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Ectomycorrhizal communities structure of Norway spruce (Picea abies L. (Karst.) was studied in four mature forest stands: Brenna, Salmopol, Zwierzyniec and Mirachowo. Morphological classification was used to distinguish the major mycorrhizal types associated with spruce in different forest types. Three of the foreststands were located within the natural geographical range of Norway spruce (Brenna, Salmopol, Zwierzyniec) and one (Mirachowo) was located in so-called “spruce-less zone”. The sites differed in terms of environmental pollution. The mountain sites (Brenna, Salmopol) were characterized by relatively high levels of air pollution. The upland forest stand (Zwierzyniec), located in the southeastern part of Poland, was affected by a moderate pollution. The lowland stand in northern Poland (Mirachowo) was free from direct impact of anthropogenic pollution. The level of mycorrhizal colonization was 100% at all the study sites. Thirty-seven mycorrhizal morphotypes were distinguished in total. The number of ectomycorrhizal morphotypes varied between sites from 12 in Salmopol to 28 in Zwierzyniec. From one to three dominant morphotypes were found at the study site. Site-specific morhotypes were also observed. The frequency of mycorrhizal morphotypes differed between the forest stands.
Sandy everlasting, Helichrysum arenarium, a perennial belonging to Asteraceae family, is a source of valuable herbal material and therefore is under partial protection in Poland. It grows in sunny places on sandy soils, in abandoned fields, along roadsides and in dry forests and thickets, where it enters into symbiosis with arbuscular mycorrhizal fungi. The studies on the biology, ecology and cultivation of sandy everlasting have been vigorously pursued since 2003. The aim of this work was assessing the influence of root colonisation by mycorrhizal fungi on the growth and development of H. arenarium cultivated on clayey soil. Two independent experiments (in the pots and in field) were performed. In the first one, under laboratory conditions, the effect of inoculation of soil with arbuscular fungus Glomus intraradices on the biometric features of sandy everlasting seedlings was analyzed. The second experiment was designed to show the association of the root colonisation level with the biometric features of generative shoots grown in an open field. It was demonstrated that sandy clay is an appropriate medium for growing sandy everlasting, enabling a proper development of seedlings and ensuring high inflorescence yield. The amendment of soil with inoculum resulted in a significant decrease in the mass of vegetative and generative shoot parts and made the cultivation more expensive. The inflorescence yield (Inflorescentia Helichrysi) obtained from inoculated plots was lower by 36%.
This preliminary study examined the arbuscular mycorrhizal (AM) status of native plant species in the Molinia meadows of Folusz in the Kujawy region, Poland. Root samples from ten plant species characteristic of Molinia meadows (Betonica officinalis, Dianthus superbus, Galium boreale, Inula salicina, Ostericum palustre, Sanguisorba officinalis, Selinum carvifolia, Serratula tinctoria, Silaum silaus, and Succisa pratensis) were collected in August 2014. Root colonization by AM fungi was considered an indicator of symbiosis development. AM was found in all plant species examined. The frequency of mycorrhizal structures ranged between 68% and 99%. The intensity of mycorrhizal colonization in roots varied with the plant species, ranging between 3.9% (O. palustre) and 40.1% (B. officinalis). To our knowledge, this is the first study to examine the mycorrhizal status of three species: D. superbus, O. palustre, S. carvifolia. Because AM colonization depends on plant genotype and environmental factors, further studies should examine seasonal variability in plant root colonization and the compositions of AM fungal communities, which may serve as indicators of site conditions
Biomass of extramatrical mycorrhizal mycelium (EMM) was examined under canopies of mature Norway spruce trees grown in different forest stands in Poland. Two mountain forest sites (Brenna and Salmopol), one upland site (Zwierzyniec) and one lowland site (Mirachowo) have been investigated, using sand-filled mesh-bags method. The in-grow mesh-bags were buried in the soil for 12 months (since October up to the next October) or for 4 months (since June up to October) at four depths at each site: 5, 15, 30 and 45 cm (Brenna and Salmopol) or 60 cm (Zwierzyniec and Mirachowo). The mycelium biomass was estimated from the ergosterol content determined in the mesh-bags. The results indicated significant differences in EMM production and their vertical distribution between the mountain and the upland and lowland forest sites. The lowest EMM biomass was found at the experimental plot in the mountainious site Brenna. Considerable decrease of EMM biomass with the soil depth was recorded after 12 months of the mesh-bags incubation in soil in the upland and lowland sites, while in the mountain forests decrease of the EMM biomass in the lower soil depths diminished more gradually EMM biomass determined in the mesh-bags placed in soil at the upper 5 and 15 cm tended to be higher after 4 months than after 12 months of incubation period. Such results suggest that the time necessary for evaluation of EMM biomass in soil may be limited to the summer–autumn months, when the production of EMM is the highest. Variable stress factors can influence decreased ectomycorrhizal mycelium production and/or their destruction. Further research in different forest types and regions are needed for better understanding factors determining EMM biomass production and surviving in soil.
