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The Effects of Soil Type, Exposure and Elevation on Leaf Size and in Quercus cerris L.
No full textOne of the main environmental factors that influence plant species and community diversity are soil types, exposure and elevation. This study aimed to evaluate differences in leaf size and shape of Quercus cerris L. along environmental gradients in the Sumadija region in Serbia by using geometric morphometrics methods. The results showed significant differences between Q. cerris individuals inhabiting sites with different soil types, exposures and elevations. Individuals growing on nutrient deficient soils had smaller leaf size, elongated petiole, wide leaf blade, and higher values of fluctuating asymmetry compared to individuals growing on nutrient-rich soils whose leaf size was larger, more variable in shape and had lower values of fluctuating asymmetry. Additionally, individuals inhabiting higher elevations had elongated and narrow leaves and short petioles. Leaf size was also greater in individuals from lower elevations and north-exposed sites. The results of this study suggest that leaf morphological traits are affected by habitat differences and exhibit considerable plasticity in response to environmental demands
Significant increase in natural disturbance impacts on European forests since 1950
No full textOver the last decades, the natural disturbance is increasingly putting pressure on European forests. Shifts in disturbance regimes may compromise forest functioning and the continuous provisioning of ecosystem services to society, including their climate change mitigation potential. Although forests are central to many European policies, we lack the long-term empirical data needed for thoroughly understanding disturbance dynamics, modeling them, and developing adaptive management strategies. Here, we present a unique database of gt 170,000 records of ground-based natural disturbance observations in European forests from 1950 to 2019. Reported data confirm a significant increase in forest disturbance in 34 European countries, causing on an average of 43.8 million m(3) of disturbed timber volume per year over the 70-year study period. This value is likely a conservative estimate due to under-reporting, especially of small-scale disturbances. We used machine learning techniques for assessing the magnitude of unreported disturbances, which are estimated to be between 8.6 and 18.3 million m(3)/year. In the last 20 years, disturbances on average accounted for 16% of the mean annual harvest in Europe. Wind was the most important disturbance agent over the study period (46% of total damage), followed by fire (24%) and bark beetles (17%). Bark beetle disturbance doubled its share of the total damage in the last 20 years. Forest disturbances can profoundly impact ecosystem services (e.g., climate change mitigation), affect regional forest resource provisioning and consequently disrupt long-term management planning objectives and timber markets. We conclude that adaptation to changing disturbance regimes must be placed at the core of the European forest management and policy debate. Furthermore, a coherent and homogeneous monitoring system of natural disturbances is urgently needed in Europe, to better observe and respond to the ongoing changes in forest disturbance regimes
The Influence of Moisture Content on Strength of Window Corner Joint
No full textThe tendency to improve the energy efficiency of windows has led to an increase in the number of panes used. The greater weight of the window sash leads to a loss of its geometry during normal usage. This deformation of geometry is caused by its own weight, and thus reduces the efficiency of preventing heat loss. All the positive effects that are obtained by using multiple panes of glass are thus lost. As window manufacturers often try to cut production costs by shortening the time of kiln drying, this paper researches the effect of using elements with different moisture content. Articles on similar topics were reviewed and it was found that there were no available data on the researched topic. Only about 20 different articles on similar topics were found, but the starting conditions or input was greatly different. Also, there are no official standards that cover the strength of window corner joints. This paper analyzes the influence of the change in moisture of the elements on the strength of the joint. Three groups of window corner joint samples were examined. The first group of