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Beech
Kinds of Beech Terms modified by Beech Selected AbstractsA global change-induced biome shift in the Montseny mountains (NE Spain)GLOBAL CHANGE BIOLOGY, Issue 2 2003Josep Peñuelas Abstract Shifts in plant species and biome distribution in response to warming have been described in past climate changes. However, reported evidence of such shifts under current climate change is still scarce. By comparing current and 1945 vegetation distribution in the Montseny mountains (Catalonia, NE Spain), we report here a progressive replacement of cold-temperate ecosystems by Mediterranean ecosystems. Beech (Fagus sylvatica) forest has shifted altitudinally upwards by ca. 70 m at the highest altitudes (1600,1700 m). Both the beech forests and the heather (Calluna vulgaris) heathlands are being replaced by holm oak (Quercus ilex) forest at medium altitudes (800,1400 m). This beech replacement has been observed to occur through a progressive isolation and degradation of beech stands. In ,isolated' (small and surrounded by holm oaks) beech stands, beech trees are 30% more defoliated, beech recruitment is 41% lower, and holm oak recruitment is three times higher than in ,continental' (large and continuous) beech stands. The progressively warmer conditions, complemented by the land use changes (mainly the cessation of traditional land management) are the apparent causes, providing a paradigmatic example of global change affecting distributions of plant species and biomes. [source] Climatic limits for the present distribution of beech (Fagus L.) species in the worldJOURNAL OF BIOGEOGRAPHY, Issue 10 2006Jingyun Fang Abstract Aim, Beech (Fagus L., Fagaceae) species are representative trees of temperate deciduous broadleaf forests in the Northern Hemisphere. We focus on the distributional limits of beech species, in particular on identifying climatic factors associated with their present range limits. Location, Beech species occur in East Asia, Europe and West Asia, and North America. We collated information on both the southern and northern range limits and the lower and upper elevational limits for beech species in each region. Methods, In total, 292 lower/southern limit and 310 upper/northern limit sites with available climatic data for all 11 extant beech species were collected by reviewing the literature, and 13 climatic variables were estimated for each site from climate normals at nearby stations. We used principal components analysis (PCA) to detect climatic variables most strongly associated with the distribution of beech species and to compare the climatic spaces for the different beech species. Results, Statistics for thermal and moisture climatic conditions at the lower/southern and upper/northern limits of all world beech species are presented. The first two PCA components accounted for 70% and 68% of the overall variance in lower/southern and upper/northern range limits, respectively. The first PCA axis represented a thermal gradient, and the second a moisture gradient associated with the world-wide distribution pattern of beech species. Among thermal variables, growing season warmth was most important for beech distribution, but winter low temperature (coldness and mean temperature for the coldest month) and climatic continentality were also coupled with beech occurrence. The moisture gradient, indicated by precipitation and moisture indices, showed regional differences. American beech had the widest thermal range, Japanese beeches the most narrow; European beeches occurred in the driest climate, Japanese beeches the most humid. Climatic spaces for Chinese beech species were between those of American and European species. Main conclusions, The distributional limits of beech species were primarily associated with thermal factors, but moisture regime also played a role. There were some regional differences in the climatic correlates of distribution. The growing season temperature regime was most important in explaining distribution of Chinese beeches, whilst their northward distribution was mainly limited by shortage of precipitation. In Japan, distribution limits of beech species were correlated with summer temperature, but the local dominance of beech was likely to be dependent on snowfall and winter low temperature. High summer temperature was probably a limiting factor for southward extension of American beech, while growing season warmth seemed critical for its northward distribution. Although the present distribution of beech species corresponded well to the contemporary climate in most areas, climatic factors could not account for some distributions, e. g., that of F. mexicana compared to its close relative F. grandifolia. It is likely that historical factors play a secondary role in determining the present distribution of beech species. The lack of F. grandifolia on the island of Newfoundland, Canada, may be due to inadequate growing season warmth. Similarly, the northerly distribution of beech in Britain has not reached its potential limit, perhaps due to insufficient time since deglaciation to expand its range. [source] Spatiotemporal changes of beetle communities across a tree diversity gradientDIVERSITY AND DISTRIBUTIONS, Issue 4 2009Stephanie Sobek Abstract Aim, Plant and arthropod diversity are often related, but data on the role of mature tree diversity on canopy insect communities are fragmentary. We compare species richness of canopy beetles across a tree diversity gradient ranging from mono-dominant beech to mixed stands within a deciduous forest, and analyse community composition changes across space and time. Location, Germany's largest exclusively deciduous forest, the Hainich National Park (Thuringia). Methods, We used flight interception traps to assess the beetle fauna of various tree species, and applied additive partitioning to examine spatiotemporal patterns of diversity. Results, Species richness of beetle communities increased across the tree diversity gradient from 99 to 181 species per forest stand. Intra- and interspecific spatial turnover among trees contributed more than temporal turnover among months to the total ,-beetle diversity of the sampled stands. However, due to parallel increases in the number of habitat generalists and the number of species in each feeding guild (herbivores, predators and fungivores), no proportional changes in community composition could be observed. If only beech trees were analysed across the gradient, patterns were similar but temporal (monthly) species turnover was higher compared to spatial turnover among trees and not related to tree diversity. Main conclusions, The changes in species richness and community composition across the gradient can be explained by habitat heterogeneity, which increased with the mix of tree species. We conclude that understanding temporal and spatial species turnover is the key to understanding biodiversity patterns. Mono-dominant beech stands are insufficient to conserve fully the regional species richness of the remaining semi-natural deciduous forest habitats in Central Europe, and analysing beech alone would have resulted in the misleading conclusion that temporal (monthly) turnover contributes more to beetle diversity than spatial turnover among different tree species or tree individuals. [source] Phytogeographical evidence for post-glacial dispersal limitation of European beech forest speciesECOGRAPHY, Issue 6 2009Wolfgang Willner The post-glacial migration of European beech Fagus sylvatica has been addressed by many studies using either genetic or fossil data or a combination of both. In contrast to this, only little is known about the migration history of beech forest understorey species. In a review of phytosociological literature, we identified 110 plant species which are closely associated with beech forest. We divided the distribution range of European beech forests into 40 geographical regions, and the presence or absence of each species was recorded for each region. We compared overall species numbers per region and numbers of narrow-range species (species present in <10 regions). A multiple regression model was used to test for the explanatory value of three potential diversity controls: range in elevation, soil type diversity, and distance to the nearest potential refuge area. A hierarchical cluster analysis of the narrow-range species was performed. The frequency of range sizes shows a U-shaped distribution, with 42 species occurring in <10 regions. The highest number of beech forest species is found in the southern