Fotosintetski odziv mladih stabala bukve (Fagus sylvatica L.) na odabranim plohama u različitim svjetlosnim uvjetima

In view of evident changes in the reaction of European beech (Fagus sylvaticaL.) to environmental changes, five plots with young trees of the same age were established and studied on natural beech sites. Beech trees were equally distributed along the light gradient and were divided according to light conditions. The parameter used for evaluation of light conditions was the indirect site factor (ISF) obtained by the WinScanopy analysis. Three groups of canopy – light conditions were defined: stand conditions (ISF25). In all categories light saturation curves and curves describing dependence between intercellular CO2concentration in leaves and assimilation rate (A-Ci) were measured under the same fixed parameters (temperature, flow and CO2concentration, humidity, and light intensity) with Li-6400, to compare responses between different light categories and different plots within comparable light conditions. Differences between canopy, edge and open area responses were confirmed with high significance on all plots as well as between studied forest complexes. On plots from Kočevje region, young beech indicated more shade tolerance, the response to increased light intensity and different CO2concentration was greater than the response of young beech on Pohorje plots within the same light intensities. Responses of trees on plots in managed and virgin forest were also different: young beech response in virgin forest plot was more shade-tolerant, compared to response of young beech from plots in managed forest.Glede uočenih promjena u reakciji bukve (Fagus sylvaticaL.) u odnosu na ekološke promjene, odabrano je pet ploha mlade bukve jednake starosti na prirodnim staništima, koje su bile jednakomjerno raspoređene na svjetlosnom gradijentu od zastora odrasle sastojine, šumskog ruba do svjetlosnih uvjeta na otvorenome. Kriterij za grupiranje bio je neizravni stanišni čimbenik (ISF), dobiven analizom hemisfernih snimaka pomoću sustava Win-Scanopy: zastor krošanja (ISF25), koji su bili jednaki na svim plohama. Za izmjere fotosintetskog kapaciteta, krivulje svjetlosnog zasićenja (0, 50, 250, 600 i 1200 µmol/m2s) i A-Ci krivulje (0, 100, 400, 700 i 1000 µmol CO2/l) dobivene su pomoću Li-Cor LI-6400 u kontroliranom okruženju (temperatura, protok i koncentracija CO2, zračna vlaga). Analize sadržaja dušika u lišću napravljene su Leco CNS-2000 analizatorom. Potvrđene su signifikantne razlike u reakciji mladih bukava između odabranih kategorija, kao i između različitih šumskih kompleksa. Mlade bukve na plohama iz Kočevskog pokazale su veću toleranciju na sjenu, a odziv na porast koncentracije CO2je pri istim intenzitetima osvijetljenosti bio veći nego kod mladih bukava iz Pohorskog kompleksa. Odziv mladih bukava bio je signifikant no različit između prašume (Rajhenav) i gospodarske šume unutar istog šumskog kompleksa: odziv u prašumi pokazuje veću toleranciju na sjenu

Phenological phases of trees on the intensive forest monitoring plots in Slovenia

