Ein Schnelltest zur Ermittlung der individuellen SO2-Empfindlichkeit bei Kiefern

Zusammenfassung Es wird eine Schnellmethode zur Rauchh?rteprüfung von Kiefernarten beschrieben, die vom Terminaltrieb abgetrennte, in Pillengl?ser gesteckte einj?hrige Kurztriebe verwendet. Die Nadeln reagieren auf akute SO₂-Immissionen kloneinheitlich und weitgehend in übereinstimmung mit der Mutterpflanze. Bei den Kurztrieben lassen sich endogene, vom Mutterbaum abh?ngige Differenzen in der Austrocknungsgeschwindigkeit nachweisen, die aber ohne wesentlichen Einflu? auf ihre Reaktion gegenüber SO₂ bleiben, sofern die Expositionsdauer kurzgehalten wird. Die entwickelte Methode ist schneller, wirtschaftlicher und auch zuverl?ssiger als Rauchh?rteprüfungen mit eingetopften Pflanzen. Sie testet lediglich die Reaktion auf akute Begasungen.

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Summary A short-time technique of testing pines for resistance against SO₂-emissions has been developed, using one-year-old needle fascicles, put into water-filled glass vials. Against actual SO₂-exposure, fascicles of the same tree react uniformly, and their reaction is very similiar to that of the parent tree. Besides, needle fascicles show endogenous clonal variation in the rate of drying out. This, however, does not influence the reaction against SO₂, provided the time of exposure is kept short. The new technique is quicker, accurate, and more economical than SO₂-tests with potted seedlings or graftings, but it only tests the reaction against short time-high doses exposure to SO₂.

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Durchgeführt mit finanzieller Unterstützung der Landesanstalt für Immissions- und Bodennutzungsschutz des Landes Nordrhein-Westfalen in Essen.     

Unterschiede im Anflugverhalten von Lymantria monacha L. und L. dispar L. an razemisches Disparlur

The attraction of the Nun Moth (L. monacha) and Gypsy Moth (L. dispar) to sticky traps (0.5×1.0 m) baited with racemic disparlure was tested in the forestry district of Freiburg-Stadt. A total of 81 traps were baited alternately with 0.01 mg (10^?5), 1 mg (10^?3) disparlure (diluted in pentane) and control (pentane only). Male pupae ofL. monacha (10.102; 19.5–12.6) andL. dispar (5.532; 14.6–4.7.) were placed in the center of the test area before the flight period of the natural population. Of 6.834L. monacha and 4.990L. dispar moths that emerged, 365 (=5.3%) and 329 (=6.6%) respectively were recaptured on the traps. During the flight of the natural population, 274L. monacha (3.7–26.8.) and 818L. dispar (14.7–3.9.) were collected from the traps. With a few exceptions, the traps were examined daily. No significant difference was noticed in the behavior of the laboratory-reared insects and the natural population.     

Kelthane,ein neues Akarizid

Zusammenfassung Kelthane ist ein neues Akarizid mit bisher festgestellter guter Wirkung gegenTetranychidae, Phytoptipalpidae, Eriophyidae, Tarsonemidae undArgasidae. Es ist nicht insektizid, daher bienenungefährlich. Kelthane kann als Emulsion, Suspension, Staub, Aerosol und Dampf angewendet werden. Es hat bei guter Initialwirkung eine lange Dauerwirkung. Die Initialwirkung ist temperaturabhängig. Kelthane wirkt ovizid auf die Eier der Tarsonemiden und auf die Sommereier der Tetranychiden, nicht aber auf deren Wintereier. Die Warmblütertoxis von Kelthane ist gering. — Die Phytotoxis von Suspensionsaufbereitungen ist gering, bei Stäuben und Aerosolen fehlt sie, lediglich bei Anwendung von Emulsionen ist Vorsicht am Platze.Es ist uns an dieser Stelle eine angenehme Pflicht, unseren Mitarbeitern, den HerrenR. Mack,H. Neeb,H. P. Fischer undO. Unger für die Durchführung der Außenversuche und Herrn Dr.G. Linden für die Untersuchung der Phytotoxis zu danken. Die Bestimmung vonTenuipalpus inornatus führte liebenswürdigerweise Herr Prof.G. Dosse, Hohenheim, durch.     

