Mycorrhizal status of selected herbaceous plants in Molinia meadows of Folusz, near Szubin (Poland)

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

Physiological activity of ectomycorrhizas in a moderately polluted forest (Ratanica catchment, southern Poland)

Ectomycorrhizas of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) were sampled in a mature forest ecosystem exposed for more than 40 years to moderate levels of gaseous and dust pollutants. Soil of the forest site was characterised by low pH and accumulation of heavy metals (Pb, Mn, Zn, Cu, Cd, Fe). Mycorrhizal vitality and enzyme activity of the root-surface and soil acid phosphatase (AcPase) were studied at 17 measurement points (0-5 cm soil depth) in relation to the content of inorganic phosphate (Pi) and aluminiumions( Al3+)inthesoil.AnatomyofScotspineandbeechmycorrhizastakenfromdifferentmeasurement points was observed. The concentration ofessential nutrients (C, N, P, Ca, Mg) and the ratios Ca/Al, Mg/AlandN/Pwereanalysedinfineroots.HighconcentrationsofAl3+inthesoil(40-118meqkg-1)andlow levels ofPi (12-44 mg P2O5kg-1) were accompanied by high activity ofthe root-surface AcPase ofpine and beech mycorrhizas (25-67 and 33-86 /./.mol pNP g-1 fresh weight h-1, respectively) and soil AcPase (6.8-22.4 //mol pNP g-1 dry weight h-1). The results indicate that fine tree roots are undoubtedly under stress as evidenced by a disturbance in P uptake and accumulation. However, the high vitality of mycorrhizas and the high Ca/Al ratio in fine roots suggest that the defence mechanisms of mycorrhizas and the rhizosphere are still able to ameliorate the influence of anthropogenic pollution

Mycorrhizal status of forest trees grown in urban and rural environments in Poland

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

Biomass of external mycelium of ectomycorrhizal fungi in Norway spruce stands in Poland

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

Acid phosphatase activity in mycorrhizal and non-mycorrhizal Scots pine seedlings in relation to nitrogen and phosphorus nutrition

Mycorrhizal and control seedlings of Scots pine (Pinus sylvestris L.) were grown under axenic conditions at various concentrations of nitrogen (0.17 mM, 3.78 mM, 18.92 mM) and phosphorus (0.25 mM, 5.58 mM, 23.5 mM). Enzyme activities of soluble acid phosphatase of excised roots (surface-accessible activity) and of crude enzyme preparations of root tissue (total soluble activity) were analyzed in control and mycorrhizal seedlings. The content of P in pine shoot was also measured. The intermediate supply of nitrogen and phosphorus (N = 3.78 mM, P= 5.58 mM) was optimal for development of ectomycorrhizae. Activity of acid phosphatase was stimulated by higher levels of N in the soil and was higher in mycorrhizal than non-mycorrhizal roots. Pine roots had greater acid phosphatase activity at the reduced than at the higher P concentrations. The presence of mycorrhizae increased the activities of both surface-accessible and total soluble enzyme activities at lower P supply (0.25 mM, 5.58 mM) and decreased it significantly at the highest P concentration (23.5 mM). P content in shoots was higher in mycorrhizal than non-mycorrhizal seedlings

Phosphate status and acid phosphatase activity in soil and ectomycorrhizas in two mature stands of scots pine (Pinus sylvestris L.) exposed to different levels of anthropogenic pollution

The relations between anthropogenic environmental pollution and the level of inorganic phosphorus in soil, enzyme activities of extracellular soil acid phosphatase and the surface acid phosphatase of excised ectomycorrhizas of Scots pine (Pinus sylvestris L.) were studied. Soil and root samples were taken from two Scots pine stands in central Poland: a polluted site exposed to long-term pollution from a steelworks and the city of Warsaw and a reference plot (control) free from direct impact of pollution. The polluted site was characterised by high concentration of trace elements (Cd, Pb, Cu, Zn, Mn, Cr) and low level of inorganic phosphate in soil. This site had significantly lower enzyme activities of soil acid phosphatase (0.54 µmoles p-nitrophenol released g-1 dry weight h-1) and surface acid phosphatase of pine ectomycorrhizas (3.37 µmoles p-nitrophenol released g-1 fresh weight h-1) than the control site (1.36 µmoles p-nitrophenol released g-1 dry weight h-1 and 12.46 µmoles p-nitrophenol released g-1 fresh weight h-1, respectively). The levels of phosphate, carbon and nitrogen in pine fine roots were also analysed. Low concentrations of P04-P and high N: P ratio in pine fine roots from polluted site were found. The results suggest that soil pollutants may have a negative effect on the extracellular acid phosphatase of soil and Scots pine ectomycorrhizas and on the phosphorus status in fine roots of the plant

The Fine Root Distribution and Morphology of Mature White Poplar in Natural Temperate Riverside Forests under Periodically Flooded or Dry Hydrological Conditions

Fine roots are a key component of carbon turnover in the terrestrial environment. Therefore, their distribution allows for the estimation of areas of carbon in the soil. The vertical distribution of roots is the result of both the tree species and various environmental factors. Research on the architecture of root systems most often includes seedlings and young trees growing under experimental conditions; however, little is known about trees in their natural habitats. The aim of this study is to analyze the fine root distribution of mature white poplar trees in natural riverside temperate zone forests of Central Europe (Poland) periodically flooded and in dry hydrological conditions. The length, diameter, and area of the fine roots, as well as the specific root length (SRL) and specific root area (SRA) of white poplar were measured in three layers of the soil, 0–10 cm, 10–20 cm, and 20–30 cm depths, in three forest sites. Two of the sites experience periodic floods, and one has been without flooding for 80 years, due to the construction of a flood embankment. The highest values of the lengths and surface areas of the poplar fine roots were observed at a depth of 0–10 cm at all sites. Soil moisture was positively correlated with the analyzed root parameters. The presence of understory plant roots contributed to the reduction in the fine root length of poplar in the subsurface layer, compared to the site that was not affected by the presence of plants other than poplar. The distribution of fine roots, the most dynamic part of the plant root system, reflects the most active areas in the soil profile. The presented research will allow for a better understanding of the functioning of natural riverside ecosystems, as well as show the great adaptability of white poplar fine roots to various conditions in the soil