Struktur und Langzeitentwicklung von subalpinen Pinus montana Miller und Pinus cembra L. W?ldern in den zentraleurop?ischen Alpen

Zusammenfassung:  Die traditionelle land- und forstwirtschaftliche Nutzung dürfte im Alpenraum in der näheren Zukunft wirtschaftlich bedingt immer häufiger aufgegeben werden. Dieser Trend wird mit großer Wahrscheinlichkeit die Dynamik von Gebirgsökosystemen und damit das Landschaftsbild stark beeinflussen. Aus diesem Grund stieg in den letzten Jahrzehnten das Interesse, die Sukzession auf nicht mehr bewirtschafteten Flächen zu verstehen. Die Bestandesstruktur und -entwicklung von subalpinen Fichtenwäldern (Picea abies L.) wurde bereits intensiv untersucht; über Entwicklungsprozesse in zentralalpinen Bergföhren- (Pinus montana Miller) und Arven-/Lärchenwälder (Pinus cembra L./Larix decidua L.) ist hingegen nur wenig bekannt. Der seit 1914 vom Menschen nur noch touristisch genutzte Schweizerische Nationalpark (SNP) ist eines der wenigen Gebiete in Westeuropa, welches über längere Zeit nicht bewirtschaftet wurde. Der Park bietet daher die einzigartige Möglichkeit, die Veränderungen in Bestandesstruktur und -zusammensetzung nach Bewirtschaftungsaufgabe zu beobachten. Wir verglichen historische (1957) und aktuelle (2001/02) Daten von 19 Beständen, welche zu drei verschiedenen Bestandestypen gehören: Bergföhre, Mischbestand und Arve. In den letzten 45 Jahren nahm die totale Stammzahl in allen drei Bestandestypen um 45 bis 57% und die Jungbaumzahl pro Hektar um 64 bis 76% signifikant ab, was vor allem auf den starken Rückgang der lichtbedürftigen Bergföhre zurückzuführen ist. Parallel zu dieser Entwicklung, nahm die Menge an liegendem Totholz in allen Bestandestypen von weniger als 4t/ha auf 36 bis 67,7t/ha zu, während die Anzahl toter Bäume pro Hektar um 72 bis 94% abnahm. Die Biomasse des stehenden Totholzes (t/ha) hat sich hingegen nur leicht verändert. Unsere Resultate beschreiben die sukzessionale Entwicklung von subalpinen Wäldern der Zentralalpen und zeigen, wie sich Wälder in ähnlichen Berggebieten in der nahen Zukunft entwickeln könnten.

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Summary:   Since traditional agriculture and forestry are no longer economically viable in many regions of the European Alps, subalpine forests will become less managed or completely abandoned in the near future. Therefore, the interest in understanding how forest stands will develop after abandonment has increased considerably over the past two decades. While much is known about stand structure and stand development of Norway spruce (Picea abies L.) forests, almost no knowledge is available about the same processes in forest communities of the Central Alps. In the Swiss National Park (SNP), the forested area is comprised of mountain pine (Pinus montana Miller), Swiss stone pine/larch, (Pinus cembra L./Larix decidua L.). and mixed stands. When the Park was founded in 1914 all management activities were stopped. Therefore, this area offers the opportunity to study stand development and changes in stand structure after abandonment. We compared historic (1957) and present data (2001/02) from 19 stands that were grouped into characteristic stand types: mountain pine, mixed, and stone pine. We detected significant decreases in total tree density (stem/ha) and sapling density (saplings/ha) of 45 to 57%, and 64 to 76%, respectively, over the 45 years of observation for all stand types. These changes were strongly related to decreases in the number of shade intolerant mountain pine trees. Simultaneously, the amount of non-standing woody residue increased from less than 4t/ha to 36 to67.7 t/ha, and the density of standing dead wood (stems/ha) decreased significantly between 72 and 94%. The biomass of standing dead wood (t/ha), however, changed only slightly between 1957 and 01/02. Our results describe the successional development of continental subalpine forests after abandonment and outlines changes that might take place in similar areas in the near future.

