Vertical distribution of soil properties under short‐rotation forestry in Northern Germany     

Petra Kahle  Christel Baum  Barbara Boelcke  Josefine Kohl  Roland Ulrich 《植物养料与土壤学杂志》2010,173(5):737-746

Short‐rotation forestry (SRF) on arable soils has high potentials for biomass production and leads to long‐term no‐tillage management. In the present study, the vertical distributions of soil chemical and microbial properties after 15 y of SRF with willows and poplar (Salix and Populus spp.) in 3‐ and 6‐year rotations on an arable soil were measured and compared to a pertinent tilled arable site. Two transects at different positions in the relief (upper and lower slope; transect 1 and 2) were investigated. Short‐rotation forestry caused significant changes in the vertical distribution of all investigated soil properties (organic and microbial C, total and microbial N, soil enzyme activities), however, the dimension and location (horizons) of significant effects varied. The rotation periods affected the vertical distribution of the soil properties within the SRF significantly. In transect 1, SRF had higher organic‐C concentrations in the subsoil (Bv horizon), whereas in transect 2, the organic‐C concentrations were increased predominantly in the topsoil (Ah horizon). Sufficient plant supply of P and K in combination with decreased concentrations of these elements in the subsoil under SRF pointed to an effective nutrient mobilization and transfer from the deeper soil horizons even in the long term. In transect 1, the microbial‐C concentrations were higher in the B and C horizons and in transect 2 in the A horizons under SRF than under arable use. The activities of β‐glucosidases and acid phosphatases in the soil were predominantly lower under SRF than under arable use in the topsoil and subsoil. We conclude, that long‐term SRF on arable sites can contribute to increased C sequestration and changes in the vertical distribution of soil microbial biomass and soil enzyme activities in the topsoil and also in the subsoil.  相似文献   

Temporal trends in the foliar nutritional status of the French, Walloon and Luxembourg broad-leaved plots of forest monitoring     

Mathieu Jonard  Frédéric André  Etienne Dambrine  Quentin Ponette  Erwin Ulrich 《Annals of Forest Science》2009,66(4):412-412

? Two decades after the launching of the monitoring program of forest ecosystems in Europe (ICP forests), a unique data set is now available regarding the foliar nutritional status of the main broad-leaved species growing in much-diversified sites (soil, climate).

? This study focuses on the foliar concentration time series (1993 to 2005) of the French (RENECOFOR), Walloon and Luxemburg broad-leaved plots. The aim is to show long-term trends while taking the inter-plot and inter-annual variability into account.

? Two kinds of statistical processing were used to analyze the data on foliar chemistry: principal component analysis (PCAs) and linear mixed models. In general, the main temporal trends reveal a decrease in the foliar P concentration and a decrease in the foliar Ca concentration, except for European beech on acid soils.

? These temporal patterns confirm the trends previously observed and could be explained by the joint actions of several processes that influence tree nutrition in the long term: tree age, N and S deposition, harvesting and climate.

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Pathogenicity determinants in smut fungi revealed by genome comparison     

Schirawski J  Mannhaupt G  Münch K  Brefort T  Schipper K  Doehlemann G  Di Stasio M  Rössel N  Mendoza-Mendoza A  Pester D  Müller O  Winterberg B  Meyer E  Ghareeb H  Wollenberg T  Münsterkötter M  Wong P  Walter M  Stukenbrock E  Güldener U  Kahmann R 《Science (New York, N.Y.)》2010,330(6010):1546-1548

Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.  相似文献   

Long-term trends of phosphorus nutrition and topsoil phosphorus stocks in unfertilized and fertilized Scots pine (Pinus sylvestris) stands at two sites in Southern Germany     

