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A number of studies have focused on urban trees to understand their mitigation capacity of air pollution. In this study particulate matter (PM) deposition on Quercus ilex leaves was quantitatively analyzed in four districts of the City of Terni (Italy) for three periods of the year. Fine (between 0.2 and 2.5 μm) and Large (between 2.5 and 10 μm) PM fractions were analyzed. Mean PM deposition value on Quercus ilex leaves was 20.6 μg cm(-2). Variations in PM deposition correlated with distance to main roads and downwind position relatively to industrial area. Epicuticular waxes were measured and related to accumulated PM. For Fine PM deposited in waxes we observed a higher value (40% of total Fine PM) than Large PM (4% of total Large PM). Results from this study allow to increase our understanding about air pollution interactions with urban vegetation and could be hopefully taken into account when guidelines for local urban green management are realized.
- MeSH
- dub (rod) chemie MeSH
- látky znečišťující vzduch analýza MeSH
- listy rostlin chemie MeSH
- monitorování životního prostředí metody MeSH
- pevné částice analýza MeSH
- stromy MeSH
- velkoměsta MeSH
- znečištění ovzduší statistika a číselné údaje MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Itálie MeSH
- velkoměsta MeSH
Rapid adaptation of insect species to environmental changes can be advantageous for their development. Forest cockchafer (Melolontha hippocastani) is herbivorous insect species with high food intake that has been widely studied within European conditions. It can cause huge economic and ecological losses especially in oak-dominated forest stands. Food preference of this species is mainly comprised of trees with a potential to accumulate manganese in their assimilation apparatus. In order to determine cockchafer's reactions to increased Mn concentration in its food, the adults were reared in laboratory conditions controlled for temperature, humidity, and light on a natural diet of oak (Quercus petraea) leaves. Food was contaminated by soaking in solutions of MnCl2·4H2O in concentrations from 0.5 to 10mgml-1. Food consumption, activity period of adults, quantity of eggs laid, body weights of individuals, as well as Mn concentrations in unconsumed food, excrement, and the bodies of cockchafers were determined to indicate how these change in reaction to food quality altered in terms of Mn content. The results showed that very high Mn content in the diet significantly influenced food consumption by M. hippocastani adults and thereby their development. This was in spite of the tendency of individuals to expel Mn through the faeces and incorporate it into undetermined parts of their bodies. Negative reactions of the experimental population were determined in treatments fed leaves with Mn concentration of 1800ppm and more. Our experiment proved that Mn can greatly influence the phytophagous cockchafer (decreased feeding time, food consumption, and fertility).
- MeSH
- brouci účinky léků růst a vývoj MeSH
- býložravci MeSH
- dieta MeSH
- dub (rod) chemie MeSH
- fertilita účinky léků MeSH
- krmivo pro zvířata analýza MeSH
- listy rostlin chemie MeSH
- mangan analýza farmakologie MeSH
- přijímání potravy účinky léků MeSH
- tělesná hmotnost účinky léků MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The decomposition of dead plant biomass contributes to the carbon cycle and is one of the key processes in temperate forests. While fungi in litter decomposition drive the chemical changes occurring in litter, the bacterial community appears to be important as well, especially later in the decomposition process when its abundance increases. In this paper, we describe the bacterial community composition in live Quercus petraea leaves and during the subsequent two years of litter decomposition. Members of the classes Alpha-, Beta- and Gammaproteobacteria and the phyla Actinobacteria, Bacteroidetes and Acidobacteria were dominant throughout the experiment. Bacteria present in the oak phyllosphere were rapidly replaced by other taxa after leaf senescence. There were dynamic successive changes in community composition, in which the early-stage (months 2-4), mid-stage (months 6-8) and late-stage (months 10-24) decomposer communities could be distinguished, and the diversity increased with time. Bacteria associated with dead fungal mycelium were important during initial decomposition, with sequence relative abundances of up to 40% of the total bacterial community in months 2 and 4 when the highest fungal biomass was observed. Cellulose-decomposing bacteria were less frequent, with abundance ranging from 4% to 15%. The bacterial community dynamics reflects changes in the availability of possible resources either of the plant or microbial origin.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace metabolismus MeSH
- biomasa MeSH
- celulosa metabolismus MeSH
- dub (rod) metabolismus mikrobiologie MeSH
- houby klasifikace metabolismus MeSH
- koloběh uhlíku fyziologie MeSH
- lesy MeSH
- listy rostlin metabolismus mikrobiologie MeSH
- mikrobiota genetika MeSH
- mycelium metabolismus MeSH
- půdní mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
Fungi are considered the primary decomposers of dead plant biomass in terrestrial ecosystems. However, current knowledge regarding the successive changes in fungal communities during litter decomposition is limited. Here we explored the development of the fungal community over 24 months of litter decomposition in a temperate forest with dominant Quercus petraea using 454-pyrosequencing of the fungal internal transcribed spacer (ITS) region and cellobiohydrolase I (cbhI) genes, which encode exocellulases, to specifically address cellulose decomposers. To quantify the involvement of phyllosphere fungi in litter decomposition, the fungal communities in live leaves and leaves immediately before abscission were also analysed. The results showed rapid succession of fungi with dramatic changes in the composition of the fungal community. Furthermore, most of the abundant taxa only temporarily dominated in the substrate. Fungal diversity was lowest at leaf senescence, increased until month 4 and did not significantly change during subsequent decomposition. Highly diverse community of phyllosphere fungi inhabits live oak leaves 2 months before abscission, and these phyllosphere taxa comprise a significant share of the fungal community during early decomposition up to the fourth month. Sequences assigned to the Ascomycota showed highest relative abundances in live leaves and during the early stages of decomposition. In contrast, the relative abundance of sequences assigned to the Basidiomycota phylum, particularly basidiomycetous yeasts, increased with time. Although cellulose was available in the litter during all stages of decomposition, the community of cellulolytic fungi changed substantially over time. The results indicate that litter decomposition is a highly complex process mediated by various fungal taxa.
