During an investigation of actinomycetes from papyrus rhizoplane samples from Egyptian wetland, 120 streptomycetes were recovered, morphologically characterised and assessed for their antimicrobial activity. The dominant rhizoplane streptomycetes were grey colour group, which represent Streptomyces anulatus. Most of the isolates (80%) were active against one or more of the organisms tested (two Gram negative bacteria, three Gram positive bacteria, two yeasts and two filamentous fungi). Most of the antibiotic- producing isolates possessed white or grey colour. Strong antibiosis was exhibited against Staphylococus aureus, Bacillus subtilis and Aspergillus niger (71, 60 and 48%, respectively), while only 8% of isolates displayed an activity against Escherichia coli.
Key words: Antimicrobial activity, Egypt, papyrus, streptomycetes, rhizoplane, wetland.
Hala M. Rifaat, Microbial Chemistry Dept., National Research Centre, Dokki, Cairo, Egypt, e-mail: halamohamed6@hotmail.com
The nutritional status of Scots pine (Pinus sylvestris L.) stands growing on a nitrogenrich, drained pine mire in western Finland was studied after refertilization using needle analysis and the response of stand volume growth. The main aim was to find out if Krefertilization alone could maintain or increase the volume growth without causing a nutrient imbalance between K and P. The initial fertilization was carried out in 1961– 62 using PK fertilizer and refertilized in 1976 and 1989 with different combinations of nitrogen (N), phosphorus (P), potassium (K) and boron (B). Needle samples were taken and the tree stands were measured in 1996 and 2001. Peat samples were taken in 2002. According to the needle analysis results, the concentration of P was above the deficiency level in all the treatments in 1995 and 2000. There was a clear shortage of K in the needles collected from the control treatment, but the concentration of K was still adequate 12 years after the latest K refertilization. The volume growth of the stands clearly responded to the 1976 refertilization with K alone, which was probably due to the fact that trees had been suffering from K deficiency before the first refertilization and 14–15 years thereafter. After the second refertilization, the combination of K and P increased the annual volume growth more than refertilization with K alone. This indicates that about 25 years after the initial fertilization, there was already some shortage of P. The highest stand volume was associated with the combined K (1976) and PK (1989) refertilization treatment. Refertilization with N did not increase stand volumes during the study period.
Key words: fertilization, refertilization, pine mire, potassium, phosphorus, yield, volume growth
Heli Rautjärvi, The Finnish Forest Research Institute, Joensuu Research Centre, Box
68, FIN-80101 Joensuu, e-mail: heli.rautjarvi@metla.fi, phone: 010211 3112
Seppo Kaunisto, Linnankoskenkatu 71, FIN-06100 Porvoo, e-mail:
seppo.kaunisto@pp4.inet.fi
Timo Tolonen, The Finnish Forest Research Institute, Parkano Research Station (2001–
2002)
We studied the natural regeneration of a cut-over peat bog in the Šumava Mountains, Czech Republic. The spontaneous revegetation by vascular plants has been limited by extreme abiotic conditions left after peat mining. Only 1–2% of the total area was recolonized by Sphagnum mosses. This was mainly because drainage channels are still drying out the bog. Only plants tolerant to water stress such as Juncus effusus, Molinia caerulea, Eriophorum angustifolium and E. vaginatum were able to establish there. A key species colonizing bare surface is a clonal plant E. angustifolium. It forms circular polycormons of densely aggregated ramets. As in other radially spreading phalanx plants, the oldest (central) part of the system gradually dies, previously connected ramets become separated, and ring polycormon becomes open to recolonization by other plant species. We analyzed the relationships between species richness of the ring and their size, percentage litter cover, distance to seed sources, and soil fertility. The number of plant species was higher in the middle of the polycormons. The soil was more fertile in the central area than in the surroundings. We conclude that the restoration of highly disturbed habitats can be facilitated by clonal behavior of pioneer populations.
Key words: Eriophorum angustifolium, cut-away peat bog, plant colonization, clonal plant
Vojtěch Lanta, Jiří Doležal & Jan Šamata
Tässä tutkimuksessa selvitettiin Suomen nykyisin viljelyssä olevien turve- ja multamaiden pinta-alat ja niiden alueellinen jakauma. Pinta-alat määritettiin kolmeen suurimpaan viljavuusanalyysejä tekevään laboratorioon lähetettyjen maanäytteiden maalajijakauman perusteella. Tämän arviointimenetelmän luotettavuus on EU-aikakaudella parempi kuin aikaisemmin, koska joka viides vuosi tehtävä viljavuusanalyysi on maatalouden ympäristötuen saamisen edellytyksenä. Ympäristötukijärjestelmän piirissä on lähes koko tällä hetkellä viljelyssä oleva peltopinta-ala. Tulosten perusteella turvemaita (orgaanisen aineksen pitoisuus vähintään 40 prosenttia) on Suomessa 85 000 ha eli 3,8 prosenttia viljelymaa-alasta ja multamaita (orgaanisen aineksen pitoisuus 20 – 39,9 prosenttia) 214 000 hehtaaria eli 9,7 prosenttia. Yhteensä näitä maita on viljelyksessä noin 300 000 ha eli 13,6 prosenttia kokonaispeltoalastamme.
Avainsanat: orgaaniset maat, turvemaat, multamaat, viljelymaa, peltoala
Merja Myllys, Maa- ja elintarviketalouden tutkimuskeskus MTT, Maaperä ja ympäristö, 31600 Jokioinen,
sähköposti merja.myllys@mtt.fi
Marko Sinkkonen, Maa- ja elintarviketalouden tutkimuskeskus MTT, Taloustutkimus MTTL, Luutnantintie 13,
PL 3, 00411 Helsinki, sähköposti marko.sinkkonen@mtt.fi