Jörg Prietzel  Ulrich Stetter 《Forest Ecology and Management》2010

For two Scots pine (Pinus sylvestris) ecosystems in S Germany with different atmospheric N deposition (Pfaffenwinkel, intermediate N deposition; Pustert, large N deposition), the supply with phosphorus (P) has been monitored for unfertilized and fertilized plots over more than four decades by foliar analysis (1964–2007). Additionally, topsoil concentrations and stocks of total P and plant-available P (citric-acid-extractable phosphate) were quantified in 10-year intervals (1982/1984, 1994, 2004). At both sites, fertilization experiments, including the variants control, NPKMgCa + lime, PKMgCa + lime + introduction of lupine, corresponding to an addition of 75 and 90 kg ha⁻¹ P in Pustert and Pfaffenwinkel, respectively had been established in 1964. Our study revealed different trends of the P nutritional status for the pines at the two sites during the recent four decades: At Pustert, elevated atmospheric N deposition together with small topsoil P pools resulted in significant deterioration of Scots pine P nutrition and in an increasingly unbalanced N/P nutrition. At Pfaffenwinkel a trend of improved P nutrition from 1964 to 1991 was replaced by an opposite trend in the most recent 15 years. For our study sites, which are characterized by acidic soils with thick O layers, the forest floor stock of citric-acid-extractable phosphate showed a strong and significant correlation with the P concentration in current-year pine foliage, and thus was an appropriate variable to predict the P nutritional status of the stands. Total P stocks as well as the concentrations of total P in the forest floor or in the mineral topsoil were poorly correlated with pine foliar P concentrations and thus inappropriate predictors of P nutrition. P fertilization in the 1960s sustainably improved the P nutritional status of the stands. At Pfaffenwinkel, foliar P concentrations and topsoil stocks of citric-acid-extractable phosphate were increased at the fertilized plots relative to the control plots even 40 years after fertilization; at Pustert, foliar P concentrations were increased for about 20 years.  相似文献   

Drivers of bryophyte diversity allow implications for forest management with a focus on climate change     

Stefanie Raabe  Jörg Müller  Michael Manthey  Oliver Dürhammer  Ulrich Teuber  Axel Göttlein  Bernhard Förster  Roland Brandl  Claus Bässler 《Forest Ecology and Management》2010

Understanding the major drivers of diversity in forests is crucial for ecologists, conservationists, and particularly forest managers. In most forested habitats, bryophytes are diverse and important primary producers. Here we report the first study of the relative importance of regional macroclimate as compared to local variables on abundance, species richness, and community composition of bryophytes growing in soil and in dead wood in a mountain temperate forest. Using PCA axes, we built predictor sets for macroclimate, microclimate, soil attributes, and dead wood availability. The explanatory power of each set was tested using variance partitioning. Abundance and species richness of soil bryophytes was best explained by microclimate, whereas the community composition did not distinctively differ between the environmental sets. In contrast, dead wood bryophyte abundance, species richness, and community composition was clearly driven by macroclimate. Among the single axes, the component represented best by soil moisture was the main driver for soil bryophyte abundance. In contrast, dead wood bryophyte abundance was mostly affected by components correlated with minimum global radiation and minimum temperatures as well as by the component represented by dead wood. The component represented by canopy openness was superior in explaining the community composition of both soil and dead wood bryophytes. We conclude that (1) dead wood amounts should be increased in closed stands to act as a buffer during climate changes, and (2) open canopy, which provides important habitats for soil-inhabiting bryophytes, should be provided by management with slow reforestation after natural or logging openings.  相似文献   

From the SedNet Oslo conference to a thematic set of articles on sediment management in Norway   总被引：1，自引：1，他引：0  

Ulrich Förstner  Almut Beate Heinrich 《Journal of Soils and Sediments》2009,9(3):161-162

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Sediments and priority substances in river basins     

Ulrich Förstner 《Journal of Soils and Sediments》2009,9(2):89-93

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Examination of the prevalence of skin injuries in debeaked fattened turkeys     

Krautwald-Junghanns ME  Ellerich R  Mitterer-Istyagin H  Ludewig M  Fehlhaber K  Schuster E  Berk J  Dressel A  Petermann S  Kruse W  Noack U  Albrecht K  Bartels T 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(1-2):8-16

Within the framework of a cooperative research project, turkey health as well as numerous aspects of animal welfare were examined in various intensive commercial farms with varying rearing forms. The present study demonstrates the prevalence of skin injuries concerning living animals as well as carcasses of slaughtered turkeys of both sexes. Although all turkeys were debeaked, prevalences of skin injuries at a value of 12.8% with male turkeys and 13.8% with female turkeys could be found at the age of 16 weeks. Within the scope of medically inspections skin injuries were mainly established in the head region, especially the snood as well as in the region of the back. By means of their clinical picture pecking wounds and scratch injuries could be distinguished. Skin lesion produced primary as a result of scratching the skin surface, could be enlarged by the animal itself or by conspecifics by beak pecking, especially after bleeding, in spite of debeaked upper beak. Injuries in the head region, especially of the snood, could be explained mainly as a result of pecking by conspecifics by reason of their clinical picture and were found mainly in male turkeys. Skin injuries in the region of the back, especially at the coxal tuberosity, were identified primarily as scratch marks. They were found mainly in female turkeys. A statistically significant correlation of the injury prevalence to particular husbandry parameters discussed in the literature as "predisposing" or "limiting" factors (e.g., population density, light regime or offer of employment material) could not be established in this study. At the meat inspection fresh scratching injuries at the chest and the hind legs were diagnosed most often. Especially fresh injuries of the carcass point to a misguided behaviour of the staff concerning animal handling during loading and transport which is not conform to animal welfare.  相似文献   

