edita stefanic - Academia.edu (original) (raw)

Papers by edita stefanic

Journal of Central European Agriculture, 2020

Field margins are pollinator-friendly habitats and important refuges for many pollinators. As a v... more Field margins are pollinator-friendly habitats and important refuges for many pollinators. As a valuable food resource throughout the vegetation season, not just when crop species are in flower, field margins need to be protect or restore in areas of intensive farming. This paper examines the floristic and functional structure of weed communities on field margins in the northeastern part of the Republic of Croatia. A phytocoenological survey was conducted during the summer period of 2017 and 2018. A total of 32 field margins was analyzed for species richness, abundance and their role for entomofauna. Floristically rich field margins consist of 72,6% plant species beneficial to pollinators. Foraging period can be stretching throughout the year, but stabile and high flowering period is from May to end of September. Among highest ranked honeybee plants, several invasive species with significant relative abundance are: Solidago gigantea, Asclepias syriaca and Amorpha fruticosa who pose a serious threat to plant biodiversity. Positive role of vegetation from field margins was not valuable for pollinators only, but they also serve as supply the substrates that provide a shelter and nesting sites.

Zbornik Veleučilišta u Rijeci

Strane, a posebno invazivne vrste često imaju negativan učinak na biološku raznolikost, ekonomi... more Strane, a posebno invazivne vrste često imaju negativan učinak na biološku raznolikost, ekonomiju, pa i ljudsko zdravlje. One su sposobne proizvoditi produktivno potomstvo i posjeduju potencijal širenja na značajnim površinama. Stoga je širenje invazivnih vrsta jedno od najvećih problema u zaštiti prirode. Praćenje rasprostranjenosti i procjena rizika invazivne vaskularne flore Požeške kotline vršeno je tijekom ljetnih mjeseci od 2017. do 2019. godine putem kombinirane procjene brojnosti i pokrovnosti. Istraživanjima je utvrđeno ukupno 34 invazivne svojte vaskularne flore kojima je pridružena porodica, životni oblik, geografsko porijeklo te je procjenjena faza procesa invazije. Za analizu povezanosti između nadmorske visine i pokrovnih vrijednosti invazivne flore Požeške kotline, primjenjena je multivarijantna statistička tehnika - CCA analiza. Najbrojnije vrstama su porodice Asteraceae i Poaceae. Analiza životnih oblika izdvojila je dominaciju terofita, ali i prisutnost hemi...

Agronomy

Weed infestation is a major cause of the poor yield of soybeans (Glycine max (L.) Merr.); therefo... more Weed infestation is a major cause of the poor yield of soybeans (Glycine max (L.) Merr.); therefore, proper weed management represents one of the most important and expensive steps in soybean production. Field experiments were established in northeastern parts of Croatia, in the Vukovar-Syrmia county from 2014 to 2016, arranged in a split-plot design with four replications. Two different studies were conducted: the first study was to determine the weed interference, weed biomass accumulation, yield, and yield components of soybeans growing in three different rows spacing (25, 50, and 70 cm), and the second study aimed to simulate a risk analysis by building models of probabilities for generating profit as a result of weed control. The weed community in soybean during the study period comprised 34 dicot and grass species of a varied perennation. Compositional differences in the weed community tended to be affected most by the year (humid–arid environment), followed by row spacing. Th...

Archives of Biological Sciences, 2020

A vegetation survey in northeastern Croatia explored the influence of intensive arable farming on... more A vegetation survey in northeastern Croatia explored the influence of intensive arable farming on the weed community in relation to the crop edge and adjacent field margin. A total of 141 vascular plants were recorded, and significant differences among the species appear in the field margins (134) as compared to the crop edges (109) and middle of the fields (49). Native plants predominated (83.7%), but among non-natives, the most abundant were Ambrosia artemisiifolia L., Abutilon theoprasti Med. and Veronica persica Poir., with the highest cover values inside the cropped areas, particularly during spring sowing of row crops. The most diverse (having significantly higher Evenness and Shannon?s diversity index) was the community from the field margin, followed by the weed community that developed on the crop edges. Three distribution patterns were observed: weeds typically limited to the crop area, weeds limited to the non-crop area and weeds with some ability to spread from the field...

