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COMMON CHIFFCHAFF AND MOUNTAIN CHIFFCHAFF RESPOND EQUALLY TO CONSPECIFIC AND HETEROSPECIFIC SONGS
No full textThis study investigated the responses of two closely related species, Common Chiffchaff (Phylloscopus collybita) and Mountain Chiffchaff (Phylloscopus sindianus), to conspecific and heterospecific songs in Armenia. The research aimed to determine if these species could discriminate between each other's songs. Using playback experiments, we tested 45 P. collybita and 37 P. sindianus males, with Erithacus rubecula serving as a negative control. The experimental protocol involved recording latency to respond and time spent within 15 m of the speaker. Generalized linear models (GLM) in R were used for statistical analysis. Results showed no significant differences in responses to conspecific and heterospecific calls for either species, suggesting that both P. collybita and P. sindianus do not discriminate between their own and the other species' songs. This finding raises potential conservation concerns, particularly for the endemic P. sindianus lorenzii subspecies, as P. collybita's range expansion and climate change may lead to increased interspecific competition in the Caucasus area and narrow down Mountain Chiffchaff range
A genetic perspective on birds’ endemism in the Caucasus
No full textThe Caucasus region is globally recognized as a biodiversity hotspot, harboring a high
concentration of endemic bird species and subspecies. This study explores the role of
geographic and ecological isolation in shaping patterns of avian endemism in the Caucasian
forests, using mitochondrial DNA and nuclear markers to investigate lineage divergence.
Focusing on peripatric speciation a special form of allopatric speciation driven by small,
peripheral populations we examine why certain forest bird species diverge while others
do not, despite sharing similar geographic barriers.
Phylogeographic analyses across multiple taxa reveal varying degrees of genetic structure,
from recent expansion with little divergence to reciprocally monophyletic lineages. Our
comparative framework highlights ecological specialization, migratory behavior, and
effective population size (Ne) as key predictors of divergence. Notably, resident and
specialist species showed greater differentiation and smaller Ne compared to migratory
generalists, underscoring the role of ecological traits in driving diversification.
These findings emphasize the importance of integrating ecological, genetic, and spatial data
to understand evolutionary processes in biodiversity hotspots. Conservation efforts in the
The Caucasus must prioritize habitat specialists and recognize cryptic diversity to effectively
protect this unique regional avifauna
EFFECT OF CHEMICAL ACTIVATORS ON PROPERTIES OF HIGH VOLUME FLY ASH BINDERS WITH MECHANICALLY ACTIVATED FLY ASH
No full textВезива састава 70 % механички активираног електрофилтерског пепела и 30 %
портланд цемента хемијски су активирана применом натријум-сулфата, натријум-карбоната,
натријум-силиката, натријум-оксалата и калцијум-формијата као активатора. Избор
оптималних услова механичке активације пепела заснован је на поређењу својстава три
узорка пепела из две термоелектране након млевења у планетарном млину у трајању од 15
минута при различитим односима кугле/пепео. Анализирани су расподела величина честица,
специфична површина, морфологија и минерални састав, садржај реактивног SiO2 и
растворљивост у алкалном раствору полазних и механички активираних узорака пепела.
Процена реактивности узорака пепела извршена је на основу одређивања индекса
активности, чврстоће при притиску везива са 70 % пепела и 30 % портланд цемента, и
чврстоће малтера геополимера. Закључено је да је млевењем при односу кугле/пепео 3
постигнуто значајно побољшање својстава и повећање реактивности пепела уз минимални
утрошак времена и енергије.
Поређење утицаја хемијских активатора на својства везива са високим уделом
електрофилтерског пепела извршено је мерењем времена везивања и чврстоће при притиску.