samples was the control group that was supposed to determine the strength of the joint when the window beams were made with the recommended moisture according to a corresponding standard (12 +/- 2%). In the second and third groups, the moisture of the beams was taken as a variable factor, namely the moisture content of 18 +/- 2%. The results of this study show that the strength values of the currently used corner joints (double mortise and tenon) are different at different moisture contents. As expected, the samples with the recommended moisture content had higher strength values than the samples with the higher moisture content. There are many challenges in proper kiln drying and the final moisture content has a crucial impact on window strength. As windows have a specific purpose in buildings, they should have sufficient strength to be properly used over a long period. These obtained results should demonstrate the importance of the moisture content of wooden beams used in window production
The European market of wooden toys
No full textWooden toys, which have a very long history, are nowadays the subject of increased demand and relevance since ecological products are gaining ever more importance and value in society. This is the reason why wooden toys were chosen as the subject of this research, while special attention was paid to wooden puzzles. The aim of this research was to determine the trade volume in these products on the EU market in the period 2000-2021, the countries that are the most important for the supply of wooden toys, as well as the countries that are the biggest importers of these products. In addition to the above, another aim of this research was to identify the regulations governing the marketing of toys on the EU market. Toys, including wooden ones, that are placed on the EU market must be produced in accordance with the requirement of the toy safety Directive 2009/48/EC and standard EN 71. They have to have the CE mark and accompanying CE documentation. In addition, toys must be produced in accordance with the requirements of the REACH regulation that restricts the use of heavy metals in the product, i.e. its packaging. Wooden toys are not subject to the European Union Timber Regulation (EUTR)
Inhibitorni efekat etarskih ulja nekih četinara prema patogenima iz roda Phytophthora
No full textPhytophthora vrste su gljivama slični organizmi u okviru carstva Chromista i
supergrupe SAR (Beakes et al. 2014). Ovi patogeni organizmi su odgovorni za više
devastirajućih epidemija u poljoprivrednim kulturama, prirodnim šumskim ekosistemima,
posađenim šumama i plantažama (Jung et al. 2018). Takođe, izvestan broj Phytophthora i
srodnih patogena napada i morsku floru nanoseći indirektno ogromne štete fauni ovih
osetljivih ekosistema (Talgø et al. 2022). Jedan od većih izazova je kontrola ovih patogenih
organizama i njihovo suzbijanje, posebno uzimajući u obzir ekološki aspekt i neophodnost
izbegavanja hemijskih pesticida, posebno u prirodnim ekosistemima. Ekološki prihvatljivi
biopesticidi bazirani na produktima biljaka, kao što su na primer etarska ulja (EU),
predstavljaju jednu od mogućnosti kontrole na kojoj treba dalje raditi (Vettraino et al. 2022).
U ovom istraživanju smo u laboratorijskim uslovima ispitivali efikasnost EU poreklom iz
niskih četinara prema tri vrste iz roda Phytophthora (P. plurivora Jung and Burgess, P.
quercina Jung i P. ×cambivora (Petri) Buisman), koje nanose štete na vrednim drvenastim
domaćinima u našim ekosistemima. Korišćene su tri koncentracije (0.05, 0.1 i 0.5%) EU
ekstrahovanih iz tri vrste četinara koje pripadaju familiji Cupressaceae, Lavsonovog
pačempresa (Chamaecyparis lawsoniana (A. Murr.) Parl., džinovske tuje (Thuja plicata Donn
ex D.Don) i obične kleke (Juniperus communis L.), koje su posle rastvaranja u 0.5% TWEEN80
(v/v) dodavane u sterilisanu V8-A hranljivu podlogu pri temperaturi od oko 50°C. Podloga sa
različitim koncentracijama EU je razlivena u Petri posude veličine 90 mm, koje su posle
hlađenja inokulisane komadima agara i micelije približne veličine 4 mm, uzetih sa oboda
napredujuće kolonije odabranih Phytophthora vrsta. Kontrolna grupa je inokulisna komadima
agara sa rastvorom TWEEN80 i destilovane vode. Eksperiment je izveden u tri ponavljanja, a
inkubacija je bila na 20°C u tami. Posle sedam dana inkubacije, utvrđeno je da je EU T. plicata
skoro potpuno inhibiralo rast kolonija sve tri Phytophthora vrste na koncentracijama 0.1% i
0.5%, dok je EU C. lawsoniana zaustavilo rast kolonija jedino na koncentraciji od 0.5%.