Preučevanje razvojnih faz gozdnega drevja v dolgem časovnem nizu je vse pomembnejše orodje za ugotavljanje medsebojne odvisnosti vremenskih spremenljivk in z njimi povezanih bioloških odzivov. V naši raziskavi smo analizirali nastop fenofaz prvih listov in iglic ter splošnega rumenenja listja za listavce na 11 ploskvah intenzivnega monitoringa gozdnih ekosistemov v Sloveniji v letih od 2004 do 2011. Obravnavali smo fenofaze za dob (Quercus robur L.) na ploskvah Krakovski gozd in Murska šumabukev (Fagus sylvatica L.) na ploskvah Lontovž pod Kumom, Temenjak na Vinski gori, Borovec v Kočevski Reki, Fondek v Trnovskem gozdu, Gorica v Loškem Potokusmreko (Picea abies (L.) Karst.) na ploskvah Kladje na Pohorju in Krucmanove Konte na Pokljukirdeči bor (Pinus sylvestris L.) na ploskvi Brdo pri Kranjučrni bor (Pinus nigra Arnold) na ploskvi Gropajski Bori pri Sežani. V povprečju je fenofaza prvih iglic (BGS) smreke nastopila na 166 julijanski dan. Za rdeči bor je BGS nastopila na 128 julijanski dan, za črni bor pa 149. julijanski dan. Fenofaza prvih listov (BGS) je za bukev v povprečju nastopila na 128, za dob pa 117. julijanski dan. Splošno rumenenje listov (EGS) za bukevje v povprečju nastopilo na 297, za dob pa 308. julijanski dan. Dolžina vegetacijskega obdobja (LGS) doba je bila v povprečju 75 dni daljša kot za bukev. Ugotavljamo, da se je v obdobju od leta 2004 do 2011 nakazoval zgodnejši nastop fenofaze prvih iglic (BGS) smreke, rdečega bora ter črnega bora na vseh obravnavanih ploskvah. Zgodnejši nastop prvih listov (BGS) bukve in doba smo zaznali le na posameznih ploskvah, ne pa vseh. Kasnejši nastop splošnega rumenenja listov (EGS) za bukev smo zaznali le na dveh ploskvah (Borovec in Gorica), za dob pa smo ugotovili kasnejše pojavljanje EGS le na ploskvi Murska Šuma. Značilna je velika variabilnost dolžine vegetacijskega obdobja (LGS) za bukev in dob po letih. Daljšanje LGS za bukev je statistično značilno za tri ploskve (Fondek, Borovec in Gorica), za dob pa spremembe LGS v opazovanem obdobju niso bile statistično značilne.Study of developmental stages of forest trees in a long time series is of increasing importance for determination of interdependence between meteorological variables and the associated biological responses. In our study we analyzed the needle appearance and leaf unfolding of conifers and deciduous trees and the autumn colouring for broad-leaved tree species. We considered the phenological phases for oak (Quercus robur L.) in research plots Krakovski gozd and Murska šuma, beech (Fagus sylvatica L.) in research plots Lontovž, Temenjak, Borovec, Fondek, Goricaspruce (Picea abies (L.) Karst.) in research plots Kladje and Krucmanove KonteScotch pine (Pinus sylvestris L.) in the research plot Brdo, black pine (Pinus nigra Arnold) in the research plot Gropajski bori. On average, the needle appearance (BGS) of spruce started on the 166th Julian day. BGS of Scotch pine started on the 128th Julian Day, BGS of black pine on the 149th Julian day, respectively. The leaf unfolding (BGS) for beech started, on average, on the 128th Julian day and BGS for oak on the 117th Julian day, respectively. The autumn colouring(EGS) for beech, on average, started on the 297th Julian day, for oak on the 308th Julian day. It was assessed that BGS possibly commenced earlier for spruce, Scotch pine and black pine in all research plots during the 2004 to 2011 period. However, earlier BGS for beech and oak was noticed only in limited number of pots. Later EGS for beech could be confirmed in only two plots (Borovec in Gorica), whereas changes in EGS for oak were later only in plot Murska Šuma. There was a large variability of LGS for beech and oak over the years. Prolonged growing season (LGS) of beech was statistically significant for 3 plots (Fondek, Borovec in Gorica) during the 2004 to 2011 period. For oak prolonged LGS was not statistically significant during the observation period

Assessment of anthropogenic beech (Fagus sylvatica l.) stress in Zasavje area

Bukev (Fagus sylvatica L.) je prevladujoča drevesna vrsta v Sloveniji in osrednji Evropi ter kot taka primeren bioindikator zračnega onesnaženja. Bukevs svojo strukturo in funkcijo odseva razmere v okolju in smiselno dopolnjuje fizikalno-kemijske meritve zračnih onesnažil. Zasavje je eno izmed bolj onesnaženih predelov v Sloveniji zaradi industrije, ki je v preteklosti zelo degradirala to območje (rudarstvo, termoenergetika, steklarska industrija, kemična industrija). Vzorčna mesta smo izbrali v bližini ekološkega informacijskega sistema Termoelektrarne Trbovlje, kjer potekajo kontinuirane meritve zračnih onesnažil in meteoroloških parametrov. Kot referenčno mesto smo izbrali Prežo v Kočevski Reki. Stanje izbranih dreves smodoločali na osnovi biokemijskih kazalcev antropogenega stresa (fotosinteznipigmenti, antioksidanti) in mineralne preskrbljenosti dreves. Rezultati so pokazali, da so drevesa v Zasavju v stresu zaradi zračnega onesnaženja, kar potrjujejo statistično značilno večje vsebnosti žvepla, vodotopnih tiolov in manjša vsebnost fotosinteznih pigmentov v listih bukve v primerjavi z referenčnim, manj onesnaženim mestom. Vsebnosti makrohranil so bile na vseh vzorčnih lokacijah zadostne ali celo optimalne.Common Beech (Fagus sylvatica L.) is the prevailing tree species in Slovenia and central Europe and thus highly appropriate as air pollution bioindicator. With its structure and function it reflects the environmental conditions and represents the supplemental measurements of physical-chemical measurements of air pollutants in the environment. Zasavje area is one of the more polluted areas in Slovenia due to industry (mining, thermal power plant, glass factory,chemical industry). The sampling sites were chosen in the vicinity of ecological information system of Trbovlje Thermal Power Plant, were air pollutants and meteorological parameters are continuously measured. Preža at Kočevska Reka was chosen as reference sampling site. The condition of samplingtrees was determined by biochemical parameters of anthropogenic stress(photosynthetic pigments, antioxidants) and macronutrients supply. The result showed stress of trees due to anthropogenic pollution by statistical higher content of total sulphur, watersoluble thiols in beech leaves and lowercontent of photosynthetic pigments. The trees were well or optimally supplied by macronutrients at all sampling plots

