larger than 0.18 µm aerodynamic particle diameter under light load conditions and less than 0.10 µm aerodynamic particle diameter under heavier load conditions. The eight hopane size distributions emitted from newer technology (>1998) vehicles were unimodal while the four hopane size distributions emitted from older technology vehicles (<1992) were bimodal. Similar trends between older and newer vehicles were not observed for sterane size distributions. The PAH composition emitted from HDDVs was a function of driving cycle and vehicle technology. Light driving cycles produced quantifiable emissions of 3, 4, 5, and 6 ring PAHs (including coronene). Heavier driving cycles produced only the 3 and 4 ring PAHs in quantifiable amounts. PM1.8 and PM0.1 source profiles constructed using the relative abundance of hopanes and steranes to total organic carbon were functions of vehicle load condition. Increasing load reduced the relative abundance of motor oil tracers in the PM1.8 size fraction and increased the abundance of these tracers in the PM0.1 size fraction. The relative abundances of PAHs in the PM0.1 and PM1.8 size fractions emitted from the oldest vehicle tested (1985 HDDV) were significantly higher than for any other vehicle tested.

Carbon storage in aboveground tree biomass and soil organic matter (in depth of A layer development i.e., up to 20 cm) was studied in 22-32 year-old post-mining sites in the northwest of the Czech Republic. Four replicated sites afforested with different tree species (spruce, pine, larch, oak, lime or alder) were compared with sites left to natural regeneration which were dominated by aspen, birch and willow. No topsoil was applied at the sites; hence carbon accumulation resulted from in situ soil development on alkaline tertiary clays that were dumped on the heaps. In aboveground tree biomass, carbon storage ranged from 17.0 ± 5.9 (mean ± SEM) to 67.6 ± 5.9 t ha -1 and the rate of C accumulation increased from 0.60 ± 0.09 to 2.31 ± 0.23 t ha -1year -1 (natural regeneration \ pine \ spruce \ oak \ lime \ alder \ larch). Carbon storage in soil organic matter varied from 4.5 ± 3.7 to 38.0 ± 7.1 t ha -1 and the rate of C accumulation in soil organic matter increased from 0.15 ± 0.05 to 1.28 ± 0.34 t ha -1 year -1 at sites in the order: natural regeneration \ spruce \ pine, oak \ larch \ alder \ lime. Carbon storage in the soil was positively correlated with aboveground tree biomass. Soil carbon was equivalent to 98.1% of the carbon found in aboveground tree biomass at lime dominated sites, but only 21.8% at sites with natural regeneration. No significant correlation was found between C storage in soil and aboveground litter input. Total soil carbon storage was correlated positively and significantly with earthworm density, and occurrence of earthworm cast in topsoil, which indicated that bioturbation could play an important role in soil carbon storage. Hence, not only restoring of wood production, but also restoring of soil community is critical for C storage in soil and whole ecosystem.

haired mature leaves of O. europaea was ineffective in ab-Quartz fibre-optic microprobes were used to monitor the sorbing most of the incident UV-B and UV-A radiation. UV light microenvironment beneath trichome layers of the xeromorphic leaves of two Mediterranean evergreen sclerophylls, and visible spectra beneath trichome layers of O. europaea in mature leaves confirmed that the light microenvironment on Olea europaea and Quercus ilex. Young developing leaves of both plants were densely pubescent on both surfaces of the the epidermis was deprived in the UV-B, UV-A and partly in the blue spectral regions. It is proposed that the occurrence of lamina, whereas the mature leaves were pubescent only on the abaxial side. Trichome layers of young as well as of a

Applying mulch on and around the root ball of newly installed trees is standard practice in many locations (Watson and Himelick 1997). However, mulch usage is less common in drier locations such as the southwestern United States. Applying mulch around the base of the tree has ...

A field study was conducted to measure the predictability of tree decay based on visual assessments. Predictions made by individual arborists, tree surgeons, and forest ecologists were compared with the actual amounts and distributions of decay in 10 hazardous laurel oaks (Quercus hemisphaerica) that were dissected. The mean deviations of predicted area of decay and predicted loss in strength from actual values were 0.4% and 2%, respectively. The interquartile range for predicted decay area was +12 to -15%; for strength loss it was +8 to -8%. Accuracy of the predictions improved with feedback. The results of this study suggest visual assessment can be a reliable means of predicting the internal extent of decay and hollow in potentially hazardous urban trees.