Alps and adjacent regions, and species numbers decrease with increasing distance from these regions. With only narrow-range species taken into consideration, secondary maxima are found in Spain, the southern Apennines, the Carpathians, and Greece. Distance to the nearest potential refuge area is the strongest predictor of beech forest species richness, while altitudinal range and soil type diversity had little or no predictive value. The clusters of narrow-range species are in good concordance with the glacial refuge areas of beech and other temperate tree species as estimated in recent studies. These findings support the hypothesis that the distribution of many beech forest species is limited by post-glacial dispersal rather than by their environmental requirements. [source] Inter- and intraspecific variation of stemflow production from Fagus grandifolia Ehrh. (American beech) and Liriodendron tulipifera L. (yellow poplar) in relation to bark microrelief in the eastern United States,ECOHYDROLOGY, Issue 1 2010J. Toland Van Stan II Abstract Stemflow is a spatially concentrated hydrologic input at the tree base. Prior work has documented the differential effects of stemflow from a wide range of plant species on ecohydrological processes, such as the alteration of soil pH and spatial patterning of understory vegetation. No known work has coupled stemflow yield with high resolution measurements of bark microrelief that definitively ascribe differential stemflow yield to bark microrelief. As such, our research objectives were to: (1) correlate inter- and intraspecific variation in stemflow yield to a quantitative bark microrelief scale and (2) compare and contrast stemflow for two co-occurring deciduous species,Fagus grandifolia Ehrh. (American beech) and Liriodendron tulipifera L. (yellow poplar). Using a newly developed instrument to measure bark microrelief, namely the LaserBarkÔ automated tree measurement system, in combination with an 11-month stemflow database for a broadleaved deciduous forest in eastern North America, it was found that bark microrelief values significantly differed between the two species [P = 0·000, F (1,19) = 49·32]. Funneling ratios [P = 0·000, H (1, 990) = 339·20] and stemflow generation [P = 0·000, H (1, 990) = 146·75] also significantly differed between the two species. Our results indicate that bark microrelief exerts a considerable effect on stemflow yield from F. grandifolia and L. tulipifera, possibly affecting water and solute flux to the forest floor. Copyright © 2009 John Wiley & Sons, Ltd. [source] Community structure of arboreal caterpillars within and among four tree species of the eastern deciduous forestECOLOGICAL ENTOMOLOGY, Issue 6 2003Keith S. Summerville Abstract., 1.,A seasonally replicated experimental design was used to address the question of how differences within and among host tree species affect arboreal caterpillar communities. 2.,Seasonal variation influenced caterpillar community composition most significantly, and the similarity among caterpillar assemblages did not necessarily follow the pattern of phylogenetic relatedness among host trees. 3.,Species richness and abundance of caterpillars were higher on oaks and maples than on American beech. Diversity partitioning models revealed that , diversity was only occasionally greater or less than expected by chance alone. 4.,When , diversity was significant, values tended to be greater than expected by chance among replicate trees within each species and lower than expected by chance among the four tree species. 5.,Differences among trees appeared important for determining patterns of species presence/absence for rare species and influencing patterns of species dominance within caterpillar assemblages. Differences among tree species had a significant effect on overall lepidopteran community composition and mean species diversity (i.e. , diversity). 6.,Because , diversity of caterpillars among host trees was lower than expected by chance, host specificity within the Lepidoptera may be less prevalent than thought previously. [source] Impact of common European tree species on the chemical and physicochemical properties of fine earth: an unusual patternEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2010L. Mareschal Case studies are necessary to assess the effects of changes to tree species on the physicochemical and chemical properties of soils. To achieve this, the fine earth under five tree species was investigated. This study was performed in the Breuil-Chenue experimental forest site located in the Morvan Mountains (France). This site contains two adjacent blocks with replicated stands. The native forest (old beech and oak coppice with standards) was partially clear-felled and replaced in 1976 with mono-specific plantations of European beech, Norway spruce, Laricio pine and Douglas fir. The same changes in soil properties were revealed in both blocks, thus confirming the tree species effect. The percentage of exchangeable acidity on the cation exchange capacity (CEC) was greater under spruce, Douglas fir and pine than under the other species. Spruce stands, and to a lesser extent those of Douglas fir and pine, had a less acidic soil pH than hardwood stands (which was unusual in view of the data in the literature) and smaller CEC values. The small quantities of carbon added to the soil under these tree species provide an explanation for these effects through a partial control of both CEC and pH. This case study thus demonstrated that the tree species effect was not unequivocal and different criteria are necessary for its interpretation. Tree species significantly influenced certain aspects of the chemical properties of topsoil and have the potential to have an impact on current soil fertility. [source] Methane oxidation kinetics differ in European beech and Norway spruce soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2009D. M. Degelmann Summary Coniferous forest soils often consume less of the greenhouse gas methane (CH4) than deciduous forest soils. The reasons for this phenomenon have not been resolved. It might be caused by differences in the diffusive flux of CH4 through the organic layer, pH or different concentrations of potentially inhibitory compounds. Soil samples were investigated from three adjacent European beech (Fagus sylvatica) and Norway spruce (Picea abies) stands in Germany. Maximal CH4 oxidation velocities (Vmax(app)) and Michaelis Menten constants (KM(app)), retrieved from intact soil cores at constant CH4 concentrations, temperature and matric potential, were twice as great in beech as in spruce soils. Also atmospheric CH4 oxidation rates measured in homogenized soil samples displayed the same trend. Greatest atmospheric CH4 oxidation rates were detected in the Oa horizon or in the upper 5 cm of the mineral soil. In contrast to the beech soils, the Oa horizon of the spruce soils consumed no CH4. A differential effect due to divergent diffusive flux through the litter layer was not found. pH and ammonium concentration were similar in samples from both forest soil types. Ethylene accumulation in all soils was negligible under oxic conditions. These collective results suggest that the different atmospheric CH4 uptake by beech and spruce soils is caused by different CH4 oxidizing capacities of methanotrophic communities in the Oa horizon and top mineral soil. [source] Methane and nitrous oxide fluxes of soils in pure and mixed stands of European beech and Norway spruceEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 5 2006W. Borken Summary Tree species can affect the sink and source strength of soils for atmospheric methane and nitrous oxide. Here we report soil methane (CH4) and nitrous oxide (N2O) fluxes of adjacent pure and mixed stands of beech and spruce at Solling, Germany. Mean CH4 uptake rates ranged between 18 and 48 ,g C m,2 hour,1 during 2.5 years and were about twice as great in both mixed and the pure beech stand as in the pure spruce stand. CH4 uptake was negatively correlated with the dry mass of the O horizon, suggesting that this diminishes the transport of atmospheric CH4 into the mineral soil. Mean N2O emission was rather small, ranging between 6 and 16 ,g N m,2 hour,1 in all stands. Forest type had a significant effect on N2O emission only in one mixed stand during the growing season. We removed the O horizon in additional plots to study its effect on gas fluxes over 1.5 years, but N2O emissions were not altered by this treatment. Surprisingly, CH4 uptake decreased in both mixed and the pure beech stands following