Takođe, ulje T. plicata je značajno redukovalo rast kolonija sve tri Phytophthora vrste na
najmanjoj testiranoj koncentraciji od 0.05%. EU J. communis je bilo najmanje efikasno i nije
inhibiralo rast na testiranim koncentracijama. Na osnovu dobijenih rezultata, EU T. plicata je
podvrgnuto enkapsulaciji u biopolimernu matricu kako bi se produžio inhibitorni efekat
putem sporog oslobađanja i sprovelo testiranje in vivo
Climate change and forests
No full textAdaptivno upravljanje osnovni je koncept strategija upravljanja šumskim ekosistemima u uslovima povećanih rizika kao što su klimatske promjene. Klimatskepromjenepredstavljajunajznačajnijiproblemdanašnjice, koji,unajkraćem,karakterišupovišenetemperature, neuravnoteženepadavine, kaoisvečešćeprisustvoekstremnihklimatskihdogađaja. Prostorne distribucije ukazuju na to da će najveći klimatski rizici biti koncentrisani u južnim suptropskim i tropskim vlažnim oblastima,gdje je pojačana suša i gdje može doći do pada produktivnosti usljed prirodnih opasnosti poput suša i poplava. Interakcija između klimatskih promjena i vazdušnih polutanata posebno stresno djeluje na drveće (šumu). Uticaji klimatskih promjena na pojedine vrste mogu biti pozitivni ili negativni, što je uslovljeno stanišnim prilikama i regionalnim klimatskim promjenama. Glavni uzrok globalnog zagrijavanja „modernog doba”, tj. perioda od industrijske revolucije, jestepovećavanje koncentracije gasova staklene bašte u atmosferi, od kojih je najodgovorniji ugljendioksid. U oblasti Mediterana rezultati ukazuju na smanjenje godišnje količine padavina za 10‒20%.Ovako intenzivnepromjene,a posebno povećanje temperature vazduha, utiču na povećanje evapotranspiracije. Brze promjene klimatskih uslova, uzdodatni stres od strane raznovrsnihljudskih direktnih uticaja,čine ekosistem Zemlje neodrživim i zahtijevaju hitnu implementaciju mjeraza ublažavanje ovih promjena. Ključni ciljevi su, pored smanjivanja emisija, povećanje udjela proizvodnje energije iz obnovljivih izvora i povećanje energetske efikasnosti. Promjena srednje temperature vazduha na području Zapadnog Balkana za period 1986‒2015.u odnosu na period 1961‒1980.iznosi1,2°C, zbog čega se ovaj region smatra jednim od ugroženijihu svijetuu smisluklimatskih promjena. Narednih decenija i dalje će se najviše povećavati temperatura tokom ljetnje sezone. Na čitavom području Republike Srpske,najtopliji mjesec je jul,sa prosječnomtemperaturom 24,3°C za Trebinje. Povećanje srednje ljetnje temperature najvećejeu centralnom dijelu regiona, naročito u većem dijelu Bosne i Hercegovine,i prevazilazi 2°C, a količina padavina smanjenajeza 10%–20%. Langova bioklimatska klasifikacija za referentni period ukazujena to da je analizirano područje Prijedora i Bijeljine sa obilježjem semihumidne klime, dok su područja Banjaluke, Doboja, Sokoca, Bileće i Trebinja sa obilježjem humidne klime.Prema godišnjem klimatskom indeksupo Torntvajtu,zareferentni period 1981–2010. godine,na području Bijeljine,kao najsuvljem dijelu Republike Srpske,dominira suphumidna‒ vlažna klima tipa C2, na području Prijedora i Doboja blago humidna klima tipa B1, Banjaluka i Sokolac imaju umjereno humidnu klimu tipa B2, a na području Istočne Hercegovine je perhumidna klima tipa A. Prema klasifikaciji klime po Elenbergu,za referentni period1981–2010. godine,čitavo područje Republike Srpske pripada zoni sa odlikama vlažne klime. Analize pokazuju neophodnost primjene odgovarajućih uzgojnih mjera u šumarstvu,u skladu sa uticajem klimatskihpromjenana šumu,uz potpomognutu prirodnu regeneraciju, gajenje mješovitih šuma i vrsta prilagođenih različitim režimima tolerancije na temperaturu, njegušuma proređivanjem, primjenusanitarnih i drugih vrsta uzgojnih mjera, očuvanje genetske raznolikosti,tj.biodiverziteta,i usvajanje prakse održivog gazdovanja šumam
