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

The 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.