the removal of the O horizon. The decrease in CH4 uptake coincided with an increase in the soil moisture content of the mineral soil. Hence, O horizons may maintain the gas diffusivity within the mineral soil by storing water which cannot penetrate into the mineral soil after rainfall. Our results indicate that conversion of beech forests to beech,spruce and pure spruce forests could decrease soil CH4 uptake, while the long-term effect on N2O emissions is expected to be rather small. [source] The effect of organic acids on base cation leaching from the forest floor under six North American tree speciesEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2001F. A. Dijkstra Summary Organic acidity and its degree of neutralization in the forest floor can have large consequences for base cation leaching under different tree species. We investigated the effect of organic acids on base cation leaching from the forest floor under six common North American tree species. Forest floor samples were analysed for exchangeable cations and forest floor solutions for cations, anions, simple organic acids and acidic properties. Citric and lactic acid were the most common of the acids under all species. Malonic acid was found mainly under Tsuga canadensis (hemlock) and Fagus grandifolia (beech). The organic acids were positively correlated with dissolved organic carbon and contributed significantly to the organic acidity of the solution (up to 26%). Forest floor solutions under Tsuga canadensis contained the most dissolved C and the most weak acidity among the six tree species. Under Tsuga canadensis we also found significant amounts of strong acidity caused by deposition of sulphuric acid from the atmosphere and by strong organic acids. Base cation exchange was the most important mechanism by which acidity was neutralized. Organic acids in solution from Tsuga canadensis, Fagus grandifolia, Acer rubrum (red maple) and Quercus rubra (red oak) were hardly neutralized while much more organic acidity was neutralized for Acer saccharum (sugar maple) and Fraxinus americana (white ash). We conclude that quantity, nature and degree of neutralization of organic acids differ among the different tree species. While the potential for base cation leaching with organic acids from the forest floor is greatest under Tsuga canadensis, actual leaching with organic anions is greatest under Acer saccharum and Fraxinus americana under which the forest floor contains more exchangeable cations than does the strongly acidified forest floor under Tsuga canadensis. [source] Early infection of Fagus sylvatica by Heterobasidion annosum sensu strictoFOREST PATHOLOGY, Issue 5 2008Akomy Summary Heterobasidion annosum sensu stricto is the most important damaging agent in Scots pine stands planted on the former agricultural lands in Poland. The routine action in pine stands which have lost stability because of H. annosum root rot is to change stand management, including species conversion. In many cases, the Fagus sylvatica is used for this purpose. This study was the first assessment of widespread infection by H. annosum in young F. sylvatica plantations. Disease symptoms included atrophy and yellowing of leaves, wilting and the presence of pathogen sporocarps around the root collars of young trees. Heterobasidion annosum s. s. was observed on both 4- and 17-year-old beech. Based on annual increments, the disease could be present for 3,4 years before tree death. A high incidence of H. annosum in pine stumps of previous stands (80,100%) and dry periods in recent years may be the main reasons for such common infection of F. sylvatica. This work also showed that mice and frost were not the main killing factors F. sylvatica in plantations. [source] Rhizoctonia solani AG 2-1 as a causative agent of cotyledon rot on European beech (Fagus sylvatica)FOREST PATHOLOGY, Issue 6 2005A. M. Hietala Summary Rhizoctonia solani was frequently isolated in the Italian Alps from nursery-grown European beech (Fagus sylvatica) seedlings displaying symptoms of cotyledon rot. Koch's postulates were verified and mode of infection of the associated isolates was investigated with light and scanning electron microscopy. Population structure of the pathogen was investigated by scoring the anastomosis reaction type in pairings between different isolates from the same seedbed. One pathogen genotype showed a large distribution area within the seedbed, this implying that the inoculum had been building up in the seedbed over a longer time period. Hyphal anastomosis tests and sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA indicated that the pathogen belongs to AG 2-1 of R. solani. ITS sequence analysis indicates that the isolates from beech are closely related to R. solani isolates causing a disease on tulip. The striking similarities between the two diseases are discussed. Résumé Rhizoctonia solani a fréquemment été isolé de semis de hêtre (Fagus sylvatica) présentant des symptômes de pourriture des cotylédons dans une pépinière forestière des Alpes italiennes. Les postulats de Koch ont été vérifiés et le mode d'infection étudié par microscopie optique et électronique à balayage. La structure de la population de l'agent pathogène a étéétudiée en examinant les réactions d'anastomoses dans les confrontations par paires des isolats d'un même lit de semences. Un génotype particulier s'est avéré largement distribué dans le lit de semence, suggérant soit une accumulation de l'inoculum pendant une longue période soit que ce génotype est capable de reproduction homocaryotique, favorisant sa dispersion. Les tests d'anastomose et l'analyse de la séquence de la région ITS de l'ADN ribosomal indiquent que l'agent pathogène appartient au groupe AG 2-1 de R. solani. L'analyse de la séquence de l'ITS montre que les isolats de hêtre sont proches d'isolats de R. solani pathogènes sur tulipe. Les ressemblances frappantes entre les deux maladies et la gestion de la maladie sur hêtre sont discutées. Zusammenfassung In einer Forstbaumschule in den italienischen Alpen wurde Rhizoctonia solani häufig aus Buchenkeimlingen (Fagus sylvatica) mit Symptomen einer Kotyledonenfäule isoliert. Die Koch'schen Postulate wurden erfüllt und die Art der Infektion der beteiligten Isolate wurde licht- und rasterelektronen-mikroskopisch untersucht. Die Populationsstruktur des Pathogens wurde anhand der Reaktionstypen (Anastomosierungsverhalten) in Paarungsversuchen mit den unterschiedlichen Isolaten aus demselben Saatbeet untersucht. Ein Kompatibilitätstyp war innerhalb des Saatbeetes weit verbreitet, was darauf hindeutet, dass sich das Inokulum über einen längeren Zeitraum dort angereichert hatte und/oder der Genotyp homokaryotisch fruchtet, was seine Ausbreitung fördert. Die Anastomosierungstests und die ITS-Sequenzanalyse der ribosomalen DNA ergaben, dass der Erreger zu der AG 2-1 Gruppe R. solani gehört. Die ITS-Sequenzen deuten darauf hin, dass die Isolate von Buche mit den R. solani, Isolaten verwandt sind, die an Tulpen pathogen sind. Die auffallende Ähnlichkeit der beiden Krankheiten und das Management der Erkrankung an Buche wird diskutiert. [source] The effect of nitrogen fertilization on fungistatic phenolic compounds in roots of beech (Fagus sylvatica) and Norway spruce (Picea abies)FOREST PATHOLOGY, Issue 4 2005L. Tomova Summary The effect of nitrogen fertilization on fungistatic phenolic compounds in fine roots of beech and Norway spruce growing in afforestation plots was analysed. The plots were situated at two sites in Switzerland on acidic soil with low base saturation. For 9 years, the trees have been treated with dry ammonium nitrate to give 0, 10, 20, 40, 80, 160 kg N ha,1 year,1, respectively. The phenolic compounds responded differently to fertilization. Fine roots of beech showed a significant decrease of (,)-epicatechin and piceatannol with increasing nitrogen fertilization. The concentration of protocatechuic acid was increased with fertilization. Roots of fertilized Norway spruce showed significantly decreased concentrations of 4-hydroxyacetophenone and piceatannol. The mycelial growth of three isolates each of Heterobasidion annosum s.l. and Cylindrocarpon destructans was tested on agar media containing various phenolic compounds in concentrations found in fine roots of Norway spruce (Picea abies) and beech (Fagus sylvatica). All three H. annosum isolates were inhibited by p-coumaric acid and (,)-epicatechin. Two isolates were inhibited by another four phenolic compounds (p-hydroxybenzoic acid, 4-hydroxyacetophenone, piceatannol and protocatechuic acid), one