Analysis of the Fire Season of 2020 in the Mediterranean Bioclimatic Zone of Croatian Adriatic

Fire season in the Mediterranean bioclimatic area is most associated with the period from June to late October. Despite this, a large number of fires occur in February and March due to the intentional burning of agricultural lands. A characteristic of the Mediterranean region is the strong adaptation of vegetation to fire, though this adaptation also depends on the frequency and intensity of fires. This frequency is shown on satellite images via MODIS. This paper provides an overview of indicators of vegetation fires in the Croatian coast and karst coastal belt in the 2020 fire season. The 2020 fire season was above average in comparison with the period 2010 to 2019, with more fires than average and more burnt area. A specificity of the 2020 season is seen in the large number of fires in February and March. Fire protection in Croatia is facilitated by the use of new remote sensing technologies, in combination with the existing surveillance and monitoring methods, and organised protection systems to prevent open fires

Vegetation conditions and fuel materials on Kornati in connection with Kornati fire of 30th August 2007.

Osim što ugrožavaju proizvodnju šumske biomase, požari mogu poremetiti i ekološku ravnotežu te narušiti trajno održivi razvoj. Uz to mogu imati i tragičnije posljedice kao što je to bilo na Kornatima u ljeto 2007. godine. U vezi s tim obavljena su istraživanja vegetacije i testiranje njene zapaljivosti i gorivosti. Testiranje zapaljivosti obavljeno je u laboratoriju u Makarskoj prema metodologiji koju je opisao Valette (1990). Samim uzorkovanjem na terenu odmah je uočeno da grmlje nije izgoreno, odnosno drvenasti dijelovi vegetacije debljine iznad 5 mm ostali su vitalni i živi. Suhi dijelovi travne vegetacije koji su zaklonjeni kamenom ostali su također neizgoreni. Iz rezultata testiranja vidljivo je da je vegetacija bila krajnje zapaljiva. Travna vegetacija imala je sadržaj vlage od 10 do 16 %, a vrijeme zapaljenja je bilo 2 s. Kod drvenaste vegetacije vrijeme zapaljenja kretalo se od 18 do 22 s, dok je sadržaj vlage bio od 13 do 53 %. Pokrovnost vegetacijom kretala se od 3425 kg/ha do 4948 kg/ha kod travne vegetacije i od 2180 kg/ha do 3425 kg/ha kod drvenaste vegetacije.Apart from endangering the production of forest biomass, fires may also disturb the ecological balance and disrupt permanent sustainable development. However, fires may have even more tragic consequences, as it was in the case of Kornati in the summer of 2007. Vegetation was investigated and its ignitability and flammability were tested. Ignitability was tested in the laboratory in Makarska using the methodology described by Valette (1990). Field sampling revealed that the shrubs were not burnt and that woody vegetation parts exceeding 5 mm in thickness remained vital and alive. The dry parts of grass vegetation sheltered by stones were also unaffected. Test results showed that the vegetation was extremely flammable. The humidity content of grass vegetation ranged from 10 to 16 % and the ignition time was 2 s. In woody vegetation the ignition time oscillated from 18 to 22 s, with humidity ranging from 13 to 53 %. Vegetation cover ranged from 3,425 kg/ha to 4,948 kg/ha in grass vegetation and from 2,180 kg/ha to 3,425 kg/ha in woody vegetation

