Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: International Journal of Biometeorology, 2010, Vol.54(1), pp.23-36
    Description: We investigated the water balances of two beech stands ( Fagus sylvatica L.) on opposite slopes (NE, SW) of a narrow valley near Tuttlingen in the southern Swabian Jura, a low mountain range in Southwest Germany. Our analysis combines results from continuous measurements of forest meteorological variables significant to the forest water balance, stand transpiration (ST) estimates from sap flow measurements, and model simulations of microclimate and water fluxes. Two different forest hydrological models (DNDC and BROOK90) were tested for their suitability to represent the particular sites. The investigation covers the years 2001–2007. Central aims were (1) to evaluate meteorological simulations of variables below the forest canopy, (2) to evaluate ST, (3) to quantify annual water fluxes for both beech stands using the evaluated hydrological models, and (4) to analyse the model simulations with regard to assumptions inherent in the respective model. Overall, both models were very well able to reproduce the observed dynamics of the soil water content in the uppermost 30 cm. However, the degree of fit depended on the year and season. The comparison of experimentally determined ST within the beech stand on the NE-slope during the growing season of 2007 with simulated transpiration did not yield a reliable statistical relationship. The simulation of water fluxes for the beech stand on the NE- and SW-slopes showed similar results for vegetation-related fluxes with both models, but different with respect to runoff and percolation flows. Overall, the higher evaporation demand on the warmer SW-slope did not lead to a significantly increased drought stress for the vegetation but was reflected mainly in decreased water loss from the system. This finding is discussed with regard to potential climate change and its impact on beech growth.
    Keywords: Water fluxes ; Beech stand ; Swabian Jura/SW Germany ; Forest meteorological measurements ; Sap flow measurements ; DNDC ; BROOK90 ; Modelling
    ISSN: 0020-7128
    E-ISSN: 1432-1254
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Forest Ecology and Management, 2011, Vol.262(2), pp.105-114
    Description: ► Competition for N between young and adult beech is reduced by seasonal timing. ► Beech seedlings favour N uptake in spring, adult beech trees in autumn. ► Removal of vegetation components does not play a role in this competition. ► Competition between plants and soil microorganisms is, therefore, not avoided. Plant growth, reproduction, and biomass allocation may be affected differently by nitrogen availability depending on tree size and age. In this context, competition for limited N may be avoided by different strategies of N acquisition between different vegetation components (i.e., seedlings, mature trees, other woody and herbaceous understorey). This study investigated in a field experiment whether the competition for N between different vegetation components in beech forests was prevented via seasonal timing of N uptake and affected by microbial N use. For this purpose, a removal approach was used to study the seasonal effects on N uptake and N metabolites in adult beech trees and beech natural regeneration, as well as soil microbial processes of inorganic N production and utilisation. We found that the competition for N between beech natural regeneration and mature beech trees was reduced by seasonal avoidance strategies (“good parenting”) of N uptake regardless of the N sources used. In spring, organic and inorganic N uptake capacity was significantly higher in beech seedlings compared to adult beech trees, whereas in autumn mature beech trees showed the highest N uptake rates. Removal of vegetation components did not result in changes in soil microbial N processes in the course of the growing season. Thus, N resources released by the removal of vegetation components were marginal. This consistency in soil microbial N processes indicates that competition between plants and soil microorganisms for N was not avoided by timing of acquisition during the vegetation period, but existed during the entire growing season. In conclusion, N nutrition in the studied forest ecosystem seems to be optimally attuned to European beech.
    Keywords: Fagus Sylvatica ; N Uptake ; N Metabolites ; Soil Microorganisms ; Soil N Processes ; Removal Approach ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Forest Ecology and Management, 01 July 2012, Vol.275, pp.60-67
    Description: ► We study two adult populations under different microclimatic conditions. ► We compare genetic diversity of the adult populations and their natural regeneration. ► Case study based on isozymes and microsatellite markers. ► We identified two “outlier microsatellite loci”, exhibiting directional selection. ► Natural selection account for different genetic structures of the adult populations. Due to its drought sensitivity, the performance and competitiveness of beech as a favoured species of forest management in Central Europe is likely to be negatively affected by the prognosticated climate change, leading to major impacts on the vulnerability of managed forest ecosystems. We studied the genetic differentiation between two populations from a relatively cold and wet northeast (representing the current climate of the majority of beech forests in Central Europe) and a relatively warm and dry southwest facing slope (representing the future climate of an increasing area covered by beech forests in Central Europe) at the same forest site to investigate the adaptation processes in these two populations under different microclimatic conditions. For this purpose, two different techniques, , nuclear microsatellites (neutral) and isozyme markers (adaptive), were applied to adult trees and natural regeneration at both slopes. Although microsatellites are considered to be neutral markers, they have been shown in several studies to give signals of selectively-driven changes. In our study, two of the five microsatellites behaved as “outlier loci”, exhibiting directional selection. Our results show independent of the technique applied that natural regeneration of the southwest slope and the natural regeneration and adult trees of the northeast slope were genetically closer than the adult trees from the southwest slope. Thus, we conclude that natural selection and potential adaptation account for genetic changes and different genetic structures among the two adult populations in this case study.
