Dejana Džigurski

Nutrient removal by Phragmites australis (Cav.) Trin. ex Steud. In the constructed wetland system

AbstractsSignificant results are achieved with the use of semiaquatic vegetation for purification of municipal wastewater as well as other types of waste waters. The first constructed system for purification of municipal wastewater was made at the end of 1970s years in the United Kingdom, with semiaquatic plants playing the role of phytoremediation plants. In Serbia, municipal waste water purification based on constructed wetland system method was applied for the first time in the village of Glo an near Novi Sad and it was put in operation in 2004. The recipient of purified municipal wastewater has been the Danube River. Biological factors in this anthropogenic ecosystem are emergent plants, with dominance of the common reed. This emergent plant with its roles in phytofiltration and phytoaccumulation positively influences the quality of waters finally discharged into the Danube. The paper presents the results of nutrients (N, P, K), organic matter and total ash contents in dry matter of dominant plant species Phragmites australis (Cav.) Trin. ex Steud. in Glo an constructed wetland system in the period from 2004 to 2007.

Vegetation of the Hydrochari-Lemnete and Potametea classes in the Danube-Tisza-Danube hydrosystem (Serbia)

Aquatic vegetation of Hydrochari-Lemnetea and Potametea classes in the Danube-Tisza-Danube hydrosystem (Hs DTD) was studied in 2009–2012, by applying the standard Braun-Blanquet method. The canal network vegetation comprises 14 associations, with Trapetum natantis and Ceratophylletum demersi being the most widely distributed. Hs DTD is also a habitat for several important endangered species, which serve as edificators of the following phytocenoses: Nymphaeetum albae, Nymphaeetum albo-luteae, Nymphoidetum peltatae, Trapetum natantis, Lemno-Spirodeletum, Salvinio-Spirodeletum polyrrhizae, Lemno-Utricularietum vulgaris, Potametum nodosi, Myriophyllo-Potametum and Najadetum marinae. In the studied vegetation, we also found an invasive phytocenosis Elodeetum canadensis that did not have an expanding tendency, and Ceratophyllo demersi-Vallisnerietum spiralis that had this tendency, which made monitoring its stands necessary. Physico-chemical analyses of water, conducted at localities in which the studied phytocenoses thrive, revealed that the development and distribution of most phytocenoses is closely linked with specific habitat conditions. Among the studied parameters, the most significant for the phytocenoses differentiation were: pH, alkalinity, COD-MnO4, BOD5, NO3−, NO2−, PO43− and the concentration of total phosphorus.

The content of microelements (Cu and Zn) in reeds ( Phragmites australis (Cav.) Trin. ex Steud.) of a constructed wetland system

The method for purification of municipal waste waters with the use of constructed wetland system (CWS) was put in operation in Serbia for the first time in 2004, in the Gložan village near Novi Sad. Biological factors in this anthropogenic ecosystem are microorganisms and reeds (Phragmites communis (Cav.) Trin. ex Steud.). In the process of bioaccumulation, among other substances, emergent plants often accumulate large quantities of microelements. Although microelements are present in plants in relatively small quantities, in emergent plants that grow on the surface where wastewater (which contains various substances, including microelements) flows, their quantity in plant dry weight can be higher. This paper presents the results of the three-year study (2004–2006) of Cu and Zn concentration in different organs of reed plants (leaf, stem, rhizome with root and inflorescence) grown in the “Gložan” CWS. The study was carried out on three fields. The first year of the study was taken as control, as that’s when the “Gložan” CWS was established, while 2005 and 2006 were the first and the second years of the system exploitation. In 2004 Cu concentration varied from 3.20 ppm in reed stems to 5.30 ppm in inflorescences. In 2005 Cu concentrations were lower in comparison to the first year, while in the third year the trend of reduction of Cu concentration was present in all analyzed organs in the third field. Concentration of Cu had diminishing tendency in all three fields over time, with exception of inflorescences where it was mostly constant.In the first year of the study the highest concentrations of Zn were recorded, ranging from 13.97 ppm in rhizomes with roots to 34.60 ppm in inflorescences. In the second year, concentration of Zn was the lowest in all three fields, and in the third year overall concentration of Zn (except for inflorescences) was lower in comparison to the first year of the study (control).

Impact of climate changes on aquatic vegetation of hydromeliorative facilities

Distributions of 20 aquatic associations in the Danube-Tisza-Danube hydrosystem were mapped using published data and personal field observations resulting in 562 georeferenced collection sites. The Maxent modeling software was used to estimate the current potential and future distribution of the associations by the year 2050 (2xCO2 climate conditions, CCM3 model). Based on the Principal Component Analysis (PCA), climate data at the collection sites described climatic preferences of different aquatic associations. The central-eastern part of the investigated area showed the most favorable climatic conditions for aquatic vegetation growth and thus the highest potential for future biodiversity. The stands of Lemnetum trisulcae, Ceratophyllo-Azolletum filiculoides, Najadetum marinae, Salvinio natantis-Spirodeletum polyrhizae, Elodeetum canadensis and Potametum denso-nodosi associations displayed a marked invasive potential in the forecasted distribution scenarios. The results revealed that the stands of Nymphaeetum albae and Nymphaeo albae-Nupharetum luteae subass. nupharetosum associations are likely to be significantly less abundant in the future. As the key climatic factors used in the analysis were annual mean temperature, as well as mean temperature of the wettest and warmest quartile, the findings suggest that, if adequate protective measures shall not be taken, these provenances could become degraded in the next decade and some could even become extinct at the locations where they presently occur naturally.

Weed Flora in Organic Common Mallow (Malva sylvestris L.)

Summary The aim of this study was to examine weed flora occurring in an organic common mallow (Malva sylvestris L.), a newly established crop at the experimental field Bački Petrovac, Institute of Field and Vegetable Crops, Novi Sad, during the growing season of 2014. The weed flora consisted of six species, with even a half being invasive for Vojvodina region (Sorghum halepense, Amaranthus retroflexus, Datura stramonium). The observed low floristic diversity may be related to unbalanced ecological conditions in a newly established crop, invasive species, comparatively low fertilization, allelopathic relations, and possibly robust habitus of the main crop. However, although the flora was low in diversity, both narrow and broadleaf species were represented, with the average infestation as high as 16 individuals per m2. In addition, since the recorded weeds flower from Mart to November, until the development of more efficient methods that are in compliance with the principles of organic agriculture, mechanical weeding should be performed at least three times during the growing season. To our knowledge, this is the first such report on organic common mallow in agro ecological conditions of Serbian province Vojvodina and represents the first step in establishing the adequate weed control measures.

ANTIOXIDANT SYSTEMS IN SOME RARE AND ENDANGERED PLANT SPECIES FROM THE PANNONIAN SALINE MEADOWS AND GRASSLANDS

In order to establish the level of oxidative stress, antioxidant status was evaluated in several rare and endangered plant species from southern parts of the Pannonian plain, in Vojvodina province. The quantities of reactive oxygen species and malonyldialdehyde, activities of several antioxidant enzymes and content of reduced glutathione were determined. Also, the DPPH-radical scavenging activity of plant extracts was measured. Several different systems were found to be involved in plant defence against oxidative stress. It seems that antioxidant status could serve as a suitable biochemical criterion for evaluation of the level of stress in plants.