Comparative behaviour studies in horses infested with flying insects treated with insecticide or repellent substances     

Sünder U  Moors E  Hagemann K  Gauly M 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(1-2):28-35

The aim of this study was to estimate the effects of flying insects (Order Diptera) on the behaviour of grazing horses in relation to the use of insecticide and repellent substances. The investigations were done between June and August in 2008 in 3 periods of 7 days each. As insecticide and repellent two substances were used: "Well-care emulsion" (Co. Essex Tierarznei, München, GER) containing Permethrin and "Bremsen-Frei-Plus" (Co. Dr. Schaette AG, Bad Waldsee, GER) based on etheric oils. Both groups were compared with a non treated control group in a crossover-design. Each group (n = 3-5) was used alternately as control and treatment group. Several climate parameters were taken during the study. Furthermore, the number of insects per animal was estimated at certain times. Once per observation period insects were caught using Malaise traps and differentiated by species. The proportion of horse relevant species of the genera Diptera, especially Culex pipiens and Musca autumnalis, caught was 9% on an average. There was no correlation between the number of Tabanidae caught in the Malaise traps and the number observed near by the horses. Behaviour parameters like tailswishing, headshaking, stamping, skintwitching, snapping at the body, and moving were observed more frequently with increasing insect infestation. When horses were infested with a high number of flying insects, feeding activity was significant lower, whereas locomotion activity was significant higher. Both substances had positive effects for about 50 hours after application with no apparent difference between the substances. However, a lower frequency of headshaking and tailswishing could be observed in the Permethrin treated horses.  相似文献   

Bovine neonatal pancytopenia in German Holstein calves     

Buck BC  Ulrich R  Kuiper H  Reinacher M  Peters M  Heimberg P  Holsteg M  Puff C  Haas L  Ganter M  Distl O 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(7-8):329-336

Profiles of blood cell counts were evaluated for 15 calves from three different farms. These calves showed petechia in the mucous membranes and in the skin and prolonged secondary bleeding after puncture. The clinical course of the disease could be observed in eleven calves. With exception of one case, the blood cell counts indicated a severe anaemia, leukocytopenia and thrombocytopenia. Out of these 15 calves, six calves survived and the other nine calves died or had to be euthanized due to the severity of the disease. Necropsy of these nine calves revealed petechia in the skin, subcutis, muscles, in inner organs and all serous membranes. Pathohistological examination showed a depletion of the bone marrow and lymphatic tissue in eight calves. These findings confirmed the diagnosis of bovine neonatal pancytopenia (BNP) for eight of these nine calves. Bluetongue virus serotype 8 was tested negatively using PCR. Bovine virus diarrhoea virus (BVDV) was negatively tested using immunofluorescence and cell culture and salmonella species were negatively tested in seven dissected calves. A cluster of toxins was negatively tested in one of the dissected calves. All 15 calves had high antibody titres for BVDV. The BVDV-antibody titres from twelve dams with affected calves were positive in six cases and not detectable in the other six cases. In three of the six dams with not detectable BVDV-antibody titres, calves were fed with colostrum of a further dam with high BVDV-antibody titres. In the further three dams without detectable BVDV-antibody titres, we could not ascertain which colostrum has been fed to the calves. BVDV-specific antigen could not be detected in any of the samples from the calves and dams tested. Using the activity of the gamma-glutamyl-transferase, we assumed a sufficient supply with colostrum for the examined calves.The cause for the occurrence of these BNP cases was due to bone marrow depletion.The reason for the bone marrow depletion remained unclear. However, it was obvious that the BNP described here is highly likely caused by colostrum from cows with positive BVDV-antibody titres.  相似文献