Механизам хидратације везива анализиран је испитивањем кинетике хидратације, састава
раствора у порама, минералног састава, садржаја везане воде и портландита и
микроструктуре везива. Установљено је да се применом комбинације механичке активације
пепела и хемијске активације везива могу превазићи главни недостаци везива са високим
уделом пепела, дуго време везивања и мале почетне чврстоће. Додатак хемијских активатора
везиву довео је до убрзавања реакција хидратације обе компоненте везива. Закључено је да је
утицај соли натријума као активатора заснован је на повећању базности раствора у порама
везива, а калцијум-формијата на повећаној концентрацији јона калцијума у везиву. Утврђено
је да су најпогоднији хемијски активатори испитиваних везива натријум-силикат и калцијум-
формијат.Binders containing 70 % mechanically activated fly ash and 30 % Portland cement were
chemically activated using sodium sulfate, sodium carbonate, sodium silicate, sodium oxalate and
calcium formate. The optimization of mechanical activation of fly ash was based on a comparison
of properties of three ash samples from two thermal power plants after milling in a planetary mill
for 15 minutes at different ball-to-ash ratios. Particle size distribution, specific surface area,
morphology and mineral composition, reactive SiO2 content and solubility in alkaline solution of
the raw and mechanically activated ash samples were analyzed. Reactivity of the ash samples was
assessed based on determination of activity index, compressive strength of the binder with 70% fly
ash and 30% Portland cement, and the strength of geopolymer mortars. It was concluded that
grinding at ball-to-ash ratio of 3 led to significant improvement in properties and to increased ash
reactivity with minimal time and energy consumption.
Comparison of the effects of the chemical activators on properties of high volume fly ash
binders was done by determining setting time and compressive strength. Hydration mechanism of
the binders was analyzed by investigating hydration kinetics, pore solution composition, mineral
composition, bound water and portlandite contents, and microstructure of the binders. It was found
that by applying a combination of mechanical activation of the ash and chemical activation of the
binder, the main disadvantages of high volume fly ash binders, long setting time and low initial
strength, can be overcome. Addition of the chemical activators to the binder led to an acceleration
of hydration reactions of both binder components. It was concluded that the effect of sodium salts
as activators was based on increasing the alkalinity of the binder pore solution, while the influence
of calcium formate was the increment of the concentration of calcium ions in the binder. Sodium
silicate and calcium formate were established as the most suitable chemical activators for the
investigated binders
Silicon enhances seasonal acquisition of phosphorus in Chardonnay grapevines grown under field conditions
No full textWe recently demonstrated that grafted grapevine (Vitis vinifera L.) can achieve high phosphorus (P)
efficiency under low-P soil conditions through seasonal coordination of rhizosphere P mobilization via
root-exuded carboxylates and subsequent P uptake/allocation mediated by PHT transporters (Trailovic
et al., Plant and Soil, 2025, https://doi.org/10.1007/s11104-025-07738-3). However, despite this
efficiency, nearly one-third of the P taken up from soil is lost each year through harvested grapes and
pruning residues. Moreover, phylloxera-resistant rootstocks have shown different efficiency in P
acquisition. In this study, we investigated the effect of silicon (Si) fertilization on the seasonal dynamics
of P acquisition in grafted grapevines grown under low-P soil conditions. The field experiment was
conducted in a 12-year-old vineyard (cv. Chardonnay grafted onto 5BB rootstock) established on soil
with extremely low available P (Olsen P < 2 mg kg⁻¹). Rhizotrons (120 cm in length × 60 cm in width
× 80 cm in depth) were installed to enable easy access to intact roots and rhizosheath soil. The treatments
included an unfertilized control, P-fertilized, and Si-fertilized vines. Phosphorus was applied as KH₂PO₄
at a rate equivalent to 20 kg P ha⁻¹, and Si was applied via irrigation using 2.5 mM Si(OH)₄ at a rate of
5 kg Si ha⁻¹. Samples of rhizosphere soil, root exudates (collected from root tips), and leaf blades were
taken at key growth stages (flowering, pea-sized berries, and veraison). Compared to the unfertilized
control, Si supply significantly enhanced root exudation of malate and citrate, particularly at the
flowering stage. This was accompanied by strong upregulation of VvPEPC (involved in carboxylate
biosynthesis) and VvALMT1 (associated with malate efflux). Additionally, Si application markedly
increased expression of the root VvPHT1;1 at all examined growth stages, whereas P fertilization