Forest fires as an ecological and landscape factor in the Dalmatian hinterland

Šumski požari predstavljaju veliku opasnost za šumska zemljišta i šume u Republici Hrvatskoj, a naročito u Dalmaciji, na otocima i u Dalmatinskoj zagori. Sve veći broj požara u značajnoj mjeri degradira ekosustav i narušava njegovu stabilnost što dovodi do smanjenja bioraznolikosti i povećanja opustošenih prostora. U posljednja dva desetljeća 20. stoljeća, godišnja izgorena površina u mediteranskim zemljama procijenjena je na oko 600 000 ha, što je gotovo dvostruko više nego tijekom 1970-tih godina. U razdoblju od 1998. do 2004. godine bilo je ukupno 115 666 požara kojim je bilo obuhvaćeno ukupno 1 250 892 ha. Od 1996. godine do 2005. godine u Republici Hrvatskoj bilo je ukupno 3 324 šumskih požara, od čega su na krškom području bila 2 792 šumska požara ili 84,00 %. Ukupna izgorena površina na krškom i kontinentalnom području Hrvatske je 183 015 ha, od čega na krško područje otpada 175 199 ha ili 95,73 %. Prosječna izgorena površina po požaru na krškom području iznosi 62,75 ha. U istom razdoblju na području Dalmatinske zagore (šumarije: Drniš, Vrgorac, Knin, Sinj, Imotski) bio je ukupno 831 požar, odnosno 29,76 % od ukupnog broja požara na krškom području, a čime je izgoreno 44 164 ha površine, odnosno 25,21 % od ukupno izgorene površine krškog područja u promatranom razdoblju. Usavršavanje metoda prevencije i borbe protiv šumskih požara omogućuje bitno smanjenje opožarenih površina. Poznavati čimbenike koji uvjetuju nastanak šumskih požara kao i čimbenike koji započinju širenje vatrene stihije bitno je zbog pripreme i vođenja preventivnih aktivnosti. Jedna od najvažnijih preventivnih mjera jest poznavanje obilježja šumskih goriva, u prvom redu njihove zapaljivosti, gorivosti i sadržaja vlage. Uzroci nastanka požara mogu biti različiti, od prirodnih (suša, visoka temperatura, niska relativna vlaga zraka, vjetreni režim, udar groma) do onih uzrokovanih ljudskim nemarom (paljenje korova na poljoprivrednim površinama, bačen neugašen opušak, neugašena izletnička vatra, razni ekološki incidenti) koji su i najčešći. Dosadašnjim spoznajama vezanim uz problematiku šumskih požara utvrđeno je da pozornost treba posvetiti pedološkim, klimatskim i vegetacijskim uvjetima nastanka i širenja požara, te svekolikim uvjetima obnove šuma poslije požara. Odluka o tome kako pristupiti obnovi šuma ili šumskog zemljišta koje je bilo zahvaćeno šumskim požarom ili je njime uništeno, ovisi o nizu biološko-ekoloških i gospodarskih činitelja. Sam požar, u pravilu, uzrokuje regresiju vegetacije te se na opožarenim površinama, ovisno o tipu vegetacije prije požara i biološko-ekološkim uvjetima javljaju specifični degradacijski tipovi vegetacije. Međutim, na brzinu, kvalitetu i uspjeh progresivne sukcesije izgorenih površina pozitivno može utjecati čovjek u vidu izbora vrsta i metoda sanacije. Uvažavanjem svega navedenog zasigurno bi se znatno pridonijelo očuvanju biološke i krajobrazne raznolikosti uz načelo održivog razvoja prirodnih ekosustava.Forest fires represent a major threat to forests and forest land in Croatia, especially in Dalmatia, the islands and the Dalmatian hinterland. An increasing number of fires significantly degrade the ecosystem and disrupt its stability, leading to a decrease in biodiversity and increase the devastated area. In the last two decades of the 20th century, the annual burned areas in Mediterranean countries is estimated at around 600 000 ha, which is almost twice as much during the 1970\u27s. From 1998 to 2004. there were a total of 115 666 fire which included a total of 1,250,892 hectares. Since 1996. year until 2005. in the Republic of Croatia had a total of 3324 forest fires, of which the karst area was 2792 forest fire, or 84.00%. The total burned area in the continental karst and Croatian territory is 183 015 ha, of which the karst area of waste 175 199 hectares or 95.73%. The average area burned per fire in the karst area is 62.75 hectares. In the same period in the Dalmatian hinterland (Forestry office: Drniš Vrgorac, Knin, Sinj, Imotski) was a total of 831 fires, or 29.76% of the total number of fires in the karst area, which burned 44 164 ha, or 25 , 21% of total burn surface area of the karst areas in the period. Improving methods of prevention and fight against forest fires allows significantly reducing the burnt areas. Knowing the factors that condition the occurrence of forest fires as well as factors that start spreading the blaze is essential for the preparation and conduct of preventive activities. One of the most important preventive measure is to know the characteristics of forest fuels, primarily their flammability, combustibility, and moisture content. Causes of fire may be different from natural (drought, high temperatures, low relative humidity, wind regime, lightning) to those caused by human negligence (burning weeds on agricultural land, thrown unquenched butt, unquenched fire excursion, various environmental incidents) which are most common. Current state of knowledge concerning the problem of forest fires has been found that attention should be paid pedological, climatic and vegetation conditions of occurrence and spread of fire, and the overall conditions of regeneration after fire. The decision on how to approach restoration of forests or forest land that was affected by forest fires or it is destroyed depends on a number of biological, ecological and economic factors. The fire, normally, causing regression of the vegetation on the burnt areas, depending on the type of vegetation before the fire and the biological and ecological conditions occurring specific degradation of vegetation types. But, however, the speed, quality and success of the progressive succession of burned areas can positively affect a man in mind the choice of types and methods of rehabilitation. Appreciating all this would certainly contribute significantly to the preservation of biological and landscape diversity with the principle of sustainable development of natural ecosystems

