Prosudba opasnih stabala korištenjem vizualnih metoda i arborikulturnih instrumenata

doctoral thesis

• Title (english): Assessment of hazardous trees using visual methods and arboricultural instruments
• Author: Vinko Paulić
• Mentor: Milan Oršanić (mentor)
• Committee member: Danko Diminić (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Forestry; Zagreb
• Defense date and country: 2015-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Forestry
• Universal decimal classification (UDC): 630; APPLIED SCIENCES. MEDICINE. TECHNOLOGY; Silviculture. Afforestation. Felling. Logging

Abstract

Opasna stabla mogu prouzročiti značajne štete ukoliko dio stabla ili cijelo stablo padne na potencijalnu 'metu'. Prosudba opasnih stabala se može napraviti vizualno ili upotrebom arborikulturnih instrumenata. Gljive truležnice na živim stablima uzrokuju degradacije drva čime povećavaju opasnost od loma stabla. Stabilnost stabla je uvjetovana karakteristikama stabla i staništa.Istraživanje prosudbe opasnih stabala je provedeno u urbanim šumama u okviru gospodarske jedinice Park-šume grada Zagreba, u šumskim predjelima Granešina, Tuškanac, Zelengaj i Jelenovac.Rezultati istraživanja prosudbe opasnih stabala vizualnim metodama ukazuju da je mali broj opasnih stabala u šumama grada Zagreba. Između korištenih vizualnih metoda utvrđene su razlike u rezultatima prosudbe. Korištenjem EHT metode dobije se veća ocjena opasnosti ocjena od VTA metode. Na ocjenu opasnosti VTA metodom najveći utjecaj imaju simptomi zadebljanja dok na ocjenu opasnosti EHT metodom najveći utjecaj imaju greške mrtve grane u krošnji i ograničena površina korijena.VINKO PAULIĆ: Prosudba opasnih stabala korištenjem vizualnih metoda i arborikulturnihinstrumenataDoktorski rad IIKorištenjem zvučnog tomograma i rezistografa moguće je točno locirati područja oslabljelog drva u unutrašnjosti stabla, dok fraktometrom nije moguće.Stabla hrasta kitnjaka koja posjeduju vidljive simptome i greške drva nemaju manju stabilnost od stabala bez grešaka i simptoma. Povećanje vlažnosti tla dovodi do smanjenja stabilnosti stabla, međutim razlika smanjenja nije statistički značajna.Upotrebom suvremenih arborikulturnih instrumenata za otkivanje opasnih stabala uz upotrebu vizualnih metoda prosudbe se utječe na povećanje sigurnosti u urbanim šumama.

Abstract (english)

Hazardous trees can cause significant damage if a portion of a tree or the entire tree falls on a potential target. Assessment of hazardous trees can be made visually or using instrumental methods. Tree decay funghi cause degradation of wood in living trees which increases hazard for tree breakage. Tree stability is influenced by tree and site characteristics.Assessment of hazardous trees research has been conducted in urban forests that are included in management unit Park-šume grada Zagreba, in forest sites Granešina, Tuškanac, Zelengaj and Jelenovac.Results accomplished in the assessment of hazardous trees using visual methods indicate that there is a small number of hazardous trees. Among used visual assessment methods differences in results have been confirmed. When using EHT method a higher hazard rating is archived than when using VTA method. Bulge symptoms have the highest influence on VTA hazard rating while defected dead tree in the crown of the tree and restricted root area has the highest influence on EHT hazard rating.Using sound tomograph and resistograph it is possible to accurately locate areas of degraded wood in a living tree, on the other hand when using fractometer this is not possible.The sessile oak trees that have visible symptoms and tree defects do not have lower tree stability than trees without defects and symptoms. Increase in soil moisture leads to decrease in tree stability but difference in reduction is not statistically significant.Using modern arboricultural instruments for detection of hazardous trees, increase in safety of urban forests can be archived.

• Keywords: Urbana stabla; hrast kitnjak; arborikultura; urbano šumarstvo; vizualna prosudba stabala; opasna stabla; trulež drva; arborikulturni instrumenti; rezistograf; zvučni tomograf; fraktometar; shigometar; potezni test; stabilnost stabla
• Keywords (english): Urban trees; sessile oak; arboriculture; urban forestry; visual tree assessment; hazardous trees; tree decay; arboricultural instruments; resistograph; sound tomograph; fractometer; shigometer; pulling test; tree stability
• Language: croatian
• URN:NBN: urn:nbn:hr:108:741630
• Study programme: Title: POSTGRADUATE UNIVERSITY DOCTORAL STUDY PROGRAMME OF FORESTRY; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje biotehničkih znanosti, polje šumarstvo (doktor/doktorica znanosti, područje biotehničkih znanosti, polje šumarstvo)
• Type of resource: Text
• Extent: 268
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-01-20 12:21:42