     

Piscine orthoreovirus (PRV) in red and melanised foci in white muscle of Atlantic salmon (Salmo salar)

Melanised focal changes (black spots) are common findings in the white skeletal muscle of seawater-farmed Atlantic salmon (Salmo salar). Fillets with melanised focal changes are considered as lower quality and cause large economic losses. It has been suggested that red focal changes (red spots) precede the melanised focal changes. In the present work, we examined different populations of captive and wild salmon for the occurrence of both types of changes, which were investigated for the presence of different viruses by immunohistochemistry and RT-qPCR. The occurrence of red or melanised foci varied significantly between the populations, from none in wild fish control group, low prevalence of small foci in fish kept in in-house tanks, to high prevalence of large foci in farm-raised salmon. Large amounts of Piscine orthoreovirus (PRV) antigen were detected in all foci. No other viruses were detected. Red focal changes contained significantly higher levels of PRV RNA than apparently non-affected areas in white muscle of the same individuals. Some changes displayed a transient form between a red and melanised pathotype, indicating a progression from an acute to a chronic manifestation. We conclude that PRV is associated with the focal pathological changes in the white muscle of farmed Atlantic salmon and is a premise for the development of focal melanised changes.     

Simultaneous detection of Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis in porcine faeces and tissue samples by multiplex-PCR

Diarrhoea in growing and finishing pigs is usually caused by infectious agents and laboratory diagnosis is a prerequisite for efficient therapy. Cultivation of Brachyspira hyodysenteriae or Brachyspira pilosicoli and detection of Lawsonia intracellularis by means of immunofluorescence tests (IFT) are time-consuming and in some cases lack sensitivity. A multiplex-PCR was designed to detect simultaneously these three pathogens in faeces and tissue samples, allowing the differential diagnosis of dysentery, intestinal spirochaetosis and proliferative enteropathy. Detection limits for B. hyodysenteriae, B. pilosicoli and L. intracellularis were 10(4), 10(2) and 10(3) copies respectively. Agreement between multiplex-PCR and nested-PCR or cultivation was considered substantial to almost perfect. Agreement between multiplex-PCR and IFT in detecting L. intracellularis was only moderate, which was probably related to false-positive results given by IFT. The multiplex-PCR described herein is a valuable tool for the rapid and simultaneous detection of three different pathogens in porcine samples causing enteric diseases.     

Distribution of endangered bryophytes in Austrian agricultural landscapes

In Austrian agricultural landscapes, 1936 sampling plots within 72 study sites selected by a random procedure were investigated with regard to their bryophyte vegetation. Out of a total of 506 species, 135 endangered species were recorded. Thirty-eight percent of all populations of endangered species showed sporophytes and 15% produced vegetative reproduction units. There is a significantly higher number of endangered species growing in upland landscapes dominated by moderately intensive cattle farming than in lowland landscapes with a wide range of mainly intensive farming styles. The percentage of species that are endangered is higher in intensively than in moderately used areas. The sampling plots differed strongly in respect to their number of endangered species. Very important habitats for endangered bryophytes are less intensively used vineyards, moderately and less intensively used meadows (including fens), field margins and fallow lands. There is a significant negative correlation between land-use intensity as defined by the hemerobic state and the number of endangered species. The distribution of endangered species according to land-use and habitat quality is discussed.     

Vergleichend-anatomische Untersuchungen im Verwandtschaftskreis vonTriticum L. undAegilops L. (Gramineae)

Zusammenfassung Bei 46 Arten der GattungenTriticum undAegilops wurden anatomische Untersuchungen im Bereich der Organe Wurzel, Halm, Blattspreite, Ährenspindel, Spelzen, Blüte und Karyopse mittels gefärbter Hand- bzw. Mikrotomschnitte vorgenommen. Bedingt durch die kleineren Sproßorgane vonAegilops ergaben sich dort oft geringere Zellgrößen. Häufig waren auch mit der Ploidiestufe korrelierte Merkmale anzutreffen. In einigen Fällen ließ sich der Einfluß bestimmter Arten bzw. Genome auf die Merkmalsausprägung der allopolyploiden Sippen deutlich nachweisen, wofür als besonders klares BeispielAegilops tauschii mit seinem Einfluß auf die hexaploiden Weizenarten und auf die SektionVertebrata der GattungAegilops zu nennen ist. Innerhalb der GattungTriticum konnte eine Beziehung der Weizenarten mit einem G-Genom zu den diploiden Arten dieser Gattung durch Merkmale aller Organe belegt werden, während mit den übrigen Weizenarten weniger Ähnlichkeit besteht. Ein Merkmal im Halmbereich gibt sogar einen Hinweis auf die mögliche Beteiligung vonTriticum urartu an der Evolution der Weizenarten mit dem G-Genom. Nach Blatt- und Spelzenmerkmalen lassen sich die meisten tetraploidenTriticum- Sippen. mit einem AB-Genom zwei verschiedenen Gruppen zuordnen. Die diploiden Weizenarten erwiesen sich als gut charakterisierbare Gruppe. Echte anatomische Unterschiede zwischen Wild- und Kulturweizen bestehen nur in Bezug auf die Brüchigkeit der Ährenspindel. Innerhalb der GattungAegilops stehen sich die SektionenSitopsis undAmblyopyrum sehr nahe und sind auch denTriticum- Sippen viel ähnlicher als die übrigen Vertreter ihrer Gattung. Ein genauerer Hinweis auf den möglichen Donor des B-Genoms läßt sich aber anhand der anatomischen Merkmale nicht geben. Im gesamten Verwandtschaftskreis vonTriticum undAegkilops nur einmal auftretende Merkmale sind sehr selten, jedoch gibt es in mehreren Gruppen relativ isoliert stehende Arten. Zahlreiche anatomische Merkmale sind durch eine so große infraspezifische Variationsbreite gekennzeichnet, daß sie keine phylogenetische Aussage erlauben.

