1,721,144 research outputs found
Die VTA-Rw/R-Grenzregel zum Baumwurf, ein weiteres wissenschaftlich nicht nachvollziehbares und praktisch inadäquates Versagenskriterium der Standsicherheit
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Top growth of adult beech trees (Fagus sylvatica (L.) on a limestone stand (Gottingen/Sodderich) in dependance upon climate factors. II. Control of the increment by weather factors
No full textThe combined annual height and radial increment of main top axes up to 4 m long of 130 year old dominant beech trees (bhd > 60 cm) on a lime stone stand was related to climatic factors of the weather station of Gottingen and Kassel. Following results are new anal of interest. Height and radial growth are controlled by the climatic factors (KIND = weather index) of the previous year (Tab. 2 and 3). More over besides the bud period (previous year) the height increment is also influenced through climatic factors during the bud primordium period pre-previous year. Precipitation., July-temperature, sunshine duration and relative humidity control radial and height growth (Fig. 1, 2. 4). Global radiation and water saturation deficit do not improve the correlation. Also important is that the climatic factors of the current year show no significant influence on the current increment under the weather conditions of the Sodderich beech stand. The increments are correlated negativly to the KINDs of sunshine duration, global radiation, temperature and water saturation deficit the precipitation is positivly correlated. The respectivly additive or multiplicative combination of the single climatic indices (KINDall) is strongly correlated to the increment curves (KINDall((Hz)): R-2 = 0.88, KINDall((Rz)); R-2 = 0.78, KINDall((Hz Rz)): R-2 = 0.84. KINDall((S Rz)): R-2 = 0.92) within the period 1970 to 1999 (Tab. 2 and 3, Fig. 5 to 8). Therefore the increments of the tops are predetermined by the climatic factors during the previous year and therefore can be nearly exactly predicted and modelled by the climate index (composed mainly of the previous year) (Fig. 9). In respect to the mean climatic index KIND the vitality of the beech trees and the damage development of the beech stands in Lower Saxony is discussed (Fig. 12 and 13). The development curve of the beech damages in Lower Saxony during 1985 to 1999 is similar to the curve of the KIND
Ein Vorschlag zur normierten Einschätzung der standörtlichen Bruch- Verkehrssicherheit von Bäumen
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Top growth of adult beech trees (Fagus sylvatica (L.) on a limestone stand (Gottingen/Sodderich) in dependance upon climate factors. I. Basic increment patterns
No full textThe combined annual height and radial increment of main top axes up to 4 m long of 130 year old dominant beech trees (bhd > 60 cm) on a lime stone stand was investigated basicly (Fig. 1). Following increment patterns are interesting for presentation: The annual height increment of the apical crown developes. synchronously within and between trees (Fig. 5 to 7). The annual radial increment of the apical. and medial crown is synchronous within and between trees, too (Fig. 8, 9, 12, 13). A strong correlation between the current annual height increment and the radial increment of the tops could be found (r(2) = 0.58. 1970 to 1999; Fig. 10, 11)
Measurement results on the identification of red hearts of European beech (Fagus sylvatica L.) with the drill devices Teredo and Resistograph 1410 and also the impulse hammer sound system IML
No full textTitle of the paper: Measurement results on the identification of red hearts of European beech (Fagus sylvatica L.) with the drill devices Teredo and Resistograph 1410 and also the impulse hammer sound system IML. a) The mean radial sound velocities of the different red heart types did not significantly differ. The values layed in the range of normal "white coloured" beech wood (1100 m/s to 1500 m/s). Gray heart wood showed lower velocities (972 m/s). Also the tangential velocities were 100 m/s to 200 m/s lower than of normal wood. The IML-sound system is not suitable for detecting red hearts of beech boles. b) Both Teredo and Resistograph system are unsuitable for detecting red hearts in beech stems (Fig. 6 to 9). c) The draw back curves of the Teredo system are problematic because not calculable systematic errors can occur. Therefore they should not be used for wood resistance interpretations (Fig. 6, 12). d) Measurements on frozen woods are impossible using the Teredo but not the resistograph system. The resistograph has problems with dense woods because of the impossibility drilling in and clamping the drilling needle. e) Diminished wood resistances such as central rotten wood and holes on beech could be exactly detected by the Teredo and Resistograph curves
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