- MeSH
- analýza hlavních komponent MeSH
- biodiverzita * MeSH
- celulosa-1,4-beta-cellobiosidasa genetika MeSH
- dub (rod) mikrobiologie MeSH
- fylogeneze MeSH
- houby klasifikace genetika růst a vývoj fyziologie MeSH
- listy rostlin mikrobiologie MeSH
- mezerníky ribozomální DNA genetika MeSH
- půdní mikrobiologie MeSH
- stromy mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The objective of the study was to evaluate changes in microbial communities with the predicted arrival of new species to Mediterranean forests under projected intensification of water stress conditions. For that, litter from three Mediterranean forests dominated respectively by Quercus pubescens Willd., Quercus ilex L. and Pinus halepensis Mill. were collected, and placed to their 'home' forest but also to the two other forests under natural and amplified drought conditions (i.e. rainfall reduction of 30%). Quantitative PCR showed that overall, actinobacteria and total bacteria were more abundant in Q. pubescens and Q. ilex than in P. halepensis litter. However, the abundance of both groups was dependent on the forest sites: placement of allochthonous litter to Q. pubescens and P. halepensis forests (i.e. P. halepensis and Q. pubescens, respectively) increased bacterial and fungal abundances, while no effect was observed in Q. ilex forest. P. halepensis litter in Q. pubescens and Q. ilex forests significantly reduced actinobacteria (A/F) and total bacteria (B/F) to fungi ratios. The reduction of rainfall did not influence actinobacteria and bacteria but caused an increase of fungi. As a result, a reduction of A/F ratio is expected with the plant community change towards the dominance of spreading P. halepensis under amplified drought conditions.
- MeSH
- Bacteria klasifikace izolace a purifikace MeSH
- borovice mikrobiologie MeSH
- dub (rod) mikrobiologie MeSH
- houby klasifikace izolace a purifikace MeSH
- lesy MeSH
- listy rostlin mikrobiologie MeSH
- mikrobiota MeSH
- období sucha MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In the Mediterranean ecosystem, wildfires are very frequent and the predicted future with a probable increase of fires could drastically modify the vegetation scenarios. Vegetation fires are an important source of gases and primary emissions of fine carbonaceous particles in the atmosphere. In this paper, we present gaseous and particulate emissions data from the combustion of different plant tissues (needles/leaves, branches and needle/leaf litter), obtained from one conifer (Pinus halepensis) and one deciduous broadleaf tree (Quercus pubescens). Both species are commonly found throughout the Mediterranean area, often subject to wildfires. Experiments were carried out in a combustion chamber continuously sampling emissions throughout the different phases of a fire (pre-ignition, flaming and smoldering). We identified and quantified 83 volatile organic compounds including important carcinogens that can affect human health. CO and CO2 were the main gaseous species emitted, benzene and toluene were the dominant aromatic hydrocarbons, methyl-vinyl-ketone and methyl-ethyl-ketone were the most abundant measured oxygenated volatile organic compounds. CO2 and methane emissions peaked during the flaming phase, while the peak of CO emissions occurred during the smoldering phase. Overall, needle/leaf combustion released a greater amount of volatile organic compounds into the atmosphere than the combustion of branches and litter. There were few differences between emissions from the combustion of the two tree species, except for some compounds. The combustion of P. halepensis released a great amount of monoterpenes as α-pinene, β-pinene, p-cymene, sabinene, 3-carene, terpinolene and camphene that are not emitted from the combustion of Q. pubescens. The combustion of branches showed the longest duration of flaming and peak of temperature. Data presented appear crucial for modeling with the intent of understanding the loss of C during different phases of fire and how different typologies of biomass can affect wildfires and their speciation emissions profile.