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Anatomical studies within the generaTriticum L. andAegilops L. (Gramineae)

Summary The anatomical characters of the root, culm, leaf lamina, ear rhachis, glume, palea, flower and caryopsis of 46Triticum andAegilops species were examined on the basis of coloured sections, made by hand or by microtome. Due to the smaller organ sizes ofAegilops also the cell sizes are mostly reduced in this genus. Often distinct character proved to be correlated with distinct ploidy levels. In some instances we were able to find a clear influence of distinct species or genomes on the characters of their alloploid taxa, e. g. an influence ofAegilops tauschii on the characters of the hexaploid wheat species and on the remaining species of sectionVertebrata ofAegilops. We found characters in all organs which point to a connection betweenTriticum species with genome G and the diploid wheats. The degree of similiarity to the other wheat species is much less strongly. One anatomical character of the culm indicates even a possible contribution ofTriticum urartu to the evolution of the wheat species with genome G. Most of the tetraploid species ofTriticum, genome AB, can be arranged into two different groups by means of leaf and glume characters. The diploid wheat species are a well characterized group. We were not able to find real anatomical differences between wild and cultivated wheat species besides the brittle ear rhachis. Within the genusAegilops the species of the sectionsSitopsis andAmblyopyrum resemble one another and theTriticum species much more than the other species ofAegilops. By anatomical characters it is not possible to indicate exactly the donor of genome B. Characters, which can be found only one time within the genera studied, are very seldom, but rather isolated species occur in several groups. Many anatomical characters are so variable even within the same species, that these characters can not be evaluated in phylogenetic respect.

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- Triticum L. Aegilops L. (Gramineae)

46 Triticum Aegilops , , , , , . Aegilops . , . ; Aegilops tauschii Vertebrata Aegilops. Triticum , G, , . Triticum urartu , G. Triticum, AB, . , . . Aegilops Sitopsis Amblyopyrum; Triticum, . - , , . , Tritcum Aegilops — , , , . , .

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Herrn Prof. Dr. Drs. h. c.Hans Stubbe zum 75. Geburtstag gewidmet.     

Taxonomy and evolution of cultivated plants: Literature review 1986 1987

Summary Important papers on taxonomy and evolution of cultivated plants published in 1986 and 1987 were compiled and briefly discussed.

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Taxonomic und Evolution der Kulturpflanzen: Litcraturübersicht 1986/1987

Zusammenfassung Wichtige Arbciton übot Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1986 und 1987 wuzden zusammengestolit und kurz kommentiert.

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: . 1986–1987

, 1986 1987 . .

     

Terrestrial liming as a tool to mitigate acidification of Woods Lake,NY

The Soil Liming Model (SLiM) has been used to simulate lake and stream water quality response to different strategies for the application of limestone to subcatchment soils in the Woods Lake, NY watershed. Simulations using doses of 3, 10, or 30 t ha^–1 forecast that a dose in excess of 10 t ha^–1 must be applied to discharge areas in order to sufficiently improve water quality in the lake. At 3 t ha^–1 inlet stream water quality could support fish populations. As expected, treatment effectiveness is strongly influenced by subcatchment hydrologic flow paths. Where shallow flow predominates, soil liming provides a more effective tool for lake water quality improvement. In subcatchments drained primarily by ground water, the effect of liming on water quality is less pronounced albeit of longer duration. Based upon the results of these model simulations, the authors compare results of conventional lake liming to simulated watershed treatment predictions.     