Ecology, 2017

Niche shifts of nonnative plants can occur when they colonize novel climatic conditions. However,... more Niche shifts of nonnative plants can occur when they colonize novel climatic conditions. However, the mechanistic basis for niche shifts during invasion is poorly understood and has rarely been captured within species distribution models. We quantified the consequence of between-population variation in phenology for invasion of common ragweed (Ambrosia artemisiifolia L.) across Europe. Ragweed is of serious concern because of its harmful effects as a crop weed and because of its impact on public health as a major aeroallergen. We developed a forward mechanistic species distribution model based on responses of ragweed development rates to temperature and photoperiod. The model was parameterized and validated from the literature and by reanalyzing data from a reciprocal common garden experiment in which native and invasive populations were grown within and beyond the current invaded range. It could therefore accommodate between-population variation in the physiological requirements for flowering, and predict the potentially invaded ranges of individual populations. Northern-origin populations that were established outside the generally accepted climate envelope of the species had lower thermal requirements for bud development, suggesting local adaptation of phenology had occurred during the invasion. The model predicts that this will extend the potentially invaded range northward and increase the average suitability across Europe by 90% in the current climate and 20% in the future climate. Therefore, trait variation observed at the population scale can trigger a climatic niche shift at the biogeographic scale. For ragweed, earlier flowering phenology in established northern populations could allow the species to spread beyond its current invasive range, substantially increasing its risk to agriculture and public health. Mechanistic species distribution models offer the possibility to represent niche shifts by varying the traits and niche responses of individual populations. Ignoring such effects could substantially underestimate the extent and impact of invasions.

PLOS ONE, 2016

The invasive weed Ambrosia artemisiifolia (common ragweed) constitutes a great threat to public h... more The invasive weed Ambrosia artemisiifolia (common ragweed) constitutes a great threat to public health and agriculture in large areas of the globe. Climate change, characterized by higher temperatures and prolonged vegetation periods, could increase the risk of establishment in northern Europe in the future. However, as the species is a short-day plant that requires long nights to induce bloom formation, it might still fail to produce mature seeds before the onset of winter in areas at northern latitudes characterized by short summer nights. To survey the genetic variation in flowering time and study the effect of latitudinal origin on this trait, a reciprocal common garden experiment, including eleven populations of A. artemisiifolia from Europe and North America, was conducted. The experiment was conducted both outside the range limit of the species, in Sweden and within its invaded range, in Croatia. Our main hypothesis was that the photoperiodic-thermal requirements of A. artemisiifolia constitute a barrier for reproduction at northern latitudes and, thus, halts the northern range shift despite expected climate change. Results revealed the presence of a northsouth gradient in flowering time at both garden sites, indicating that certain European populations are pre-adapted to photoperiodic and thermal conditions at latitudes up to, at least, 60˚N. This was confirmed by phenological recordings performed in a region close to the northern range limit, the north of Germany. Thus, we conclude that there exists a high risk for establishment and spread of A. artemisiifolia in FennoScandinavia in the near future. The range shift might occur independently of climate change, but would be accelerated by it.

The objective of the investigation was to determine influence of weather conditions on activity o... more The objective of the investigation was to determine influence of weather conditions on activity of honey bees during blooming time of six sunflower hybrids. The investigation was carried out in 2002 growing season at Kneževi Vinogradi located in Baranja county, north-eastern edge of Croatia. Honey bees communities were moved to the field trial site inside Langstroth-Rooth's bee-hives. Honey bees visiting sunflower head inflorescence was measured at 100, 200, and 300 meters by counting honey bees four times a day (9.00 am, 11.00 am, 1.00 pm, and 5.00 pm). The influence of weather conditions was analysed by Spearman correlation coefficient. Results of the investigation show significant differences regarding honey-bee visit to the head inflorescences in six hybrids, as well as significant influence of air temperature, humidity, precipitation, minimum and maximum air temperature, as well as wind strength.