The significance of root colonization by mycorrhizal fungi for the growth and development of Helichrysum arenarium was investigated in two independent experiments. In the first experiment the association of root colonization level with the pluviothermal conditions within the growing season and the age of a natural plant population was analyzed. In the second one, under controlled conditions, the influence of artificial inoculation with the arbuscular fungus Glomus intraradices on the features of plants raised from achenes was studied. It was shown that hydrothermal conditions during blooming period had a greater influence on reproduction processes of sandy everlasting than both the population age (the secondary succession progress) and the level of root colonization by mycorrhizal fungi. High amount of precipitation at plant generative development phase positively influences the potential and actual fertility of ramets. The presence of arbuscular fungus in the soil favors the growth and development of sandy everlasting specimens at their early growing stages: they have a better-developed root system and a greater photosynthetic area.
Mycorrhizal status of mature forest trees (horse chestnut, Aesculus hippocastanum L.; white poplar, Populus alba L.; black poplar, P. nigra L.) was investigated in urban habitats under different intensity of anthropogenic pressures (restricted root zone, soil compaction, low air and soil humidity), compared to trees grown in rural environments that were used as reference biological material. Horse chestnut roots were colonized by arbuscular mycorrhizal (AM) fungi, and the two poplar species (white poplar and black poplar) were dually colonized by AM and ectomycorrhizal (ECM) fungi, regardless of habitat, except P. nigra grown close to a trafficked street, which had only ECM associations. The AM colonization of horse chestnut roots was higher in May than October, regardless of habitat and showed a tendency to be lower in the roots of trees from urban environments, however, only mycorrhizal frequency differed significantly between the urban habitat and the reference plot. In roots of two poplar species the intensity of AM colonization was significantly lower in disturbed urban habitats than in the rural sites. ECM colonization of white poplar did not differ between the urban and rural environments, and in black poplar roots it was lower at the city sites than in the reference plot. Significantly lower levels of available magnesium and total carbon was recorded in soils at the urban sites compared to reference plots. The concentrations of the other macro- and microelements did not differ significantly. A tendency to reduced water content in two of three urban sites was also recorded. The results indicated that mycorrhizal fungi native of urban habitats are able to develop effective symbiosis with mature tree roots and they suggested that environmental factors, such as availability of water and nutrient and carbohydrates production and allocation, are the most important factor influencing the mycorrhizal colonization of urban trees.
Activity of soil dehydrogenase (DHA) was measured in the mineral soil in a forest stand of 15 to 16-year-old Scots pine (Pinus sylvestris L.) from geographically diverse populations, as an indicator of biological activity of soil microorganisms, in a provenance experiment in Poland. The pine populations originated from six European countries (Sweden, Russia, Latvia, Poland, Germany, France) and differed widely in aboveground biomass and productivity. Soil DHA during two growing seasons showed pronounced seasonal variability, which was significantly related to the fine root concentration of nonstructural carbohydrates. Higher DHA was found in soil under canopies of the central and southern European populations than in those from more northern parts of the Scots pine range. Significant positive correlation between soil DHA and aboveground tree biomass suggest that these patterns most likely resulted from differences in carbon dynamics and productivity among populations.
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