magistrsko delo
Tomaž Medved (Avtor), Nives Ogrinc (Mentor), Tom Levanič (Komentor), Bor Krajnc (Komentor)

Povzetek

Podnebne spremembe so vedno bolj izrazite in ne vplivajo samo na človeka, ampak tudi na naravo, med drugim tudi na gozd in drevesa. Ta se nanje različno prilagajajo, kar se beleži v izotopski sestavi celuloze v branikah. V magistrski nalogi smo s pomočjo stabilnih izotopov kisika in ogljika v drevesnih branikah ugotavljali kako se drevesa odzivajo na okoljske spremembe na raziskovalni ploskvi Brdo pri Kranju. S pomočjo delignifikacije, homogenizacije in liofilizacije smo pridobili čisto celulozo iz drevesnih branik rdečega bora. Tej smo nato s pomočjo elementarnega analizatorja sklopljenega z masnim spektrometrom za analizo razmerja stabilnih izotopov določili izotopsko sestavo ogljika in kisika. Rezultati meritev so podani z δ vrednostmi (δ18O, δ13C). Meritve smo nato primerjali z vremenskimi podatki za obdobje 1992-2021 in meritvami izotopske sestave kisika v talni vodi in padavinah. Statistična obdelava podatkov nakazuje najboljšo korelacijo med δ18O vrednostmi v celulozi branik in povprečno mesečno temperaturo, količino padavin ter številom sončnih ur v mesecu avgustu. Dobre korelacije so bile ugotovljene tudi za meseca februar in maj. Iz primerjave med δ18O vrednostmi celuloze branik, talne vode in padavin smo ugotovili, da imajo branike črnega bora na tem področju sposobnost rekonstrukcije signala padavin meseca avgusta in novembra. Korelacije δ13C vrednosti v celulozi branik in vremenskimi spremenljivkami niso bile tako izrazite. Izpostaviti velja korelacijo med δ13C vrednostmi in količino padavin meseca maja. Prav tako nismo zasledili dobre korelacije med δ13C in δ18O vrednostmi v celulozi lesnih branik, kar kaže na velik vpliv hitrosti fotosinteze na δ13C vrednosti ter manjši prispevek regulacije stomatalne prevodnosti na učinkovito porabo vode. Čeprav v magistrski nalogi nismo opazili jasnega vzorca v izotopski sestavi kisika in ogljika v celulozi branik črnega bora na klimatske spremembe opažene v zadnjem obdobju 20 let, rezultati nakazujejo, hiter odziv in relativno dobro pripravljenost dreves na podnebne spremembe.

Ključne besede

drevesne branike;stabilni izotopi;dendrokronologija;magistrske naloge;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UM FS - Fakulteta za strojništvo
Založnik: [T. Medved]
UDK: 551.583.1+[54.02:630*56](043.2)
COBISS: 152176131 Povezava se bo odprla v novem oknu
Št. ogledov: 153
Št. prenosov: 0
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Influence of climate change on the isotopic composition of oxygen and carbon in tree cellulose
Sekundarni povzetek: Climate change is becoming more and more pronounced and affects not only humans, but also nature, including forests and trees. As the effects of climate change become increasingly pronounced, forests and trees adapt in different ways, which is recorded in the isotopic composition of the tree cellulose. In my master's thesis, stable isotopes of oxygen and carbon in tree rings were used to determine how trees in the Brdo pri Kranju research area respond to environmental changes. With the help of delignification, homogenization and lyophilization, It was possible to obatin pure cellulose from red pine tree rings. The isotopic composition of carbon and oxygen was then determined using an elemental analyzer coupled to an isotope ratio mass spectrometery (IRMS), and the ratios were expressed in δ-values (δ18O, δ13C). The measurements were then compared with weather data for 1992-2021 and δ18O values in ground water and precipitation. Statistical analysis found the best correlation between three cellulose δ18O values and the average monthly temperature, amount of precipitation and sunshine hours in August. A good correlation was also found for the months of February and May. From a comparison of δ18O values of tree cellulose, soil water and precipitation, it was found that black pine tree rings in this area can reconstruct the rainfall signal in August and November. Correlations of δ13C values in tree rings and weather variables were not significant. However, the correlation between δ13C values and the amount of precipitation in May is noteworthly. There was also no correlation between δ13C and δ18O values in the cellulose of tree rings, which indicates a significant influence of the rate of photosynthesis on δ13C values and only a minor contribution of regulation of stomatal conductance to efficient water consumption. Although a clear pattern in the isotopic composition of oxygen and carbon in the tree rings of the black pine bumper to the climatic changes was not observed over the past 20 years, the results indicate a quick response of the trees to climate change.
Sekundarne ključne besede: tree rings;stable isotopes;dendrochronology;
Vrsta dela (COBISS): Magistrsko delo/naloga
Konec prepovedi (OpenAIRE): 2025-01-31
Komentar na gradivo: Univ. v Mariboru, Fak. za strojništvo, Tehniško varstvo okolja
Strani: 1 spletni vir (1 datoteka PDF (XVI, 54 f.))
ID: 17616198