Restoration of burned pine stands in the area of forestry offices Metković

Problematika šumskih požara i sanacija izgorenih površina u posljednjim je desetljećima sve više interes šire javnosti. Zadatak šumarske struke je kod sanacije izgorenih sastojina pronaći što efikasnije i što rentabilnije metode sanacije staništa i očuvanja tla od degradacije u smjeru razvitka što otpornijih i ekološki stabilnijih sastojina, te određivanje površina koje su prioritetnije za revitalizaciju. 34,55 % zelenika te ostatak ostale vrste uključujući i obični čempres koji je nešto jače zastupljen. U narednom razdoblju potrebno je nastaviti s uzgojnim zahvatima u cilju razvoja stabilne sastojine i njezine zaštite od požara. Promatrajući i analizirajući sanaciju izgorenih površina na pokusnim plohama koje su postavljene na području šumarije Metković možemo zaključiti kako je svim ovim površinama zajedničko djelomičan uspjeh sanacije pionirskim vrstama. Rezultati istraživanja ukazuju na potrebu uzgojnih radova s ciljem dobivanja ekološki stabilnije, mješovite sastojine jer se javlja problem u izostanku tj. nedovoljnom broju autohtonih listača. Na površinama koje su izgorene prije sanacije potrebno je provesti šumski red u vidu uklanjanja preostalih nagorjelih stabala i grana. Šumarsko gospodarenje na Mediteranu trebalo biti u skladu sa čimbenicima u prostoru, gdje se u prvom redu misli na turističke, ekološke i zaštitne čimbenike.The problem of forest fires and rehabilitation of burned areas in recent decades more and more interest in the general public. The task of the forestry profession in the rehabilitation of burned stands to find more efficient and cost-effective methods as rehabilitation of habitats and conservation of soil degradation in the direction of the development of such resistant and environmentally stable stand, and determine areas of high priority for the revitalization. 34.55 % Holly and the rest of other types including plain cypress, which is somewhat more represented. In the coming period it is necessary to continue with the breeding operations in order to develop a stable stand and fire the same. By observing and analyzing the rehabilitation of burnt areas on plots that were set in the area of forestry offices Metković we can conclude that all of these areas share a partial success of rehabilitation pioneer species. The research results point to the need for breeding work in order to obtain ecologically stable, mixed stands because there is a problem in the absence of that, an insufficient number of indigenous hardwoods. In areas that have been burned before rehabilitation should be implemented in the form of forest order to remove the remaining burned trees and branches. Forestry management in the Mediterranean should be in accordance with the factors in the area, where first of all the tourist, environmental and safety factors