Fulvic acid composition in degraded fenlands

Fulvic acids (FAs) from topsoil and ground water solutions were investigated to discover effects of land use and peat degradation on their molecular chemical composition and thermal properties. The FAs were extracted from three Gleysols under arable land, intensive and extensive grassland, and from three Histosols under alder forest, extensive grassland, and a natural succession in a long‐term (> 200 years) cultivated fen area. Functional groups and molecular subunits of the FAs were investigated by ¹³C Nuclear Magnetic Resonance (¹³C NMR) spectroscopy. Thermal properties and structural molecular subunits were investigated by off‐line pyrolysis, and Pyrolysis‐Field Ionization Mass Spectrometry (Py‐FIMS). The ¹³C NMR spectra showed that the FAs from topsoil solutions had smaller proportions of alkyl C (mean: —8 %) and more aromatic C (mean: + 6 %) than FAs from ground water. This clear differentiation of dissolved FAs in the soil profiles is consistent with Py‐FIMS data which have shown enrichments of lipids in ground water FAs. Furthermore, Py‐FIMS revealed that the FAs from topsoils were richer in phenols + lignin monomers, carbohydrates, as well as mostly aromatic N‐containing compounds. These molecular subunits of FAs, relatively enriched in topsoil, were also the main indicators of land use and peat degradation. For topsoil solutions, the proportions of phenols + lignin monomers and carbohydrates increased stepwise with peat degradation in Gleysols and Histosols. Correspondingly, the thermal properties indicated the incorporation of these compounds into FAs by chemical bonds of larger thermal stability. Statistical evaluation by principal component analysis of Py‐FIMS clearly supported the differentiation of FAs according to the origin from topsoils and ground water, different soil types, and land use and peat degradation. Hence, it is concluded that water soluble FAs can be utilized as objective ecological indicators for soil effects on adjacent ground and surface waters.     

Nitrogen compounds extracted by electroultrafiltration (EUF) or CaCl2 solution and their relationships to nitrogen mineralization in soils

The objective of the investigation was to identify the most important organic N-containing fractions extracted from soils by electroultrafiltration (EUF) or a CaCl₂ solution, respectively, and their importance for nitrogen mineralization. The investigation comprised 19 agricultural and one forest top soil. Net N mineralization was tested in Mitscherlich pot experiments with three treatments: (1) fallow soil without N fertilizer, (2) soil cultivated with rye grass without N fertilizer, (3) soil cultivated with rye grass with N fertilizer. The highest proportion of N in the extracts was the amino N fraction (amino acids + peptides) amounting to approximately 60% of the total N extracted by CaCl₂ and to about 40% of the total N extracted by EUF. The proportion of amino sugars from total N extracted was in average 10% for the CaCl₂ and 5.2% for the EUF extracts. The proportion of heterocyclic N bases derived from nucleic acids amounted in average to 4.8% and 3.6% for the CaCl₂ and EUF extract, respectively. Amino N (amino acids + peptides) were correlated best with net N mineralization (EUF, r = 0.81***, CaCl₂, r = 0.86***). The correlation between amino sugars and net N mineralization was r = 0.55* for the EUF extract and r = 0.49* for the CaCl₂ extract. The heterocyclic N bases did not correlate with net N mineralization. Correlations between Norg extracted by CaCl₂ versus net N mineralization were higher than those obtained by the EUF extract. Net N mineralization was about four times higher in the fallow soils than in the treatment with grass and no N fertilizer. In the treatment with grass + N fertilizer on average no net N mineralization occurred, moreover there was a tendency of N immobilization. It is assumend that in the treatments with grass cultivation, organic C released by roots stimulated the assimilation of mineral N and amino acids by soil microorganisms resulting in a low net N mineralization. Net N mineralization led to a highly significant depletion in the Norg pools and particularly in the amino N and amino sugar pools in the treatment with grass and without N fertilizer. This depletion was particularly evident in the CaCl₂ extracts. The results justify the conclusion that the Norg obtained with both extraction methods originates from a dynamic N pool into which N flows in and out. The amino N extractable with EUF or CaCl₂ is a reliable indicator for the net N mineralization potential of soils.