Identification of Key Indicators for Drinking Water Protection Services in the Urban Forests of Ljubljana

Background and purpose: The importance of forest ecosystem services, related to provisioning of fresh water and water purification are of increasing importance, especially in urbanized areas. This study investigates key indicators for ecosystem services, related to drinking water protection, provided by urban and peri-urban forests. Materials and methods: Seven different monitoring programs, projects or directives, assessing water quality variables were analysed. We determined which indicators, describing the drinking water protection services in forest ecosystems, can be applied to urban forests. A list of core indicators sensitive to the specifics of the drinking water supply and urban forest ecosystems in Ljubljana were suggested. Results and conclusions: Analysis included over 86 potential indicators related to nutrient regulation, storage capacity and water purification in forest canopies, forest soils, surface streams, lakes and groundwater. Through scientific review and the application of “necessary” and “feasible” criteria to urban forests the number of indicators was reduced to 62. According to the specifics of drinking water supply and urban forest in Ljubljana 52 core indicators have been selected. Due to the influence of urbanization on water bodies, special emphasis should be given to indicators for storage capacity and water purification capacity of urban forest ecosystems for hazardous substances. This might increase the willingness of decision and policy makers to acknowledge the water protection capacity of urban forests

Vpliv vremenskih spremenljivk in osutosti krošenj na fenološke faze dreves na ploskvah intenzivnega monitoringa gozdnih ekosistemov v Sloveniji

Data from the forest monitoring programme in Slovenia were used to assess the relationship between tree phenology, crown defoliation and meteorological conditions in Fagus sylvatica, Quercus robur and Picea abies forests in the 2004-2013 period. We hypothesized a species-specific response of first leaf unfolding, general leaf colouring, the length of the growing season to crown defoliation, air temperature, precipitation and soil water. In accordance with the hypothesis, we found a high sensitivity of first leaf unfolding to air temperature and precipitation for all species, exhibiting contrasting responses. We observed strong sensitivity of beech defoliation to precipitation and soil water conditions. Oak crown defoliation and next-year phenology were correlated, with higher crown defoliation contributing to earlier leaf unfolding, later autumn leaf colouring and longer growing season of oak in next year. Correlation between crown defoliation and phenology was found neither for beech nor spruce.V naši raziskavi smo na podlagi podatkov spremljanja stanja gozdnih ekosistemov v Sloveniji ugotavljali povezanost fenofaz dreves, osutosti krošenj dreves in vremenskih razmer v gozdovih bukve, doba in smreke v letih 2004-2013. Predpostavili smo, da je odziv fenofaz prvih listov in iglic, splošnega rumenenja listja in dolžine vegetacijskega obdobja na osutost krošenj, temperaturo zraka, padavine in vsebnost vode v tleh vrstno specifičen. Ugotovili smo veliko odzivnost nastopa fenofaze prvih listov in iglic na temperaturo zraka in padavine za vse obravnavane drevesne vrste, vendar so se odzivi razlikovali. Ugotovili smo tudi veliko odzivnost osutosti krošnje bukve na količino padavin in vsebnost vode v tleh. Osutost krošenj in fenofaze doba v sledečem letu so bile korelirane, pri čemer je večja osutost krošenj prispevala k zgodnejšemu nastopu fenofaze prvih listov, splošnega rumenenja listja in dolžine vegetacijskega obdobja za dob v sledečem letu. Nismo pa ugotovili povezanosti med osutostjo krošenj in fenofazami bukve ali smreke

AN ADVANCED COARSE-FINE SEARCH APPROACH FOR DIGITAL IMAGE CORRELATION APPLICATIONS

The paper presents a newly developed fine search algorithm used in the application of digital correlation. In order to evaluate its performance a special purpose application was developed using C# programming language. The algorithm was then tested on a pre-prepared set of the computer generated speckled images. It turned out to be much faster than the conventional fine search algorithm. Consequently, it is a major step forward in a never ending quest for a fast digital correlation execution with sub pixel accuracy