Assessing nitrogen fixation in mixed- and single-species plantations of Eucalyptus globulus and Acacia mearnsii

Mixtures of Eucalyptus globulus Labill. and Acacia mearnsii de Wildeman are twice as productive as E. globulus monocultures growing on the same site in East Gippsland, Victoria, Australia, possibly because of increased nitrogen (N) availability owing to N(2) fixation by A. mearnsii. To investigate whether N(2) fixation by A. mearnsii could account for the mixed-species growth responses, we assessed N(2) fixation by the accretion method and the (15)N natural abundance method. Nitrogen gained by E. globulus and A. mearnsii mixtures and monocultures was calculated by the accretion method with plant and soil samples collected 10 years after plantation establishment. Nitrogen in biomass and soil confirmed that A. mearnsii influenced N dynamics. Assuming that the differences in soil, forest floor litter and biomass N of plots containing A. mearnsii compared with E. globulus monocultures were due to N(2) fixation, the 10-year annual mean rates of N(2) fixation were 38 and 86 kg ha(-1) year(-1) in 1:1 mixtures and A. mearnsii monocultures, respectively. Nitrogen fixation by A. mearnsii could not be quantified on the basis of the natural abundance of (15)N because such factors as mycorrhization type and fractionation of N isotopes during N cycling within the plant confounded the effect of the N source on the N isotopic signature of plants. This study shows that A. mearnsii fixed significant quantities of N(2) when mixed with E. globulus. A decline in delta(15)N values of E. globulus and A. mearnsii with time, from 2 to 10 years, is further evidence that N(2) was fixed and cycled through the stands. The increased aboveground biomass production of E. globulus trees in mixtures when compared with monocultures can be attributed to increases in N availability.     

Screening of antioxidant activity of three Euphorbia species from Turkey

Euphorbia acanthothamnos, E. macroclada and E. rigida were investigated for their antioxidant activity. The antioxidant potential of extracts of E. acanthothamnos, E. macroclada and E. rigida was evaluated using different complementary antioxidant tests.     

Modeling spatial variability in the life-cycle costs of low-volume forest roads

Cost estimation is probably the most decisive factor in the process of computer-aided, preliminary planning for low-volume road networks. However, the cost of construction is normally assumed to be route-independent for a specific project area, resulting in sub-optimal layouts. This is especially true for mountainous terrain and in areas with unstable subsoil. Here, we present a model for more accurately estimating spatial variability in road life-cycle costs, based on terrain surface properties as well as geological properties of the subsoil. This parametric model incorporates four structural components: embankment, retaining structures, pavement, and drainage and stream-crossing structures. It is linked to a geo-database that allows users to derive location-specific parameter values as input. In applying this model, we have demonstrated that variability in costs ranges widely for mountainous areas, with the most expensive construction being approximately five times greater there than on more favorable sites. This variability strongly affects the optimal layout of a road network. First, when location-specific slope gradients are considered, costs are reduced by about 17% from those calculated via currently available engineering practices; when both slope gradient and geotechnical formations are included, those costs are decreased by about 20%. Second, the length of the road network is increased by about 4% and 10% respectively, compared with current practices.     

Effects of different ecological and silvicultural factors on beetle catches in the Turkish fir (<Emphasis Type="Italic">Abies bornmülleriana</Emphasis> Mattf.) ecosystems

To study the bark beetle attacks on Turkish fir stands and to determine the principle site and stand factors influencing beetle attacks, trap log method was used in the Western Black Sea Region of Turkey. The study was carried out in ten different locations prior to flying time in February 2003. On each experimental plot, three healthy fir trees with 30–50 cm diameter and 200 m apart were cut down with a chainsaw. From each sampling tree, needles were sub-sampled for determination of specific leaf-area and macro-nutrient concentrations. In addition, on each experimental plot, crown closure, basal-area, and stand density were measured. To determine the bulk density and nutrient concentrations of the soil, samples were taken around trees on each plot. The relationship between measured stand variables, the number of beetle species and beetle populations were evaluated using correlation and stepwise multiple regression procedure. Eight different species belonging to four different families from Coleoptera were identified in examining the trap logs. Six of these eight species (Pissodes piceae Illig., Pissodes notatus Fabr., Cryphalus piceae Ratz., Pityophthorus pityographus Ratz., Xyloterus lineatus Oliv., Pityokteines curvidens Germ.) were identified as harmful beetles (HB). The other two (Thanasimus formicarius L. and Rhizophagus dispar Payk.) were identified as predator species. The analysis showed that the total number of HB increased as the site’s slope and needle specific leaf area increased. However, as needle N concentrations increased, HB population decreased. Increased Ca concentration in fir needle reduced total insect attack.