downregulated VvPHT1;1 expression. As a result, leaf P concentrations in Si fertilized vines were
significantly higher than in the control and similar to those in P-fertilized plants. In conclusion, Si
fertilization enhances P acquisition in grapevine by promoting the mobilization of inorganic P in the
rhizosheath via root-released carboxylates and by stimulating the expression of
root VvPHT1;1 transporters. These lead to improved P accumulation in leaves comparable to
conventional P fertilization. Our findings suggest that Si application may offer a sustainable alternative
to P fertilizers for improving P acquisition in grapevine under low-P soil conditions
Associations Between Mineral Composition and Aflatoxin B1 in Maize (Zea mays L.) Seeds: Toward Contamination Indicators and Food Safety
No full textMaize (Zea mays L.), a globally important cereal crop, is often threatened by aflatoxin
contamination, compromising seed quality, nutritional value, and food safety. This study
investigated the distribution of macro- and microelements in inner and outer seed fractions
of maize with varying aflatoxin B1 (AFB1) levels to identify potential elemental markers of
contamination. Macro- and microelements were quantified using ICP-OES and ICP-QMS,
and principal component and correlation analyses were applied to explore interelement
relationships and sample separation. The inner fraction was enriched in metabolically
active elements such as K, Mg, Fe, Zn, Mn, and Ni, while the outer fraction contained
higher Na, Ca, Cr, and Co, supporting structural integrity and defense. Strong positive
correlations were observed between Mn and Zn in the inner fraction (r = 0.818), as well
as between Cr and Zn (r = 0.82) and Co and Zn (r = 0.797) in the outer fraction, whereas
Na and Zn showed a negative correlation in the inner fraction (r = −0.739). Na exhibited a
nonlinear relationship with AFB1, suggesting complex regulatory mechanisms. Increasing
AFB1 concentrations affected elemental composition, with dynamic changes in Cr, Mn,
Zn, and Co and reductions in K, reflecting adaptive responses at low toxin levels and
disrupted metal homeostasis at higher contamination. Strong associations of Mn, Zn,
and Cr with AFB1 indicate their potential as contamination markers. These findings
highlight compartment-specific mineral dynamics and their relevance for seed resilience
and food safety
THE BEECH PROVENANCE TRIAL AT THE “GOČ”TEACHING BASE- A BASIS FOR ASSESSING THE ADAPTIVE AND PRODUCTIVE POTENTIALOF 14 SERBIAN PROVENANCES
No full textProvenijenični test bukve u Nastavnoj bazi „Goč” osnovan je od 14srpskih provenijencija. Procena njihovog adaptivnog i proizvodnog poten-cijala započeta je analizom prijema i preživljavanja sadnica. Istovremenosu evidentirana i oštećenja na sadnicama. Prijem sadnica na nivou testa izno-sio je 91,4%, dok je preživljavanje 87,7%. Procenat prijema kretao se od mini-malnih 86,7% (provenijencija Boranja) do maksimalnih 100% (provenijencijaBrezovica). Najmanji procenat preživljavanja sadnica imala je provenijen-cija Rudnik (77,3%), dok je najveći zabeležen kod provenijencije Brezovica(97,1%). Značajan uticaj na smanjenje procenta preživljavanja sadnica imalaje stoka koja se slobodno kreće na području osnovanog provenijeničnog testa.Ukupno, na kraju prve vegetacije (oktobar, 2024. godine), oštećeno je 33,5% sad-nica, od čega je približno polovina sadnica suhovrha, dok je druga polovinaprevršena. Započeta istraživanja potrebno je nastaviti, naročito u nerednihnekoliko godina, kako bi se mogli doneti adekvatni zaključci o adaptivnompotencijalu analiziranih provenijencija, koji zajedno sa proizvodnim poten-cijalom treba da bude predmet istraživanja u dužem vremenskom periodu.The beech provenance trial in the “Goč” Teaching Base was establishedfrom 14 Serbian provenances. The assessment of their adaptive and productive po-tential began with the analysis of the establishment and survival of seedlings. Atthe same time, damage to seedlings was recorded. The seedling establishment rateat the trial level was 91.4%, while the survival rate was 87.7%. The establishmentrate ranged from a minimum of 86.7% (Boranja provenance) to a maximum of 100%(Brezovica provenance). The lowest seedling survival rate was recorded in the Rudnikprovenance (77.3%), while the highest was observed in the Brezovica provenance(97.1%). A significant factor contributing to the reduction in seedling survival ratewas the presence of freely roaming livestock within the area of the established prov-enance trial. By the end of the first growing season (October, 2024), a total of 33.5% ofthe seedlings had sustained damage. Approximately half of the damaged seedlingsexhibited terminal shoot dieback, while the other half showed signs of “topped seed-ling” due to browsing. The initiated research needs to be continued, particularly inthe next few years, to draw conclusions about the adaptive potential of the analyzedprovenances, which together with the production potential, should be the subjectof research over a longer period
