Utjecaj požara na odabrana kemijska svojstva tla

master's thesis

• Title (english): The impact of fire on selected chemical soil properties
• Author: Nika Krulčić
• Mentor: Aleksandra Bensa (mentor)
• Committee member: Aleksandra Bensa (predsjednik povjerenstva)
• Committee member: Kristina Krklec (član povjerenstva)
• Committee member: Aleksandra Perčin (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Soil Science); Zagreb
• Defense date and country: 2019-02-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Požari uzrokuju značajne promjene kemijskih svojstava tla, ovisno o intenzitetu i trajanju, svojstvima tla, vrsti vegetacije, vremenu uzorkovanja u odnosu na požar kao i dubini uzorkovanja tla. U ovom preglednom radu analiziran je utjecaj požara na pH, organsku tvar, te fiziološki aktivni fosfor, kalij i ukupni dušik u tlu. Većina autora utvrdila je povećanje pH tla neposredno nakon požara, uz više ili manje izražene razlike u odnosu na izvorni pH. Kao glavne razloge naveli su stvaranje pepela i razgradnju organske tvari, odnosno povećanje sadržaja karbonata i baznih kationa. Također, vrijeme potrebno za povratak na prvobitno stanje je jako varijabilno. Požari smanjuju sadržaj organske tvari u tlu, kao i njenu kvalitetu. U većini istraživanja utvrđeno je smanjenje ukupnih humusnih tvari, udjela huminskih kiselina i povećanje fulvo kiselina u humusnim tvarima uslijed požara. Također, sadržaj ugljikohidrata kao termolabilnih spojeva očekivano se smanjuje nakon požara, a sadržaj aromatskih ugljikovodika se povećava. Većina autora utvrdila je povećanje koncentracija hranjivih tvari u tlu neposredno nakon požara, posebice fiziološki aktivnog fosfora i kalija, iako postoje i istraživanja koja odudaraju od navedenog. Uglavnom se svi slažu da utvrđeno povećanje uzrokuje količina pepela koja je zaostala nakon požara. Pojedini autori posebno ističu oslobađanje fiziološki aktivnog fosfora izgaranjem organske tvari. Fluktuacije ukupnog dušika u tlu poslije požara najčešće se pripisuju eroziji i volatizaciji. Kao ključne čimbenike za intenzitet promjena kemijskih svojstava tla autori uglavnom navode temperature i duljinu trajanja požara.

Abstract (english)

Fires cause significant changes of chemical soil properties, depending on the intensity and duration, soil properties, type of vegetation, time of sampling in relation to the fire, and the depth of soil sampling. In this review the impact of fire on pH, soil organic matter, physiologically active phosphorus, potassium, and total nitrogen was analyzed. Most authors found an increase of the soil pH immediately after the fire, with more or less pronounced differences compared to the initial pH. The soil pH increase is attributed to the effect of ash, and degradation of soil organic matter. Likewise, the time to return to the initial condition is highly variable. Fires reduce the content of soil organic matter in addition to its quality. Numerous studies have shown the reduction of total amount of humus substances and the proportion of humic acids, but as well the increase of fulvic acids in humus substances after the fire. Also, the carbohydrate content as a thermolabile compound is expected to decrease after the fire and the content of the aromatic hydrocarbon is increased. Several authors have found an increase in concentrations of nutrients in the soil immediately after the fire, especially for physiologically active phosphorus and potassium, although there are studies that differ from above. Mostly all agree that the determined increase is caused by the amount of ash left behind after the fire. Some authors specifically emphasize the release of physiologically active phosphorus by combustion of soil organic matter. Fluctuations of total nitrogen in the soil after the fire are most often attributed to erosion and volatilization. Authors generally indicate the temperature and duration of the fire as the key factors for the intensity of changes in chemical soil properties.

• Keywords: fiziološki aktivni fosfor; fiziološki aktivni kalij; organska tvar; pH; ukupni dušik
• Keywords (english): physiologically active phosphorus; physiologically active potassium; soil organic matter; pH; total nitrogen
• Language: croatian
• URN:NBN: urn:nbn:hr:204:445551
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologija (magistar/ magistra inženjer/inženjerka agroekologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-03-27 13:08:29