by (+)-catechin. Two of three C. destructans isolates were inhibited by all phenolic compounds except for (+)-catechin which affected only one isolate, one isolate did not respond at all. Résumé L'effet d'une fertilisation azotée sur les composés phénoliques fongistatiques des racines fines de Hêtre (Fagus sylvatica) et d'Epicea (Picea abies) a été analysé dans des parcelles de reboisement. Ces parcelles sont situées dans deux localités de Suisse sur sol acide, avec un faible taux de saturation en bases. Pendant neuf ans, les arbres ont été traités par apports secs de nitrate d'ammonium à raison de 0, 10, 20, 40, 80, 160 kg N par hectare et par an, respectivement. La réponse des composés phénoliques à la fertilisation est variable. Les racines fines de hêtres ont montré une baisse significative d'épicatèchine (,) et de piceatannol avec l'augmentation de la fertilisation azotée. Les concentrations d'acide protocatéchique ont augmenté avec la fertilisation. Les racines d'épicèas fertilisés ont montré une baisse significative des concentrations de 4-hydroxyacétophénone et de piceatannol. La croissance mycélienne de trois isolats de chacune des espèces H .annosum s.l. et Cylindrocarpon destructans a été testée sur milieu agar contenant les différents composés phénoliques aux concentrations trouvées dans les racines fines d'épicèas (Picea abies) et de hêtres (Fagus sylvatica). Les trois isolats d'Heterobasidion annosum s.l. ont été inhibés par l'acide p-coumarique et l'épicatèchine (,). Deux isolats ont été inhibés par quatre autres composés phénoliques (acide p-hydroxybenzoïque, 4-hydroxyacétophénone, piceatannol et acide protocatéchique) et un par la catéchine (+). Deux des trois isolats de Cylindrocarpon destructans ont été inhibés par tous les composés phénoliques à l'exception de la catéchine (+) pour l'un des deux, le dernier isolat ne répondant à aucun composé. Zusammenfassung In einer Aufforstungs-Versuchsfläche wurde der Einfluss einer Stickstoffdüngung auf die fungistatischen phenolischen Verbindungen in Feinwurzeln von jungen Buchen und Fichten untersucht. Die Versuchsflächen befanden sich an zwei Standorten in der Schweiz mit sauren, basenarmen Bodenverhältnissen. Die Bäume wurden über neun Jahre mit 0, 10, 20, 40, 80 und 160 kg N ha,1 a,1 in Form von Ammoniumnitrat gedüngt. Die phenolischen Verbindungen reagierten unterschiedlich auf die Düngung. Die Feinwurzeln von Buchen zeigten mit zunehmender Stickstoffdüngung eine signifikante Abnahme von (,) Epicatechin und Piceatannol, während die Konzentration von Protocatechinsäure durch die Düngung erhöht wurde. Die Feinwurzeln gedüngter Fichten wiesen ebenfalls signifikant tiefere Konzentrationen von 4-Hydroyacetophenon und Piceatannol auf. In in-vitro-Tests wurde das Myzelwachstum von allen drei geprüften Isolaten von Heterobasidion annosum s. l. durch die in den Wurzeln gefundenen Konzentrationen von p-Coumarinsäure und (,)Epicatechin gehemmt. Zwei Pilzisolate zeigten zudem eine Hemmung durch vier weitere in den Wurzeln gefundene phenolische Verbindungen, nämlich p-Hydroxybenzoesäure, 4-Hydroxyacetophenon, Piceatannol und Protocatechinsäure, und eines wurde auch durch (+)-Catechin gehemmt. Bei zwei von drei geprüften Isolaten von Cylindrocarpon destructans wurde das Myzelwachstum durch alle untersuchten phenolischen Verbindungen gehemmt, mit Ausnahme von (+)-Catechin, welches sich nur auf ein Isolat negativ auswirkte. Ein Isolat von C. destructans reagierte auf keine der genannten Substanzen. [source] Biscogniauxia nummularia: pathogenic agent of a beech declineFOREST PATHOLOGY, Issue 6 2004G. Granata Summary Decline of European beech (Fagus sylvatica) in Sicily and Calabria (Italy) was observed to be associated with the ascomycete Biscogniauxia nummularia. This fungus is naturally present in beech stands and to date has not been considered a primary pathogenic agent. Artificial inoculations were performed to assess its pathogenicity on beech and to determine if Sicilian and Calabrian isolates differ in virulence. Biscogniauxia nummularia played an evident primary pathogenic role under the environmental conditions studied. Virulence of the isolates was variable and did not depend neither on the geographic origin nor the environmental conditions at the sites where pathogenicity testing was performed. Résumé Le champignon ascomycète Biscogniauxia nummularia a été observé en association avec un dépérissement du hêtre européen (Fagus sylvatica) en Sicile et en Calabre (Italie). Ce champignon est naturellement présent dans les hêtraies et n'était pas considéré jusqu'à présent comme un agent pathogène primaire. Des inoculations artificielles ont été réalisées pour évaluer son pouvoir pathogène sur hêtre et déterminer si les isolats de Sicile et de Calabre présentent des différences de virulence. Dans les conditions de l'étude, B. nummularia prèsente clairement un rôle pathogène primaire. Les isolats ont une virulence variable, qui ne peut pas être reliée à l'origine géographique ou aux conditions environnementales des sites d'étude du pouvoir pathogène. Zusammenfassung Der Ascomycet Biscogniauxia nummularia wurde im Zusammenhang mit dem Absterben von Buchen (Fagus sylvatica) in Sizilien und Kalabrien (Italien) beobachtet. Der Pilz stellt eine natürliche Komponente von Buchenwäldern dar und wurde bis anhin nicht als ein primäres Pathogen eingestuft. Die Pathogenität von B. nummularia wurde mittels Infektionsversuchen an Buchen neu beurteilt, und die Virulenz von sizilianischen und kalabrischen Isolaten verglichen. Unter den getesteten Umweltbedingungen wirkte B. nummularia als primäres Pathogen. Die Virulenz der Isolate war unterschiedlich, hing aber weder von der Herkunft der Isolate noch den Umweltbedingungen an den Versuchsstandorten ab. [source] Biomass, nutrient and pigment content of beech (Fagus sylvatica) saplings infected with Phytophthora citricola, P. cambivora, P. pseudosyringae and P. undulataFOREST PATHOLOGY, Issue 2 2004F. Fleischmann Summary Fagus sylvatica saplings were infected with Phytophthora citricola, Phytophthora cambivora, Phytophthora pseudosyringae and Phytophthora undulata to study the influence of these root pathogens on total belowground and aboveground biomass, on the nutrient distribution within plants, on the concentration of plastid pigments, including tocopherol and on components of the xanthophyll cycle. Phytophthora citricola and P. cambivora infection significantly reduced total biomass of beech when compared with control plants and finally most of these plants died at the end of the experiment. However, beech invaded by the other two Phytophthora spp. did not differ from control plants and none of them was killed. Fine root length as well as the number of root tips of all infected beeches were reduced between 30 and 50%. The excellent growth of beech infected with P. pseudosyringae and P. undulata when compared with control plants was correlated with a strong increase of important root efficiency parameters. Phytophthora citricola and P. cambivora caused a significant reduction in nitrogen concentration of leaves in comparison with control and other infected plants, whereas this nutrient was slightly increased in fine and coarse roots. Furthermore, the phosphorus and potassium concentrations in leaves were impaired after infection with P. citricola. However, foliar concentrations of Ca and Mg were not affected by the different Phytophthora spp., whereas fine and coarse roots were significantly enriched with Ca in beech infected with P. citricola or P. cambivora. The concentrations of , -tocopherol and xanthophyll cycle pigments were increased in plants infected by P. citricola and P. cambivora, indicating that several reactive oxygen species might be formed in leaves during infection. Résumé Des plants de Fagus sylvatica ont été infectés par Phytophthora citricola, Phytophthora cambivora, Phytophthora pseudosyringae et Phytophthora undulata pour étudier l'effet de ces pathogènes racinaires sur la biomasse totale aérienne et racinaire, la distribution des éléments minéraux dans les plantes et la concentration en pigments des plastes, tocophérol et composants du cycle des xanthophylles. L'infection par P. citricola et P. cambivora a entraîné une réduction significative de la biomasse totale par rapport aux plantes témoins et la plupart des plants infectés sont morts au cours de l'expérience. Par contre, les hêtres infectés par les deux autres espèces de Phytophthora ne différent pas des témoins et aucune mortalité n'a été observée. Chez tous les hêtres infectés, une réduction de 30 à 