Die Parasiten und Krankheiten der Ahorneule (Acronicta aceris L.)

Ohne Zusammenfassung     

Vom Wesen waldbaulicher Arbeit heute und morgen

Summary The crisis of classical silviculture in the middle-european sustained yield forestry becomes evident—above all—in the large discrepancy between scientific findings and practical management. Numerous inhibiting factors are to be held responsible for this: lack of a silivcultural basis for combined objectives in the management of productive and social forests, forest-technical development aid from the boreal wood-exploitation areas, the modernization of forest management being too onesided oriented to industry, a lack of professional improvement, sociological problems as a denaturation of man by technology and economy etc. An integral silviculture, based on ecological fundaments and following a free style, must lead to an optimization of interdisciplinary conflicts of objective under the aspect of long-term objectives. The comprehensive life-work of the man whose jubilee we celebrate has readied the way to a solution.      

Coherent response of a group of plantation-grown Scots pine trees to wind loading

Wind-induced motion of 29 neighbouring trees growing in a Scots pine plantation was measured over the period 14 March to 24 March 2008. The bi-orthogonal decomposition (BOD) of the complex tree motion field into a limited number of spatio-temporal modes provided the basis for the analysis of the response behaviour to wind excitation of the group of sample trees. It is shown that the first BOD-mode was the most energetic and differed from all other BOD-modes. The BOD-results as well as the results from wavelet analysis of the temporal eigenvectors of the BOD-modes demonstrate that two concomitant low-frequency components in the streamwise wind velocity component stimulated coherent response of the sample trees at the tree group level. However, in the range of the wind speed measured close to the top of the Scots pine forest canopy (hourly mean wind speed values lower than 6 m s⁻¹), the wind loads associated with these low-frequency airflow structures were too low to harmonise the motion of the sample trees completely. It is shown that instantaneous single tree responses to wind excitation were highly irregular in magnitude and direction. Results from Fourier and wavelet analysis demonstrate that sway in the first mode dominated the wind-induced sway behaviour at the tree level.     

Non-escaping frost tolerant QTL linked genetic loci at reproductive stage in six wheat DH populations

Reproductive stage frost poses a major constraint for wheat production in countries such as Australia.However,little progress has been made in identifying key genes to overcome the constraint.In the present study,a severe frost event hit two large-scale field trials consisting of six doubled haploid(DH)wheat populations at reproductive stage(young microspore stage)in Western Australia,leading to the identification of 30 robust frost QTL on 17 chromosomes.The major 18 QTL with the phenotype variation over 9.5%were located on 13 chromosomes including 2 A,2 B,2 D,3 A,4 A,4 B,4 D,5 A,5 D,6 D,7 A,7 B and7 D.Most frost QTL were closely linked to the QTL of anthesis,maturity,Zadok stages as well as linked to anthesis related genes.Out of those,six QTL were repetitively detected on the homologous regions on 2 B,4 B,4 D,5 A,5 D,7 A in more than two populations.Results showed that the frost damage is associated with alleles of Vrn-A1 a,Vrn-D1 a,Rht-B1 b,Rht-D1 b,and the high copy number of Ppd-B1.However,anthesis QTL and anthesis related genes of Vrn-B1 a and Ta FT3-1 B on chromosomes 5 B and 1 B did not lead to frost damage,indicating that these early-flowering phenotype related genes are compatible with frost tolerance and thus can be utilised in breeding.Our results also indicate that wild-type alleles Rht-B1 a and Rht-D1 a can be used when breeding for frost-tolerant varieties without delaying flowering time.