Water samples were collected from the long-term ecological research (LTER) site at Helgoland and the eukaryotic microbial community was assessed. 18S V4 region was amplified using the primer set 528iF /964iR and amplicon sequencing was performed on an Illumina MiSeq™ sequencer in a 2 × 300 bp paired-end run. Sequence data have been deposited in the European Nucleotide Archive (ENA) at the European Bioinformatics Institute (EMBL-EBI) under accession number PRJEB37135 using the data brokerage service of the German Federation for Biological Data (GFBio). 21 million sequences remained after bioinformatic processing and were clustered into Operational Taxonomic Units (OTUs). The Protist Ribosomal Reference database (PR2), version 4.11.1 was used as reference database.
Objective: The aims of the programme are focussed on identification, assessement and stress-specific analysis of possible causes for recent forest decline. General information: the aims of the four projects with technical, soil-scientific and ecophysiological goals in open top chambers will attempts to correlate the degree of tree damage and pollutant concentration. Besides pilot stage testing of a new type of open top chamber both the leaching phenomenon and the activity of respiration and photosynthesis will be analysed. Using samples from theses OTC's as well as from conifers from varying natural stands the content of important metabolic intermediates shall be related to the phenomenological symptoms of damage. Special emphasis will be placed on the elucidation of intermediate steps in the causal chain of needle yellowing in material taken at medium altitude stands. The role of airborne nitrogenous compounds and the study of detoxification regulation in conifer seedlings is also subject to investigation. In connection with the effects of different stress factors on forest trees the reaction of the rhizosphere and predominantly of the mycorrhiza is of special interest. The qualitative and quantitative dependence of the fructification of mycorrhiza fungi on air pollution conditions, on the degree of tree damage and on fertilisation measures is to be determined in spruce stands of the southern black forest. In connection with such therapies the repeatedly raised question of endangered ground water resources and the aspect of hyper fertilisation by increased nitrogen input will be investigated in a catchment study at three well separated watersheds in the southern black forest. All the projects are being carried out in cooperation with research groups in the french programme deforpa. Achievements: In 1989 the comparative ecophysiological measurements started in 1988 on 20-year old spruce trees growing on natural sites in open top chambers with charcoal filtered and ambient air were continued. One part of our studies was the determination of diurnal courses of carbon dioxide and water vapour exchange parameters under normal ambient conditions. Additional to this, measurements for the characterisation of the performance of photosynthetic apparatus were carried out by studies of light and carbon dioxide response curves under controlled conditions. Comparison of 20 year old spruce trees kept in non filtered air, in charcoal filtered air and on outside standing trees resulted in slight differences in microclimate factors between the experimental chambers and ambient climate. However, conditions for radiation, wind and deposition in chambers were more disadvantageous. The exclusion rate of sulphur dioxide, ozone, nitrogen oxides, dust and aerosols in charcoal filtered air was found to be more than 75 per cent. Investigations were carried out on the uptake, storage and possible detoxification of minerals, especially aluminium ions, by ectomy corrhizae of
Ziel des Forschungsvorhabens ist es, durch Einfuehrung neuer Wirkstoffe, verbesserter Pflanzenschutztechnik, Beachtung von Auflagen (Uferrandstreifen, Abtrift) und Randbedingungen (Bodenfeuchtigkeit, Temperatur, EC-Stadien) die Aufwandmengen von Herbiziden zu senken und ein abgeschlossenes Gebiet (Funne mit Zufluessen), welches der Trinkwassergewinnung dient, zu sanieren. Dh, dass die Eintraege von PSM soweit gesenkt werden, dass der Trinkwassergrenzwert von 0,1 myg/l eingehalten werden kann. Dies beinhaltet auch den teilweisen Verzicht auf die Wirkstoffe IPU und CTU (Isoproturon und Chlortoluron).