A survey of the crown status of Turkey oak (Quercus cerris L.) trees in the boron-rich area at Travale (Southern Tuscany, Italy) was carried out in order to evaluate the impact of geothermal power plants. Crown thinness was assessed and morphological and chemical tests were carried out on leaf samples. Leaf area and dry weight were determined as morphological parameters; while the chemical measurements performed included nitrogen and potassium (among the nutrients), and sulphur, boron, arsenic and mercury (among the elements of geothermal origin). Acute damage was found only in the area immediately adjacent to the outlets and is the result of the action of boron; crown thinness, on the other hand, is affected by the nature of the geological substrate. High quantities of sulphur were found in leaves throughout the survey area, due both to the availability of this element in the geopedological substrate and to the atmospheric input of geothermal H2S. The leaf content of this element correlates negatively with the distance from the power plants. Boron and arsenic are the other geothermal origin elements most commonly found in plant matrices. The presence of these two elements is associated with leaf area reduction and/or an increase of specific dry weight. The most significant impact on the environment appears to be exerted by the southernmost power plant, where there is an unfavourable ratio between quantity of emissions and height of the chimneys.

1. We investigated the effect of moderate eutrophication on leaf litter decomposition and associated invertebrates in five reference and five eutrophied streams in central Portugal. Fungal parameters and litter N and P dynamics were followed in one pair of streams. Benthic invertebrate parameters that are considered useful in bioassessment were estimated in all streams. Finally, we evaluated the utility of decomposition as a tool to assess stream ecosystem functional integrity.2. Decomposition of alder and oak leaves in coarse mesh bags was on average 2.3–2.7× faster in eutrophied than in reference streams. This was attributed to stimulation of fungal activity (fungal biomass accrual and sporulation of aquatic hyphomycetes) by dissolved nutrients. These effects were more pronounced for oak litter (lower quality substrate) than alder. N content of leaf litter did not differ between stream types, while P accrual was higher in the eutrophied than in the reference stream. Total invertebrate abundances and richness associated with oak litter, but not with alder, were higher in eutrophied streams.3. We found only positive correlations between stream nutrients (DIN and SRP) and leaf litter decomposition rates in both fine and coarse mesh bags, associated sporulation rates of aquatic hyphomycetes and, in some cases, total invertebrate abundances and richness.4. Some metrics based on benthic invertebrate community data (e.g. % shredders, % shredder taxa) were significantly lower in eutrophied than in reference streams, whereas the IBMWP index that is specifically designed for the Iberian peninsula classified all 10 streams in the highest possible class as having ‘very good’ ecological conditions.5. Leaf litter decomposition was sufficiently sensitive to respond to low levels of eutrophication and could be a useful functional measure to complement assessment programmes based on structural parameters.

A rainfall interception measuring system was developed and tested for open-grown trees. The system includes direct measurements of gross precipitation, throughfall and stem¯ow, as well as continuous collection of micrometeorological data. The data were sampled every second and collected at 30-s time steps using pressure transducers monitoring water depth in collection containers coupled to Campbell CR10 dataloggers. The system was tested on a 9-year-old broadleaf deciduous tree ( pear, Pyrus calleryana`Bradford') and an 8-yearold broadleaf evergreen tree (cork oak, Quercus suber) representing trees having divergent canopy distributions of foliage and stems. Partitioning of gross precipitation into throughfall, stem¯ow and canopy interception is presented for these two mature open-grown trees during the 1996±1998 rainy seasons. Interception losses accounted for about 15% of gross precipitation for the pear tree and 27% for the oak tree. The fraction of gross precipitation reaching the ground included 8% by stem¯ow and 77% by throughfall for the pear tree, as compared with 15% and 58%, respectively, for the oak tree. The analysis of temporal patterns in interception indicates that it was greatest at the beginning of each rainfall event. Rainfall frequency is more signi®cant than rainfall rate and duration in determining interception losses. Both stem¯ow and throughfall varied with rainfall intensity and wind speed. Increasing precipitation rates and wind speed increased stem¯ow but reduced throughfall. Analysis of rainfall interception processes at dierent time-scales indicates that canopy interception varied from 100% at the beginning of the rain event to about 3% at the maximum rain intensity for the oak tree. These values re¯ected the canopy surface water storage changes during the rain event. The winter domain precipitation at our study site in the Central Valley of California limited our opportunities to collect interception data during non-winter seasons. This precipitation pattern makes the results more speci®c to the Mediterranean climate region.

