Subfosilno drvo

undergraduate thesis

• Title (english): Subfossil wood
• Author: Ana Bekavac
• Mentor: Sara Essert (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Subfosilno drvo ili abonos je drvo koje je više stotina ili tisuća godina odležalo na dnu močvare,
rijeke, jezera ili mora pod naslagama šljunka, blata i mulja u anoksičnim uvjetima. Karakteristična
crna boja abonosa potječe od kemijske reakcije tanina iz drva i željeza iz vode. Subfosilno drvo
ima promijenjena fizikalna i mehanička svojstva, zbog specifičnih uvjeta u kojima je nastajalo.
Recentno i subfosilno drvo razlikuju se u sastavu, jer se u subfosilnom drvu tijekom godina
smanjivao sadržaj ekstraktivnih tvari i fenolnih spojeva, te se također smanjivao udio
ugljikohidrata. Uspoređivanjem sadržaja anorganskih elemenata u subfosilnom i recentnom drvu
iste vrste dokazalo se da subfosilno drvo ima veći ukupni sadržaj željeza, kalcija i magnezija, dok
recentno drvo ima veći ukupni sadržaj kalija. Sadržaj celuloze u subfosilnom drvu manji je nego u
recentnom, dok je sadržaj lignina puno veći u subfosilnom drvu. Gustoće recentne i subfosilne
hrastovine slične su, ali pokazalo se da povećanjem starosti abonosa dolazi do povećanja njegove
gustoće. Subfosilno drvo ima širok spektar upotrebe, može se koristit pri izradi jedinstvenih
skupocjenih ukrasa, namještaja ili glazbenih instrumenata.

Abstract (english)

Subfossil wood or abonos is wood that has lain for hundreds or thousands of years at the bottom of
a swamp, river, lake or sea under deposits of gravel, mud and silt in anoxic conditions. The
characteristic black color of abonos comes from the chemical reaction of tannins from the wood
and iron from the water. Subfossil wood has changed physical and mechanical properties, due to
the specific conditions in which it was formed. Recent and subfossil wood differ in composition,
because the content of extractive substances and phenolic compounds in subfossil wood has
decreased over the years, and the proportion of carbohydrates has also decreased. By comparing
the content of inorganic elements in subfossil and recent wood of the same species, it was proven
that subfossil wood has a higher total content of iron, calcium and magnesium, while recent wood
has a higher total content of potassium. The cellulose content in subfossil wood is lower than in
recent wood, while the lignin content is much higher in subfossil wood. The densities of recent and
subfossil oak are similar, but it has been shown that increasing the age of abonos leads to an
increase in its density. Subfossil wood has a wide range of uses, it can be used to make unique
expensive decorations, furniture or musical instruments.

• Keywords: subfosilno drvo; abonos; recentno drvo hrasta; mehanička i kemijska svojstva drva
• Keywords (english): subfossil wood; abonos; recent oak wood; mechanical and chemical properties of wood
• Language: croatian
• URN:NBN: urn:nbn:hr:217:132859
• Study programme: Title: Ecology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-09-26 14:04:45