DIET OF THE BREEDING TAWNY OWL (Strix aluco L.) IN NORTHWESTERN SERBIA
No full textIstraživanje ishrane predatora omogućava potpunije razumevanje njihove uloge u trofičkim
mrežama, praćenje dinamike brojnosti i diverziteta plena, otkrivanje antropogenih uticaja, kao
i definisanje mera očuvanja i upravljanja populacijama. Sove predstavljaju noćne ptice
grabljivice čija je ishrana, uz određene manjkavosti, relativno dobro proučena na prostoru
većeg dela Evroazije. Ipak na prostoru jugoistočne Evrope, ishrana sova je znatno slabije
ispitana, naročito u šumskim ekosistemima. Osnovni cilj rada jeste istraživanje kvalitativnih i
kvantitativnih parametara trofičke ekologije šumske sove (Strix aluco) na prostoru
severozapadne Srbije tokom perioda gnežđenja. Materijal u vidu izbljuvaka i ostataka plena u
gnezdima i u njihovoj neposrednoj okolini sakupljan je u periodu mart-jun tokom pet
istraživanih godina (2011-2015.) na području nizijskih vodoplavnih šuma severozapadne
Srbije. Prikupljen materijal je uz pomoć binokularne lupe i odgovarajućih zooloških ključeva
identifikovan do najnižeg mogućeg taksonomskog nivoa. Ukupno je identifikovano 346 jedinki
plena u okviru 4 klase (Mammalia, Aves, Amphibia i Insecta). Do nivoa vrste prepoznato je
275 jedinki u okviru 33 različita taksona. Najučestaliji plen šumske sove bili su sitni sisari
(65,9%) među kojima su dominirali šumski miš (Apodemus sylvaticus) i poljska voluharica
(Microtus arvalis). Prosečna telesna masa plena iznosila je 42,5 g. Pored relativno bogate
trofičke osnove, mere α diverziteta i širine trofičke niše ukazuju na umerenu dominaciju
nekoliko ključnih vrsta i srednji stepen specijalizacije. Dobijeni rezultati sugerišu da se ishrana
šumske sove u severozapadnoj Srbiji odlikuje širokom ekološkom plastičnošću i umerenom
trofičkom fleksibilnošću. Ovakav obrazac ishrane omogućava visoku trofičku prilagodljivost
u uslovima promenjive dostupnosti hranidbenih resursa.The study of predator diets provides insight into their role in trophic networks, enables
monitoring of prey abundance and diversity, reveals anthropogenic influences, and helps define
measures for conservation and management of populations. Owls are nocturnal raptors whose
feeding ecology has been relatively well studied across much of Eurasia, despite specific gaps
in knowledge. In Southeastern Europe, however, owl diets remain considerably less
investigated, especially within forest ecosystems. This study aims to make qualitative and
quantitative contributions to the knowledge of the trophic ecology of the Tawny Owl (Strix
aluco) in north-western Serbia during the breeding season. Between March and June over five
years (2011-2015), we collected pellets and prey remains from nests and their surroundings in
the lowland floodplain forests of north-western Serbia. Collected material was identified to the
lowest possible taxonomic level using a stereo microscope and appropriate zoological keys. In
total, 346 prey individuals were identified, distributed among four classes (Mammalia, Aves,
Amphibia, and Insecta) and representing 33 different species. The most abundant prey group
were small mammals (65.9%), primarily the wood mouse (Apodemus sylvaticus) and the
common vole (Microtus arvalis). The mean prey body mass was 42.5 g. Despite the relatively
broad trophic spectrum, measures of α-diversity and niche breadth suggested a moderate
dominance of several key species and an intermediate level of diet specialisation. These results
indicate that the diet of the Tawny Owl in north-western Serbia is characterised by broad
ecological plasticity and moderate trophic flexibility, enabling high adaptability to fluctuations
in prey availability
Agrobiodiversity and health safe food production
No full textAgrobiodiversity, as the variety of plant, animal and microorganism species within the agroecosystem, is a key factor in preserving sustainable and safe food systems. The paper studies the connection between agrobiodiversity and food production, with special reference to the influence of genetic and species diversity on the nutritional quality and food health safety. Using an analytical and comparative approach, the paper examines how the loss of agrobiodiversity, caused by intensive agricultural production and other anthropogenic influences, negatively effects on food health safety. The results indicate that the preservation of local varieties, soil biogenicity and production based on ecological principles not only contribute to food safety, but also increase crop resistance to diseases and pests. Based on the analysis, it is recommended to strengthen institutional support, raise the awareness of producers and consumers, as well as develop tendencies that include production based on ecological principles with the aim of preserving the environment, agrobiodiversity and food health safety. The conclusion is that agrobiodiversity is not only an ecological, but also a health and economic resource of strategic importance for food production in the future