The Socioeconomic Impact of Truffle Cultivation in Rural Spain. Commercial black truffle (Tuber melanosporum) plantations have been promoted in Europe with the intention of benefiting rural economies while conserving biodiversity through the expansion of oak woodlands. In this context, a socioeconomic study was conducted around the town of Sarrión in eastern Spain, where government subsidies have supported oak reforestation and truffle cultivation in unproductive hilly areas since 1987. Currently there are about 4,500 ha of truffle orchards in the surrounding county and 530 members in the local truffle association, which has provided a key forum for truffle cultivators to share technical, financial and administrative experiences. Structured interviews were carried out in 2002 with a number of orchard owners, as well as representatives of financial and governmental institutions. Truffles, which are harvested using trained dogs, typically fetch local cultivators average prices of 220-670 EUR/kg, although retail prices of highquality specimens may reach twice this amount. In addition to the direct economic impact, an increase in local land prices was also documented, as well as a tendency for continued expansion of truffle orchards, and thus oak reforestation. In conclusion, the promotion of truffle cultivation through autonomous community and provincial government subsidies, in conjunction with support by local banks, a dedicated local truffle association, and growing interest on behalf of local farmers, seems to have achieved the mutual goals of biodiversity conservation and improving the rural economy in this region of Spain.

Isoprene emission capacity measurements are presented from 18 North American oak (Quercus) species and species from six other genera previously found to emit signi"cant quantities of isoprene. Sampling was conducted at physiographically diverse locations in North Carolina, Central California, and Northern Oregon. Emissions from several sun leaves of each species were measured at or near standard conditions (leaf temperature of 303C and photosynthetically active radiation of 1000 mol m\ s\) using environmentally controlled cuvette systems and gas chromatography with reduction gas detectors. Species mean emission capacity ranged from 39 to 158 g C g\ h\ (mean of 86), or 22 to 79 nmol m\ s\ (mean of 44). These rates are 2}28 times higher than those previously reported from the same species, which were summarized in a recent study where isoprene emission rates were assigned based on published data and taxonomy. These discrepancies were attributed to di!erences in leaf environment during development, measurement technique (branch or plant enclosure versus leaf enclosure), and lack of environmental measurements associated with some of the earlier branch enclosure measurements. Mass-based emission capacities for 15 of 18 oak species, sweetgum (Liquidambar styraciyua), and poplars (Populus trichocarpa and P. deltoides) were within ranges used in current biogenic volatile organic compound (BVOC) emission models, while measured rates for the remaining three oak species, Nyssa sylvatica, Platanus occidentalis, Robinia pseudoacacia, Salix nigra, and Populus hybrids (Populus trichocarpa ; P. deltoides) were considerably higher. In addition, mean speci"c leaf mass of the oak species was 30% higher than assumed in current emission models. Emission rates reported here and in other recent studies support recent conclusions that isoprene emission capacities for sun leaves of high emitting species may be better represented by a value of 100$50 g C g\ h\ during hot summer conditions. We also "nd that intermediate isoprene emission rates previously suggested for some tree species may not represent their true emission capacities, and that broadleaf plant species may have either low ( (1.0 g C g\ h\) or very high ( &100 g C g\ h\) genetic capacity to emit isoprene when mature foliage is exposed to a high ambient temperature and light environment. Published by Elsevier Science Ltd.

& Introduction The limited ability of Quercus species to regenerate naturally in Mediterranean forests has led to the development of various artificial regeneration methods; however, there is no general consensus as to what specific method is the best one for this purpose. & Material and methods In this work, we assessed morphology, growth and survival of two Quercus species (Quercus ilex ssp. ballota and Quercus suber) using two different methods of artificial regeneration (viz. direct seeding and planting) and two seedling ages (1-year-old seedlings and 3-year-old seedlings) in southern Spain. & Results and discussion The 1-year-old seedlings of both species were found to exhibit the highest survival percentages and direct-seeded plants intermediate survival values. For direct-seeded plants, seed mass was found to have a significantly positive effect on the establishment success in both species. No clear-cut trend in survival was detected in the 3year-old seedlings. The survival of the 3-year-old Q. suber seedlings and the direct-seeded plants was similar, but not in Q. ilex, where the survival of the 3-year-old seedlings was the lowest. The latter result may have been a consequence of cultivation in smaller containers leading to root deformation and limiting plant access to water. Differences in survival could not be ascribed to morphological and growth variables or stomatal conductance. & Conclusion Based on the results, all three artificial regeneration methods can be similarly effective provided appropriate nursery cultivation conditions are used and seeds are protected against predators, the best choice in each case being dictated by the particular restoration goals.