Bee World, 2003

Goldenrod, native to North America was introduced into Europe in the 19th centuary as ornamental ... more Goldenrod, native to North America was introduced into Europe in the 19th centuary as ornamental plant. However, this plant has become widespread and is a serious invader of abandoned fields, forest edges and river banks. Goldenrod represents an important source of nectar for honey bees, particularly as a reserve to help colonies survive the winter period. Although is insect pollinated plant, it shed much more pollen than is carried off by insects. The pollen may become atmospheric and can cause hay fewer during its pollination period in August.

Annals of agricultural and environmental medicine : AAEM, 2007

Pollen concentration in the atmosphere of Vinkovci (northeastern Croatia) has been analyzed using... more Pollen concentration in the atmosphere of Vinkovci (northeastern Croatia) has been analyzed using a Hirst-type volumetric spore trap. During the year 2005, 58 pollen types were recorded with the sum of annual totals of 14,011. The pollen spectrum reflected the floristic diversity of the region. Non-arboreal pollen predominantly contributed to the total pollen sum with a percentage of 81.80%. The main pollen producers characterized by allergenic pollen were: Betula, Quercus, Fraxinus, Populus, Pinus, Urticaceae, Ambrosia, Poaceae, Plantago and Artemisia. Urticaceae was the most frequent and most abundant pollen type accounting for 46.58% of the total annual pollen, followed by Ambrosia (19.66%) and Poaceae (11.01%).

Annals of agricultural and environmental medicine : AAEM, 2005

Airborne ragweed pollen concentration in the north-eastern part of Croatia was investigated in re... more Airborne ragweed pollen concentration in the north-eastern part of Croatia was investigated in relation to some meteorological factors. Data was obtained for three consecutive years (2001, 2002 and 2003) using volumetric method (Burkard trap). The correlation between the concentration of pollen grains in the atmosphere and maximum, minimum and mean daily temperature, daily temperature range, sunshine hours, relative humidity and precipitation from daily monitoring was studied. The critical ragweed pollen season appears from 33rd to 38th week, with its peak at the beginning of September each year. Statistically significant correlation between the ragweed pollen count and selected meteorological variables were found in some study years, but only a correlation with the mean air temperature and ragweed pollen presence in the air was significant over time.

XL. znanstveni skup …, 2005

... sur. 1996,Allen-Wardell i sur. 1998, Kearns i sur 1997). Od 1993. tri ... nestanak. U posljed... more ... sur. 1996,Allen-Wardell i sur. 1998, Kearns i sur 1997). Od 1993. tri ... nestanak. U posljednje vrijeme dolaze izvještaji o znatnom smanjenju populacija oprašivača na svim kontinentima, osim na Antartici (Kearns i sur 1998). Naban ...

Journal of Apicultural Research, 2009

Innovations in Education and Teaching International, 2019

This paper explores students' perceptions of an experimental, cross-cultural entrepreneurial blen... more This paper explores students' perceptions of an experimental, cross-cultural entrepreneurial blended learning course. This course, developed jointly by North Carolina State University and Josip Juraj Strossmayer University, Croatia, employed a variety of face-to-face and technology-based approaches to facilitate crosscultural teaching. The impact of socioeconomic status on participants' satisfaction with the course is also investigated. This study also clarifies that active learning and new roles for teachers and students in a cross-cultural perspective setting are possible between a western setting and east European countries. The study found that teachers need to focus not only on the technical aspects of course delivery, but must also seek to understand students' expectations and perceptions as well as support student learning across the whole course. Instructors, interaction with peers, and overall course design and organization play an important role in student satisfaction.