50% de la longueur de racines fines et du nombre d'extrémités racinaires a été observée. La très bonne croissance des plants infectés par P. pseudosyringae et P. undulata par rapport aux témoins est associée à une forte augmentation de paramètres importants d'efficience racinaire. P. citricola et P. cambivora ont causé une réduction significative de la concentration foliaire en azote par rapport aux plantes témoins et aux autres plantes infectées, alors que la concentration était légèrement augmentée dans les fines et grosses racines. De plus, la concentration foliaire en phosphore et potassium a été altérée après infection par P. citricola. Les concentrations foliaires en Ca et Mg n'ont pas été affectées par les différentes espèces de Phytophthora, les fines et grosses racines étant significativement enrichies en Ca chez les plants infectés par P. citricola ou P. cambivora. La concentration en , -tocophérol et pigments du cycle des xanthophylles a augmenté dans les plants infectés par P. citricola et P. cambivora, suggérant la formation de plusieurs espèces actives de l'oxygène dans les feuilles pendant l'infection. Zusammenfassung Buchensämlinge wurden mit Phytophthora citricola, Phytophthora cambivora, Phytophthora pseudosyringae und mit Phytophthora undulata infiziert, um den Einfluss dieser Wurzelpathogene auf die oberirdische und unterirdische Biomasse, auf die Nährstoffverteilung innerhalb verschiedener Pflanzenorgane, sowie auf die Gehalte unterschiedlicher Photosynthesepigmente und Komponenten des Xanthophyll- Zyklus studieren zu können. Die Infektion mit P. citricola und P. cambivora führte zu einer deutlich reduzierten Gesamtbiomasse und am Versuchsende waren die meisten Pflanzen abgestorben. Dagegen überlebten alle mit P. pseudosyringae oder P. undulata infizierten Buchen und sie zeigten keine Unterschiede in ihren Biomassen verglichen mit Kontrollpflanzen bzw. übertrafen diese sogar. Die Feinwurzellänge und die Anzahl ihrer Wurzelspitzen war bei allen Phytophthora infizierten Pflanzen zwischen 30 und 50% im Vergleich zu denen der Kontrollen reduziert. Das ausgezeichnete Wachstum der P. pseudosyringae und P. undulata infizierten Pflanzen ging mit stark gesteigerten Wurzeleffizienzparametern einher. Die P. citricola und P. cambivora Infektion führte zu reduzierten Stickstoffgehalten in den Blättern. Die Gehalte in den Wurzeln waren jedoch leicht erhöht. Zudem wurden reduzierte Gehalte an Phosphor und Kalium in den Blättern gemessen. Die Calcium und Magnesium- Konzentrationen der Blätter unterschieden sich nicht von denen der Kontrollen. Allerdings wurde eine Calcium-Anreicherung in den Fein- und Grobwurzeln infizierter Pflanzen gemessen. Weiterhin zeigten wir, dass die Konzentrationen von , -Tocopherol und Pigmenten des Xanthophyll-Zyklus in Blättern P. citricola und P. cambivora infizierter Pflanzen erhöht waren, was möglicherweise auf die Bildung reaktiver Sauerstoffspezies hindeutet. [source] Colonization of beech leaves by two endophytic fungi in northern JapanFOREST PATHOLOGY, Issue 2 2000N. Sahashi Summary Leaves of Japanese beech (Fagus crenata) were collected monthly during the vegetation period at five sites in the Tohoku district in Japan to isolate endophytic fungi. Leaves were also collected only once at two additional sites. Two endophytic fungi were dominant, a Discula species and a sterile mycelium. This result strongly suggests that these two fungi are generally associated with leaves of the Japanese beech at different sites. At most sites the isolation frequency of Discula sp. was greatest in June and gradually decreased from July to October whereas the isolation frequency of the sterile mycelium increased during the vegetation period and remained at a high isolation frequency in October. Spores of Discula sp. were released for a very short time in late May, just after the disappearance of the snow cover on the forest floor. These spores may be important for the infection of newly sprouting leaves. [source] Biological control of beech and hornbeam affects species richness via changes in the organic layer, pH and soil moisture characteristicsFUNCTIONAL ECOLOGY, Issue 2 2010Anne Mieke Kooijman Summary 1. ,Litter quality is an important ecosystem factor, which may affect undergrowth species richness via decomposition and organic layers directly, but also via longer-term changes in soil pH and moisture. The impact of beech trees with low-degradable and hornbeam trees with high-degradable litter on biodiversity and soil characteristics was studied in ancient forests on decalcified marl, a parent material sensitive to changes in pH and clay content, and characteristic of large parts of western Europe. 2. ,Vegetation analysis clearly separated beech and hornbeam plots, and showed that species richness was consistently lower under beech. Low species richness under beech was associated with low pH, high mass of the organic layer and low soil moisture, which were all interrelated. 3. ,Development of the organic layer was affected by, not only litter quality, but also by pH levels and soil moisture. Under hornbeam, older organic matter increased from almost zero to 1 kg m,2 in drier and more acid soil. Under beech tree litter decay was generally slow, but slowed further in acid soils, where older organic matter amounted to 4 kg m,2. 4. ,Soil moisture and pH levels were strongly related, possibly due to long-term soil development. Under hornbeam, which is more palatable to soil organisms, moisture, bulk density, clay content and pH were high. Acidification and clay eluviation may be counteracted by earthworms, which bring base cations and clay particles back to the surface, and stimulate erosion, so that the impermeable, clay-rich subsoil remains close to the surface. Soils remain base-rich and moist, which further stimulates litter decay and species richness. 5. ,The unpalatable beech showed low pH and clay content, and high porosity, air-filled pore space and depth to the impermeable subsoil. Acidification and clay eluviation may proceed uninhibited, because earthworm activity is low, and erosion limited by protective litter covers. This may lead to drier and more acid soils, which reduce litter decay and species richness even further. 6. ,Trees with low and high litter quality may thus act as an ecosystem engineer, and not only affect ecosystem functioning via mass of the organic layer, but also via longer-term changes in soil characteristics, which in turn affect species richness of the understorey. [source] Leaf dark respiration as a function of canopy position in Nothofagus fusca trees grown at ambient and elevated CO2 partial pressures for 5 yearsFUNCTIONAL ECOLOGY, Issue 4 2001K. L. Griffin Summary 1,Mass-based and area-based rates of respiration, leaf nitrogen content, leaf total protein content, non-structural carbohydrates and leaf mass per unit area (LMA) all decreased with depth in the canopy of Nothofagus fusca (Hook. F.) Oerst. (Red beech) trees grown for 5 years at ambient (36 Pa) or elevated (66 Pa) CO2 partial pressures. 2Elevated CO2 partial pressure had a strong effect on dark respiration, decreasing both mass-based and area-based rates at all canopy positions, but had little or no effect on leaf physical and biochemical properties. 3Leaf sugars, starch, protein, N and LMA were all correlated with respiration rate, and are therefore strong predictors of area-based dark respiration rates. The y axis intercept of regressions of respiration rate on mean leaf N, protein, starch and LMA was lower for plants grown at elevated compared to ambient CO2 partial pressures because of the differential effect of growth at elevated CO2 partial pressure on leaf gas-exchange, chemical and physical characteristics. 