Plants have suberized cells that act as protective interfaces with the environment or between different plant tissues. A lamellar structure of alternating dark and light bands has been found upon transmission electron microscopy~TEM! observation of cork cells and considered a typical feature of the suberized secondary wall. We observed cork cells from periderms of Quercus suber, Quercus cerris, Solanum tuberosum, and Calotropis procera by TEM after uranyl acetate and lead citrate staining. A lamellated structure was observed in S. tuberosum and C. procera but not in Q. suber and Q. cerris where the suberized cell wall showed a predominantly hyaline aspect with only a dark dotted staining. Removal of suberin from Q. suber cells left a thinner secondary wall that lost the translucent aspect. We hypothesize that the species' specific chemical composition of suberin will result in different three-dimensional macromolecular development and in a different spatial location of lignin and other aromatics. A lamellated ultrastructure is therefore not a general feature of suberized cells.

Baseline information on the biogeography of the species Quercus humboldtii Bonpl is presented. This species, commonly known as Roble, has many uses for local communities, but has recently been placed in the IUCN category of "low risk/conservation depending". Prior to initiating conservation efforts, it is important to have baseline information on the species. This study analyses the geographic distribution of the species, and examines its climatic adaptation. A database of all known observations of Q. humboldtii in Colombia and Panama is presented, including a new registry of the species between the Western and Central cordilleras, in the Serranía de San Lucas at 1.200 meters above sea level. The database was used to examine the species distribution. This is done using both a qualitative assessment of the points of observation, and through predictive species distribution modeling. The species is found across all three cordilleras of the northern Andean region, from the department of Nariño in Colombia to the southern regions of Panama. Q. humboldtii has a wide climatic adaptation, from low to high elevations (representing a mean temperature from 9.3 o C to 27.9 o C), and wet to dry environments (788mm/year -2681mm/year). The species could be split into two climatic clusters, with differing adaptations to mean temperature; low elevations and high elevations. The main municipalities where the species is likely to be found are listed. No climatically unique and geographically succinct clusters of Q. humboldtii populations are found, providing little evidence for splitting the species apart. Genetic and morphological studies are needed to reach concrete conclusions.

Crown defoliation of oak (Quercus robur and Q. petraea) was analysed in 808 trees during three forest condition surveys (1988, 1993, and 1999) in the southern Sweden. From 1988 to 1999 crown defoliation increased by more than 20%. Changes in crown defoliation were related to the pH in the upper 20-30 cm of the mineral soils, which was closely connected to other measures of soil fertility (cation exchange capacity, CEC and C/N ratio). Trees growing on soils with a high pH (≥4.00, in BaCl 2 filtrate), high CEC and low C/N ratio had significantly lower crown defoliation than trees growing on more acid soils (pH <4.00), indicating that less favourable soil conditions may further enhance oak decline. Age did not differentiate trees with respect to crown defoliation, indicating that decline in crown condition was not due to an age-related increase in crown transparency. Considering only trees younger than 100 years, a significant interaction was observed between changes in crown defoliation and soil pH. Trees younger than 100 years old growing on more acidic soils had a greater increase in crown transparency than trees on more basic soils between 1988 and 1999. Trees ≥100 years old had significantly higher defoliation on more acidic than on more basic soils, however defoliation dynamics of these trees over 1988-99 was not related to soil acidity. Two biotic agents (insect and fungal leaf infections) evaluated in this study did not prove to be important drivers of defoliation dynamics.

We analyse the consequences of traditional use on forest characteristics during the last millennium in a mountain area of Spanish Central System, using information contained in documents, as well as cartography and toponymy. In the Middle Ages the local forests were transformed into municipal dehesas (communal fenced woods), communal wood pastures and arable lands. Pinewoods located in areas above 1500 m decreased because of the high grazing pressure. In the fifteenth century two manors were created (Buitrago and Montesclaros). Livestock became an important factor during this period. As a consequence an open wood was formed and oak coppices were also abundant (the felling of this species was at that time permitted by the Ordinances). At the end of the period of traditional management, pinewoods were disappearing and the main forest areas were located only in municipal dehesas. The area of beech was reduced in favour of melojo oak and scrub, due to the lower sprouting capacity of the beeches and their lower drought tolerance. Open wood pastures remain only in the eastern part of the study area, where there has been less intense human intervention. After the abolition of manors in the nineteenth century, arable land increased in the western part of the area, which had a higher population density. In the twentieth century, both human and livestock pressure decreased substantially and pine species were reintroduced by reforestation. The primitive savannah was transformed into 'infilled savannah', while temperate species spread around their refuges in municipal woods.