Shrubs are a significant component of urban vegetation found in parks, but they experience various influences from biotic and abiotic agents, among which aphids play an important role. In this work, the effects of aphid colonisation on three shrub species in urban environments were examined. Fourteen parameters were analysed, describing the photosynthetic pigment content and gas exchange to carbon, nitrogen, and hydrogen partitions. While no significant effect of colonisation was found on photosynthetic pigment parameters, the effect was significant on gas exchange parameters. The strongest effect of aphid colonisation achieved was on nitrogen partition and the C/N ratio, parameters that could be suggested for further similar studies. All parameters were classified into two groups according to their principal component analysis, suggesting a correlation between nitrogen and carbon content, the C/N ratio, measured gas exchange parameters, and chlorophyll a content. The ratio between net photosynthesis and dark respiration (A/K) was classified in the second group, suggesting that this parameter provides additional information on the effect of aphid colonisation and deserves special attention in further studies. There were differences in the effect of aphid colonisation on the physiology of the examined shrub species, especially in cases where a decrease in the C/N ratio was achieved in Spirea trilobata and Cydonia japonica, while an increase in the same parameter was recorded in Hybiscus syriacus.

Although sessile oak is one of the most important deciduous forest tree species in Europe, data on the diversity of ectomycorrhizal (ECM) fungi on sessile oaks in the Republic of Serbia are scarce. The aim of this study was to provide the first insig...

Oak lace bug Corythucha arcuata represents a new pest of oaks in Europe, introduced from North America in year 2000. Damage is caused by adults and larvae that feed on the underside of leaves. The paper presents the results of investigation of impact of Corythucha arcuata on pedunculate oak growth. The two variant experiment was established in 2019 and included the evaluation of the effect of oak lace bug on the height of the seedlings (i) grown under the shade of the adult trees after the intermediate felling and (ii) seedlings grown unshaded after the final felling. Both variants included eight plots of which four were treated with the insecticide thiamethoxam, while other four were untreated. Assessment of the intensity of the attack was performed in June, July and August in 2019, 2020 and 2021, while the height of the plants was measured at the end of the vegetation period in 2019, 2020 and 2021.The results indicate significant decrease in the intensity of the attack on seedlings grown unshaded by the old trees. After first year, there was no difference in average height of the treated and untreated seedlings grown after the intermediate felling, while the difference was evident after second and third year. Such results indicate cumulative effect of the oak lace bug attack on the seedlings of the penduculate oak. On the other hand, during whole experiment, the differences between treated and untreated plant average height after the final felling were not evident.

European beech (Fagus sylvatica L.) forests are one of the largest natural renewable reservoirs of stored carbon in Europe, as well as in the Balkans and Serbia. A number of factors have been identified which influence the state of stored carbon, but a unique influence can be expected from the degree of stand preservation and the history of forest management. In the present paper, the influence of the preservation of stands and management methods on the state of ecosystem carbon (biomass carbon and soil carbon) were analyzed in beech forests situated at the Fruška Gora Mountain, Serbia. The research was conducted in three stands that were managed in the past in three different ways: a virgin forest without any management, a high stand and a coppice stand. The stored biomass carbon and soil carbon was estimated using standard methods that have been previously proven useful in Europe for the last decades. Above-ground biomass was also assessed using remote sensing. The results show a significant impact of conservation and management history on the stock of stored biomass carbon and soil carbon, but also on their mutual relationship. This research initiates that moderate management measures and the application of management systems based on the principles of continuous cover forestry (selective and group cutting) are, in addition to their well-known advantages, more efficient in carbon storage than the application of systems with surface management (clear and shelterwood cutting).

The paper analyzes the soil monitoring data of the last last research period (2014 and 2024) at 13 bioindication plots (BIP) in AP Vojvodina, Republic of Serbia. The data were collected as part of the forest monitoring network in Europe (ICP Forests) and analyzed based on the manual of ICP Forests program. The analysis includes the most important soil physical (textural classes) and chemical properties (pH in water, content of CaCO3, nitrogen, carbon, potassium, calcium, magnesium, iron, chromium, nickel, manganese, zinc, copper, lead). Soil samples were taken from standard depths according to the ICP forests methodology. An analysis of mandatory and some optional soil properties was performed. Physical properties did not change significantly between the two monitoring periods. The soil solution reaction mostly showed a decrease in the soil solution reaction. It is also necessary to point out that an increase in the soil solution reaction was recorded at two bioindication plots. Potassium content indicates a decreasing trend at most bioindication points. An increasing trend was established for copper content at almost all points and at all depths, as well as for lead at the largest number of plots and depths. Cadmium showed the lowest rate of content growth. Lead and zinc indicated the strongest correlation among various heavy metals. In add to the aforementioned, the correlation between lead and cadmium strongest in 2014 at a depth of 0 to 10 cm. Grouping according to the heavy metal load in the layer from 0 to 10 cm on large distances was for Arenosols, as well as for Solonjec and Cambisols in the Vršac Mountains. Cambisols on Fruška Gora were grouped at small distances.

This study presents investigation of sessile oak cynipid gall wasps fauna of Mt Fruška Gora. Gall wasps are insects, from the family Cynipidae, that induces galls mainly on oaks. Complex of sessile oak cynipid gall wasps were investigated during 4-year period (2016 - 2019). The survey was carried out on five sites: Kraljeve stolice, Spomenik, Brankovac, Ležimir and Rohalj baze. At total, number of seventeen cynipid gall wasps species were identified: Andricus aries (Girauld, 1859), Andricus caliciformis (Giraud, 1859), Andricus coriarius (Hartig, 1843), Andricus curvator (Hartig, 1840), Andricus dentimitratus (Rejto, 1887), Andricus glutinosus (Giraud, 1859), Andricus kollari (Hartig, 1843), Andricus lignicolus (Hartig,1840), Andricus lucidus (Hartig, 1843), Andricus solitarius (Fonscolombe, 1832), Cynips quercusfolii (Linnaeus, 1758), Cynips quercus (Fourcroy, 1785), Biorhiza pallida (Oliver, 1791), Neuroterus albipes (Schenck, 1863), Neuroterus anthracinus (Curtis, 1838), Neuroterus numismalis (Fourcroy, 1785) and Neuroterus quercusbaccarum (Linnaeus, 1758). Gall wasp A. dentimitratus is first record for Serbia. The most frequent species were A. lignicolus and A. glutinosus, which were found on all five observed sites.