- MeSH
- biomasa MeSH
- borovice chemie MeSH
- cévnaté rostliny chemie MeSH
- dub (rod) chemie MeSH
- látky znečišťující vzduch analýza MeSH
- monoterpeny analýza MeSH
- ničivé požáry * MeSH
- pevné částice analýza MeSH
- plyny analýza MeSH
- prach analýza MeSH
- stromy chemie MeSH
- těkavé organické sloučeniny analýza MeSH
- terpeny analýza MeSH
- Publikační typ
- časopisecké články MeSH
We measured gas exchange and various leaf parameters of ash (Fraxinus angustifolia Vahl.) and oak (Quercus robur L.) in the high canopy and of lime (Tilia cordata Mill.) in the lower canopy of a planted, 120-year-old floodplain forest in southern Moravia, Czech Republic. The high-canopy leaves of F. angustifolia and Q. robur had nitrogen concentrations on a leaf area basis (N(area)) that were twice those of low-canopy leaves of T. cordata. Upper-canopy leaves of F. angustifolia had a photosynthetic rate at light saturation (A(max)) of about 16 micromol CO2 m(-2) s(-1), whereas A(max) of the upper-canopy foliage of Q. robur achieved only about two thirds of this value. Contrary to previous investigations of photosynthetic performance in monospecific stands, leaves of the uppermost branches of T. cordata at 15-m height had the highest A(max) and transpiration rate among the species studied. Water-use efficiency (WUE) was low in T. cordata at 15-m canopy height, whereas WUE was significantly higher for Q. robur leaves at 27-m height than for the other species. Leaves of T. cordata at 15-m height showed the strongest relationship between A(max) and N(area) (R2 = 0.90) followed by F. angustifolia (R2 = 0.69). The strong correlation between photosynthesis and nitrogen concentration in T. cordata at 15 m, together with the steep regression slope for the A(max):N(area) relationship, indicated that nitrogen allocation to the photosynthetic apparatus resulted in high nitrogen-use efficiency of light-saturated photosynthesis (PNUE). Despite differences in PNUE among species, PNUE was fairly constant for leaves sampled from the same canopy position, suggesting that single-leaf parameters are matched to optimize PNUE for prevailing light conditions. High PNUE in T. cordata at 15 m partially compensated for the species' subordinate position in the canopy, and may be an important mechanism for its coexistence in highly structured vegetation.
- MeSH
- dusík fyziologie MeSH
- fotosyntéza fyziologie MeSH
- listy rostlin anatomie a histologie fyziologie MeSH
- oxid uhličitý fyziologie MeSH
- stromy fyziologie MeSH
- světlo MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Cryptogein is a proteinaceous elicitor secreted by Phytophthora cryptogea that can induce resistance to P. parasitica in tobacco plants. On the basis of previous computer modelling experiments, by site-directed mutagenesis a series of cryptogein variants was prepared with altered abilities to bind sterols, phospholipids or both. The sterol binding and phospholipid transfer activities corresponded well with the previously reported structural data. Induction of the synthesis of reactive oxygen species (ROS) in tobacco cells in suspension and proteomic analysis of intercellular fluid changes in tobacco leaves triggered by these mutant proteins were not proportional to their ability to bind or transfer sterols and phospholipids. However, changes in the intercellular proteome corresponded to transcription levels of defence genes and resistance to P. parasitica and structure-prediction of mutants did not reveal any significant changes in protein structure. These results suggest, contrary to previous proposals, that the sterol-binding ability of cryptogein and its mutants, and the associated conformational change in the ω-loop, might not be principal factors in either ROS production or resistance induction. Nevertheless, the results support the importance of the ω-loop for the interaction of the protein with the high affinity binding site on the plasma membrane.
- MeSH
- fosfolipidy metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- imunita rostlin imunologie MeSH
- kyselina chlorogenová analýza MeSH
- listy rostlin genetika imunologie parazitologie fyziologie MeSH
- mutace MeSH
- nemoci rostlin imunologie parazitologie MeSH
- Phytophthora genetika metabolismus patogenita MeSH
- proteiny genetika metabolismus MeSH
- proteomika metody MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rekombinantní proteiny MeSH
- seskviterpeny analýza MeSH
- steroly metabolismus MeSH
- tabák genetika imunologie parazitologie fyziologie MeSH
- vazba proteinů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Accurate estimations of leaf area index (LAI), defined as half of the total leaf surface area per unit of horizontal ground surface area, are crucial for describing the vegetation structure in the fields of ecology, forestry, and agriculture. Therefore, procedures of three commercially used methods (litter traps, needle technique, and a plant canopy analyzer) for performing LAI estimation were presented step-by-step. Specific methodological approaches were compared, and their current advantages, controversies, challenges, and future perspectives were discussed in this protocol. Litter traps are usually deemed as the reference level. Both the needle technique and the plant canopy analyzer (e.g., LAI-2000) frequently underestimate LAI values in comparison with the reference. The needle technique is easy to use in deciduous stands where the litter completely decomposes each year (e.g., oak and beech stands). However, calibration based on litter traps or direct destructive methods is necessary. The plant canopy analyzer is a commonly used device for performing LAI estimation in ecology, forestry, and agriculture, but is subject to potential error due to foliage clumping and the contribution of woody elements in the field of view (FOV) of the sensor. Eliminating these potential error sources was discussed. The plant canopy analyzer is a very suitable device for performing LAI estimations at the high spatial level, observing a seasonal LAI dynamic, and for long-term monitoring of LAI.