Ecological - coenological vitality of artificially-established austrian pine stands in nm “Košutnjak forest”, Belgrade - Serbia
No full textS obzirom na specifičnu namenu SP „Šuma Košutnjak“ u Beogradu, koja je proizašla iz prostorno-orografskog položaja i neposredne potrebe stanovništva velike urbane sredine za višefunkcionalnim sadržajima te s obzirom na plansku projekciju, proizašlu iz zakonske regulative, ova gradska šuma reonirana je na tri funkcionalne celine. One su utvrđene na osnovu valorizacije elemenata vezanih za posebnu namenu i značaj šume. Najveća površina vezana je za obezbeđivanje socijalne funkcije, kao prioritetne funkcije šume. U ovoj namenskoj celini zastupljene su različite alohtone i autohtone vrste drveća, koje su vezane za primarna tipološka staništa ili vrste koje pripadaju sekundarnim staništima. Sprovedena istraživanja vezana su za funkcionalnu održivost prioritetne namene šume te je izvršena analiza ekološko- cenološke vitalnosti crnog bora na staništu primarnog tipa šume cera i krupnolisnog medunca (Orno - Quercetum cerris - virgilianae) na pararendzinama, tip šume kitnjaka, graba i cera (Carpino - Quercetum petraeae - cerris) na lesiviranim gajnjačama i tip šume medunca i krupnolisnog medunca (Orno - Quercetum pubescentis - virgilianae) na pararendzinama na lesu. Dinamizam sukcesije je različit, to jest, crni bor se potiskuje od vrsta (edifikatora) primarnog tipa. Ovo je značajna spoznaja u projekciji narednih funkcionalno održivih planova gazdovanja. To se, prvenstveno, odnosi na opravdanost budućih planskih postupaka kada su u pitanju veštački podignute sastojine crnog bora na sekundarnim staništima
Physiological, Haematological And Production Characteristics Of Pheasants In Different Rearing Conditions
No full textThis paper presents a physiological, hematological, and biochemical study of the impact of
different rearing conditions on pheasant production outcomes and mortality rates in both the
pheasant parent flock and pheasant chicks up to 6 weeks old. Pheasant breeding holds
significance within hunting activities and meat production for the food market due to its high
biological and nutritive value. Pheasant meat contains high-quality proteins, minerals,
essential unsaturated fatty acids, and boasts a low-fat percentage. The quality of pheasant meat
derived from natural habitats holds a higher biological value compared to that of pheasants
raised on farms, featuring higher water, protein, and calcium contents, and a lower fat
percentage. The dry mass of breast muscles from farm-reared birds contains more protein and
less fat when compared to drumstick muscles. Notably, during the egg-laying period,
alterations in hematological parameters linked to oxygen transport, decreased erythropoiesis,
and increased values in white blood cell parameters were observed. Changes in blood
biochemical parameters signify increased energy requirements in pheasant hens during egg
laying, as well as heightened transportation of minerals, proteins, and cholesterol, which
accumulate in the eggshell, albumen, and yolk. The elevated metabolic requirements in
pheasant hens manifest significantly through increased levels of cholesterol, uric acid, lactates,
aspartate aminotransferase (AST), alanine aminotransferase (ALT), calcium, and phosphorus.