Potentially forest fuel in Eumediterranean area

Opterećenost Sredozemlja požarima seže u daleku prošlost. U Hrvatskoj požarima su najopterećeniji otoci i priobalno područje iako su, u novije vrijeme, požari sve učestaliji i u unutrašnjosti zbog sve povoljnijih klimatskih prilika. Potencijalno šumsko gorivo je cjelokupni materijal koji se nalazi iznad mineralnog dijela tla. Ono se sastoji od prizemnog sloja, sloja otpadnog materijala, sloja posječenog materijala, travne vegetacije, sloja prizemnog rašća, sloja grmlja i sloja drveća. Po svojoj prirodi to gorivo može biti živo (živi biljni materijal) i mrtvo (odumrli biljni materijal). Poznavanje obilježja šumskih goriva jedan je od najvažnijih faktora u problematici šumskih požara. Temeljna obilježja šumskih goriva su zapaljivost, trajanje gorenja i sadržaj vlage. Istraživanja su provedena na otoku Rabu, na Nastavno-pokusnom šumskom objektu Rab te u eksperimentalnom laboratoriju za zaštitu šuma od požara u Makarskoj. Istraživanja su provedena na biljnim vrstama koje se smatra najrelevantnijim za najugroženije područje od šumskih požara (topliji dio priobalja i otoka - Eumediteran). Utvrđivanje osnovnih obilježja šumskih goriva izvršeno je korištenjem metodologije koju je definirao Valette (1990). Svi rezultati su statistički obrađeni te prikazani tablično i grafički. Praksa je da se pojedine, vrlo značajne, varijable za šumske požare, kao što su npr. sadržaj vlage potencijalnog goriva, zatim njegova zapaljivosti ili gorivost nastoje dobiti primjenom raznih modela, iako je poznato da ti modeli ne mogu utvrditi prave vrijednosti potrebnih varijabli za razliku od stvarnih, empirijskih istraživanja. Rezultatima ovih istraživanja utvrđene su točne vrijednosti pojedinih istraživanih varijabli za vrste našeg podneblja. S obzirom na navedeno, očekuje se kvalitetna primjena spomenutih rezultata po uzoru na neke druge mediteranske zemlje. Rezultati ovih istraživanja trebali biti od velike koristi svim potencijalnim korisnicima (vatrogasci, službe za zaštitu i spašavanje, jedinice lokalne i regionalne uprave, ostali pojedinačni korisnici). Osim toga, trebali bi pomoći kao smjernice u što boljoj protupožarnoj politici, a na korist potrajnog gospodarenja i očuvanja općekorisnih funkcija.Burden on Mediterranean fires back many years. In Croatia, the fires are most burdened islands and the coast. Although, in recent times, fires are more common in the interior due to favorable climatic conditions. Potentially forest fuel is all the material that is placed over the mineral part of the soil. It consists of a ground layer, the layer of waste material, harvested material layer, grassy vegetation, ground vegetation layer, shrub layer and a layer of trees. By its nature, this fuel can be alive (live plant material) and dead (dead plant material). Knowing the characteristics of forest fuels is one of the most important factors in the problem of forest fires. The basic characteristics of forest fuels are flammable, flame duration and moisture content. Investigations were carried out on the island, the Teaching experimental forest object Rab and in experimental laboratory for the protection of forests against fire in Makarska. Studies have been conducted on the plant species that are considered most relevant for the most vulnerable area of forest fires (warmer part of littoral - Eumediterranean). Determining the basic characteristics of forest fuels was conducted using the methodology defined by the Valette (1990). All results were statistically analyzed and presented in tables and graphs. The practice is that some very important variables for forest fires, such as the moisture content of available fuel, then its flammability and combustibility are trying to get by using various models, although it is known that these models can not determine the true value of the required variables as opposed to the actual , empirical research. The results of these studies were determined accurate values ​​of the examined variables for species of our region. Given this expected quality applications mentioned results, modeled to some other Mediterranean countries. The results of these studies should be of great benefit to all potential users (fire department, to protect and rescue, local and regional government, other individual users). In addition should help to guide you better fire policy, and in favor of sustainable management and conservation of beneficial functions

Knowledge of the flammability and fuel parameters of the lemvir (Viburnum tinus L.)

Osim razumijevanja i poznavanja biološko-ekoloških posljedica šumskih požara, kao i metoda sanacije i obnove opožarenih površina, poznavanje čimbenika koji uvjetuju nastanak šumskih požara te čimbenika koji uzrokuju početno širenje vatre bitno je zbog smanjenja opožarenih površina te pripreme i vođenja preventivnih aktivnosti. Stoga, bolje razumijevanje parametara zapaljivosti i gorivosti može doprinijeti poboljšanju spoznaja o protupožarnoj problematici i identificirati kritična razdoblja visokog rizika od šumskih požara. Za testiranje parametara zapaljivosti i gorivosti korištena je propisana metodologija. Rezultatima ovih istraživanja utvrđene su točne vrijednosti pojedinih istraživanih varijabli za vrstu našeg podneblja. Oni bi trebali pomoći kao smjernice u što boljoj protupožarnoj stategiji, a na korist potrajnog gospodarenja i očuvanja općekorisnih funkcija.In addition to understanding and knowing the biological and ecological consequences of forest fires as well as methods of recovery and restoration of fired surfaces, the knowledge of factors that cause the occurrence of forest fires and the factors causing initial spread of fire is essential due to the reduction of burned surfaces and the preparation and management of preventative activities. Therefore, a better understanding of flammability and fuel parameters can contribute to improve the knowledge of fire hazard issues and identifying critical periods of high risk of forest fires. The prescribed methodology was used to test the flammability and fuel parameters. The results of these studies have determined the exact values of the individual investigated variables for the type of our environment. They should serve as guidelines for a better firefighting policy, in favor of sustainable management and preservation of general-interest functions