The Importance of using Biopesticides in Organic Farming
No full textBiopesticides, natural origin products, represent a significant tool in sustainable and environmentally friendly agriculture, particularly in organic farming. Derived from microorganisms, plant extracts, and natural minerals, biopesticides offer an eco-friendly alternative to synthetic pesticides. Their application enables effective control of pests, diseases and weeds with minimal impact on the environment, biodiversity, and human and animal health. This paper examines the advantages and limitations of biopesticides, highlighting their potential in ecosystem preservation and productivity improvement in organic farming. The aim of this paper is to point out the importance of the use of biopesticides in organic agriculture based on the available literature. In the paper, the method of data analysis was applied, which were collected from scientific studies, published in scientific works and at scientific conferences, including scientific publications of the authors of the paper. The results of numerous scientific research, including the research of the authors of this paper, indicate that, in addition to being used as biofertilizers, microorganisms also produce biologically active substances with pronounced antimicrobial and antifungal effects, so they can also be used as biopesticides, which significantly contribute to food safety. The role of biopesticides in reducing carbon dioxide emissions and contributing to global efforts in combating climate change underscores their importance as an indispensable tool for sustainable agriculture in the future. The specificity of biopesticides in targeting harmful organisms makes them safe for beneficial insects, such as pollinators, and contributes to the preservation of natural resources like soil and water. Their use in organic farming reduces the negative effects of synthetic pesticides and aids in maintaining ecological balance. However, the effectiveness of biopesticides often depends on ecological factors, formulation, and proper application. Despite these challenges, their contribution to sustainable production is significant, as they help reduce the use of chemicals, preserve food quality, and support sustainable development goals. Based on the review of scientific research, it can be concluded that development of new formulations, increased market availability of biopesticides and farmer education on their proper application are crucial for broader adoption of these solutions in organic agriculture
High-performance cathodes for alkaline water electrolysis in a zero-gap setting: Ni–Sn/Ni foam prepared by galvanostatic electrodeposition
No full textIn an attempt to obtain fully functional cathode materials for zero-gap alkaline water electrolysis Ni foam substrates with various pore diameters were modified through galvanostatic electrodeposition of Ni-Sn alloys as an easily scalable procedure. To optimize the production process for each substrate, Ni-Sn alloys were electrodeposited at five different constant current densities. Obtained cathodes were primarily subjected to hydrogen evolution in 1 M KOH to evaluate their activity, while the best-performing samples were further investigated in 30wt.% KOH at 70 ⁰C in a three- and two-electrode arrangement. Detailed electrochemical impedance spectroscopy (EIS) analysis of hydrogen evolution reaction (HER) conducted with a three-electrode arrangement, indicated two semi-circles on the Nyquist plots that confirmed that the adsorption of intermediate (Hads) is potential dependent. Relevant HER parameters such as exchange current density and relaxation time showed exceptional performance of optimized electrodes. During zero-gap single cell tests with bare Ni foam used as the anode, onset voltages for Ni-Sn cathodes were around 1.64 V (for bare foams 1.99 V), with cell voltage at 1 A cm–2 being as low as 2.03 V (for bare foams 2.57 V). The cathodes were also subjected to a long-term stability test, showing excellent activity preservation. Great stability, low cell voltage and low production cost confirm their suitability for industrial applications. Top-view as well as cross-section electron microscopy analysis have shown that the entire foam surface was evenly covered with Ni-Sn coating. The composition of the investigated coatings was within the range of Ni(1+x)Sn (0 < x < 0.5) metastable phase, and practically independent of deposition current density. Aberration-corrected scanning transmission electron microscopy (AC-STEM) revealed that the so-called metastable phase is in fact Ni3Sn2 phase, which is shown for the first time for electrodeposited Ni-Sn alloys