4,The lower respiration rates for leaves from trees grown at elevated CO2 partial pressure resulted in a significant increase in the ratio of light-saturated net photosynthesis to respiration, increasing the potential carbon-use efficiency of these leaves. [source] Conversion of hardwood forests to spruce and pine plantations strongly reduced soil methane sink in GermanyGLOBAL CHANGE BIOLOGY, Issue 6 2003WERNER BORKEN Abstract Well-drained forest soils are thought to be a significant sink for atmospheric methane. Recent research suggests that land use change reduces the soil methane sink by diminishing populations of methane oxidizing bacteria. Here we report soil CH4 uptake from ,natural' mature beech forests and from mature pine and spruce plantations in two study areas of Germany with distinct climate and soils. The CH4 uptake rates of both beech forests at Solling and Unterlüß were about two,three times the CH4 uptake rates of the adjacent pine and spruce plantations, indicating a strong impact of forest type on the soil CH4 sink. The CH4 uptake rates of sieved mineral soils from our study sites confirmed the tree species effect and indicate that methanotrophs were mainly reduced in the 0,5 cm mineral soil depth. The reasons for the reduction are still unknown. We found no site effect between Solling and Unterlüß, however, CH4 uptake rates from Solling were significantly higher at the same effective CH4 diffusivity. This potential site effect was masked by higher soil water contents at Solling. Soil pH (H2O) explained 71% of the variation in CH4 uptake rates of sieved mineral soils from the 0,5 cm depth, while cation exchange capacity, soil organic carbon, soil nitrogen and total phosphorous content were not correlated with CH4 uptake rates. Comparing 1998,99, annual CH4 uptake rates increased by 69,111% in the beech and spruce stands and by 5,25% in the pine stands, due primarily to differences in growing season soil moisture. Cumulative CH4 uptake rates from November throughout April were rather constant in both years. The CH4 uptake rates of each stand were separately predicted using daily average soil matric potential and a previously developed empirical model. The model results revealed that soil matric potential explains 53,87% of the temporal variation in CH4 uptake. The differences between measured and predicted annual CH4 uptake rates were less than 10%, except for the spruce stand at Solling in 1998 (17%). Based on data from this study and from the literature, we calculated a total reduction in the soil CH4 sink of 31% for German forests due in part to conversion of deciduous to coniferous forests. [source] Estimation of the carbon sequestration by a heterogeneous forest: night flux corrections, heterogeneity of the site and inter-annual variabilityGLOBAL CHANGE BIOLOGY, Issue 11 2002MARC AUBINET Abstract Continuous measurements of the net CO2 flux exchanged in a mixed forest with the atmosphere were performed over 5 years at the Vielsalm experimental site. The carbon sequestration at the site was deduced by a summation of the measurements. Problems associated with this summation procedure were discussed. The carbon sequestration in the ecosystem was presented and its interannual variability was discussed. An estimation of the night flux correction was given. The correction was applied by replacing measurements made during quiet nights by a parameterization. The impact of the correction was shown to vary between 10 and 20% of the uncorrected flux, according to the year. The need to include the storage flux during turbulent periods was emphasized: its neglect leads to an error which will be greater than the one it tries to correct. It was also shown that the heterogeneity of the site made it necessary to split the data into separate series corresponding to the different vegetation patches and to fill the data gaps by using an algorithm that takes account of the weather conditions. Two series were defined, one corresponding to a beech subplot, the other to a conifer subplot. The uncertainty owing to the data split and the data gap-filling was about 15,20% annually. The carbon sequestration was then analysed in both the subplots. The length of the growing season was about 210 days in the beech and 240 days in the conifer. The carbon sequestration over 5 years was 2.28 kg C m2,2 in the beech and 3.58 kg C m2,2 in the conifer. The main difference between the species appeared in spring, between March and May, when the beeches were leafless. Significant interannual variations were observed in both the subplots. They appeared mainly in summer and were primarily because of the variations in the radiation and air humidity regimes. In addition, an impact of the interannual variation of the vegetation area index (VAI) and of the leaf initiation date was observed in the beech. Finally, a decline of the carbon sequestration efficiency of the ecosystem during the season was observed in both the subplots. It was because of neither the variation in any climatic variables nor VAI variation. [source] Dynamics of common wasps in New Zealand beech forests: a model with density dependence and weatherJOURNAL OF ANIMAL ECOLOGY, Issue 4 2002N. D. Barlow Summary 1Nest densities of the common wasp ( Vespula vulgaris (L.)) were monitored at six sites for 13 years in the honeydew-rich southern beech ( Nothofagus spp.) forests of New Zealand's South Island. 2Densities of wasp nests were among the highest in the world, up to 30 ha ,1 , and at any one site varied approximately twofold over the study period. 3Strong but not overcompensating density dependence was identified, together with a negative effect of spring rainfall. 4The density dependence appeared to act from the number of autumn queens produced during one year to the number of mature (autumn) nests the next year, rather than through variations in queen production per nest. The same stage was also responsible for most of the variability in autumn nest numbers from year to year, with queen production per nest contributing less. 5Yearly changes in nest density could be summarized by a simple Ricker model including both density dependence and weather, thereby incorporating both previous hypotheses for the determination of wasp abundance. [source] Single host trees in a closed forest canopy matrix: a highly fragmented landscape?JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2007J. Müller Abstract:, Whether trees represent habitat islands and therefore are influenced by similar biogeographic processes as ,real' islands is controversial. For trees in highly fragmented landscapes the impacts of spatial isolation on arthropod communities have already been demonstrated. However, we have almost no evidence that in large forests the arthropod communities on single trees in a closed canopy matrix are influenced by similar processes. In the present study the influence of spatial isolation on the specialized oak crown fauna was analysed in a large broadleaved forest area in northern Bavaria, Germany. The dependence of specialists on the proportion of oaks in the surrounding forest was investigated by using flight interception traps (67 on oak, 19 on beech). As target species, saproxylic and herbivorous Coleoptera and Heteroptera were sampled. The following two hypotheses were tested: (1) The proportion of oak specialists differs for oaks in beech forests and oaks in oak forests. (2) The proportion of oak specialists increases with the proportion of oaks in the surrounding forest. For all species groups, the proportion of oak specialists was higher in oak crowns than in beech crowns. Herbivorous beetles and true bugs showed a higher proportion of specialists in oak forests than on single oaks in beech forests. The proportion of herbivorous oak specialists increased significantly with increasing numbers of adjacent oak trees, while saproxylic Coleoptera showed no relationship to oak density. For herbivorous Coleoptera a threshold of higher proportion occurred where >30% oak was present, and for Heteroptera a first threshold was identified at values >70% and a second at >30%. This indicates that larger habitat patches within a closed forest canopy matrix support larger populations of herbivorous oak specialists. Hence, similar effects of spatial isolation might occur in a closed forest as have already been shown for highly fragmented open landscapes. [source] Response of beech (Fagus sylvatica) to elevated CO2 and N: Influence on larval performance of the gypsy moth Lymantria dispar (Lep., Lymantriidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2001M. W. Henn Two-year-old beech seedlings were kept from germination to bioassays with Lymantriadispar under the following conditions: ambient CO2/low N, elevated CO2/low N, ambient CO2/elevated N, and elevated CO2/elevated N. The effect of these growing conditions of the trees on the performance of the defoliator L. dispar was studied 2 years after initiating the tree cultivation. The developmental success of third-instar larvae of L. dispar was characterized by the weight gained, percentage of weight gain, relative growth rate (RGR), relative consumption rate (RCR), and efficiency of conversion of ingested food into body substance (ECI). Contrary to our expectations, additional N-fertilization did not increase and elevated CO2 did not delay larval growth rate. However, the environmental treatments of the beech seedlings were