Regeneration of burned stands of pubescent oak (Quercus pubescens Willd.) and holm oak (Quercus ilex L.) in the Zadar area

Background and Purpose: Pubescent oak (Quercus pubescensWilld.) and holm oak (Quercus ilex L.) are climatozonal species in the area of Zadar, where the communities formed by these two species have an ecological- protective role. The aim of this research is to address the problem of the disturbed stability of these stands and the possibility of their post-fire regeneration. Materials and Methods: Research was undertaken in burned and unburned areas of the Zadar Forest Office. This included pubescent oak coppices, scrub, thickets, maquis and garrigue. The relevés were made according to the plant sociology method (Braun-Blanquet 1964, Dierschke 1994). Pedological research involved taking composite samples of the humus-accumulative horizon. Chemical soil analyses were performed according to the standard methods. Results: The number of pubescent oak individuals was about 2.5 times higher in burned areas compared to unburned ones. This was in contrast to holm oak, which showed poorer occurrence in burned areas in relation to unburned ones. The average number of all trees and shrubs in degraded forms of pubescent oak was 11.567 per hectare, whereas in degraded forms of holm oak forest this number was more than twice as high and amounted to 2.550 individuals per hectare. Conclusions: Forest fires are an important cause of soil degradation. Burned areas are subject to erosion, the disappearance of or a decrease in soil biological activity, and extreme ecological effects. In order to mitigate the problem, certain prescribed post-fire recovery methods should be urgently applied

Autochthonous woody species as an element of the Medditerranean urban area in Croatia

The Mediterranean area in Croatia is characterised by geomorphological, relief, climatic, pedological and vegetational synecological factors. Apart from autochthonous (climatozonal) species, a large number of alochthonous (foreign) species were introduced for the purpose of carrying out ameliorative operations in degraded sites and meeting the horticultural and landscape objectives. Unfortunately, unfamiliarity with biological-ecological properties of foreign species gave rise to a number of mistakes in terms of the choice of species. Horticulturally, the introduced species frequently failed to fulfil the desired aesthetic and composition effects. However, there were also situations in which the newly introduced species adapted exceptionally well to the new conditions and developed far beyond expectations, suppressing the autochthonous vegetation from its original areas. Wherever possible, autochthonous vegetation should be favoured over aloththonous vegetation because the former is already well adapted to the environmental and habitat conditions. The possibilities and quality of autochthonous species as elements of urban vegetation in the Mediterranean are still insufficiently utilised. The auto-chthonous floral elements have, apart from their decorative-aesthetic values (the qualities shared with the alochthonous species), a historical-traditional value. For this reason old plantations of autochthonous species in urban areas should be replaced with the same (or similar) autochthonous ones. The Croatian insular, coastal and hinterland areas are inhabited by a large number of mainly evergreen autochthonous species. The warmer eu-Mediterranean belt is characterised by the following interesting species: holm oak (Quercus ilex L.), strawberry tree (Arbutus unedo L.), laurustinus (Viburnum tinus L.), privet (Phillyrea latifolia L., Phillyrea media L.), bay laurel (Laurus nobilis L.), common myrtle (Myrtus communis L.), Italian buckthorn (Rhamnus alaternus L.), cyprus (Cupressus sempervirens L.), juniper (Juniperus oxycedrus L.), Juniperus macrocarpa Sibth. Et Sm., creeping juniper (Juniperus horizontalis Moench.), curry plant (Helichrysum angustifolium D. C.), tree purslane (Atriplex halimus L.) and others. From an ecological-aesthetic standpoint, the colder, sub-Mediterranean area is characterised by the following species: pubescent oak (Quercus pubescens Willd.), manna ash (Fraxinus ornus L.), Montpelier maple (Acer monspessulanum L.), terebinth tree (Pistacia terebinthus L.), smoke tree (Cotinus coggygria Scop.), hop hornbeam (Ostrya carpinifolia Scop.), oriental hornbeam (Carpinus orientalis Mill.), whitebeam (Sorbus aria L.), wild service tree (Sorbus torminalis Crantz), Bosnian maple (Acer obtusatum Kit.), common juniper (Juniperus communis), winter savory (Satureia montana L.) and others