Simultaneously, there is a noteworthy decrease in plasma total proteins, albumins, glucose, and
lactate dehydrogenase (LDH) concentrations. Several challenges persist throughout all
production stages, leading to reduced egg yield, compromised egg quality and fertility, as well
as increased mortality rates. These issues stem from factors such as high population density, an
inappropriate male-to-female sex ratio, inadequate nutrition, and insufficient assessment of the
biological quality of hatching eggs
Spatial variability of organic carbon in sandy soils: case study of deliblato sands (Serbia)
No full textU ovom radu su prikazani rezultati proučavanja i varijabilnosti sadržaja organskog ugljenika u zemljištima obrazovanim na pesku Deliblatske peščare, specijalnom rezervatu prirode (SRP). Peskovita zemljišta Deliblatske peščare su veoma osetljiva na degradaciju, dok je sistem korišćenja zemljišta regulisan zakonom. Analize su obavljene za slojeve zemljišta 0-10 cm i 10-20 cm prema referentnim tipovima zemljišta i identifikovanim tipovima vegetacije. Srednje vrednosti sadržaja SOC (eng. Soil Organic Carbon) (g/kg) su 23,13 (0-10 cm) i 11,20 (10-20 cm), dok su vrednosti za SOCD (eng. Soil Organic Carbon Density) (g/m2 ) 2,40 (0-10 cm) i 1,22 (10-20 cm). Ukupne rezerve SOC-a u zemljištima Deliblatske peščare procenjene su na 1,18×106 Mg u gornjim slojevima (0-20 cm). Analize prostorne varijabilnosti SOC (g/kg) i SOCD (g/m2 ) sprovedene su primenom GIS tehnika u cilju mapiranja distribucije ovih parametara. Utvrđen je visok stepen prostorne varijabilnosti u pogledu sadržaja i gustine SOC-a, kako po referentnim tipovima zemljišta tako i po tipovima vegetacije. Dobijeni rezultati pokazuju da u procesu upravljanja SRP Deliblatska peščara, a samim tim i rezervama SOC-a, pažnju treba usmeriti na zaštitu autohtone vegetacije
Structural properties of pure and mixed bosnian pine stands on mt. Zeletin
No full textPredmet istraživanja su sastojine munike na području planinskog masiva Visitor sa Zeletinom u Crnoj Gori. S obzirom na neistraženost ovih šuma, zbog male površinske zastupljenosti i odsustva ekonomskog interesa (najstroži režim zaštite), zadatak rada je bio da se u strukturnom, delimično i u proizvodnom, smislu što bolje prouči jedna od najočuvanijih populacija munike na ovim prostorima. Sastojine munike na Zeletinu pripadaju dvema gazdinskim jedinicama: GJ „Piševska rijeka – Zeletin“ i GJ „Kutska rijeka“ i zauzimaju površinu od 160 ha. Istraživanjima su obuhvaćeni pristupačni delovi odseka 2/b, 3/a, 5/a, 28/a i 28/s, u kojima je postavljeno 8 oglednih površina (OP) veličine po 30 ari (4 OP u čistim i 4 OP u mešovitim sastojinama). OP su vertikalno distribuirane između 1.550 i 1.850 m n.v. U čistim sastojinama prosečan (za 4 OP) broj stabala je 723 kom∙ha-1, temeljnica 74 m2 ∙ha-1, a zapremina 529 m3 ∙ha-1, što su visoke vrednosti s obzirom na uslove u kojima se ove sastojine razvijaju. U mešovitim sastojinama, numerički elementi su značajno veći: broj stabala je 875 kom∙ha-1, temeljnica 87 m2 ∙ha-1 i zapremina 721 m3 ∙ha-1. Utvrđen je visok stepen korelacija između vrednosti zapremina (neponderisanih i ponderisanih) i vrednosti dominantnih visina. Mešovite sastojine imaju heterogeniju strukturnu izgrađenost. Stabla munike se grupišu na malim distancama, što je verovatno posledica borbe za opstanak u veoma nepovoljnim uslovima. Kako se radi o sastojinama prepuštenim spontanom razvoju u dugom vremenskom periodu, istraživanja pružaju mogućnost boljem upoznavanju ekologije munike. S obzirom na skromne zahteve prema uslovima staništa, munika poseduje izražene prednosti pri izboru vrsta za pošumljavanje najnepovoljnijih staništa