    Keywords: Fagus Sylvatica ; Climate Change ; Isozymes ; Nuclear Microsatellites ; Beech ; Adaptation ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Meteorologische Zeitschrift, 2011, Vol.20(5), pp.241-552
    Description: Abstract in Undetermined This study deals with a current problem of urban human-biometeorology on the micro-scale, which becomes more important due to the future increase of severe summer heat in Central Europe. The impact of street design parameters...
    Keywords: Atmospheric Conditions ; Air Temperature ; Absolute Values ; Building Height ; Central Europe ; Fish-Eye ; Germany ; Human Thermal Comfort ; Mean Radiant Temperature ; Mean Values ; Measuring Systems ; Meteorological Variables ; Micro-Scales ; Physiologically Equivalent Temperatures ; Quantitative Result ; Radiative Fluxes ; Sky View Factor ; Spatial Differences ; Street Canyon ; Street Design ; Summer Heat ; Tree Canopy ; Urban Street Canyon ; Weather Conditions ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Naturgeografi ; Natural Sciences ; Earth And Related Environmental Sciences ; Physical Geography
    ISSN: 1610-1227
    ISSN: 09412948
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Advances in Meteorology, 2013
    Description: Increasing heat will be a significant problem for Central European cities in the future. Shading devices are discussed as a method to mitigate heat stress on citizens. To analyze the physical processes, which are characteristic of shading in terms of urban humanbiometeorology, experimental investigations on the thermal effects of shading by a building and shading by tree canopies were conducted in Freiburg (Southwest Germany) during typical Central European summer weather. Urban human-biometeorology stands for the variables air temperature Ta, mean radiant temperature [T.sub.mrt], and physiologically equivalent temperature PET, that is the human-biometeorological concept to assess the thermal environment which was applied. The measuring setup consists of specific human-biometeorological stations, which enable the direct or indirect determination of [T.sub.a], [T.sub.mrt],and PET. With respect to both shading devices, the [T.sub.a] reduction did not exceed 2[degrees]C, while PET as a measure for human heat stress was lowered by two thermal sensation steps according to the ASHRAE scale. As [T.sub.mrt] has the role of a key variable for outdoor thermal comfort during Central European summer weather, all radiant flux densities relevant to the determination of [T.sub.mrt] were directly measured and analyzed in detail. The results show the crucial significance of the horizontal radiant flux densities for [T.sub.mrt] and consequently PET.
    Keywords: Roads – Environmental Aspects ; Roads – Europe ; Metropolitan Areas – Environmental Aspects ; Weather Modification – Methods ; Solar Radiation – Environmental Aspects
    ISSN: 1687-9309
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Research Dataset
    Research Dataset
    Zenodo
    Description: Raw measurement data from the research flight with the Sky Arrow ERA over the post-forest fire area in Västmanland, Sweden, on 2015/10/03. Measurements of standard meteorological parameters as well as high frequency concentrations of CO2, H2O and CH4 and 3D wind components....
    Keywords: Airborne Flux Data
    Source: DataCite
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    In: Applied and Environmental Microbiology, 2010, Vol. 76(6), p.1831
    Description: The relationships between plant carbon resources, soil carbon and nitrogen content, and ectomycorrhizal fungal (EMF) diversity in a monospecific, old-growth beech (Fagus sylvatica) forest were investigated by manipulating carbon flux by girdling. We hypothesized that disruption of the carbon supply would not affect diversity and EMF species numbers if EM fungi can be supplied by plant internal carbohydrate resources or would result in selective disappearance of EMF taxa because of differences in carbon demand of different fungi. Tree carbohydrate status, root demography, EMF colonization, and EMF taxon abundance were measured repeatedly during 1 year after girdling. Girdling did not affect root colonization but decreased EMF species richness of an estimated 79 to 90 taxa to about 40 taxa. Cenococcum geophilum, Lactarius blennius, and Tomentella lapida were dominant, colonizing about 70% of the root tips, and remained unaffected by girdling. Mainly cryptic EMF species disappeared. Therefore, the Shannon-Wiener index (H') decreased but evenness was unaffected. H' was positively correlated with glucose, fructose, and starch concentrations of fine roots and also with the ratio of dissolved organic carbon to dissolved organic nitrogen (DOC/DON), suggesting that both H' and DOC/DON were governed by changes in belowground carbon allocation. Our results suggest that beech maintains numerous rare EMF species by recent photosynthate. These EM fungi may constitute biological insurance for adaptation to changing environmental conditions. The preservation of taxa previously not known to colonize beech may, thus, form an important reservoir for future forest development.