found to affect the larval performance. Larvae consumed significantly higher amounts of foliage (RCR) on beech trees under controlled conditions (ambient CO2 and low N) compared to those under elevated CO2 and enhanced N. The opposite was true for ECI. The lowest efficacy to convert consumed food to body substance was observed under control conditions and the highest when the larvae were kept on beech trees grown under elevated CO2 and additional N-fertilization. These opposite effects resulted in the weight gain-based parameters (absolute growth, percentage of growth, and RGR) of the gypsy moth larvae remaining unaffected. The results indicate that the gypsy moth larvae are able to change their ECI and RCR to obtain a specific growth rate. This is discussed as an adaptation to specific food qualities. [source] Impact of impregnation chemical on surface glossiness of synthetic, acrylic, polyurethane, and water-based varnishesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Hakan Keskin Abstract This study was performed to determine the effects of impregnation chemical on surface glossiness of some varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods according to ASTM D 358 were impregnated with Imersol-Aqua according to ASTM D 1413 and producer's definition by short-term (S), medium-term (M), and long-term (L) of dipping methods and coated by synthetic (Sv), acrylic (Ac), water-based (Wb), and polyurethane (Pu) varnishes according to ASTM D 3023. After the varnishing process, the surface glossiness parallel to fibers was determined according to TS 4318. Consequently, among the nonimpregnated wood samples, surface glossiness parallel to fibers was found to be the highest in Oriental spruce and the lowest in European oak. As for the period of dipping, the highest surface glossiness was obtained in medium-term dipping and the lowest in long-term dipping. As for the varnish types, the surface glossiness was found to be the highest in polyurathane varnish and the lowest in water-based varnish. Considering the interaction of wood type, period of impregnation, and type of varnish, surface glossiness was the highest in Uludag fir, long-term dipping, and polyurathane varnish (103.9 gloss) and the lowest in Oriental beech, long-term dipping, and water-based varnish (67.78 gloss). In consequence, in the massive constructions and furniture elements the surface glossiness parallel to fibers after the impregnation with Imersol-Aqua is of great concern, long-term impregnation of Uludag fir materials could be recommended. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Climatic limits for the present distribution of beech (Fagus L.) species in the worldJOURNAL OF BIOGEOGRAPHY, Issue 10 2006Jingyun Fang Abstract Aim, Beech (Fagus L., Fagaceae) species are representative trees of temperate deciduous broadleaf forests in the Northern Hemisphere. We focus on the distributional limits of beech species, in particular on identifying climatic factors associated with their present range limits. Location, Beech species occur in East Asia, Europe and West Asia, and North America. We collated information on both the southern and northern range limits and the lower and upper elevational limits for beech species in each region. Methods, In total, 292 lower/southern limit and 310 upper/northern limit sites with available climatic data for all 11 extant beech species were collected by reviewing the literature, and 13 climatic variables were estimated for each site from climate normals at nearby stations. We used principal components analysis (PCA) to detect climatic variables most strongly associated with the distribution of beech species and to compare the climatic spaces for the different beech species. Results, Statistics for thermal and moisture climatic conditions at the lower/southern and upper/northern limits of all world beech species are presented. The first two PCA components accounted for 70% and 68% of the overall variance in lower/southern and upper/northern range limits, respectively. The first PCA axis represented a thermal gradient, and the second a moisture gradient associated with the world-wide distribution pattern of beech species. Among thermal variables, growing season warmth was most important for beech distribution, but winter low temperature (coldness and mean temperature for the coldest month) and climatic continentality were also coupled with beech occurrence. The moisture gradient, indicated by precipitation and moisture indices, showed regional differences. American beech had the widest thermal range, Japanese beeches the most narrow; European beeches occurred in the driest climate, Japanese beeches the most humid. Climatic spaces for Chinese beech species were between those of American and European species. Main conclusions, The distributional limits of beech species were primarily associated with thermal factors, but moisture regime also played a role. There were some regional differences in the climatic correlates of distribution. The growing season temperature regime was most important in explaining distribution of Chinese beeches, whilst their northward distribution was mainly limited by shortage of precipitation. In Japan, distribution limits of beech species were correlated with summer temperature, but the local dominance of beech was likely to be dependent on snowfall and winter low temperature. High summer temperature was probably a limiting factor for southward extension of American beech, while growing season warmth seemed critical for its northward distribution. Although the present distribution of beech species corresponded well to the contemporary climate in most areas, climatic factors could not account for some distributions, e. g., that of F. mexicana compared to its close relative F. grandifolia. It is likely that historical factors play a secondary role in determining the present distribution of beech species. The lack of F. grandifolia on the island of Newfoundland, Canada, may be due to inadequate growing season warmth. Similarly, the northerly distribution of beech in Britain has not reached its potential limit, perhaps due to insufficient time since deglaciation to expand its range. [source] The forests of presettlement New England, USA: spatial and compositional patterns based on town proprietor surveysJOURNAL OF BIOGEOGRAPHY, Issue 10-11 2002Charles V. Cogbill Abstract Aim, This study uses the combination of presettlement tree surveys and spatial analysis to produce an empirical reconstruction of tree species abundance and vegetation units at different scales in the original landscape. Location, The New England study area extends across eight physiographic sections, from the Appalachian Mountains to the Atlantic Coastal Plain. The data are drawn from 389 original towns in what are now seven states in the north-eastern United States. These towns have early land division records which document the witness trees growing in the town before European settlement (c. seventeenth to eighteenth century ad). Methods, Records of witness trees from presettlement surveys were collated from towns throughout the study area (1.3 × 105 km2). Tree abundance was averaged over town-wide samples of multiple forest types, integrating proportions of taxa at a local scale (102 km2). These data were summarized into genus groups over the sample towns, which were then mapped [geographical information system (GIS)], classified (Cluster Analysis) and ordinated [detrended correspondence analysis (DCA)]. Modern climatic and topographic variables were also derived from GIS analyses for each town and all town attributes were quantitatively compared. Distributions of both individual species and vegetation units were analysed and displayed for spatial analysis of vegetation structure. Results, The tally of 153,932 individual tree citations show a dominant latitudinal trend in the vegetation. Spatial patterns are concisely displayed as pie charts of genus composition arrayed on sampled towns. Detailed interpolated frequency surfaces show spatial patterns of range and abundance of the dominant taxa. Oak, spruce, hickory and chestnut reach distinctive range limits within the study area. Eight vegetation clusters are distinguished. The northern vegetation is a continuous geographical sequence typified by beech while the southern vegetation is an amorphous group typified by oak. Main conclusions, The wealth of information recorded in the New England town presettlement surveys is an ideal data base to elucidate the natural patterns of vegetation over an extensive spatial area. The timing, town-wide scale, expansive coverage, quantitative enumeration and unbiased estimates are critical advantages of proprietor lotting surveys in determining original tree distributions. This historical,geographical approach produces a vivid reconstruction of the natural vegetation and species distributions as portrayed on maps. The spatial, vegetational and environmental patterns all demonstrate a distinct ,tension zone' separating ,northern hardwood' and ,central hardwood' towns. The presettlement northern hardwood forests, absolutely dominated by beech, forms a continuum responding to a complex climatic gradient of altitude and latitude. The oak forests to the south are distinguished by non-zonal units, probably affected by fire. Although at the continental scale, the forests seem to be a broad transition, at a finer scale they respond to topography such as the major valleys or the northern mountains. This study resets some preconceptions about the original forest, such as the overestimation of the role of pine, hemlock and chestnut and the underestimation of the distinctiveness of the tension zone. Most importantly, the forests of the past and their empirical description provide a basis for many ecological, educational and management applications today. [source] Effects of size, competition and altitude on tree growthJOURNAL OF ECOLOGY, Issue 5 2007DAVID A. COOMES Summary 1,Understanding the factors influencing tree growth is central to forest ecology because of the significance of growth to forest structure and biomass. One of the simplest, yet most controversial growth models, proposed by Enquist and colleagues, predicts that stem-diameter growth scales as the one-third power of stem diameter. Recent analyses of large-scale data sets have challenged the generality of this theory and highlighted the influence of resource competition on the scaling of growth with size. 2Here we explore the factors regulating the diameter growth of 3334 trees of mountain beech (Nothofagus solandri var. cliffortioides) growing in natural single-species forests in New Zealand. Maximum-likelihood modelling was used to quantify the influences of tree size, altitude, the basal area of taller neighbours (BL) and the basal area of all neighbours (BT) on growth. Our interpretation of the models assumed that taller neighbours compete for light whereas all neighbours compete for nutrients. 3The regression analyses indicate that competition for light has a strong influence on the growth of small trees, whereas competition for nutrients affects trees of all sizes. These findings are consistent with experimental manipulation studies showing that competition for light and nutrients inhibits the growth of small mountain beech trees, and fertilizer application studies showing that nitrogen limits the growth of large trees. 4Tree growth declined with altitude. The regression analyses suggest that the intensity of light competition also declines with altitude, when trees with similar BT and BL values were compared along the gradient. These results are consistent with observations that trees become stunted and have more open canopies at high altitudes. 5Our study is the first to build the effects of competition and environment into Enquist's model of tree growth. We show that competitive interactions alter the scaling of mean growth rate with size, whereas altitude does not influence the scaling of potential growth rate with size. [source] Long-term canopy dynamics in a large area of temperate old-growth beech (Fagus crenata) forest: analysis by aerial photographs and digital elevation modelsJOURNAL OF ECOLOGY, Issue 6 2004YUKO HENBO Summary 1Long-term canopy dynamics in a large area of temperate old-growth beech forest in the Daisen Forest Reserve, south-western Japan (11.56 ha studied over 43 years), were investigated using digital elevation models (DEMs) of the canopy surface, constructed from aerial photographs taken in the growing season (i.e. with foliage) in 1958, 1978, 1992 and 2001. A ground surface DEM at the same resolution (a 2.5 × 2.5 m grid) was constructed using aerial photographs taken when foliage was absent (winter 2002). Canopy height data were obtained by calculating differences in elevation between the canopy and the ground surface, and a canopy height profile was constructed. 2Topographic data for a 4-ha plot, located within the 11.56-ha area, were obtained via a ground survey and used to validate the ground surface DEM derived from aerial photographs. 3Canopy height class distributions changed significantly over the 43 years. The total number of gaps, defined as areas where canopy height was , 15 m, decreased but total gap area increased over time. Total gap area in 2001 was twice that of 1958. The density of gaps decreased as gap size increased. 4Gap formation rates increased from 0.47% year,1 (1958,78) to 1.30% year,1 (1992,2001), with a mean of 0.77% year,1, and substantially exceeded closure rates, which fluctuated from 0.28% year,1 (1958,78) to 0.54% year,1 (1978,92), with a mean of 0.39% year,1. Gaps generally expanded and became connected to each other. 5Temporal variation in gap formation and closure might be correlated with the frequency and severity of typhoon disturbances but, if the observed trends continue, this old-growth beech stand may become an open stand. The long-term dynamics of this forest type appear to be far from equilibrium. [source] Diversity of canopy and understorey spiders in north-temperate hardwood forestsAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2009Maxim Larrivée Abstract 1,We characterized and compared diversity patterns of canopy and understorey spiders (Arachnida: Araneae) on sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.) in hardwood forests of southern Québec, Canada. 2,We sampled canopies of 45 sugar maple and 45 American beech trees and associated understorey saplings in mature protected forests near Montréal. Samples were obtained by beating the crown foliage at various heights and by beating saplings around each tree. 3,Eighty-two species were identified from 13 669 individuals. Forty-eight species and 3860 individuals and 72 species and 9809 individuals were collected from the canopy and the understorey, respectively. 4,Multivariate analyses (NMDS ordination and NPMANOVA) showed the composition of canopy and understorey assemblages differed significantly, and canopy assemblages differed between tree species. Rank-abundance distribution models fitted to the canopy and understorey data indicated that different mechanisms structure the assemblages in both habitats. Three abundant spider species were significantly more common in the canopy; ten species were collected significantly more often in the understorey. 5,The forest canopy was shown to be an important reservoir for spider diversity in north-temperate forests. [source] Feeding by short-snouted weevils on seedlings of seven tree species planted beneath Norway spruce at differing stand densitiesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009M. Löf Abstract 1,Short-snouted weevils, including Strophosoma spp. and related species, may damage tree seedlings. We investigated the damage caused by these weevils feeding on seedlings of seven tree species planted in clear-cuts and under shelterwoods with three densities (control, dense, and sparse). 2,There were no pronounced differences in damage caused by short-snouted weevils in the various shelterwood densities. Most feeding occurred in the clear-cuts during the first year, whereas more seedlings were damaged in the shelterwoods of all densities in the second year. In the third year, virtually no feeding occurred in either the clear-cuts or shelterwoods. We cannot explain this pattern of damage, but a fallow period of 2 years seems to prevent short-snouted weevil damage. 3,We determined the general feeding preferences for short-snouted weevils to be cherry, lime > beech, oak, spruce > maple, ash. However, although Strophosoma mellanogrammum [Correction added after online publication 8 December 2008: Strophosoma melanogrammum corrected to Strophosoma mellanogrammum] was observed feeding on seedlings, no full short-snouted weevil inventory was conducted, so caution must be exercised when drawing conclusions from this study regarding weevil damage patterns and feeding preferences. 4,Short-snouted weevils can sometimes occur in large numbers and may destroy entire reforestation projects, but in our study their influence on seedling growth and survival was minor. [source] | |||||||||||||||||||||||||||||||||||||