    Keywords: Engineering ; Biology ; Economics;
    ISSN: 0099-2240
    ISSN: 00992240
    E-ISSN: 10985336
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    In: Advances in Meteorology, 2013, Vol.2013, 13 pages
    Description: Increasing heat will be a significant problem for Central European cities in the future. Shading devices are discussed as a method to mitigate heat stress on citizens. To analyze the physical processes, which are characteristic of shading in terms of urban human-biometeorology, experimental investigations on the thermal effects of shading by a building and shading by tree canopies were conducted in Freiburg (Southwest Germany) during typical Central European summer weather. Urban human-biometeorology stands for the variables air temperature , mean radiant temperature , and physiologically equivalent temperature PET, that is the human-biometeorological concept to assess the thermal environment which was applied. The measuring setup consists of specific human-biometeorological stations, which enable the direct or indirect determination of , , and PET. With respect to both shading devices, the reduction did not exceed 2°C, while PET as a measure for human heat stress was lowered by two thermal sensation steps according to the ASHRAE scale. As has the role of a key variable for outdoor thermal comfort during Central European summer weather, all radiant flux densities relevant to the determination of were directly measured and analyzed in detail. The results show the crucial significance of the horizontal radiant flux densities for and consequently PET.
    Keywords: Roads – Environmental Aspects ; Roads – Europe ; Metropolitan Areas – Environmental Aspects ; Weather Modification – Methods ; Solar Radiation – Environmental Aspects;
    ISSN: 1687-9309
    E-ISSN: 1687-9317
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Atmospheric Environment, 2008, Vol.42(20), pp.5071-5078
    Description: The air quality index LAQx ( ong-term ir uality Inde ), which has been recently developed to evaluate the long-term integral air quality related to well-being and health of people, was applied to analyse the evolution of air pollution from 1985 to 2005 at different urban and rural sites in SW Germany. The LAQx method including the air pollutants taken into account is briefly discussed. LAQx is grouped into six classes according to the German school grade system, i.e. LAQx class 1 indicates a very good air quality, while very poor air quality is described by LAQx class 6. For an additional differentiation, the six LAQx classes are subdivided into LAQx values based on the decimal system. In accordance with the trends of the air pollutants taken into account in LAQx, the results show decreasing LAQx values at urban sites, which reflect an improvement of the integral air quality. In 1985 it was very poor and poor, respectively, whereas it reached the sufficient and satisfying level in 2005. For the rural sites, where LAQx could be determined only from 1995 to 2005, it fluctuated around a mean level indicating good to satisfying air quality but without any decreasing tendency. Differences of LAQx between the investigated sites were primarily caused by different local emission conditions. The trend of decreasing LAQx values, i.e. improvement of the integral air quality, was modified by distinctly higher LAQx values in years characterised by a relatively high portion of consecutive extremely hot summer days like during the heat waves in 2003 in Central Europe, which particularly increased the ozone concentration.
    Keywords: Evolution of Air Pollution ; Air Quality Index Laqx ; Trends of Air Pollutants ; Sw Germany ; Engineering ; Environmental Sciences
    ISSN: 1352-2310
    E-ISSN: 1873-2844
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Biogeosciences Discussions, 2014, Vol. 11, pp. 4225-4233
    Description: Fluxes of carbon dioxide (CO2) and methane (CH4) from lakes may have a large impact on the magnitude of the terrestrial carbon sink. Traditionally lake fluxes have been measured using the floating chamber (FC) technique; however, several recent studies use the eddy covariance (EC) method. We present simultaneous flux measurements using both methods at lake Tämnaren in Sweden during field campaigns in 2011 and 2012. Only very few similar studies exist. For CO2 flux, the two methods agree relatively well during some periods, but deviate substantially at other times. The large discrepancies might be caused by heterogeneity of partial pressure of CO2 (pCO2w) in the EC flux footprint. The methods agree better for CH4 fluxes. It is, however, clear that short-term discontinuous FC measurements are likely to miss important high flux events.
    Keywords: Natural Sciences ; Naturvetenskap ; Natural Sciences ; Earth And Related Environmental Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Natural Sciences ; Earth And Related Environmental Sciences ; Meteorology And Atmospheric Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Meteorologi Och Atmosfärforskning ; Natural Sciences ; Earth And Related Environmental Sciences ; Climate Research ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Klimatforskning ; Natural Sciences ; Earth And Related Environmental Sciences ; Geosciences, Multidisciplinary ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Multidisciplinär Geovetenskap
    ISSN: 1810-6277
    ISSN: 17264189
    E-ISSN: 17264189
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages